Merge github.com:grpc/grpc into flow_control_v2

113 files changed, 3232 insertions, 1120 deletions

diff --git a/src/core/ext/client_channel/README.md b/src/core/ext/client_channel/README.md
index eda01e3e71..7c209db12e 100644
--- a/src/core/ext/client_channel/README.md
+++ b/src/core/ext/client_channel/README.md
@@ -5,28 +5,27 @@ This library provides high level configuration machinery to construct client
 channels and load balance between them.
 
 Each grpc_channel is created with a grpc_resolver. It is the resolver's duty
-to resolve a name into configuration data for the channel. Such configuration
-data might include:
+to resolve a name into a set of arguments for the channel. Such arguments
+might include:
 
 - a list of (ip, port) addresses to connect to
 - a load balancing policy to decide which server to send a request to
 - a set of filters to mutate outgoing requests (say, by adding metadata)
 
-The resolver provides this data as a stream of grpc_resolver_result objects to
-the channel. We represent configuration as a stream so that it can be changed
-by the resolver during execution, by reacting to external events (such as a
-new configuration file being pushed to some store).
+The resolver provides this data as a stream of grpc_channel_args objects to
+the channel. We represent arguments as a stream so that they can be changed
+by the resolver during execution, by reacting to external events (such as
+new service configuration data being pushed to some store).
 
 
 Load Balancing
 --------------
 
-Load balancing configuration is provided by a grpc_lb_policy object, stored as
-part of grpc_resolver_result.
+Load balancing configuration is provided by a grpc_lb_policy object.
 
-The primary job of the load balancing policies is to pick a target server given only the
-initial metadata for a request. It does this by providing a grpc_subchannel
-object to the owning channel.
+The primary job of the load balancing policies is to pick a target server
+given only the initial metadata for a request. It does this by providing
+a grpc_subchannel object to the owning channel.
 
 
 Sub-Channels
diff --git a/src/core/ext/client_channel/client_channel.c b/src/core/ext/client_channel/client_channel.c
index 55bb877576..ff773ac334 100644
--- a/src/core/ext/client_channel/client_channel.c
+++ b/src/core/ext/client_channel/client_channel.c
@@ -43,7 +43,6 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/method_config.h"
 #include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
@@ -56,6 +55,7 @@
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/metadata.h"
 #include "src/core/lib/transport/metadata_batch.h"
+#include "src/core/lib/transport/method_config.h"
 #include "src/core/lib/transport/static_metadata.h"
 
 /* Client channel implementation */
@@ -127,7 +127,7 @@ typedef struct client_channel_channel_data {
   /** maps method names to method_parameters structs */
   grpc_mdstr_hash_table *method_params_table;
   /** incoming resolver result - set by resolver.next() */
-  grpc_resolver_result *resolver_result;
+  grpc_channel_args *resolver_result;
   /** a list of closures that are all waiting for config to come in */
   grpc_closure_list waiting_for_config_closures;
   /** resolver callback */
@@ -232,35 +232,42 @@ static void on_resolver_result_changed(grpc_exec_ctx *exec_ctx, void *arg,
 
   if (chand->resolver_result != NULL) {
     grpc_lb_policy_args lb_policy_args;
-    lb_policy_args.server_name =
-        grpc_resolver_result_get_server_name(chand->resolver_result);
-    lb_policy_args.addresses =
-        grpc_resolver_result_get_addresses(chand->resolver_result);
-    lb_policy_args.additional_args =
-        grpc_resolver_result_get_lb_policy_args(chand->resolver_result);
+    lb_policy_args.args = chand->resolver_result;
     lb_policy_args.client_channel_factory = chand->client_channel_factory;
 
+    // Find LB policy name.
+    const char *lb_policy_name = NULL;
+    const grpc_arg *channel_arg =
+        grpc_channel_args_find(lb_policy_args.args, GRPC_ARG_LB_POLICY_NAME);
+    if (channel_arg != NULL) {
+      GPR_ASSERT(channel_arg->type == GRPC_ARG_STRING);
+      lb_policy_name = channel_arg->value.string;
+    }
     // Special case: If all of the addresses are balancer addresses,
     // assume that we should use the grpclb policy, regardless of what the
     // resolver actually specified.
-    const char *lb_policy_name =
-        grpc_resolver_result_get_lb_policy_name(chand->resolver_result);
-    bool found_backend_address = false;
-    for (size_t i = 0; i < lb_policy_args.addresses->num_addresses; ++i) {
-      if (!lb_policy_args.addresses->addresses[i].is_balancer) {
-        found_backend_address = true;
-        break;
+    channel_arg =
+        grpc_channel_args_find(lb_policy_args.args, GRPC_ARG_LB_ADDRESSES);
+    if (channel_arg != NULL) {
+      GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
+      grpc_lb_addresses *addresses = channel_arg->value.pointer.p;
+      bool found_backend_address = false;
+      for (size_t i = 0; i < addresses->num_addresses; ++i) {
+        if (!addresses->addresses[i].is_balancer) {
+          found_backend_address = true;
+          break;
+        }
       }
-    }
-    if (!found_backend_address) {
-      if (lb_policy_name != NULL && strcmp(lb_policy_name, "grpclb") != 0) {
-        gpr_log(GPR_INFO,
-                "resolver requested LB policy %s but provided only balancer "
-                "addresses, no backend addresses -- forcing use of grpclb LB "
-                "policy",
-                (lb_policy_name == NULL ? "(none)" : lb_policy_name));
+      if (!found_backend_address) {
+        if (lb_policy_name != NULL && strcmp(lb_policy_name, "grpclb") != 0) {
+          gpr_log(GPR_INFO,
+                  "resolver requested LB policy %s but provided only balancer "
+                  "addresses, no backend addresses -- forcing use of grpclb LB "
+                  "policy",
+                  lb_policy_name);
+        }
+        lb_policy_name = "grpclb";
       }
-      lb_policy_name = "grpclb";
     }
     // Use pick_first if nothing was specified and we didn't select grpclb
     // above.
@@ -274,15 +281,15 @@ static void on_resolver_result_changed(grpc_exec_ctx *exec_ctx, void *arg,
       state =
           grpc_lb_policy_check_connectivity(exec_ctx, lb_policy, &state_error);
     }
-    const grpc_arg *channel_arg = grpc_channel_args_find(
-        lb_policy_args.additional_args, GRPC_ARG_SERVICE_CONFIG);
+    channel_arg =
+        grpc_channel_args_find(lb_policy_args.args, GRPC_ARG_SERVICE_CONFIG);
     if (channel_arg != NULL) {
       GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
       method_params_table = grpc_method_config_table_convert(
           (grpc_method_config_table *)channel_arg->value.pointer.p,
           method_config_convert_value, &method_parameters_vtable);
     }
-    grpc_resolver_result_unref(exec_ctx, chand->resolver_result);
+    grpc_channel_args_destroy(chand->resolver_result);
     chand->resolver_result = NULL;
   }
 
@@ -1015,6 +1022,10 @@ static void cc_destroy_call_elem(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(calld->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING);
   gpr_mu_destroy(&calld->mu);
   GPR_ASSERT(calld->waiting_ops_count == 0);
+  if (calld->connected_subchannel != NULL) {
+    GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, calld->connected_subchannel,
+                                    "picked");
+  }
   gpr_free(calld->waiting_ops);
   gpr_free(and_free_memory);
 }
diff --git a/src/core/ext/client_channel/client_channel_factory.c b/src/core/ext/client_channel/client_channel_factory.c
index db1cc9093c..4900832d57 100644
--- a/src/core/ext/client_channel/client_channel_factory.c
+++ b/src/core/ext/client_channel/client_channel_factory.c
@@ -44,14 +44,14 @@ void grpc_client_channel_factory_unref(grpc_exec_ctx* exec_ctx,
 
 grpc_subchannel* grpc_client_channel_factory_create_subchannel(
     grpc_exec_ctx* exec_ctx, grpc_client_channel_factory* factory,
-    grpc_subchannel_args* args) {
+    const grpc_subchannel_args* args) {
   return factory->vtable->create_subchannel(exec_ctx, factory, args);
 }
 
 grpc_channel* grpc_client_channel_factory_create_channel(
     grpc_exec_ctx* exec_ctx, grpc_client_channel_factory* factory,
     const char* target, grpc_client_channel_type type,
-    grpc_channel_args* args) {
+    const grpc_channel_args* args) {
   return factory->vtable->create_client_channel(exec_ctx, factory, target, type,
                                                 args);
 }
diff --git a/src/core/ext/client_channel/client_channel_factory.h b/src/core/ext/client_channel/client_channel_factory.h
index 28828c2eb6..2b8fc577b3 100644
--- a/src/core/ext/client_channel/client_channel_factory.h
+++ b/src/core/ext/client_channel/client_channel_factory.h
@@ -60,12 +60,12 @@ struct grpc_client_channel_factory_vtable {
   void (*unref)(grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory);
   grpc_subchannel *(*create_subchannel)(grpc_exec_ctx *exec_ctx,
                                         grpc_client_channel_factory *factory,
-                                        grpc_subchannel_args *args);
+                                        const grpc_subchannel_args *args);
   grpc_channel *(*create_client_channel)(grpc_exec_ctx *exec_ctx,
                                          grpc_client_channel_factory *factory,
                                          const char *target,
                                          grpc_client_channel_type type,
-                                         grpc_channel_args *args);
+                                         const grpc_channel_args *args);
 };
 
 void grpc_client_channel_factory_ref(grpc_client_channel_factory *factory);
@@ -75,11 +75,12 @@ void grpc_client_channel_factory_unref(grpc_exec_ctx *exec_ctx,
 /** Create a new grpc_subchannel */
 grpc_subchannel *grpc_client_channel_factory_create_subchannel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory,
-    grpc_subchannel_args *args);
+    const grpc_subchannel_args *args);
 
 /** Create a new grpc_channel */
 grpc_channel *grpc_client_channel_factory_create_channel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory,
-    const char *target, grpc_client_channel_type type, grpc_channel_args *args);
+    const char *target, grpc_client_channel_type type,
+    const grpc_channel_args *args);
 
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
diff --git a/src/core/ext/client_channel/connector.h b/src/core/ext/client_channel/connector.h
index e08244b2c0..ed7d5450de 100644
--- a/src/core/ext/client_channel/connector.h
+++ b/src/core/ext/client_channel/connector.h
@@ -35,7 +35,7 @@
 #define GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H
 
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/transport/transport.h"
 
 typedef struct grpc_connector grpc_connector;
@@ -49,7 +49,7 @@ typedef struct {
   /** set of pollsets interested in this connection */
   grpc_pollset_set *interested_parties;
   /** address to connect to */
-  const struct sockaddr *addr;
+  const grpc_resolved_address *addr;
   size_t addr_len;
   /** initial connect string to send */
   gpr_slice initial_connect_string;
diff --git a/src/core/ext/client_channel/default_initial_connect_string.c b/src/core/ext/client_channel/default_initial_connect_string.c
index a70da4a84a..0b251372fd 100644
--- a/src/core/ext/client_channel/default_initial_connect_string.c
+++ b/src/core/ext/client_channel/default_initial_connect_string.c
@@ -32,8 +32,7 @@
  */
 
 #include <grpc/support/slice.h>
-#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 
-void grpc_set_default_initial_connect_string(struct sockaddr **addr,
-                                             size_t *addr_len,
+void grpc_set_default_initial_connect_string(grpc_resolved_address **addr,
                                              gpr_slice *initial_str) {}
diff --git a/src/core/ext/client_channel/initial_connect_string.c b/src/core/ext/client_channel/initial_connect_string.c
index fd8ddb83a8..fb1493d77d 100644
--- a/src/core/ext/client_channel/initial_connect_string.c
+++ b/src/core/ext/client_channel/initial_connect_string.c
@@ -35,9 +35,8 @@
 
 #include <stddef.h>
 
-extern void grpc_set_default_initial_connect_string(struct sockaddr **addr,
-                                                    size_t *addr_len,
-                                                    gpr_slice *initial_str);
+extern void grpc_set_default_initial_connect_string(
+    grpc_resolved_address **addr, gpr_slice *initial_str);
 
 static grpc_set_initial_connect_string_func g_set_initial_connect_string_func =
     grpc_set_default_initial_connect_string;
@@ -47,7 +46,7 @@ void grpc_test_set_initial_connect_string_function(
   g_set_initial_connect_string_func = func;
 }
 
-void grpc_set_initial_connect_string(struct sockaddr **addr, size_t *addr_len,
+void grpc_set_initial_connect_string(grpc_resolved_address **addr,
                                      gpr_slice *initial_str) {
-  g_set_initial_connect_string_func(addr, addr_len, initial_str);
+  g_set_initial_connect_string_func(addr, initial_str);
 }
diff --git a/src/core/ext/client_channel/initial_connect_string.h b/src/core/ext/client_channel/initial_connect_string.h
index 39f6465fc9..68adb0373c 100644
--- a/src/core/ext/client_channel/initial_connect_string.h
+++ b/src/core/ext/client_channel/initial_connect_string.h
@@ -35,16 +35,16 @@
 #define GRPC_CORE_EXT_CLIENT_CHANNEL_INITIAL_CONNECT_STRING_H
 
 #include <grpc/support/slice.h>
-#include "src/core/lib/iomgr/sockaddr.h"
 
-typedef void (*grpc_set_initial_connect_string_func)(struct sockaddr **addr,
-                                                     size_t *addr_len,
-                                                     gpr_slice *initial_str);
+#include "src/core/lib/iomgr/resolve_address.h"
+
+typedef void (*grpc_set_initial_connect_string_func)(
+    grpc_resolved_address **addr, gpr_slice *initial_str);
 void grpc_test_set_initial_connect_string_function(
     grpc_set_initial_connect_string_func func);
 
 /** Set a string to be sent once connected. Optionally reset addr. */
-void grpc_set_initial_connect_string(struct sockaddr **addr, size_t *addr_len,
+void grpc_set_initial_connect_string(grpc_resolved_address **addr,
                                      gpr_slice *connect_string);
 
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_INITIAL_CONNECT_STRING_H */
diff --git a/src/core/ext/client_channel/lb_policy_factory.c b/src/core/ext/client_channel/lb_policy_factory.c
index 45753e6942..8a474c8818 100644
--- a/src/core/ext/client_channel/lb_policy_factory.c
+++ b/src/core/ext/client_channel/lb_policy_factory.c
@@ -38,19 +38,20 @@
 
 #include "src/core/ext/client_channel/lb_policy_factory.h"
 
-grpc_lb_addresses* grpc_lb_addresses_create(size_t num_addresses) {
+grpc_lb_addresses* grpc_lb_addresses_create(
+    size_t num_addresses, const grpc_lb_user_data_vtable* user_data_vtable) {
   grpc_lb_addresses* addresses = gpr_malloc(sizeof(grpc_lb_addresses));
   addresses->num_addresses = num_addresses;
+  addresses->user_data_vtable = user_data_vtable;
   const size_t addresses_size = sizeof(grpc_lb_address) * num_addresses;
   addresses->addresses = gpr_malloc(addresses_size);
   memset(addresses->addresses, 0, addresses_size);
   return addresses;
 }
 
-grpc_lb_addresses* grpc_lb_addresses_copy(grpc_lb_addresses* addresses,
-                                          void* (*user_data_copy)(void*)) {
-  grpc_lb_addresses* new_addresses =
-      grpc_lb_addresses_create(addresses->num_addresses);
+grpc_lb_addresses* grpc_lb_addresses_copy(const grpc_lb_addresses* addresses) {
+  grpc_lb_addresses* new_addresses = grpc_lb_addresses_create(
+      addresses->num_addresses, addresses->user_data_vtable);
   memcpy(new_addresses->addresses, addresses->addresses,
          sizeof(grpc_lb_address) * addresses->num_addresses);
   for (size_t i = 0; i < addresses->num_addresses; ++i) {
@@ -58,9 +59,9 @@ grpc_lb_addresses* grpc_lb_addresses_copy(grpc_lb_addresses* addresses,
       new_addresses->addresses[i].balancer_name =
           gpr_strdup(new_addresses->addresses[i].balancer_name);
     }
-    if (user_data_copy != NULL) {
-      new_addresses->addresses[i].user_data =
-          user_data_copy(new_addresses->addresses[i].user_data);
+    if (new_addresses->addresses[i].user_data != NULL) {
+      new_addresses->addresses[i].user_data = addresses->user_data_vtable->copy(
+          new_addresses->addresses[i].user_data);
     }
   }
   return new_addresses;
@@ -71,6 +72,7 @@ void grpc_lb_addresses_set_address(grpc_lb_addresses* addresses, size_t index,
                                    bool is_balancer, char* balancer_name,
                                    void* user_data) {
   GPR_ASSERT(index < addresses->num_addresses);
+  if (user_data != NULL) GPR_ASSERT(addresses->user_data_vtable != NULL);
   grpc_lb_address* target = &addresses->addresses[index];
   memcpy(target->address.addr, address, address_len);
   target->address.len = address_len;
@@ -79,18 +81,70 @@ void grpc_lb_addresses_set_address(grpc_lb_addresses* addresses, size_t index,
   target->user_data = user_data;
 }
 
-void grpc_lb_addresses_destroy(grpc_lb_addresses* addresses,
-                               void (*user_data_destroy)(void*)) {
+int grpc_lb_addresses_cmp(const grpc_lb_addresses* addresses1,
+                          const grpc_lb_addresses* addresses2) {
+  if (addresses1->num_addresses > addresses2->num_addresses) return 1;
+  if (addresses1->num_addresses < addresses2->num_addresses) return -1;
+  if (addresses1->user_data_vtable > addresses2->user_data_vtable) return 1;
+  if (addresses1->user_data_vtable < addresses2->user_data_vtable) return -1;
+  for (size_t i = 0; i < addresses1->num_addresses; ++i) {
+    const grpc_lb_address* target1 = &addresses1->addresses[i];
+    const grpc_lb_address* target2 = &addresses2->addresses[i];
+    if (target1->address.len > target2->address.len) return 1;
+    if (target1->address.len < target2->address.len) return -1;
+    int retval = memcmp(target1->address.addr, target2->address.addr,
+                        target1->address.len);
+    if (retval != 0) return retval;
+    if (target1->is_balancer > target2->is_balancer) return 1;
+    if (target1->is_balancer < target2->is_balancer) return -1;
+    const char* balancer_name1 =
+        target1->balancer_name != NULL ? target1->balancer_name : "";
+    const char* balancer_name2 =
+        target2->balancer_name != NULL ? target2->balancer_name : "";
+    retval = strcmp(balancer_name1, balancer_name2);
+    if (retval != 0) return retval;
+    if (addresses1->user_data_vtable != NULL) {
+      retval = addresses1->user_data_vtable->cmp(target1->user_data,
+                                                 target2->user_data);
+      if (retval != 0) return retval;
+    }
+  }
+  return 0;
+}
+
+void grpc_lb_addresses_destroy(grpc_lb_addresses* addresses) {
   for (size_t i = 0; i < addresses->num_addresses; ++i) {
     gpr_free(addresses->addresses[i].balancer_name);
-    if (user_data_destroy != NULL) {
-      user_data_destroy(addresses->addresses[i].user_data);
+    if (addresses->addresses[i].user_data != NULL) {
+      addresses->user_data_vtable->destroy(addresses->addresses[i].user_data);
     }
   }
   gpr_free(addresses->addresses);
   gpr_free(addresses);
 }
 
+static void* lb_addresses_copy(void* addresses) {
+  return grpc_lb_addresses_copy(addresses);
+}
+static void lb_addresses_destroy(void* addresses) {
+  grpc_lb_addresses_destroy(addresses);
+}
+static int lb_addresses_cmp(void* addresses1, void* addresses2) {
+  return grpc_lb_addresses_cmp(addresses1, addresses2);
+}
+static const grpc_arg_pointer_vtable lb_addresses_arg_vtable = {
+    lb_addresses_copy, lb_addresses_destroy, lb_addresses_cmp};
+
+grpc_arg grpc_lb_addresses_create_channel_arg(
+    const grpc_lb_addresses* addresses) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = GRPC_ARG_LB_ADDRESSES;
+  arg.value.pointer.p = (void*)addresses;
+  arg.value.pointer.vtable = &lb_addresses_arg_vtable;
+  return arg;
+}
+
 void grpc_lb_policy_factory_ref(grpc_lb_policy_factory* factory) {
   factory->vtable->ref(factory);
 }
diff --git a/src/core/ext/client_channel/lb_policy_factory.h b/src/core/ext/client_channel/lb_policy_factory.h
index 3e53972445..e2b8080a32 100644
--- a/src/core/ext/client_channel/lb_policy_factory.h
+++ b/src/core/ext/client_channel/lb_policy_factory.h
@@ -59,19 +59,26 @@ typedef struct grpc_lb_address {
   void *user_data;
 } grpc_lb_address;
 
+typedef struct grpc_lb_user_data_vtable {
+  void *(*copy)(void *);
+  void (*destroy)(void *);
+  int (*cmp)(void *, void *);
+} grpc_lb_user_data_vtable;
+
 typedef struct grpc_lb_addresses {
   size_t num_addresses;
   grpc_lb_address *addresses;
+  const grpc_lb_user_data_vtable *user_data_vtable;
 } grpc_lb_addresses;
 
 /** Returns a grpc_addresses struct with enough space for
- * \a num_addresses addresses. */
-grpc_lb_addresses *grpc_lb_addresses_create(size_t num_addresses);
+    \a num_addresses addresses.  The \a user_data_vtable argument may be
+    NULL if no user data will be added. */
+grpc_lb_addresses *grpc_lb_addresses_create(
+    size_t num_addresses, const grpc_lb_user_data_vtable *user_data_vtable);
 
-/** Creates a copy of \a addresses.  If \a user_data_copy is not NULL,
- * it will be invoked to copy the \a user_data field of each address. */
-grpc_lb_addresses *grpc_lb_addresses_copy(grpc_lb_addresses *addresses,
-                                          void *(*user_data_copy)(void *));
+/** Creates a copy of \a addresses. */
+grpc_lb_addresses *grpc_lb_addresses_copy(const grpc_lb_addresses *addresses);
 
 /** Sets the value of the address at index \a index of \a addresses.
  * \a address is a socket address of length \a address_len.
@@ -81,20 +88,21 @@ void grpc_lb_addresses_set_address(grpc_lb_addresses *addresses, size_t index,
                                    bool is_balancer, char *balancer_name,
                                    void *user_data);
 
-/** Destroys \a addresses.  If \a user_data_destroy is not NULL, it will
- * be invoked to destroy the \a user_data field of each address. */
-void grpc_lb_addresses_destroy(grpc_lb_addresses *addresses,
-                               void (*user_data_destroy)(void *));
+/** Compares \a addresses1 and \a addresses2. */
+int grpc_lb_addresses_cmp(const grpc_lb_addresses *addresses1,
+                          const grpc_lb_addresses *addresses2);
+
+/** Destroys \a addresses. */
+void grpc_lb_addresses_destroy(grpc_lb_addresses *addresses);
+
+/** Returns a channel arg containing \a addresses. */
+grpc_arg grpc_lb_addresses_create_channel_arg(
+    const grpc_lb_addresses *addresses);
 
 /** Arguments passed to LB policies. */
-/* TODO(roth, ctiller): Consider replacing this struct with
-   grpc_channel_args.  See comment in resolver_result.h for details. */
 typedef struct grpc_lb_policy_args {
-  const char *server_name;
-  grpc_lb_addresses *addresses;
   grpc_client_channel_factory *client_channel_factory;
-  /* Can be used to pass implementation-specific parameters to the LB policy. */
-  grpc_channel_args *additional_args;
+  grpc_channel_args *args;
 } grpc_lb_policy_args;
 
 struct grpc_lb_policy_factory_vtable {
diff --git a/src/core/ext/client_channel/parse_address.c b/src/core/ext/client_channel/parse_address.c
index 31ca44299b..b1d55ad0f5 100644
--- a/src/core/ext/client_channel/parse_address.c
+++ b/src/core/ext/client_channel/parse_address.c
@@ -32,10 +32,11 @@
  */
 
 #include "src/core/ext/client_channel/parse_address.h"
+#include "src/core/lib/iomgr/sockaddr.h"
 
 #include <stdio.h>
 #include <string.h>
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 #include <sys/un.h>
 #endif
 
@@ -44,33 +45,39 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#ifdef GPR_HAVE_UNIX_SOCKET
-int parse_unix(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len) {
-  struct sockaddr_un *un = (struct sockaddr_un *)addr;
+#ifdef GRPC_HAVE_UNIX_SOCKET
+
+int parse_unix(grpc_uri *uri, grpc_resolved_address *resolved_addr) {
+  struct sockaddr_un *un = (struct sockaddr_un *)resolved_addr->addr;
 
   un->sun_family = AF_UNIX;
   strcpy(un->sun_path, uri->path);
-  *len = strlen(un->sun_path) + sizeof(un->sun_family) + 1;
+  resolved_addr->len = strlen(un->sun_path) + sizeof(un->sun_family) + 1;
 
   return 1;
 }
-#endif
 
-int parse_ipv4(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len) {
+#else /* GRPC_HAVE_UNIX_SOCKET */
+
+int parse_unix(grpc_uri *uri, grpc_resolved_address *resolved_addr) { abort(); }
+
+#endif /* GRPC_HAVE_UNIX_SOCKET */
+
+int parse_ipv4(grpc_uri *uri, grpc_resolved_address *resolved_addr) {
   const char *host_port = uri->path;
   char *host;
   char *port;
   int port_num;
   int result = 0;
-  struct sockaddr_in *in = (struct sockaddr_in *)addr;
+  struct sockaddr_in *in = (struct sockaddr_in *)resolved_addr->addr;
 
   if (*host_port == '/') ++host_port;
   if (!gpr_split_host_port(host_port, &host, &port)) {
     return 0;
   }
 
-  memset(in, 0, sizeof(*in));
-  *len = sizeof(*in);
+  memset(resolved_addr, 0, sizeof(grpc_resolved_address));
+  resolved_addr->len = sizeof(struct sockaddr_in);
   in->sin_family = AF_INET;
   if (inet_pton(AF_INET, host, &in->sin_addr) == 0) {
     gpr_log(GPR_ERROR, "invalid ipv4 address: '%s'", host);
@@ -96,13 +103,13 @@ done:
   return result;
 }
 
-int parse_ipv6(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len) {
+int parse_ipv6(grpc_uri *uri, grpc_resolved_address *resolved_addr) {
   const char *host_port = uri->path;
   char *host;
   char *port;
   int port_num;
   int result = 0;
-  struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
+  struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)resolved_addr->addr;
 
   if (*host_port == '/') ++host_port;
   if (!gpr_split_host_port(host_port, &host, &port)) {
@@ -110,7 +117,7 @@ int parse_ipv6(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len) {
   }
 
   memset(in6, 0, sizeof(*in6));
-  *len = sizeof(*in6);
+  resolved_addr->len = sizeof(*in6);
   in6->sin6_family = AF_INET6;
   if (inet_pton(AF_INET6, host, &in6->sin6_addr) == 0) {
     gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host);
diff --git a/src/core/ext/client_channel/parse_address.h b/src/core/ext/client_channel/parse_address.h
index 3aa6c41546..bf99c5298a 100644
--- a/src/core/ext/client_channel/parse_address.h
+++ b/src/core/ext/client_channel/parse_address.h
@@ -37,20 +37,18 @@
 #include <stddef.h>
 
 #include "src/core/ext/client_channel/uri_parser.h"
-#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 
-#ifdef GPR_HAVE_UNIX_SOCKET
 /** Populate \a addr and \a len from \a uri, whose path is expected to contain a
  * unix socket path. Returns true upon success. */
-int parse_unix(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len);
-#endif
+int parse_unix(grpc_uri *uri, grpc_resolved_address *resolved_addr);
 
 /** Populate /a addr and \a len from \a uri, whose path is expected to contain a
  * host:port pair. Returns true upon success. */
-int parse_ipv4(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len);
+int parse_ipv4(grpc_uri *uri, grpc_resolved_address *resolved_addr);
 
 /** Populate /a addr and \a len from \a uri, whose path is expected to contain a
  * host:port pair. Returns true upon success. */
-int parse_ipv6(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len);
+int parse_ipv6(grpc_uri *uri, grpc_resolved_address *resolved_addr);
 
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_PARSE_ADDRESS_H */
diff --git a/src/core/ext/client_channel/resolver.c b/src/core/ext/client_channel/resolver.c
index 0c26d95f2f..2ae4fe862e 100644
--- a/src/core/ext/client_channel/resolver.c
+++ b/src/core/ext/client_channel/resolver.c
@@ -76,7 +76,6 @@ void grpc_resolver_channel_saw_error(grpc_exec_ctx *exec_ctx,
 }
 
 void grpc_resolver_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
-                        grpc_resolver_result **result,
-                        grpc_closure *on_complete) {
+                        grpc_channel_args **result, grpc_closure *on_complete) {
   resolver->vtable->next(exec_ctx, resolver, result, on_complete);
 }
diff --git a/src/core/ext/client_channel/resolver.h b/src/core/ext/client_channel/resolver.h
index 0951613175..96ece92b9d 100644
--- a/src/core/ext/client_channel/resolver.h
+++ b/src/core/ext/client_channel/resolver.h
@@ -34,15 +34,13 @@
 #ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H
 #define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H
 
-#include "src/core/ext/client_channel/resolver_result.h"
 #include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/iomgr/iomgr.h"
 
 typedef struct grpc_resolver grpc_resolver;
 typedef struct grpc_resolver_vtable grpc_resolver_vtable;
 
-/** grpc_resolver provides grpc_resolver_result objects to grpc_channel
-    objects */
+/** \a grpc_resolver provides \a grpc_channel_args objects to its caller */
 struct grpc_resolver {
   const grpc_resolver_vtable *vtable;
   gpr_refcount refs;
@@ -53,7 +51,7 @@ struct grpc_resolver_vtable {
   void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
   void (*channel_saw_error)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
   void (*next)(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
-               grpc_resolver_result **result, grpc_closure *on_complete);
+               grpc_channel_args **result, grpc_closure *on_complete);
 };
 
 #ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
@@ -81,14 +79,12 @@ void grpc_resolver_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver);
 void grpc_resolver_channel_saw_error(grpc_exec_ctx *exec_ctx,
                                      grpc_resolver *resolver);
 
-/** Get the next client config. Called by the channel to fetch a new
-    configuration. Expected to set *result with a new configuration,
-    and then schedule on_complete for execution.
+/** Get the next result from the resolver.  Expected to set \a *result with
+    new channel args and then schedule \a on_complete for execution.
 
-    If resolution is fatally broken, set *result to NULL and
-    schedule on_complete. */
+    If resolution is fatally broken, set \a *result to NULL and
+    schedule \a on_complete. */
 void grpc_resolver_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
-                        grpc_resolver_result **result,
-                        grpc_closure *on_complete);
+                        grpc_channel_args **result, grpc_closure *on_complete);
 
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H */
diff --git a/src/core/ext/client_channel/resolver_factory.h b/src/core/ext/client_channel/resolver_factory.h
index 1ad018ce1f..4da42e84d2 100644
--- a/src/core/ext/client_channel/resolver_factory.h
+++ b/src/core/ext/client_channel/resolver_factory.h
@@ -41,13 +41,14 @@
 typedef struct grpc_resolver_factory grpc_resolver_factory;
 typedef struct grpc_resolver_factory_vtable grpc_resolver_factory_vtable;
 
-/** grpc_resolver provides grpc_resolver_result objects to grpc_channel
-    objects */
 struct grpc_resolver_factory {
   const grpc_resolver_factory_vtable *vtable;
 };
 
-typedef struct grpc_resolver_args { grpc_uri *uri; } grpc_resolver_args;
+typedef struct grpc_resolver_args {
+  grpc_uri *uri;
+  const grpc_channel_args *args;
+} grpc_resolver_args;
 
 struct grpc_resolver_factory_vtable {
   void (*ref)(grpc_resolver_factory *factory);
diff --git a/src/core/ext/client_channel/resolver_registry.c b/src/core/ext/client_channel/resolver_registry.c
index ee43329874..d0f0fc3f33 100644
--- a/src/core/ext/client_channel/resolver_registry.c
+++ b/src/core/ext/client_channel/resolver_registry.c
@@ -131,14 +131,16 @@ static grpc_resolver_factory *resolve_factory(const char *target,
   return factory;
 }
 
-grpc_resolver *grpc_resolver_create(const char *target) {
+grpc_resolver *grpc_resolver_create(const char *target,
+                                    const grpc_channel_args *args) {
   grpc_uri *uri = NULL;
   grpc_resolver_factory *factory = resolve_factory(target, &uri);
   grpc_resolver *resolver;
-  grpc_resolver_args args;
-  memset(&args, 0, sizeof(args));
-  args.uri = uri;
-  resolver = grpc_resolver_factory_create_resolver(factory, &args);
+  grpc_resolver_args resolver_args;
+  memset(&resolver_args, 0, sizeof(resolver_args));
+  resolver_args.uri = uri;
+  resolver_args.args = args;
+  resolver = grpc_resolver_factory_create_resolver(factory, &resolver_args);
   grpc_uri_destroy(uri);
   return resolver;
 }
diff --git a/src/core/ext/client_channel/resolver_registry.h b/src/core/ext/client_channel/resolver_registry.h
index 0a39d4a187..2a95a669f0 100644
--- a/src/core/ext/client_channel/resolver_registry.h
+++ b/src/core/ext/client_channel/resolver_registry.h
@@ -57,8 +57,11 @@ void grpc_register_resolver_type(grpc_resolver_factory *factory);
     was not NULL).
     If a resolver factory was found, use it to instantiate a resolver and
     return it.
-    If a resolver factory was not found, return NULL. */
-grpc_resolver *grpc_resolver_create(const char *target);
+    If a resolver factory was not found, return NULL.
+    \a args is a set of channel arguments to be included in the result
+    (typically the set of arguments passed in from the client API). */
+grpc_resolver *grpc_resolver_create(const char *target,
+                                    const grpc_channel_args *args);
 
 /** Find a resolver factory given a name and return an (owned-by-the-caller)
  *  reference to it */
diff --git a/src/core/ext/client_channel/resolver_result.c b/src/core/ext/client_channel/resolver_result.c
deleted file mode 100644
index ab1c215955..0000000000
--- a/src/core/ext/client_channel/resolver_result.c
+++ /dev/null
@@ -1,94 +0,0 @@
-//
-// Copyright 2015, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-
-#include "src/core/ext/client_channel/resolver_result.h"
-
-#include <string.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/string_util.h>
-
-#include "src/core/lib/channel/channel_args.h"
-
-struct grpc_resolver_result {
-  gpr_refcount refs;
-  char* server_name;
-  grpc_lb_addresses* addresses;
-  char* lb_policy_name;
-  grpc_channel_args* lb_policy_args;
-};
-
-grpc_resolver_result* grpc_resolver_result_create(
-    const char* server_name, grpc_lb_addresses* addresses,
-    const char* lb_policy_name, grpc_channel_args* lb_policy_args) {
-  grpc_resolver_result* result = gpr_malloc(sizeof(*result));
-  memset(result, 0, sizeof(*result));
-  gpr_ref_init(&result->refs, 1);
-  result->server_name = gpr_strdup(server_name);
-  result->addresses = addresses;
-  result->lb_policy_name = gpr_strdup(lb_policy_name);
-  result->lb_policy_args = lb_policy_args;
-  return result;
-}
-
-void grpc_resolver_result_ref(grpc_resolver_result* result) {
-  gpr_ref(&result->refs);
-}
-
-void grpc_resolver_result_unref(grpc_exec_ctx* exec_ctx,
-                                grpc_resolver_result* result) {
-  if (gpr_unref(&result->refs)) {
-    gpr_free(result->server_name);
-    grpc_lb_addresses_destroy(result->addresses, NULL /* user_data_destroy */);
-    gpr_free(result->lb_policy_name);
-    grpc_channel_args_destroy(result->lb_policy_args);
-    gpr_free(result);
-  }
-}
-
-const char* grpc_resolver_result_get_server_name(grpc_resolver_result* result) {
-  return result->server_name;
-}
-
-grpc_lb_addresses* grpc_resolver_result_get_addresses(
-    grpc_resolver_result* result) {
-  return result->addresses;
-}
-
-const char* grpc_resolver_result_get_lb_policy_name(
-    grpc_resolver_result* result) {
-  return result->lb_policy_name;
-}
-
-grpc_channel_args* grpc_resolver_result_get_lb_policy_args(
-    grpc_resolver_result* result) {
-  return result->lb_policy_args;
-}
diff --git a/src/core/ext/client_channel/resolver_result.h b/src/core/ext/client_channel/resolver_result.h
deleted file mode 100644
index 5421fd9470..0000000000
--- a/src/core/ext/client_channel/resolver_result.h
+++ /dev/null
@@ -1,68 +0,0 @@
-//
-// Copyright 2015, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_RESULT_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_RESULT_H
-
-#include "src/core/ext/client_channel/lb_policy_factory.h"
-
-// TODO(roth, ctiller): In the long term, we are considering replacing
-// the resolver_result data structure with grpc_channel_args.  The idea is
-// that the resolver will return a set of channel args that contains the
-// information that is currently in the resolver_result struct.  For
-// example, there will be specific args indicating the set of addresses
-// and the name of the LB policy to instantiate.  Note that if we did
-// this, we would probably want to change the data structure of
-// grpc_channel_args such to a hash table or AVL or some other data
-// structure that does not require linear search to find keys.
-
-/// Results reported from a grpc_resolver.
-typedef struct grpc_resolver_result grpc_resolver_result;
-
-/// Takes ownership of \a addresses and \a lb_policy_args.
-grpc_resolver_result* grpc_resolver_result_create(
-    const char* server_name, grpc_lb_addresses* addresses,
-    const char* lb_policy_name, grpc_channel_args* lb_policy_args);
-
-void grpc_resolver_result_ref(grpc_resolver_result* result);
-void grpc_resolver_result_unref(grpc_exec_ctx* exec_ctx,
-                                grpc_resolver_result* result);
-
-/// Accessors.  Caller does NOT take ownership of results.
-const char* grpc_resolver_result_get_server_name(grpc_resolver_result* result);
-grpc_lb_addresses* grpc_resolver_result_get_addresses(
-    grpc_resolver_result* result);
-const char* grpc_resolver_result_get_lb_policy_name(
-    grpc_resolver_result* result);
-grpc_channel_args* grpc_resolver_result_get_lb_policy_args(
-    grpc_resolver_result* result);
-
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_RESULT_H */
diff --git a/src/core/ext/client_channel/subchannel.c b/src/core/ext/client_channel/subchannel.c
index 672e5c3a91..789966cb69 100644
--- a/src/core/ext/client_channel/subchannel.c
+++ b/src/core/ext/client_channel/subchannel.c
@@ -95,8 +95,7 @@ struct grpc_subchannel {
   /** channel arguments */
   grpc_channel_args *args;
   /** address to connect to */
-  struct sockaddr *addr;
-  size_t addr_len;
+  grpc_resolved_address *addr;
 
   grpc_subchannel_key *key;
 
@@ -184,9 +183,10 @@ static void connection_destroy(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_free(c);
 }
 
-void grpc_connected_subchannel_ref(
+grpc_connected_subchannel *grpc_connected_subchannel_ref(
     grpc_connected_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
   GRPC_CHANNEL_STACK_REF(CHANNEL_STACK_FROM_CONNECTION(c), REF_REASON);
+  return c;
 }
 
 void grpc_connected_subchannel_unref(grpc_exec_ctx *exec_ctx,
@@ -298,7 +298,7 @@ void grpc_subchannel_weak_unref(grpc_exec_ctx *exec_ctx,
 
 grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                                         grpc_connector *connector,
-                                        grpc_subchannel_args *args) {
+                                        const grpc_subchannel_args *args) {
   grpc_subchannel_key *key = grpc_subchannel_key_create(connector, args);
   grpc_subchannel *c = grpc_subchannel_index_find(exec_ctx, key);
   if (c) {
@@ -320,12 +320,11 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
   } else {
     c->filters = NULL;
   }
-  c->addr = gpr_malloc(args->addr_len);
-  if (args->addr_len) memcpy(c->addr, args->addr, args->addr_len);
+  c->addr = gpr_malloc(sizeof(grpc_resolved_address));
+  if (args->addr->len)
+    memcpy(c->addr, args->addr, sizeof(grpc_resolved_address));
   c->pollset_set = grpc_pollset_set_create();
-  c->addr_len = args->addr_len;
-  grpc_set_initial_connect_string(&c->addr, &c->addr_len,
-                                  &c->initial_connect_string);
+  grpc_set_initial_connect_string(&c->addr, &c->initial_connect_string);
   c->args = grpc_channel_args_copy(args->args);
   c->root_external_state_watcher.next = c->root_external_state_watcher.prev =
       &c->root_external_state_watcher;
@@ -376,7 +375,6 @@ static void continue_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
 
   args.interested_parties = c->pollset_set;
   args.addr = c->addr;
-  args.addr_len = c->addr_len;
   args.deadline = c->next_attempt;
   args.channel_args = c->args;
   args.initial_connect_string = c->initial_connect_string;
diff --git a/src/core/ext/client_channel/subchannel.h b/src/core/ext/client_channel/subchannel.h
index c4a7da0c24..93bd72d20d 100644
--- a/src/core/ext/client_channel/subchannel.h
+++ b/src/core/ext/client_channel/subchannel.h
@@ -97,7 +97,7 @@ grpc_subchannel *grpc_subchannel_weak_ref(
 void grpc_subchannel_weak_unref(grpc_exec_ctx *exec_ctx,
                                 grpc_subchannel *channel
                                     GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
-void grpc_connected_subchannel_ref(
+grpc_connected_subchannel *grpc_connected_subchannel_ref(
     grpc_connected_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 void grpc_connected_subchannel_unref(grpc_exec_ctx *exec_ctx,
                                      grpc_connected_subchannel *channel
@@ -167,13 +167,12 @@ struct grpc_subchannel_args {
   /** Server name */
   const char *server_name;
   /** Address to connect to */
-  struct sockaddr *addr;
-  size_t addr_len;
+  grpc_resolved_address *addr;
 };
 
 /** create a subchannel given a connector */
 grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                                         grpc_connector *connector,
-                                        grpc_subchannel_args *args);
+                                        const grpc_subchannel_args *args);
 
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H */
diff --git a/src/core/ext/client_channel/subchannel_index.c b/src/core/ext/client_channel/subchannel_index.c
index bf22975fba..227013a7d7 100644
--- a/src/core/ext/client_channel/subchannel_index.c
+++ b/src/core/ext/client_channel/subchannel_index.c
@@ -73,7 +73,7 @@ static grpc_exec_ctx *current_ctx() {
 }
 
 static grpc_subchannel_key *create_key(
-    grpc_connector *connector, grpc_subchannel_args *args,
+    grpc_connector *connector, const grpc_subchannel_args *args,
     grpc_channel_args *(*copy_channel_args)(const grpc_channel_args *args)) {
   grpc_subchannel_key *k = gpr_malloc(sizeof(*k));
   k->connector = grpc_connector_ref(connector);
@@ -87,17 +87,17 @@ static grpc_subchannel_key *create_key(
     k->args.filters = NULL;
   }
   k->args.server_name = gpr_strdup(args->server_name);
-  k->args.addr_len = args->addr_len;
-  k->args.addr = gpr_malloc(args->addr_len);
-  if (k->args.addr_len > 0) {
-    memcpy(k->args.addr, args->addr, k->args.addr_len);
+  k->args.addr = gpr_malloc(sizeof(grpc_resolved_address));
+  k->args.addr->len = args->addr->len;
+  if (k->args.addr->len > 0) {
+    memcpy(k->args.addr, args->addr, sizeof(grpc_resolved_address));
   }
   k->args.args = copy_channel_args(args->args);
   return k;
 }
 
-grpc_subchannel_key *grpc_subchannel_key_create(grpc_connector *connector,
-                                                grpc_subchannel_args *args) {
+grpc_subchannel_key *grpc_subchannel_key_create(
+    grpc_connector *connector, const grpc_subchannel_args *args) {
   return create_key(connector, args, grpc_channel_args_normalize);
 }
 
@@ -109,14 +109,14 @@ static int subchannel_key_compare(grpc_subchannel_key *a,
                                   grpc_subchannel_key *b) {
   int c = GPR_ICMP(a->connector, b->connector);
   if (c != 0) return c;
-  c = GPR_ICMP(a->args.addr_len, b->args.addr_len);
+  c = GPR_ICMP(a->args.addr->len, b->args.addr->len);
   if (c != 0) return c;
   c = GPR_ICMP(a->args.filter_count, b->args.filter_count);
   if (c != 0) return c;
   c = strcmp(a->args.server_name, b->args.server_name);
   if (c != 0) return c;
-  if (a->args.addr_len) {
-    c = memcmp(a->args.addr, b->args.addr, a->args.addr_len);
+  if (a->args.addr->len) {
+    c = memcmp(a->args.addr->addr, b->args.addr->addr, a->args.addr->len);
     if (c != 0) return c;
   }
   if (a->args.filter_count > 0) {
diff --git a/src/core/ext/client_channel/subchannel_index.h b/src/core/ext/client_channel/subchannel_index.h
index 5b3af6b054..a67bd5e219 100644
--- a/src/core/ext/client_channel/subchannel_index.h
+++ b/src/core/ext/client_channel/subchannel_index.h
@@ -43,8 +43,8 @@
 typedef struct grpc_subchannel_key grpc_subchannel_key;
 
 /** Create a key that can be used to uniquely identify a subchannel */
-grpc_subchannel_key *grpc_subchannel_key_create(grpc_connector *con,
-                                                grpc_subchannel_args *args);
+grpc_subchannel_key *grpc_subchannel_key_create(
+    grpc_connector *con, const grpc_subchannel_args *args);
 
 /** Destroy a subchannel key */
 void grpc_subchannel_key_destroy(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index 412090158a..6da4febf26 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -96,6 +96,12 @@
  * - Implement LB service forwarding (point 2c. in the doc's diagram).
  */
 
+/* With the addition of a libuv endpoint, sockaddr.h now includes uv.h when
+   using that endpoint. Because of various transitive includes in uv.h,
+   including windows.h on Windows, uv.h must be included before other system
+   headers. Therefore, sockaddr.h must always be included first */
+#include "src/core/lib/iomgr/sockaddr.h"
+
 #include <errno.h>
 
 #include <string.h>
@@ -114,7 +120,6 @@
 #include "src/core/ext/lb_policy/grpclb/grpclb.h"
 #include "src/core/ext/lb_policy/grpclb/load_balancer_api.h"
 #include "src/core/lib/channel/channel_args.h"
-#include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/call.h"
@@ -338,6 +343,21 @@ static bool is_server_valid(const grpc_grpclb_server *server, size_t idx,
   return true;
 }
 
+/* vtable for LB tokens in grpc_lb_addresses. */
+static void *lb_token_copy(void *token) {
+  return token == NULL ? NULL : GRPC_MDELEM_REF(token);
+}
+static void lb_token_destroy(void *token) {
+  if (token != NULL) GRPC_MDELEM_UNREF(token);
+}
+static int lb_token_cmp(void *token1, void *token2) {
+  if (token1 > token2) return 1;
+  if (token1 < token2) return -1;
+  return 0;
+}
+static const grpc_lb_user_data_vtable lb_token_vtable = {
+    lb_token_copy, lb_token_destroy, lb_token_cmp};
+
 /* Returns addresses extracted from \a serverlist. */
 static grpc_lb_addresses *process_serverlist(
     const grpc_grpclb_serverlist *serverlist) {
@@ -349,7 +369,8 @@ static grpc_lb_addresses *process_serverlist(
   }
   if (num_valid == 0) return NULL;
 
-  grpc_lb_addresses *lb_addresses = grpc_lb_addresses_create(num_valid);
+  grpc_lb_addresses *lb_addresses =
+      grpc_lb_addresses_create(num_valid, &lb_token_vtable);
 
   /* second pass: actually populate the addresses and LB tokens (aka user data
    * to the outside world) to be read by the RR policy during its creation.
@@ -396,7 +417,7 @@ static grpc_lb_addresses *process_serverlist(
       gpr_log(GPR_ERROR,
               "Missing LB token for backend address '%s'. The empty token will "
               "be used instead",
-              grpc_sockaddr_to_uri((struct sockaddr *)&addr.addr));
+              grpc_sockaddr_to_uri(&addr));
       user_data = GRPC_MDELEM_LB_TOKEN_EMPTY;
     }
 
@@ -410,11 +431,6 @@ static grpc_lb_addresses *process_serverlist(
   return lb_addresses;
 }
 
-/* A plugin for grpc_lb_addresses_destroy that unrefs the LB token metadata. */
-static void lb_token_destroy(void *token) {
-  if (token != NULL) GRPC_MDELEM_UNREF(token);
-}
-
 /* perform a pick over \a rr_policy. Given that a pick can return immediately
  * (ignoring its completion callback) we need to perform the cleanups this
  * callback would be otherwise resposible for */
@@ -454,20 +470,27 @@ static grpc_lb_policy *create_rr_locked(
     glb_lb_policy *glb_policy) {
   GPR_ASSERT(serverlist != NULL && serverlist->num_servers > 0);
 
+  if (glb_policy->addresses != NULL) {
+    /* dispose of the previous version */
+    grpc_lb_addresses_destroy(glb_policy->addresses);
+  }
+  glb_policy->addresses = process_serverlist(serverlist);
+
   grpc_lb_policy_args args;
   memset(&args, 0, sizeof(args));
-  args.server_name = glb_policy->server_name;
   args.client_channel_factory = glb_policy->cc_factory;
-  args.addresses = process_serverlist(serverlist);
-  args.additional_args = glb_policy->args;
 
-  grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args);
+  // Replace the LB addresses in the channel args that we pass down to
+  // the subchannel.
+  static const char *keys_to_remove[] = {GRPC_ARG_LB_ADDRESSES};
+  const grpc_arg arg =
+      grpc_lb_addresses_create_channel_arg(glb_policy->addresses);
+  args.args = grpc_channel_args_copy_and_add_and_remove(
+      glb_policy->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &arg,
+      1);
 
-  if (glb_policy->addresses != NULL) {
-    /* dispose of the previous version */
-    grpc_lb_addresses_destroy(glb_policy->addresses, lb_token_destroy);
-  }
-  glb_policy->addresses = args.addresses;
+  grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args);
+  grpc_channel_args_destroy(args.args);
 
   return rr;
 }
@@ -563,6 +586,12 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
 static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
                                   grpc_lb_policy_factory *factory,
                                   grpc_lb_policy_args *args) {
+  /* Get server name. */
+  const grpc_arg *arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
+  const char *server_name =
+      arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL;
+
   /* Count the number of gRPC-LB addresses. There must be at least one.
    * TODO(roth): For now, we ignore non-balancer addresses, but in the
    * future, we may change the behavior such that we fall back to using
@@ -570,24 +599,27 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
    * time, this should be changed to allow a list with no balancer addresses,
    * since the resolver might fail to return a balancer address even when
    * this is the right LB policy to use. */
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+  GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+  grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_grpclb_addrs = 0;
-  for (size_t i = 0; i < args->addresses->num_addresses; ++i) {
-    if (args->addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
+  for (size_t i = 0; i < addresses->num_addresses; ++i) {
+    if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
   }
   if (num_grpclb_addrs == 0) return NULL;
 
   glb_lb_policy *glb_policy = gpr_malloc(sizeof(*glb_policy));
   memset(glb_policy, 0, sizeof(*glb_policy));
 
-  /* All input addresses in args->addresses come from a resolver that claims
+  /* All input addresses in addresses come from a resolver that claims
    * they are LB services. It's the resolver's responsibility to make sure
    * this
    * policy is only instantiated and used in that case.
    *
    * Create a client channel over them to communicate with a LB service */
-  glb_policy->server_name = gpr_strdup(args->server_name);
+  glb_policy->server_name = gpr_strdup(server_name);
   glb_policy->cc_factory = args->client_channel_factory;
-  glb_policy->args = grpc_channel_args_copy(args->additional_args);
+  glb_policy->args = grpc_channel_args_copy(args->args);
   GPR_ASSERT(glb_policy->cc_factory != NULL);
 
   /* construct a target from the addresses in args, given in the form
@@ -595,22 +627,19 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
    * TODO(dgq): support mixed ip version */
   char **addr_strs = gpr_malloc(sizeof(char *) * num_grpclb_addrs);
   size_t addr_index = 0;
-  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
-    if (args->addresses->addresses[i].user_data != NULL) {
+  for (size_t i = 0; i < addresses->num_addresses; i++) {
+    if (addresses->addresses[i].user_data != NULL) {
       gpr_log(GPR_ERROR,
               "This LB policy doesn't support user data. It will be ignored");
     }
-    if (args->addresses->addresses[i].is_balancer) {
+    if (addresses->addresses[i].is_balancer) {
       if (addr_index == 0) {
-        addr_strs[addr_index++] = grpc_sockaddr_to_uri(
-            (const struct sockaddr *)&args->addresses->addresses[i]
-                .address.addr);
+        addr_strs[addr_index++] =
+            grpc_sockaddr_to_uri(&addresses->addresses[i].address);
       } else {
-        GPR_ASSERT(grpc_sockaddr_to_string(
-                       &addr_strs[addr_index++],
-                       (const struct sockaddr *)&args->addresses->addresses[i]
-                           .address.addr,
-                       true) > 0);
+        GPR_ASSERT(grpc_sockaddr_to_string(&addr_strs[addr_index++],
+                                           &addresses->addresses[i].address,
+                                           true) > 0);
       }
     }
   }
@@ -618,10 +647,29 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
   char *target_uri_str = gpr_strjoin_sep((const char **)addr_strs,
                                          num_grpclb_addrs, ",", &uri_path_len);
 
-  /* will pick using pick_first */
+  /* Create a channel to talk to the LBs.
+   *
+   * We strip out the channel arg for the LB policy name, since we want
+   * to use the default (pick_first) in this case.
+   *
+   * We also strip out the channel arg for the resolved addresses, since
+   * that will be generated by the name resolver used in the LB channel.
+   * Note that the LB channel will use the sockaddr resolver, so this
+   * won't actually generate a query to DNS (or some other name service).
+   * However, the addresses returned by the sockaddr resolver will have
+   * is_balancer=false, whereas our own addresses have is_balancer=true.
+   * We need the LB channel to return addresses with is_balancer=false
+   * so that it does not wind up recursively using the grpclb LB policy,
+   * as per the special case logic in client_channel.c.
+   */
+  static const char *keys_to_remove[] = {GRPC_ARG_LB_POLICY_NAME,
+                                         GRPC_ARG_LB_ADDRESSES};
+  grpc_channel_args *new_args = grpc_channel_args_copy_and_remove(
+      args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove));
   glb_policy->lb_channel = grpc_client_channel_factory_create_channel(
       exec_ctx, glb_policy->cc_factory, target_uri_str,
-      GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, NULL);
+      GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, new_args);
+  grpc_channel_args_destroy(new_args);
 
   gpr_free(target_uri_str);
   for (size_t i = 0; i < num_grpclb_addrs; i++) {
@@ -662,7 +710,7 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
   }
   gpr_mu_destroy(&glb_policy->mu);
-  grpc_lb_addresses_destroy(glb_policy->addresses, lb_token_destroy);
+  grpc_lb_addresses_destroy(glb_policy->addresses);
   gpr_free(glb_policy);
 }
 
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index 270fe3fe70..ac3c6a305a 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -34,7 +34,9 @@
 #include <string.h>
 
 #include <grpc/support/alloc.h>
+
 #include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 typedef struct pending_pick {
@@ -207,7 +209,7 @@ static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   /* Check atomically for a selected channel */
   grpc_connected_subchannel *selected = GET_SELECTED(p);
   if (selected != NULL) {
-    *target = selected;
+    *target = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked");
     return 1;
   }
 
@@ -216,7 +218,7 @@ static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   selected = GET_SELECTED(p);
   if (selected) {
     gpr_mu_unlock(&p->mu);
-    *target = selected;
+    *target = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked");
     return 1;
   } else {
     if (!p->started_picking) {
@@ -308,7 +310,7 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         /* update any calls that were waiting for a pick */
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
-          *pp->target = selected;
+          *pp->target = GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked");
           grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL);
           gpr_free(pp);
         }
@@ -432,14 +434,22 @@ static void pick_first_factory_unref(grpc_lb_policy_factory *factory) {}
 static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
                                          grpc_lb_policy_factory *factory,
                                          grpc_lb_policy_args *args) {
-  GPR_ASSERT(args->addresses != NULL);
   GPR_ASSERT(args->client_channel_factory != NULL);
 
+  /* Get server name. */
+  const grpc_arg *arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
+  const char *server_name =
+      arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL;
+
   /* Find the number of backend addresses. We ignore balancer
    * addresses, since we don't know how to handle them. */
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+  GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+  grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_addrs = 0;
-  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
-    if (!args->addresses->addresses[i].is_balancer) ++num_addrs;
+  for (size_t i = 0; i < addresses->num_addresses; i++) {
+    if (!addresses->addresses[i].is_balancer) ++num_addrs;
   }
   if (num_addrs == 0) return NULL;
 
@@ -450,23 +460,21 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
   memset(p->subchannels, 0, sizeof(*p->subchannels) * num_addrs);
   grpc_subchannel_args sc_args;
   size_t subchannel_idx = 0;
-  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+  for (size_t i = 0; i < addresses->num_addresses; i++) {
     /* Skip balancer addresses, since we only know how to handle backends. */
-    if (args->addresses->addresses[i].is_balancer) continue;
+    if (addresses->addresses[i].is_balancer) continue;
 
-    if (args->addresses->addresses[i].user_data != NULL) {
+    if (addresses->addresses[i].user_data != NULL) {
       gpr_log(GPR_ERROR,
               "This LB policy doesn't support user data. It will be ignored");
     }
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
     /* server_name will be copied as part of the subchannel creation. This makes
-     * the copying of args->server_name (a borrowed pointer) OK. */
-    sc_args.server_name = args->server_name;
-    sc_args.addr =
-        (struct sockaddr *)(&args->addresses->addresses[i].address.addr);
-    sc_args.addr_len = args->addresses->addresses[i].address.len;
-    sc_args.args = args->additional_args;
+     * the copying of server_name (a borrowed pointer) OK. */
+    sc_args.server_name = server_name;
+    sc_args.addr = &addresses->addresses[i].address;
+    sc_args.args = args->args;
 
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
         exec_ctx, args->client_channel_factory, &sc_args);
diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/lb_policy/round_robin/round_robin.c
index b32f6be99e..37a9b18b97 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -64,6 +64,7 @@
 #include <grpc/support/alloc.h>
 
 #include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/static_metadata.h"
@@ -396,7 +397,9 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   gpr_mu_lock(&p->mu);
   if ((selected = peek_next_connected_locked(p))) {
     /* readily available, report right away */
-    *target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
+    *target = GRPC_CONNECTED_SUBCHANNEL_REF(
+        grpc_subchannel_get_connected_subchannel(selected->subchannel),
+        "picked");
 
     if (user_data != NULL) {
       *user_data = selected->user_data;
@@ -462,8 +465,9 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
 
-          *pp->target =
-              grpc_subchannel_get_connected_subchannel(selected->subchannel);
+          *pp->target = GRPC_CONNECTED_SUBCHANNEL_REF(
+              grpc_subchannel_get_connected_subchannel(selected->subchannel),
+              "picked");
           if (pp->user_data != NULL) {
             *pp->user_data = selected->user_data;
           }
@@ -577,7 +581,9 @@ static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   gpr_mu_lock(&p->mu);
   if ((selected = peek_next_connected_locked(p))) {
     gpr_mu_unlock(&p->mu);
-    target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
+    target = GRPC_CONNECTED_SUBCHANNEL_REF(
+        grpc_subchannel_get_connected_subchannel(selected->subchannel),
+        "picked");
     grpc_connected_subchannel_ping(exec_ctx, target, closure);
   } else {
     gpr_mu_unlock(&p->mu);
@@ -598,14 +604,22 @@ static void round_robin_factory_unref(grpc_lb_policy_factory *factory) {}
 static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
                                           grpc_lb_policy_factory *factory,
                                           grpc_lb_policy_args *args) {
-  GPR_ASSERT(args->addresses != NULL);
   GPR_ASSERT(args->client_channel_factory != NULL);
 
+  /* Get server name. */
+  const grpc_arg *arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
+  const char *server_name =
+      arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL;
+
   /* Find the number of backend addresses. We ignore balancer
    * addresses, since we don't know how to handle them. */
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+  GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+  grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_addrs = 0;
-  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
-    if (!args->addresses->addresses[i].is_balancer) ++num_addrs;
+  for (size_t i = 0; i < addresses->num_addresses; i++) {
+    if (!addresses->addresses[i].is_balancer) ++num_addrs;
   }
   if (num_addrs == 0) return NULL;
 
@@ -618,18 +632,16 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
 
   grpc_subchannel_args sc_args;
   size_t subchannel_idx = 0;
-  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+  for (size_t i = 0; i < addresses->num_addresses; i++) {
     /* Skip balancer addresses, since we only know how to handle backends. */
-    if (args->addresses->addresses[i].is_balancer) continue;
+    if (addresses->addresses[i].is_balancer) continue;
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
     /* server_name will be copied as part of the subchannel creation. This makes
-     * the copying of args->server_name (a borrowed pointer) OK. */
-    sc_args.server_name = args->server_name;
-    sc_args.addr =
-        (struct sockaddr *)(&args->addresses->addresses[i].address.addr);
-    sc_args.addr_len = args->addresses->addresses[i].address.len;
-    sc_args.args = args->additional_args;
+     * the copying of server_name (a borrowed pointer) OK. */
+    sc_args.server_name = server_name;
+    sc_args.addr = &addresses->addresses[i].address;
+    sc_args.args = args->args;
 
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
         exec_ctx, args->client_channel_factory, &sc_args);
@@ -641,7 +653,7 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
       sd->policy = p;
       sd->index = subchannel_idx;
       sd->subchannel = subchannel;
-      sd->user_data = args->addresses->addresses[i].user_data;
+      sd->user_data = addresses->addresses[i].user_data;
       ++subchannel_idx;
       grpc_closure_init(&sd->connectivity_changed_closure,
                         rr_connectivity_changed, sd);
diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
index b4ceee340e..958b8af8b2 100644
--- a/src/core/ext/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -40,6 +40,7 @@
 #include "src/core/ext/client_channel/http_connect_handshaker.h"
 #include "src/core/ext/client_channel/lb_policy_registry.h"
 #include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/support/backoff.h"
@@ -53,12 +54,12 @@
 typedef struct {
   /** base class: must be first */
   grpc_resolver base;
-  /** target name */
-  char *target_name;
-  /** name to resolve (usually the same as target_name) */
+  /** name to resolve */
   char *name_to_resolve;
   /** default port to use */
   char *default_port;
+  /** channel args. */
+  grpc_channel_args *channel_args;
 
   /** mutex guarding the rest of the state */
   gpr_mu mu;
@@ -71,9 +72,9 @@ typedef struct {
   /** pending next completion, or NULL */
   grpc_closure *next_completion;
   /** target result address for next completion */
-  grpc_resolver_result **target_result;
+  grpc_channel_args **target_result;
   /** current (fully resolved) result */
-  grpc_resolver_result *resolved_result;
+  grpc_channel_args *resolved_result;
   /** retry timer */
   bool have_retry_timer;
   grpc_timer retry_timer;
@@ -94,7 +95,7 @@ static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
 static void dns_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
 static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
 static void dns_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
-                     grpc_resolver_result **target_result,
+                     grpc_channel_args **target_result,
                      grpc_closure *on_complete);
 
 static const grpc_resolver_vtable dns_resolver_vtable = {
@@ -127,7 +128,7 @@ static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx,
 }
 
 static void dns_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
-                     grpc_resolver_result **target_result,
+                     grpc_channel_args **target_result,
                      grpc_closure *on_complete) {
   dns_resolver *r = (dns_resolver *)resolver;
   gpr_mu_lock(&r->mu);
@@ -162,22 +163,23 @@ static void dns_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
 static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
                             grpc_error *error) {
   dns_resolver *r = arg;
-  grpc_resolver_result *result = NULL;
+  grpc_channel_args *result = NULL;
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(r->resolving);
   r->resolving = false;
   if (r->addresses != NULL) {
-    grpc_lb_addresses *addresses =
-        grpc_lb_addresses_create(r->addresses->naddrs);
+    grpc_lb_addresses *addresses = grpc_lb_addresses_create(
+        r->addresses->naddrs, NULL /* user_data_vtable */);
     for (size_t i = 0; i < r->addresses->naddrs; ++i) {
       grpc_lb_addresses_set_address(
           addresses, i, &r->addresses->addrs[i].addr,
           r->addresses->addrs[i].len, false /* is_balancer */,
           NULL /* balancer_name */, NULL /* user_data */);
     }
+    grpc_arg new_arg = grpc_lb_addresses_create_channel_arg(addresses);
+    result = grpc_channel_args_copy_and_add(r->channel_args, &new_arg, 1);
     grpc_resolved_addresses_destroy(r->addresses);
-    result = grpc_resolver_result_create(r->target_name, addresses,
-                                         NULL /* lb_policy_name */, NULL);
+    grpc_lb_addresses_destroy(addresses);
   } else {
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
     gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
@@ -197,8 +199,8 @@ static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
     grpc_timer_init(exec_ctx, &r->retry_timer, next_try, dns_on_retry_timer, r,
                     now);
   }
-  if (r->resolved_result) {
-    grpc_resolver_result_unref(exec_ctx, r->resolved_result);
+  if (r->resolved_result != NULL) {
+    grpc_channel_args_destroy(r->resolved_result);
   }
   r->resolved_result = result;
   r->resolved_version++;
@@ -222,10 +224,9 @@ static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
                                          dns_resolver *r) {
   if (r->next_completion != NULL &&
       r->resolved_version != r->published_version) {
-    *r->target_result = r->resolved_result;
-    if (r->resolved_result) {
-      grpc_resolver_result_ref(r->resolved_result);
-    }
+    *r->target_result = r->resolved_result == NULL
+                            ? NULL
+                            : grpc_channel_args_copy(r->resolved_result);
     grpc_exec_ctx_sched(exec_ctx, r->next_completion, GRPC_ERROR_NONE, NULL);
     r->next_completion = NULL;
     r->published_version = r->resolved_version;
@@ -235,12 +236,12 @@ static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
 static void dns_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   dns_resolver *r = (dns_resolver *)gr;
   gpr_mu_destroy(&r->mu);
-  if (r->resolved_result) {
-    grpc_resolver_result_unref(exec_ctx, r->resolved_result);
+  if (r->resolved_result != NULL) {
+    grpc_channel_args_destroy(r->resolved_result);
   }
-  gpr_free(r->target_name);
   gpr_free(r->name_to_resolve);
   gpr_free(r->default_port);
+  grpc_channel_args_destroy(r->channel_args);
   gpr_free(r);
 }
 
@@ -260,9 +261,14 @@ static grpc_resolver *dns_create(grpc_resolver_args *args,
   memset(r, 0, sizeof(*r));
   gpr_mu_init(&r->mu);
   grpc_resolver_init(&r->base, &dns_resolver_vtable);
-  r->target_name = gpr_strdup(path);
   r->name_to_resolve = proxy_name == NULL ? gpr_strdup(path) : proxy_name;
   r->default_port = gpr_strdup(default_port);
+  grpc_arg server_name_arg;
+  server_name_arg.type = GRPC_ARG_STRING;
+  server_name_arg.key = GRPC_ARG_SERVER_NAME;
+  server_name_arg.value.string = (char *)path;
+  r->channel_args =
+      grpc_channel_args_copy_and_add(args->args, &server_name_arg, 1);
   gpr_backoff_init(&r->backoff_state, BACKOFF_MULTIPLIER, BACKOFF_JITTER,
                    BACKOFF_MIN_SECONDS * 1000, BACKOFF_MAX_SECONDS * 1000);
   return &r->base;
diff --git a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
index 9924fc6fec..5fec03a8e4 100644
--- a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
+++ b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
@@ -41,8 +41,10 @@
 #include <grpc/support/port_platform.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/ext/client_channel/lb_policy_factory.h"
 #include "src/core/ext/client_channel/parse_address.h"
 #include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/support/string.h"
@@ -50,10 +52,10 @@
 typedef struct {
   /** base class: must be first */
   grpc_resolver base;
-  /** the path component of the uri passed in */
-  char *target_name;
   /** the addresses that we've 'resolved' */
   grpc_lb_addresses *addresses;
+  /** channel args */
+  grpc_channel_args *channel_args;
   /** mutex guarding the rest of the state */
   gpr_mu mu;
   /** have we published? */
@@ -61,7 +63,7 @@ typedef struct {
   /** pending next completion, or NULL */
   grpc_closure *next_completion;
   /** target result address for next completion */
-  grpc_resolver_result **target_result;
+  grpc_channel_args **target_result;
 } sockaddr_resolver;
 
 static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
@@ -73,7 +75,7 @@ static void sockaddr_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
 static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
                                        grpc_resolver *r);
 static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
-                          grpc_resolver_result **target_result,
+                          grpc_channel_args **target_result,
                           grpc_closure *on_complete);
 
 static const grpc_resolver_vtable sockaddr_resolver_vtable = {
@@ -102,7 +104,7 @@ static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
 }
 
 static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
-                          grpc_resolver_result **target_result,
+                          grpc_channel_args **target_result,
                           grpc_closure *on_complete) {
   sockaddr_resolver *r = (sockaddr_resolver *)resolver;
   gpr_mu_lock(&r->mu);
@@ -117,10 +119,9 @@ static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
                                               sockaddr_resolver *r) {
   if (r->next_completion != NULL && !r->published) {
     r->published = true;
-    *r->target_result = grpc_resolver_result_create(
-        r->target_name,
-        grpc_lb_addresses_copy(r->addresses, NULL /* user_data_copy */),
-        NULL /* lb_policy_name */, NULL /* lb_policy_args */);
+    grpc_arg arg = grpc_lb_addresses_create_channel_arg(r->addresses);
+    *r->target_result =
+        grpc_channel_args_copy_and_add(r->channel_args, &arg, 1);
     grpc_exec_ctx_sched(exec_ctx, r->next_completion, GRPC_ERROR_NONE, NULL);
     r->next_completion = NULL;
   }
@@ -129,8 +130,8 @@ static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
 static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   sockaddr_resolver *r = (sockaddr_resolver *)gr;
   gpr_mu_destroy(&r->mu);
-  gpr_free(r->target_name);
-  grpc_lb_addresses_destroy(r->addresses, NULL /* user_data_destroy */);
+  grpc_lb_addresses_destroy(r->addresses);
+  grpc_channel_args_destroy(r->channel_args);
   gpr_free(r);
 }
 
@@ -150,7 +151,7 @@ static char *ipv6_get_default_authority(grpc_resolver_factory *factory,
   return ip_get_default_authority(uri);
 }
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 char *unix_get_default_authority(grpc_resolver_factory *factory,
                                  grpc_uri *uri) {
   return gpr_strdup("localhost");
@@ -161,8 +162,7 @@ static void do_nothing(void *ignored) {}
 
 static grpc_resolver *sockaddr_create(grpc_resolver_args *args,
                                       int parse(grpc_uri *uri,
-                                                struct sockaddr_storage *dst,
-                                                size_t *len)) {
+                                                grpc_resolved_address *dst)) {
   if (0 != strcmp(args->uri->authority, "")) {
     gpr_log(GPR_ERROR, "authority based uri's not supported by the %s scheme",
             args->uri->scheme);
@@ -174,17 +174,15 @@ static grpc_resolver *sockaddr_create(grpc_resolver_args *args,
   gpr_slice_buffer path_parts;
   gpr_slice_buffer_init(&path_parts);
   gpr_slice_split(path_slice, ",", &path_parts);
-  grpc_lb_addresses *addresses = grpc_lb_addresses_create(path_parts.count);
+  grpc_lb_addresses *addresses =
+      grpc_lb_addresses_create(path_parts.count, NULL /* user_data_vtable */);
   bool errors_found = false;
   for (size_t i = 0; i < addresses->num_addresses; i++) {
     grpc_uri ith_uri = *args->uri;
     char *part_str = gpr_dump_slice(path_parts.slices[i], GPR_DUMP_ASCII);
     ith_uri.path = part_str;
-    if (!parse(
-            &ith_uri,
-            (struct sockaddr_storage *)(&addresses->addresses[i].address.addr),
-            &addresses->addresses[i].address.len)) {
-      errors_found = true;
+    if (!parse(&ith_uri, &addresses->addresses[i].address)) {
+      errors_found = true; /* GPR_TRUE */
     }
     gpr_free(part_str);
     if (errors_found) break;
@@ -192,14 +190,19 @@ static grpc_resolver *sockaddr_create(grpc_resolver_args *args,
   gpr_slice_buffer_destroy(&path_parts);
   gpr_slice_unref(path_slice);
   if (errors_found) {
-    grpc_lb_addresses_destroy(addresses, NULL /* user_data_destroy */);
+    grpc_lb_addresses_destroy(addresses);
     return NULL;
   }
   /* Instantiate resolver. */
   sockaddr_resolver *r = gpr_malloc(sizeof(sockaddr_resolver));
   memset(r, 0, sizeof(*r));
-  r->target_name = gpr_strdup(args->uri->path);
   r->addresses = addresses;
+  grpc_arg server_name_arg;
+  server_name_arg.type = GRPC_ARG_STRING;
+  server_name_arg.key = GRPC_ARG_SERVER_NAME;
+  server_name_arg.value.string = args->uri->path;
+  r->channel_args =
+      grpc_channel_args_copy_and_add(args->args, &server_name_arg, 1);
   gpr_mu_init(&r->mu);
   grpc_resolver_init(&r->base, &sockaddr_resolver_vtable);
   return &r->base;
@@ -224,7 +227,7 @@ static void sockaddr_factory_unref(grpc_resolver_factory *factory) {}
   static grpc_resolver_factory name##_resolver_factory = {                  \
       &name##_factory_vtable}
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 DECL_FACTORY(unix);
 #endif
 DECL_FACTORY(ipv4);
@@ -233,7 +236,7 @@ DECL_FACTORY(ipv6);
 void grpc_resolver_sockaddr_init(void) {
   grpc_register_resolver_type(&ipv4_resolver_factory);
   grpc_register_resolver_type(&ipv6_resolver_factory);
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
   grpc_register_resolver_type(&unix_resolver_factory);
 #endif
 }
diff --git a/src/core/ext/transport/chttp2/alpn/alpn.c b/src/core/ext/transport/chttp2/alpn/alpn.c
index 48b0217265..55710dc5ae 100644
--- a/src/core/ext/transport/chttp2/alpn/alpn.c
+++ b/src/core/ext/transport/chttp2/alpn/alpn.c
@@ -36,7 +36,7 @@
 #include <grpc/support/useful.h>
 
 /* in order of preference */
-static const char *const supported_versions[] = {"h2"};
+static const char *const supported_versions[] = {"grpc-exp", "h2"};
 
 int grpc_chttp2_is_alpn_version_supported(const char *version, size_t size) {
   size_t i;
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.c b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
index 41432b54a9..71a06e118b 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
@@ -52,6 +52,10 @@
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/channel.h"
 
+//
+// connector
+//
+
 typedef struct {
   grpc_connector base;
   gpr_refcount refs;
@@ -151,41 +155,26 @@ static void connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *con,
   grpc_closure_init(&c->connected, connected, c);
   grpc_tcp_client_connect(exec_ctx, &c->connected, &c->tcp,
                           args->interested_parties, args->channel_args,
-                          args->addr, args->addr_len, args->deadline);
+                          args->addr, args->deadline);
 }
 
 static const grpc_connector_vtable connector_vtable = {
     connector_ref, connector_unref, connector_shutdown, connector_connect};
 
-typedef struct {
-  grpc_client_channel_factory base;
-  gpr_refcount refs;
-  grpc_channel_args *merge_args;
-} client_channel_factory;
+//
+// client_channel_factory
+//
 
 static void client_channel_factory_ref(
-    grpc_client_channel_factory *cc_factory) {
-  client_channel_factory *f = (client_channel_factory *)cc_factory;
-  gpr_ref(&f->refs);
-}
+    grpc_client_channel_factory *cc_factory) {}
 
 static void client_channel_factory_unref(
-    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory) {
-  client_channel_factory *f = (client_channel_factory *)cc_factory;
-  if (gpr_unref(&f->refs)) {
-    grpc_channel_args_destroy(f->merge_args);
-    gpr_free(f);
-  }
-}
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory) {}
 
 static grpc_subchannel *client_channel_factory_create_subchannel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
-    grpc_subchannel_args *args) {
-  client_channel_factory *f = (client_channel_factory *)cc_factory;
+    const grpc_subchannel_args *args) {
   connector *c = gpr_malloc(sizeof(*c));
-  grpc_channel_args *final_args =
-      grpc_channel_args_merge(args->args, f->merge_args);
-  grpc_subchannel *s;
   memset(c, 0, sizeof(*c));
   c->base.vtable = &connector_vtable;
   gpr_ref_init(&c->refs, 1);
@@ -197,23 +186,18 @@ static grpc_subchannel *client_channel_factory_create_subchannel(
         grpc_http_connect_handshaker_create(proxy_name, args->server_name));
     gpr_free(proxy_name);
   }
-  args->args = final_args;
-  s = grpc_subchannel_create(exec_ctx, &c->base, args);
+  grpc_subchannel *s = grpc_subchannel_create(exec_ctx, &c->base, args);
   grpc_connector_unref(exec_ctx, &c->base);
-  grpc_channel_args_destroy(final_args);
   return s;
 }
 
 static grpc_channel *client_channel_factory_create_channel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
     const char *target, grpc_client_channel_type type,
-    grpc_channel_args *args) {
-  client_channel_factory *f = (client_channel_factory *)cc_factory;
-  grpc_channel_args *final_args = grpc_channel_args_merge(args, f->merge_args);
-  grpc_channel *channel = grpc_channel_create(exec_ctx, target, final_args,
-                                              GRPC_CLIENT_CHANNEL, NULL);
-  grpc_channel_args_destroy(final_args);
-  grpc_resolver *resolver = grpc_resolver_create(target);
+    const grpc_channel_args *args) {
+  grpc_channel *channel =
+      grpc_channel_create(exec_ctx, target, args, GRPC_CLIENT_CHANNEL, NULL);
+  grpc_resolver *resolver = grpc_resolver_create(target, args);
   if (!resolver) {
     GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel,
                                 "client_channel_factory_create_channel");
@@ -221,7 +205,7 @@ static grpc_channel *client_channel_factory_create_channel(
   }
 
   grpc_client_channel_finish_initialization(
-      exec_ctx, grpc_channel_get_channel_stack(channel), resolver, &f->base);
+      exec_ctx, grpc_channel_get_channel_stack(channel), resolver, cc_factory);
   GRPC_RESOLVER_UNREF(exec_ctx, resolver, "create_channel");
 
   return channel;
@@ -232,6 +216,9 @@ static const grpc_client_channel_factory_vtable client_channel_factory_vtable =
      client_channel_factory_create_subchannel,
      client_channel_factory_create_channel};
 
+static grpc_client_channel_factory client_channel_factory = {
+    &client_channel_factory_vtable};
+
 /* Create a client channel:
    Asynchronously: - resolve target
                    - connect to it (trying alternatives as presented)
@@ -245,16 +232,12 @@ grpc_channel *grpc_insecure_channel_create(const char *target,
       (target, args, reserved));
   GPR_ASSERT(!reserved);
 
-  client_channel_factory *f = gpr_malloc(sizeof(*f));
-  memset(f, 0, sizeof(*f));
-  f->base.vtable = &client_channel_factory_vtable;
-  gpr_ref_init(&f->refs, 1);
-  f->merge_args = grpc_channel_args_copy(args);
-
+  grpc_client_channel_factory *factory =
+      (grpc_client_channel_factory *)&client_channel_factory;
   grpc_channel *channel = client_channel_factory_create_channel(
-      &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, NULL);
+      &exec_ctx, factory, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, args);
 
-  grpc_client_channel_factory_unref(&exec_ctx, &f->base);
+  grpc_client_channel_factory_unref(&exec_ctx, factory);
   grpc_exec_ctx_finish(&exec_ctx);
 
   return channel != NULL ? channel : grpc_lame_client_channel_create(
diff --git a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
index 2e6b3f2fc8..57e1a8ec01 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
@@ -54,6 +54,10 @@
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/tsi/transport_security_interface.h"
 
+//
+// connector
+//
+
 typedef struct {
   grpc_connector base;
   gpr_refcount refs;
@@ -208,19 +212,21 @@ static void connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *con,
   GPR_ASSERT(c->connecting_endpoint == NULL);
   gpr_mu_unlock(&c->mu);
   grpc_closure_init(&c->connected_closure, connected, c);
-  grpc_tcp_client_connect(exec_ctx, &c->connected_closure,
-                          &c->newly_connecting_endpoint,
-                          args->interested_parties, args->channel_args,
-                          args->addr, args->addr_len, args->deadline);
+  grpc_tcp_client_connect(
+      exec_ctx, &c->connected_closure, &c->newly_connecting_endpoint,
+      args->interested_parties, args->channel_args, args->addr, args->deadline);
 }
 
 static const grpc_connector_vtable connector_vtable = {
     connector_ref, connector_unref, connector_shutdown, connector_connect};
 
+//
+// client_channel_factory
+//
+
 typedef struct {
   grpc_client_channel_factory base;
   gpr_refcount refs;
-  grpc_channel_args *merge_args;
   grpc_channel_security_connector *security_connector;
 } client_channel_factory;
 
@@ -236,19 +242,15 @@ static void client_channel_factory_unref(
   if (gpr_unref(&f->refs)) {
     GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
                                   "client_channel_factory");
-    grpc_channel_args_destroy(f->merge_args);
     gpr_free(f);
   }
 }
 
 static grpc_subchannel *client_channel_factory_create_subchannel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
-    grpc_subchannel_args *args) {
+    const grpc_subchannel_args *args) {
   client_channel_factory *f = (client_channel_factory *)cc_factory;
   connector *c = gpr_malloc(sizeof(*c));
-  grpc_channel_args *final_args =
-      grpc_channel_args_merge(args->args, f->merge_args);
-  grpc_subchannel *s;
   memset(c, 0, sizeof(*c));
   c->base.vtable = &connector_vtable;
   c->security_connector = f->security_connector;
@@ -262,25 +264,19 @@ static grpc_subchannel *client_channel_factory_create_subchannel(
   }
   gpr_mu_init(&c->mu);
   gpr_ref_init(&c->refs, 1);
-  args->args = final_args;
-  s = grpc_subchannel_create(exec_ctx, &c->base, args);
+  grpc_subchannel *s = grpc_subchannel_create(exec_ctx, &c->base, args);
   grpc_connector_unref(exec_ctx, &c->base);
-  grpc_channel_args_destroy(final_args);
   return s;
 }
 
 static grpc_channel *client_channel_factory_create_channel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
     const char *target, grpc_client_channel_type type,
-    grpc_channel_args *args) {
+    const grpc_channel_args *args) {
   client_channel_factory *f = (client_channel_factory *)cc_factory;
-
-  grpc_channel_args *final_args = grpc_channel_args_merge(args, f->merge_args);
-  grpc_channel *channel = grpc_channel_create(exec_ctx, target, final_args,
-                                              GRPC_CLIENT_CHANNEL, NULL);
-  grpc_channel_args_destroy(final_args);
-
-  grpc_resolver *resolver = grpc_resolver_create(target);
+  grpc_channel *channel =
+      grpc_channel_create(exec_ctx, target, args, GRPC_CLIENT_CHANNEL, NULL);
+  grpc_resolver *resolver = grpc_resolver_create(target, args);
   if (resolver != NULL) {
     grpc_client_channel_finish_initialization(
         exec_ctx, grpc_channel_get_channel_stack(channel), resolver, &f->base);
@@ -290,7 +286,6 @@ static grpc_channel *client_channel_factory_create_channel(
                                 "client_channel_factory_create_channel");
     channel = NULL;
   }
-
   return channel;
 }
 
@@ -307,19 +302,13 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
                                          const char *target,
                                          const grpc_channel_args *args,
                                          void *reserved) {
-  grpc_arg connector_arg;
-  grpc_channel_args *args_copy;
-  grpc_channel_args *new_args_from_connector;
-  grpc_channel_security_connector *security_connector;
-  client_channel_factory *f;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-
   GRPC_API_TRACE(
       "grpc_secure_channel_create(creds=%p, target=%s, args=%p, "
       "reserved=%p)",
       4, (creds, target, args, reserved));
   GPR_ASSERT(reserved == NULL);
-
+  // Make sure security connector does not already exist in args.
   if (grpc_find_security_connector_in_args(args) != NULL) {
     gpr_log(GPR_ERROR, "Cannot set security context in channel args.");
     grpc_exec_ctx_finish(&exec_ctx);
@@ -327,7 +316,9 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
         target, GRPC_STATUS_INTERNAL,
         "Security connector exists in channel args.");
   }
-
+  // Create security connector and construct new channel args.
+  grpc_channel_security_connector *security_connector;
+  grpc_channel_args *new_args_from_connector;
   if (grpc_channel_credentials_create_security_connector(
           creds, target, args, &security_connector, &new_args_from_connector) !=
       GRPC_SECURITY_OK) {
@@ -335,35 +326,30 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
     return grpc_lame_client_channel_create(
         target, GRPC_STATUS_INTERNAL, "Failed to create security connector.");
   }
-
-  connector_arg = grpc_security_connector_to_arg(&security_connector->base);
-  args_copy = grpc_channel_args_copy_and_add(
+  grpc_arg connector_arg =
+      grpc_security_connector_to_arg(&security_connector->base);
+  grpc_channel_args *new_args = grpc_channel_args_copy_and_add(
       new_args_from_connector != NULL ? new_args_from_connector : args,
       &connector_arg, 1);
-
-  f = gpr_malloc(sizeof(*f));
-  memset(f, 0, sizeof(*f));
-  f->base.vtable = &client_channel_factory_vtable;
-  gpr_ref_init(&f->refs, 1);
-
-  f->merge_args = grpc_channel_args_copy(args_copy);
-  grpc_channel_args_destroy(args_copy);
   if (new_args_from_connector != NULL) {
     grpc_channel_args_destroy(new_args_from_connector);
   }
-
+  // Create client channel factory.
+  client_channel_factory *f = gpr_malloc(sizeof(*f));
+  memset(f, 0, sizeof(*f));
+  f->base.vtable = &client_channel_factory_vtable;
+  gpr_ref_init(&f->refs, 1);
   GRPC_SECURITY_CONNECTOR_REF(&security_connector->base,
                               "grpc_secure_channel_create");
   f->security_connector = security_connector;
-
+  // Create channel.
   grpc_channel *channel = client_channel_factory_create_channel(
-      &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, NULL);
-
+      &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, new_args);
+  // Clean up.
   GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
                                 "client_channel_factory_create_channel");
-
+  grpc_channel_args_destroy(new_args);
   grpc_client_channel_factory_unref(&exec_ctx, &f->base);
   grpc_exec_ctx_finish(&exec_ctx);
-
   return channel; /* may be NULL */
 }
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c
index 2c64878c0c..d42611b863 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c
@@ -148,9 +148,7 @@ int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
   const size_t naddrs = resolved->naddrs;
   errors = gpr_malloc(sizeof(*errors) * naddrs);
   for (i = 0; i < naddrs; i++) {
-    errors[i] = grpc_tcp_server_add_port(
-        tcp, (struct sockaddr *)&resolved->addrs[i].addr,
-        resolved->addrs[i].len, &port_temp);
+    errors[i] = grpc_tcp_server_add_port(tcp, &resolved->addrs[i], &port_temp);
     if (errors[i] == GRPC_ERROR_NONE) {
       if (port_num == -1) {
         port_num = port_temp;
diff --git a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
index 88afcb6dea..7ad687042d 100644
--- a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
@@ -287,9 +287,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
 
   errors = gpr_malloc(sizeof(*errors) * resolved->naddrs);
   for (i = 0; i < resolved->naddrs; i++) {
-    errors[i] = grpc_tcp_server_add_port(
-        tcp, (struct sockaddr *)&resolved->addrs[i].addr,
-        resolved->addrs[i].len, &port_temp);
+    errors[i] = grpc_tcp_server_add_port(tcp, &resolved->addrs[i], &port_temp);
     if (errors[i] == GRPC_ERROR_NONE) {
       if (port_num == -1) {
         port_num = port_temp;
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index ce12f2dc26..fe1cdd3fa0 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -880,61 +880,60 @@ static bool contains_non_ok_status(grpc_metadata_batch *batch) {
 
 static void add_fetched_slice_locked(grpc_exec_ctx *exec_ctx,
                                      grpc_chttp2_transport *t,
-                                     grpc_chttp2_stream *s);
+                                     grpc_chttp2_stream *s) {
+  s->fetched_send_message_length +=
+      (uint32_t)GPR_SLICE_LENGTH(s->fetching_slice);
+  gpr_slice_buffer_add(&s->flow_controlled_buffer, s->fetching_slice);
+  if (s->id != 0) {
+    grpc_chttp2_become_writable(exec_ctx, t, s, true, "op.send_message");
+  }
+}
 
 static void continue_fetching_send_locked(grpc_exec_ctx *exec_ctx,
                                           grpc_chttp2_transport *t,
                                           grpc_chttp2_stream *s) {
-  if (s->fetching_send_message == NULL) {
-    /* Stream was cancelled before message fetch completed */
-    abort(); /* TODO(ctiller): what cleanup here? */
-    return;
-  }
-  if (s->fetched_send_message_length == s->fetching_send_message->length) {
-    int64_t notify_offset = s->next_message_end_offset;
-    if (notify_offset <= s->flow_controlled_bytes_written) {
-      grpc_chttp2_complete_closure_step(
-          exec_ctx, t, s, &s->fetching_send_message_finished, GRPC_ERROR_NONE,
-          "fetching_send_message_finished");
-    } else {
-      grpc_chttp2_write_cb *cb = t->write_cb_pool;
-      if (cb == NULL) {
-        cb = gpr_malloc(sizeof(*cb));
+  for (;;) {
+    if (s->fetching_send_message == NULL) {
+      /* Stream was cancelled before message fetch completed */
+      abort(); /* TODO(ctiller): what cleanup here? */
+      return;  /* early out */
+    }
+    if (s->fetched_send_message_length == s->fetching_send_message->length) {
+      int64_t notify_offset = s->next_message_end_offset;
+      if (notify_offset <= s->flow_controlled_bytes_written) {
+        grpc_chttp2_complete_closure_step(
+            exec_ctx, t, s, &s->fetching_send_message_finished, GRPC_ERROR_NONE,
+            "fetching_send_message_finished");
       } else {
-        t->write_cb_pool = cb->next;
+        grpc_chttp2_write_cb *cb = t->write_cb_pool;
+        if (cb == NULL) {
+          cb = gpr_malloc(sizeof(*cb));
+        } else {
+          t->write_cb_pool = cb->next;
+        }
+        cb->call_at_byte = notify_offset;
+        cb->closure = s->fetching_send_message_finished;
+        s->fetching_send_message_finished = NULL;
+        cb->next = s->on_write_finished_cbs;
+        s->on_write_finished_cbs = cb;
       }
-      cb->call_at_byte = notify_offset;
-      cb->closure = s->fetching_send_message_finished;
-      s->fetching_send_message_finished = NULL;
-      cb->next = s->on_write_finished_cbs;
-      s->on_write_finished_cbs = cb;
+      s->fetching_send_message = NULL;
+      return; /* early out */
+    } else if (grpc_byte_stream_next(exec_ctx, s->fetching_send_message,
+                                     &s->fetching_slice, UINT32_MAX,
+                                     &s->complete_fetch)) {
+      add_fetched_slice_locked(exec_ctx, t, s);
     }
-    s->fetching_send_message = NULL;
-  } else if (grpc_byte_stream_next(exec_ctx, s->fetching_send_message,
-                                   &s->fetching_slice, UINT32_MAX,
-                                   &s->complete_fetch)) {
-    add_fetched_slice_locked(exec_ctx, t, s);
   }
 }
 
-static void add_fetched_slice_locked(grpc_exec_ctx *exec_ctx,
-                                     grpc_chttp2_transport *t,
-                                     grpc_chttp2_stream *s) {
-  s->fetched_send_message_length +=
-      (uint32_t)GPR_SLICE_LENGTH(s->fetching_slice);
-  gpr_slice_buffer_add(&s->flow_controlled_buffer, s->fetching_slice);
-  if (s->id != 0) {
-    grpc_chttp2_become_writable(exec_ctx, t, s, true, "op.send_message");
-  }
-  continue_fetching_send_locked(exec_ctx, t, s);
-}
-
 static void complete_fetch_locked(grpc_exec_ctx *exec_ctx, void *gs,
                                   grpc_error *error) {
   grpc_chttp2_stream *s = gs;
   grpc_chttp2_transport *t = s->t;
   if (error == GRPC_ERROR_NONE) {
     add_fetched_slice_locked(exec_ctx, t, s);
+    continue_fetching_send_locked(exec_ctx, t, s);
   } else {
     /* TODO(ctiller): what to do here */
     abort();
@@ -1021,9 +1020,14 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
       }
       if (!s->write_closed) {
         if (t->is_client) {
-          GPR_ASSERT(s->id == 0);
-          grpc_chttp2_list_add_waiting_for_concurrency(t, s);
-          maybe_start_some_streams(exec_ctx, t);
+          if (!t->closed) {
+            GPR_ASSERT(s->id == 0);
+            grpc_chttp2_list_add_waiting_for_concurrency(t, s);
+            maybe_start_some_streams(exec_ctx, t);
+          } else {
+            grpc_chttp2_cancel_stream(exec_ctx, t, s,
+                                      GRPC_ERROR_CREATE("Transport closed"));
+          }
         } else {
           GPR_ASSERT(s->id != 0);
           grpc_chttp2_become_writable(exec_ctx, t, s, true,
@@ -2081,7 +2085,7 @@ grpc_chttp2_incoming_byte_stream *grpc_chttp2_incoming_byte_stream_create(
 }
 
 /*******************************************************************************
- * BUFFER POOLS
+ * RESOURCE QUOTAS
  */
 
 static void post_benign_reclaimer(grpc_exec_ctx *exec_ctx,
@@ -2125,6 +2129,8 @@ static void benign_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_chttp2_transport *t = arg;
   if (error == GRPC_ERROR_NONE &&
       grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
+    /* Channel with no active streams: send a goaway to try and make it
+     * disconnect cleanly */
     if (grpc_resource_quota_trace) {
       gpr_log(GPR_DEBUG, "HTTP2: %s - send goaway to free memory",
               t->peer_string);
@@ -2161,6 +2167,10 @@ static void destructive_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                            GRPC_ERROR_INT_HTTP2_ERROR,
                                            GRPC_CHTTP2_ENHANCE_YOUR_CALM));
     if (n > 1) {
+      /* Since we cancel one stream per destructive reclamation, if
+         there are more streams left, we can immediately post a new
+         reclaimer in case the resource quota needs to free more
+         memory */
       post_destructive_reclaimer(exec_ctx, t);
     }
   }
diff --git a/src/core/lib/channel/channel_args.c b/src/core/lib/channel/channel_args.c
index 2957d2c818..cfc072c0b5 100644
--- a/src/core/lib/channel/channel_args.c
+++ b/src/core/lib/channel/channel_args.c
@@ -66,22 +66,59 @@ static grpc_arg copy_arg(const grpc_arg *src) {
 grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
                                                   const grpc_arg *to_add,
                                                   size_t num_to_add) {
+  return grpc_channel_args_copy_and_add_and_remove(src, NULL, 0, to_add,
+                                                   num_to_add);
+}
+
+grpc_channel_args *grpc_channel_args_copy_and_remove(
+    const grpc_channel_args *src, const char **to_remove,
+    size_t num_to_remove) {
+  return grpc_channel_args_copy_and_add_and_remove(src, to_remove,
+                                                   num_to_remove, NULL, 0);
+}
+
+static bool should_remove_arg(const grpc_arg *arg, const char **to_remove,
+                              size_t num_to_remove) {
+  for (size_t i = 0; i < num_to_remove; ++i) {
+    if (strcmp(arg->key, to_remove[i]) == 0) return true;
+  }
+  return false;
+}
+
+grpc_channel_args *grpc_channel_args_copy_and_add_and_remove(
+    const grpc_channel_args *src, const char **to_remove, size_t num_to_remove,
+    const grpc_arg *to_add, size_t num_to_add) {
+  // Figure out how many args we'll be copying.
+  size_t num_args_to_copy = 0;
+  if (src != NULL) {
+    for (size_t i = 0; i < src->num_args; ++i) {
+      if (!should_remove_arg(&src->args[i], to_remove, num_to_remove)) {
+        ++num_args_to_copy;
+      }
+    }
+  }
+  // Create result.
   grpc_channel_args *dst = gpr_malloc(sizeof(grpc_channel_args));
-  size_t i;
-  size_t src_num_args = (src == NULL) ? 0 : src->num_args;
-  if (!src && !to_add) {
-    dst->num_args = 0;
+  dst->num_args = num_args_to_copy + num_to_add;
+  if (dst->num_args == 0) {
     dst->args = NULL;
     return dst;
   }
-  dst->num_args = src_num_args + num_to_add;
   dst->args = gpr_malloc(sizeof(grpc_arg) * dst->num_args);
-  for (i = 0; i < src_num_args; i++) {
-    dst->args[i] = copy_arg(&src->args[i]);
+  // Copy args from src that are not being removed.
+  size_t dst_idx = 0;
+  if (src != NULL) {
+    for (size_t i = 0; i < src->num_args; ++i) {
+      if (!should_remove_arg(&src->args[i], to_remove, num_to_remove)) {
+        dst->args[dst_idx++] = copy_arg(&src->args[i]);
+      }
+    }
   }
-  for (i = 0; i < num_to_add; i++) {
-    dst->args[i + src_num_args] = copy_arg(&to_add[i]);
+  // Add args from to_add.
+  for (size_t i = 0; i < num_to_add; ++i) {
+    dst->args[dst_idx++] = copy_arg(&to_add[i]);
   }
+  GPR_ASSERT(dst_idx == dst->num_args);
   return dst;
 }
 
diff --git a/src/core/lib/channel/channel_args.h b/src/core/lib/channel/channel_args.h
index a80340c0fa..1e05303471 100644
--- a/src/core/lib/channel/channel_args.h
+++ b/src/core/lib/channel/channel_args.h
@@ -51,6 +51,17 @@ grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
                                                   const grpc_arg *to_add,
                                                   size_t num_to_add);
 
+/** Copies the arguments in \a src except for those whose keys are in
+    \a to_remove. */
+grpc_channel_args *grpc_channel_args_copy_and_remove(
+    const grpc_channel_args *src, const char **to_remove, size_t num_to_remove);
+
+/** Copies the arguments from \a src except for those whose keys are in
+    \a to_remove and appends the arguments in \a to_add. */
+grpc_channel_args *grpc_channel_args_copy_and_add_and_remove(
+    const grpc_channel_args *src, const char **to_remove, size_t num_to_remove,
+    const grpc_arg *to_add, size_t num_to_add);
+
 /** Concatenate args from \a a and \a b into a new instance */
 grpc_channel_args *grpc_channel_args_merge(const grpc_channel_args *a,
                                            const grpc_channel_args *b);
diff --git a/src/core/lib/channel/message_size_filter.c b/src/core/lib/channel/message_size_filter.c
index b8b2546035..7dc5ae0df1 100644
--- a/src/core/lib/channel/message_size_filter.c
+++ b/src/core/lib/channel/message_size_filter.c
@@ -38,8 +38,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/method_config.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/transport/method_config.h"
 
 #define DEFAULT_MAX_SEND_MESSAGE_LENGTH -1  // Unlimited.
 // The protobuf library will (by default) start warning at 100 megs.
diff --git a/src/core/lib/http/httpcli.c b/src/core/lib/http/httpcli.c
index 26baae1eab..411e669b53 100644
--- a/src/core/lib/http/httpcli.c
+++ b/src/core/lib/http/httpcli.c
@@ -32,7 +32,6 @@
  */
 
 #include "src/core/lib/http/httpcli.h"
-#include "src/core/lib/iomgr/sockaddr.h"
 
 #include <string.h>
 
@@ -128,7 +127,7 @@ static void append_error(internal_request *req, grpc_error *error) {
     req->overall_error = GRPC_ERROR_CREATE("Failed HTTP/1 client request");
   }
   grpc_resolved_address *addr = &req->addresses->addrs[req->next_address - 1];
-  char *addr_text = grpc_sockaddr_to_uri((struct sockaddr *)addr->addr);
+  char *addr_text = grpc_sockaddr_to_uri(addr);
   req->overall_error = grpc_error_add_child(
       req->overall_error,
       grpc_error_set_str(error, GRPC_ERROR_STR_TARGET_ADDRESS, addr_text));
@@ -232,9 +231,9 @@ static void next_address(grpc_exec_ctx *exec_ctx, internal_request *req,
   arg.value.pointer.p = req->resource_quota;
   arg.value.pointer.vtable = grpc_resource_quota_arg_vtable();
   grpc_channel_args args = {1, &arg};
-  grpc_tcp_client_connect(
-      exec_ctx, &req->connected, &req->ep, req->context->pollset_set, &args,
-      (struct sockaddr *)&addr->addr, addr->len, req->deadline);
+  grpc_tcp_client_connect(exec_ctx, &req->connected, &req->ep,
+                          req->context->pollset_set, &args, addr,
+                          req->deadline);
 }
 
 static void on_resolved(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
diff --git a/src/core/lib/iomgr/endpoint_pair_posix.c b/src/core/lib/iomgr/endpoint_pair_posix.c
index fc80064a60..b9ff969e81 100644
--- a/src/core/lib/iomgr/endpoint_pair_posix.c
+++ b/src/core/lib/iomgr/endpoint_pair_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/endpoint_pair.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
diff --git a/src/core/lib/security/credentials/google_default/credentials_windows.c b/src/core/lib/iomgr/endpoint_pair_uv.c
index 208b8fd9ad..7941e20388 100644
--- a/src/core/lib/security/credentials/google_default/credentials_windows.c
+++ b/src/core/lib/iomgr/endpoint_pair_uv.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,31 +31,23 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINDOWS
+#ifdef GRPC_UV
 
-#include "src/core/lib/security/credentials/google_default/google_default_credentials.h"
+#include <stdlib.h>
 
-#include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/iomgr/endpoint_pair.h"
 
-char *grpc_get_well_known_google_credentials_file_path_impl(void) {
-  char *result = NULL;
-  char *appdata_path = gpr_getenv("APPDATA");
-  if (appdata_path == NULL) {
-    gpr_log(GPR_ERROR, "Could not get APPDATA environment variable.");
-    return NULL;
-  }
-  gpr_asprintf(&result, "%s/%s/%s", appdata_path,
-               GRPC_GOOGLE_CLOUD_SDK_CONFIG_DIRECTORY,
-               GRPC_GOOGLE_WELL_KNOWN_CREDENTIALS_FILE);
-  gpr_free(appdata_path);
-  return result;
+grpc_endpoint_pair grpc_iomgr_create_endpoint_pair(const char *name,
+                                                   size_t read_slice_size) {
+  grpc_endpoint_pair endpoint_pair;
+  // TODO(mlumish): implement this properly under libuv
+  GPR_ASSERT(false &&
+             "grpc_iomgr_create_endpoint_pair is not suppoted with libuv");
+  return endpoint_pair;
 }
 
-#endif /* GPR_WINDOWS */
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/endpoint_pair_windows.c b/src/core/lib/iomgr/endpoint_pair_windows.c
index 582704e267..5c78c95492 100644
--- a/src/core/lib/iomgr/endpoint_pair_windows.c
+++ b/src/core/lib/iomgr/endpoint_pair_windows.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 #include "src/core/lib/iomgr/endpoint_pair.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index e5909d9380..db51ec4939 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -32,10 +32,10 @@
  */
 
 #include <grpc/grpc_posix.h>
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
 /* This polling engine is only relevant on linux kernels supporting epoll() */
-#ifdef GPR_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL
 
 #include "src/core/lib/iomgr/ev_epoll_linux.h"
 
@@ -1711,6 +1711,12 @@ retry:
             "pollset_add_fd: Raced creating new polling island. pi_new: %p "
             "(fd: %d, pollset: %p)",
             (void *)pi_new, fd->fd, (void *)pollset);
+
+        /* No need to lock 'pi_new' here since this is a new polling island and
+         * no one has a reference to it yet */
+        polling_island_remove_all_fds_locked(pi_new, true, &error);
+
+        /* Ref and unref so that the polling island gets deleted during unref */
         PI_ADD_REF(pi_new, "dance_of_destruction");
         PI_UNREF(exec_ctx, pi_new, "dance_of_destruction");
         goto retry;
@@ -2049,13 +2055,13 @@ const grpc_event_engine_vtable *grpc_init_epoll_linux(void) {
   return &vtable;
 }
 
-#else /* defined(GPR_LINUX_EPOLL) */
-#if defined(GPR_POSIX_SOCKET)
+#else /* defined(GRPC_LINUX_EPOLL) */
+#if defined(GRPC_POSIX_SOCKET)
 #include "src/core/lib/iomgr/ev_posix.h"
-/* If GPR_LINUX_EPOLL is not defined, it means epoll is not available. Return
+/* If GRPC_LINUX_EPOLL is not defined, it means epoll is not available. Return
  * NULL */
 const grpc_event_engine_vtable *grpc_init_epoll_linux(void) { return NULL; }
-#endif /* defined(GPR_POSIX_SOCKET) */
+#endif /* defined(GRPC_POSIX_SOCKET) */
 
 void grpc_use_signal(int signum) {}
-#endif /* !defined(GPR_LINUX_EPOLL) */
+#endif /* !defined(GRPC_LINUX_EPOLL) */
diff --git a/src/core/lib/iomgr/ev_epoll_linux.h b/src/core/lib/iomgr/ev_epoll_linux.h
index 7a494aba19..8fc3ff59a3 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.h
+++ b/src/core/lib/iomgr/ev_epoll_linux.h
@@ -35,13 +35,14 @@
 #define GRPC_CORE_LIB_IOMGR_EV_EPOLL_LINUX_H
 
 #include "src/core/lib/iomgr/ev_posix.h"
+#include "src/core/lib/iomgr/port.h"
 
 const grpc_event_engine_vtable *grpc_init_epoll_linux(void);
 
-#ifdef GPR_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL
 void *grpc_fd_get_polling_island(grpc_fd *fd);
 void *grpc_pollset_get_polling_island(grpc_pollset *ps);
 bool grpc_are_polling_islands_equal(void *p, void *q);
-#endif /* defined(GPR_LINUX_EPOLL) */
+#endif /* defined(GRPC_LINUX_EPOLL) */
 
 #endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLL_LINUX_H */
diff --git a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
index 1829440a6e..bf51404203 100644
--- a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
@@ -42,9 +42,9 @@
  *  - ev_epoll_posix.{h,c}
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/ev_poll_and_epoll_posix.h"
 
@@ -1338,7 +1338,7 @@ static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null) {
  * pollset_multipoller_with_poll_posix.c
  */
 
-#ifndef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+#ifndef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
 
 typedef struct {
   /* all polled fds */
@@ -1520,13 +1520,13 @@ static void poll_become_multipoller(grpc_exec_ctx *exec_ctx,
   }
 }
 
-#endif /* !GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+#endif /* !GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
 
 /*******************************************************************************
  * pollset_multipoller_with_epoll_posix.c
  */
 
-#ifdef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+#ifdef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
 
 #include <errno.h>
 #include <poll.h>
@@ -1839,11 +1839,11 @@ static void epoll_become_multipoller(grpc_exec_ctx *exec_ctx,
   }
 }
 
-#else /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+#else /* GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
 
 static void remove_fd_from_all_epoll_sets(int fd) {}
 
-#endif /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+#endif /* GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
 
 /*******************************************************************************
  * pollset_set_posix.c
@@ -2063,7 +2063,7 @@ static const grpc_event_engine_vtable vtable = {
 };
 
 const grpc_event_engine_vtable *grpc_init_poll_and_epoll_posix(void) {
-#ifdef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+#ifdef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
   platform_become_multipoller = epoll_become_multipoller;
 #else
   platform_become_multipoller = poll_become_multipoller;
diff --git a/src/core/lib/iomgr/ev_poll_posix.c b/src/core/lib/iomgr/ev_poll_posix.c
index 27e966c18c..e1d620cfff 100644
--- a/src/core/lib/iomgr/ev_poll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/ev_poll_posix.h"
 
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index 9857b0bce9..ef36ba89b2 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/ev_posix.h"
 
@@ -282,4 +282,4 @@ void grpc_workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
   g_event_engine->workqueue_enqueue(exec_ctx, workqueue, closure, error);
 }
 
-#endif  // GPR_POSIX_SOCKET
+#endif  // GRPC_POSIX_SOCKET
diff --git a/src/core/lib/iomgr/iocp_windows.c b/src/core/lib/iomgr/iocp_windows.c
index 2532e52e48..60ebe43676 100644
--- a/src/core/lib/iomgr/iocp_windows.c
+++ b/src/core/lib/iomgr/iocp_windows.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <winsock2.h>
 
@@ -166,4 +166,4 @@ void grpc_iocp_add_socket(grpc_winsocket *socket) {
   GPR_ASSERT(ret == g_iocp);
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/iomgr.h b/src/core/lib/iomgr/iomgr.h
index 6c82de78ac..c1cfaf302e 100644
--- a/src/core/lib/iomgr/iomgr.h
+++ b/src/core/lib/iomgr/iomgr.h
@@ -34,6 +34,8 @@
 #ifndef GRPC_CORE_LIB_IOMGR_IOMGR_H
 #define GRPC_CORE_LIB_IOMGR_IOMGR_H
 
+#include "src/core/lib/iomgr/port.h"
+
 /** Initializes the iomgr. */
 void grpc_iomgr_init(void);
 
diff --git a/src/core/lib/iomgr/iomgr_posix.c b/src/core/lib/iomgr/iomgr_posix.c
index cede97f4c6..f5ee0c9ee4 100644
--- a/src/core/lib/iomgr/iomgr_posix.c
+++ b/src/core/lib/iomgr/iomgr_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/iomgr/ev_posix.h"
diff --git a/src/core/lib/iomgr/iomgr_uv.c b/src/core/lib/iomgr/iomgr_uv.c
new file mode 100644
index 0000000000..96516ff167
--- /dev/null
+++ b/src/core/lib/iomgr/iomgr_uv.c
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/iomgr/pollset_uv.h"
+#include "src/core/lib/iomgr/tcp_uv.h"
+
+void grpc_iomgr_platform_init(void) {
+  grpc_pollset_global_init();
+  grpc_register_tracer("tcp", &grpc_tcp_trace);
+}
+void grpc_iomgr_platform_flush(void) {}
+void grpc_iomgr_platform_shutdown(void) { grpc_pollset_global_shutdown(); }
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/iomgr_windows.c b/src/core/lib/iomgr/iomgr_windows.c
index 7653f6e635..b659264ede 100644
--- a/src/core/lib/iomgr/iomgr_windows.c
+++ b/src/core/lib/iomgr/iomgr_windows.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 
diff --git a/src/core/lib/iomgr/pollset_set_uv.c b/src/core/lib/iomgr/pollset_set_uv.c
new file mode 100644
index 0000000000..e5ef8b29e0
--- /dev/null
+++ b/src/core/lib/iomgr/pollset_set_uv.c
@@ -0,0 +1,62 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include "src/core/lib/iomgr/pollset_set.h"
+
+grpc_pollset_set* grpc_pollset_set_create(void) {
+  return (grpc_pollset_set*)((intptr_t)0xdeafbeef);
+}
+
+void grpc_pollset_set_destroy(grpc_pollset_set* pollset_set) {}
+
+void grpc_pollset_set_add_pollset(grpc_exec_ctx* exec_ctx,
+                                  grpc_pollset_set* pollset_set,
+                                  grpc_pollset* pollset) {}
+
+void grpc_pollset_set_del_pollset(grpc_exec_ctx* exec_ctx,
+                                  grpc_pollset_set* pollset_set,
+                                  grpc_pollset* pollset) {}
+
+void grpc_pollset_set_add_pollset_set(grpc_exec_ctx* exec_ctx,
+                                      grpc_pollset_set* bag,
+                                      grpc_pollset_set* item) {}
+
+void grpc_pollset_set_del_pollset_set(grpc_exec_ctx* exec_ctx,
+                                      grpc_pollset_set* bag,
+                                      grpc_pollset_set* item) {}
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/pollset_set_windows.c b/src/core/lib/iomgr/pollset_set_windows.c
index a35a9766fc..645650db9b 100644
--- a/src/core/lib/iomgr/pollset_set_windows.c
+++ b/src/core/lib/iomgr/pollset_set_windows.c
@@ -31,10 +31,10 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
 #include <stdint.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/pollset_set_windows.h"
 
@@ -60,4 +60,4 @@ void grpc_pollset_set_del_pollset_set(grpc_exec_ctx* exec_ctx,
                                       grpc_pollset_set* bag,
                                       grpc_pollset_set* item) {}
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/pollset_uv.c b/src/core/lib/iomgr/pollset_uv.c
new file mode 100644
index 0000000000..3a74b842b6
--- /dev/null
+++ b/src/core/lib/iomgr/pollset_uv.c
@@ -0,0 +1,142 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include <uv.h>
+
+#include <string.h>
+
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+
+#include "src/core/lib/iomgr/pollset.h"
+#include "src/core/lib/iomgr/pollset_uv.h"
+
+struct grpc_pollset {
+  uv_timer_t timer;
+  int shutting_down;
+};
+
+/* Indicates that grpc_pollset_work should run an iteration of the UV loop
+   before running callbacks. This defaults to 1, and should be disabled if
+   grpc_pollset_work will be called within the callstack of uv_run */
+int grpc_pollset_work_run_loop;
+
+gpr_mu grpc_polling_mu;
+
+size_t grpc_pollset_size() { return sizeof(grpc_pollset); }
+
+void grpc_pollset_global_init(void) {
+  gpr_mu_init(&grpc_polling_mu);
+  grpc_pollset_work_run_loop = 1;
+}
+
+void grpc_pollset_global_shutdown(void) { gpr_mu_destroy(&grpc_polling_mu); }
+
+void grpc_pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
+  *mu = &grpc_polling_mu;
+  memset(pollset, 0, sizeof(grpc_pollset));
+  uv_timer_init(uv_default_loop(), &pollset->timer);
+  pollset->shutting_down = 0;
+}
+
+static void timer_close_cb(uv_handle_t *handle) { handle->data = (void *)1; }
+
+void grpc_pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                           grpc_closure *closure) {
+  GPR_ASSERT(!pollset->shutting_down);
+  pollset->shutting_down = 1;
+  if (grpc_pollset_work_run_loop) {
+    // Drain any pending UV callbacks without blocking
+    uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+  }
+  grpc_exec_ctx_sched(exec_ctx, closure, GRPC_ERROR_NONE, NULL);
+}
+
+void grpc_pollset_destroy(grpc_pollset *pollset) {
+  uv_close((uv_handle_t *)&pollset->timer, timer_close_cb);
+  // timer.data is a boolean indicating that the timer has finished closing
+  pollset->timer.data = (void *)0;
+  if (grpc_pollset_work_run_loop) {
+    while (!pollset->timer.data) {
+      uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+    }
+  }
+}
+
+void grpc_pollset_reset(grpc_pollset *pollset) {
+  GPR_ASSERT(pollset->shutting_down);
+  pollset->shutting_down = 0;
+}
+
+static void timer_run_cb(uv_timer_t *timer) {}
+
+grpc_error *grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                              grpc_pollset_worker **worker_hdl,
+                              gpr_timespec now, gpr_timespec deadline) {
+  uint64_t timeout;
+  gpr_mu_unlock(&grpc_polling_mu);
+  if (grpc_pollset_work_run_loop) {
+    if (gpr_time_cmp(deadline, now) >= 0) {
+      timeout = (uint64_t)gpr_time_to_millis(gpr_time_sub(deadline, now));
+    } else {
+      timeout = 0;
+    }
+    /* We special-case timeout=0 so that we don't bother with the timer when
+       the loop won't block anyway */
+    if (timeout > 0) {
+      uv_timer_start(&pollset->timer, timer_run_cb, timeout, 0);
+      /* Run until there is some I/O activity or the timer triggers. It doesn't
+         matter which happens */
+      uv_run(uv_default_loop(), UV_RUN_ONCE);
+      uv_timer_stop(&pollset->timer);
+    } else {
+      uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+    }
+  }
+  if (!grpc_closure_list_empty(exec_ctx->closure_list)) {
+    grpc_exec_ctx_flush(exec_ctx);
+  }
+  gpr_mu_lock(&grpc_polling_mu);
+  return GRPC_ERROR_NONE;
+}
+
+grpc_error *grpc_pollset_kick(grpc_pollset *pollset,
+                              grpc_pollset_worker *specific_worker) {
+  return GRPC_ERROR_NONE;
+}
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/pollset_uv.h b/src/core/lib/iomgr/pollset_uv.h
new file mode 100644
index 0000000000..0715eb4295
--- /dev/null
+++ b/src/core/lib/iomgr/pollset_uv.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_POLLSET_UV_H
+#define GRPC_CORE_LIB_IOMGR_POLLSET_UV_H
+
+extern int grpc_pollset_work_run_loop;
+
+void grpc_pollset_global_init(void);
+void grpc_pollset_global_shutdown(void);
+
+#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_UV_H */
diff --git a/src/core/lib/iomgr/pollset_windows.c b/src/core/lib/iomgr/pollset_windows.c
index 626dd784b3..5540303e49 100644
--- a/src/core/lib/iomgr/pollset_windows.c
+++ b/src/core/lib/iomgr/pollset_windows.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <grpc/support/log.h>
 #include <grpc/support/thd.h>
@@ -241,4 +241,4 @@ grpc_error *grpc_pollset_kick(grpc_pollset *p,
 
 void grpc_kick_poller(void) { grpc_iocp_kick(); }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/port.h b/src/core/lib/iomgr/port.h
new file mode 100644
index 0000000000..c0bb3b5a23
--- /dev/null
+++ b/src/core/lib/iomgr/port.h
@@ -0,0 +1,131 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifndef GRPC_CORE_LIB_IOMGR_PORT_H
+#define GRPC_CORE_LIB_IOMGR_PORT_H
+
+#if defined(GRPC_UV)
+// Do nothing
+#elif defined(GPR_MANYLINUX1)
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_MSG_NOSIGNAL 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
+#define GRPC_TIMER_USE_GENERIC 1
+#elif defined(GPR_WINDOWS)
+#define GRPC_TIMER_USE_GENERIC 1
+#define GRPC_WINSOCK_SOCKET 1
+#define GRPC_WINDOWS_SOCKETUTILS 1
+#elif defined(GPR_ANDROID)
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_MSG_NOSIGNAL 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_LINUX_EVENTFD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
+#define GRPC_TIMER_USE_GENERIC 1
+#elif defined(GPR_LINUX)
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_MSG_NOSIGNAL 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_LINUX_MULTIPOLL_WITH_EPOLL 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_WAKEUP_FD 1
+#define GRPC_TIMER_USE_GENERIC 1
+#ifdef __GLIBC_PREREQ
+#if __GLIBC_PREREQ(2, 9)
+#define GRPC_LINUX_EPOLL 1
+#define GRPC_LINUX_EVENTFD 1
+#endif
+#if __GLIBC_PREREQ(2, 10)
+#define GRPC_LINUX_SOCKETUTILS 1
+#endif
+#endif
+#ifndef GRPC_LINUX_EVENTFD
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#endif
+#ifndef GRPC_LINUX_SOCKETUTILS
+#define GRPC_POSIX_SOCKETUTILS
+#endif
+#elif defined(GPR_APPLE)
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_SO_NOSIGPIPE 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_MSG_IOVLEN_TYPE int
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
+#define GRPC_TIMER_USE_GENERIC 1
+#elif defined(GPR_FREEBSD)
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_SO_NOSIGPIPE 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
+#define GRPC_TIMER_USE_GENERIC 1
+#elif defined(GPR_NACL)
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
+#define GRPC_TIMER_USE_GENERIC 1
+#elif !defined(GPR_NO_AUTODETECT_PLATFORM)
+#error "Platform not recognized"
+#endif
+
+#if defined(GRPC_POSIX_SOCKET) + defined(GRPC_WINSOCK_SOCKET) + \
+        defined(GRPC_CUSTOM_SOCKET) + defined(GRPC_UV) !=       \
+    1
+#error Must define exactly one of GRPC_POSIX_SOCKET, GRPC_WINSOCK_SOCKET, GPR_CUSTOM_SOCKET
+#endif
+
+#endif /* GRPC_CORE_LIB_IOMGR_PORT_H */
diff --git a/src/core/lib/iomgr/resolve_address.h b/src/core/lib/iomgr/resolve_address.h
index ddbe375755..275924448a 100644
--- a/src/core/lib/iomgr/resolve_address.h
+++ b/src/core/lib/iomgr/resolve_address.h
@@ -36,7 +36,6 @@
 
 #include <stddef.h>
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/iomgr/iomgr.h"
 
 #define GRPC_MAX_SOCKADDR_SIZE 128
 
diff --git a/src/core/lib/iomgr/resolve_address_posix.c b/src/core/lib/iomgr/resolve_address_posix.c
index 4e9f978584..de791b2b67 100644
--- a/src/core/lib/iomgr/resolve_address_posix.c
+++ b/src/core/lib/iomgr/resolve_address_posix.c
@@ -31,12 +31,13 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
-#ifdef GPR_POSIX_SOCKET
+#include "src/core/lib/iomgr/port.h"
+#ifdef GRPC_POSIX_SOCKET
 
-#include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 
+#include "src/core/lib/iomgr/resolve_address.h"
+
 #include <string.h>
 #include <sys/types.h>
 
@@ -49,7 +50,6 @@
 #include <grpc/support/useful.h>
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
-#include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/string.h"
diff --git a/src/core/lib/iomgr/resolve_address_uv.c b/src/core/lib/iomgr/resolve_address_uv.c
new file mode 100644
index 0000000000..b8295acfa1
--- /dev/null
+++ b/src/core/lib/iomgr/resolve_address_uv.c
@@ -0,0 +1,231 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+#ifdef GRPC_UV
+
+#include <uv.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/iomgr/closure.h"
+#include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+
+#include <string.h>
+
+typedef struct request {
+  grpc_closure *on_done;
+  grpc_resolved_addresses **addresses;
+  struct addrinfo *hints;
+} request;
+
+static grpc_error *handle_addrinfo_result(int status, struct addrinfo *result,
+                                          grpc_resolved_addresses **addresses) {
+  struct addrinfo *resp;
+  size_t i;
+  if (status != 0) {
+    grpc_error *error;
+    *addresses = NULL;
+    error = GRPC_ERROR_CREATE("getaddrinfo failed");
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR, uv_strerror(status));
+    return error;
+  }
+  (*addresses) = gpr_malloc(sizeof(grpc_resolved_addresses));
+  (*addresses)->naddrs = 0;
+  for (resp = result; resp != NULL; resp = resp->ai_next) {
+    (*addresses)->naddrs++;
+  }
+  (*addresses)->addrs =
+      gpr_malloc(sizeof(grpc_resolved_address) * (*addresses)->naddrs);
+  i = 0;
+  for (resp = result; resp != NULL; resp = resp->ai_next) {
+    memcpy(&(*addresses)->addrs[i].addr, resp->ai_addr, resp->ai_addrlen);
+    (*addresses)->addrs[i].len = resp->ai_addrlen;
+    i++;
+  }
+
+  {
+    for (i = 0; i < (*addresses)->naddrs; i++) {
+      char *buf;
+      grpc_sockaddr_to_string(&buf, &(*addresses)->addrs[i], 0);
+      gpr_free(buf);
+    }
+  }
+  return GRPC_ERROR_NONE;
+}
+
+static void getaddrinfo_callback(uv_getaddrinfo_t *req, int status,
+                                 struct addrinfo *res) {
+  request *r = (request *)req->data;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_error *error;
+  error = handle_addrinfo_result(status, res, r->addresses);
+  grpc_exec_ctx_sched(&exec_ctx, r->on_done, error, NULL);
+  grpc_exec_ctx_finish(&exec_ctx);
+
+  gpr_free(r->hints);
+  gpr_free(r);
+  gpr_free(req);
+  uv_freeaddrinfo(res);
+}
+
+static grpc_error *try_split_host_port(const char *name,
+                                       const char *default_port, char **host,
+                                       char **port) {
+  /* parse name, splitting it into host and port parts */
+  grpc_error *error;
+  gpr_split_host_port(name, host, port);
+  if (host == NULL) {
+    char *msg;
+    gpr_asprintf(&msg, "unparseable host:port: '%s'", name);
+    error = GRPC_ERROR_CREATE(msg);
+    gpr_free(msg);
+    return error;
+  }
+  if (port == NULL) {
+    if (default_port == NULL) {
+      char *msg;
+      gpr_asprintf(&msg, "no port in name '%s'", name);
+      error = GRPC_ERROR_CREATE(msg);
+      gpr_free(msg);
+      return error;
+    }
+    *port = gpr_strdup(default_port);
+  }
+  return GRPC_ERROR_NONE;
+}
+
+static grpc_error *blocking_resolve_address_impl(
+    const char *name, const char *default_port,
+    grpc_resolved_addresses **addresses) {
+  char *host;
+  char *port;
+  struct addrinfo hints;
+  uv_getaddrinfo_t req;
+  int s;
+  grpc_error *err;
+
+  req.addrinfo = NULL;
+
+  err = try_split_host_port(name, default_port, &host, &port);
+  if (err != GRPC_ERROR_NONE) {
+    goto done;
+  }
+
+  /* Call getaddrinfo */
+  memset(&hints, 0, sizeof(hints));
+  hints.ai_family = AF_UNSPEC;     /* ipv4 or ipv6 */
+  hints.ai_socktype = SOCK_STREAM; /* stream socket */
+  hints.ai_flags = AI_PASSIVE;     /* for wildcard IP address */
+
+  s = uv_getaddrinfo(uv_default_loop(), &req, NULL, host, port, &hints);
+  err = handle_addrinfo_result(s, req.addrinfo, addresses);
+
+done:
+  gpr_free(host);
+  gpr_free(port);
+  if (req.addrinfo) {
+    uv_freeaddrinfo(req.addrinfo);
+  }
+  return err;
+}
+
+grpc_error *(*grpc_blocking_resolve_address)(
+    const char *name, const char *default_port,
+    grpc_resolved_addresses **addresses) = blocking_resolve_address_impl;
+
+void grpc_resolved_addresses_destroy(grpc_resolved_addresses *addrs) {
+  if (addrs != NULL) {
+    gpr_free(addrs->addrs);
+  }
+  gpr_free(addrs);
+}
+
+static void resolve_address_impl(grpc_exec_ctx *exec_ctx, const char *name,
+                                 const char *default_port,
+                                 grpc_closure *on_done,
+                                 grpc_resolved_addresses **addrs) {
+  uv_getaddrinfo_t *req;
+  request *r;
+  struct addrinfo *hints;
+  char *host;
+  char *port;
+  grpc_error *err;
+  int s;
+  err = try_split_host_port(name, default_port, &host, &port);
+  if (err != GRPC_ERROR_NONE) {
+    grpc_exec_ctx_sched(exec_ctx, on_done, err, NULL);
+    return;
+  }
+  r = gpr_malloc(sizeof(request));
+  r->on_done = on_done;
+  r->addresses = addrs;
+  req = gpr_malloc(sizeof(uv_getaddrinfo_t));
+  req->data = r;
+
+  /* Call getaddrinfo */
+  hints = gpr_malloc(sizeof(struct addrinfo));
+  memset(hints, 0, sizeof(struct addrinfo));
+  hints->ai_family = AF_UNSPEC;     /* ipv4 or ipv6 */
+  hints->ai_socktype = SOCK_STREAM; /* stream socket */
+  hints->ai_flags = AI_PASSIVE;     /* for wildcard IP address */
+  r->hints = hints;
+
+  s = uv_getaddrinfo(uv_default_loop(), req, getaddrinfo_callback, host, port,
+                     hints);
+
+  if (s != 0) {
+    *addrs = NULL;
+    err = GRPC_ERROR_CREATE("getaddrinfo failed");
+    err = grpc_error_set_str(err, GRPC_ERROR_STR_OS_ERROR, uv_strerror(s));
+    grpc_exec_ctx_sched(exec_ctx, on_done, err, NULL);
+    gpr_free(r);
+    gpr_free(req);
+    gpr_free(hints);
+  }
+}
+
+void (*grpc_resolve_address)(grpc_exec_ctx *exec_ctx, const char *name,
+                             const char *default_port, grpc_closure *on_done,
+                             grpc_resolved_addresses **addrs) =
+    resolve_address_impl;
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/resolve_address_windows.c b/src/core/lib/iomgr/resolve_address_windows.c
index 2af8af82dc..e139293c03 100644
--- a/src/core/lib/iomgr/resolve_address_windows.c
+++ b/src/core/lib/iomgr/resolve_address_windows.c
@@ -31,12 +31,13 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
-#ifdef GPR_WINSOCK_SOCKET
+#include "src/core/lib/iomgr/port.h"
+#ifdef GRPC_WINSOCK_SOCKET
 
-#include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 
+#include "src/core/lib/iomgr/resolve_address.h"
+
 #include <string.h>
 #include <sys/types.h>
 
@@ -124,8 +125,7 @@ static grpc_error *blocking_resolve_address_impl(
   {
     for (i = 0; i < (*addresses)->naddrs; i++) {
       char *buf;
-      grpc_sockaddr_to_string(
-          &buf, (struct sockaddr *)&(*addresses)->addrs[i].addr, 0);
+      grpc_sockaddr_to_string(&buf, &(*addresses)->addrs[i], 0);
       gpr_free(buf);
     }
   }
diff --git a/src/core/lib/iomgr/resource_quota.c b/src/core/lib/iomgr/resource_quota.c
index 5466973408..bfc905845d 100644
--- a/src/core/lib/iomgr/resource_quota.c
+++ b/src/core/lib/iomgr/resource_quota.c
@@ -49,6 +49,7 @@ struct grpc_resource_quota {
   gpr_refcount refs;
 
   /* Master combiner lock: all activity on a quota executes under this combiner
+   * (so no mutex is needed for this data structure)
    */
   grpc_combiner *combiner;
   /* Size of the resource quota */
@@ -75,7 +76,7 @@ struct grpc_resource_quota {
  * list management
  */
 
-static void rulist_add_tail(grpc_resource_user *resource_user,
+static void rulist_add_head(grpc_resource_user *resource_user,
                             grpc_rulist list) {
   grpc_resource_quota *resource_quota = resource_user->resource_quota;
   grpc_resource_user **root = &resource_quota->roots[list];
@@ -88,10 +89,11 @@ static void rulist_add_tail(grpc_resource_user *resource_user,
     resource_user->links[list].prev = (*root)->links[list].prev;
     resource_user->links[list].next->links[list].prev =
         resource_user->links[list].prev->links[list].next = resource_user;
+    *root = resource_user;
   }
 }
 
-static void rulist_add_head(grpc_resource_user *resource_user,
+static void rulist_add_tail(grpc_resource_user *resource_user,
                             grpc_rulist list) {
   grpc_resource_quota *resource_quota = resource_user->resource_quota;
   grpc_resource_user **root = &resource_quota->roots[list];
@@ -104,7 +106,6 @@ static void rulist_add_head(grpc_resource_user *resource_user,
     resource_user->links[list].prev = *root;
     resource_user->links[list].next->links[list].prev =
         resource_user->links[list].prev->links[list].next = resource_user;
-    *root = resource_user;
   }
 }
 
@@ -113,8 +114,8 @@ static bool rulist_empty(grpc_resource_quota *resource_quota,
   return resource_quota->roots[list] == NULL;
 }
 
-static grpc_resource_user *rulist_pop(grpc_resource_quota *resource_quota,
-                                      grpc_rulist list) {
+static grpc_resource_user *rulist_pop_head(grpc_resource_quota *resource_quota,
+                                           grpc_rulist list) {
   grpc_resource_user **root = &resource_quota->roots[list];
   grpc_resource_user *resource_user = *root;
   if (resource_user == NULL) {
@@ -149,22 +150,22 @@ static void rulist_remove(grpc_resource_user *resource_user, grpc_rulist list) {
 }
 
 /*******************************************************************************
- * buffer pool state machine
+ * resource quota state machine
  */
 
 static bool rq_alloc(grpc_exec_ctx *exec_ctx,
                      grpc_resource_quota *resource_quota);
-static bool rq_scavenge(grpc_exec_ctx *exec_ctx,
-                        grpc_resource_quota *resource_quota);
+static bool rq_reclaim_from_per_user_free_pool(
+    grpc_exec_ctx *exec_ctx, grpc_resource_quota *resource_quota);
 static bool rq_reclaim(grpc_exec_ctx *exec_ctx,
                        grpc_resource_quota *resource_quota, bool destructive);
 
-static void rq_step(grpc_exec_ctx *exec_ctx, void *bp, grpc_error *error) {
-  grpc_resource_quota *resource_quota = bp;
+static void rq_step(grpc_exec_ctx *exec_ctx, void *rq, grpc_error *error) {
+  grpc_resource_quota *resource_quota = rq;
   resource_quota->step_scheduled = false;
   do {
     if (rq_alloc(exec_ctx, resource_quota)) goto done;
-  } while (rq_scavenge(exec_ctx, resource_quota));
+  } while (rq_reclaim_from_per_user_free_pool(exec_ctx, resource_quota));
   rq_reclaim(exec_ctx, resource_quota, false) ||
       rq_reclaim(exec_ctx, resource_quota, true);
 done:
@@ -185,8 +186,8 @@ static void rq_step_sched(grpc_exec_ctx *exec_ctx,
 static bool rq_alloc(grpc_exec_ctx *exec_ctx,
                      grpc_resource_quota *resource_quota) {
   grpc_resource_user *resource_user;
-  while ((resource_user =
-              rulist_pop(resource_quota, GRPC_RULIST_AWAITING_ALLOCATION))) {
+  while ((resource_user = rulist_pop_head(resource_quota,
+                                          GRPC_RULIST_AWAITING_ALLOCATION))) {
     gpr_mu_lock(&resource_user->mu);
     if (resource_user->free_pool < 0 &&
         -resource_user->free_pool <= resource_quota->free_pool) {
@@ -194,13 +195,13 @@ static bool rq_alloc(grpc_exec_ctx *exec_ctx,
       resource_user->free_pool = 0;
       resource_quota->free_pool -= amt;
       if (grpc_resource_quota_trace) {
-        gpr_log(GPR_DEBUG, "BP %s %s: grant alloc %" PRId64
+        gpr_log(GPR_DEBUG, "RQ %s %s: grant alloc %" PRId64
                            " bytes; rq_free_pool -> %" PRId64,
                 resource_quota->name, resource_user->name, amt,
                 resource_quota->free_pool);
       }
     } else if (grpc_resource_quota_trace && resource_user->free_pool >= 0) {
-      gpr_log(GPR_DEBUG, "BP %s %s: discard already satisfied alloc request",
+      gpr_log(GPR_DEBUG, "RQ %s %s: discard already satisfied alloc request",
               resource_quota->name, resource_user->name);
     }
     if (resource_user->free_pool >= 0) {
@@ -217,18 +218,18 @@ static bool rq_alloc(grpc_exec_ctx *exec_ctx,
 }
 
 /* returns true if any memory could be reclaimed from buffers */
-static bool rq_scavenge(grpc_exec_ctx *exec_ctx,
-                        grpc_resource_quota *resource_quota) {
+static bool rq_reclaim_from_per_user_free_pool(
+    grpc_exec_ctx *exec_ctx, grpc_resource_quota *resource_quota) {
   grpc_resource_user *resource_user;
-  while ((resource_user =
-              rulist_pop(resource_quota, GRPC_RULIST_NON_EMPTY_FREE_POOL))) {
+  while ((resource_user = rulist_pop_head(resource_quota,
+                                          GRPC_RULIST_NON_EMPTY_FREE_POOL))) {
     gpr_mu_lock(&resource_user->mu);
     if (resource_user->free_pool > 0) {
       int64_t amt = resource_user->free_pool;
       resource_user->free_pool = 0;
       resource_quota->free_pool += amt;
       if (grpc_resource_quota_trace) {
-        gpr_log(GPR_DEBUG, "BP %s %s: scavenge %" PRId64
+        gpr_log(GPR_DEBUG, "RQ %s %s: reclaim_from_per_user_free_pool %" PRId64
                            " bytes; rq_free_pool -> %" PRId64,
                 resource_quota->name, resource_user->name, amt,
                 resource_quota->free_pool);
@@ -248,10 +249,10 @@ static bool rq_reclaim(grpc_exec_ctx *exec_ctx,
   if (resource_quota->reclaiming) return true;
   grpc_rulist list = destructive ? GRPC_RULIST_RECLAIMER_DESTRUCTIVE
                                  : GRPC_RULIST_RECLAIMER_BENIGN;
-  grpc_resource_user *resource_user = rulist_pop(resource_quota, list);
+  grpc_resource_user *resource_user = rulist_pop_head(resource_quota, list);
   if (resource_user == NULL) return false;
   if (grpc_resource_quota_trace) {
-    gpr_log(GPR_DEBUG, "BP %s %s: initiate %s reclamation",
+    gpr_log(GPR_DEBUG, "RQ %s %s: initiate %s reclamation",
             resource_quota->name, resource_user->name,
             destructive ? "destructive" : "benign");
   }
@@ -314,11 +315,12 @@ static gpr_slice ru_slice_create(grpc_resource_user *resource_user,
 }
 
 /*******************************************************************************
- * grpc_resource_quota internal implementation
+ * grpc_resource_quota internal implementation: resource user manipulation under
+ * the combiner
  */
 
-static void ru_allocate(grpc_exec_ctx *exec_ctx, void *bu, grpc_error *error) {
-  grpc_resource_user *resource_user = bu;
+static void ru_allocate(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
+  grpc_resource_user *resource_user = ru;
   if (rulist_empty(resource_user->resource_quota,
                    GRPC_RULIST_AWAITING_ALLOCATION)) {
     rq_step_sched(exec_ctx, resource_user->resource_quota);
@@ -326,9 +328,9 @@ static void ru_allocate(grpc_exec_ctx *exec_ctx, void *bu, grpc_error *error) {
   rulist_add_tail(resource_user, GRPC_RULIST_AWAITING_ALLOCATION);
 }
 
-static void ru_add_to_free_pool(grpc_exec_ctx *exec_ctx, void *bu,
+static void ru_add_to_free_pool(grpc_exec_ctx *exec_ctx, void *ru,
                                 grpc_error *error) {
-  grpc_resource_user *resource_user = bu;
+  grpc_resource_user *resource_user = ru;
   if (!rulist_empty(resource_user->resource_quota,
                     GRPC_RULIST_AWAITING_ALLOCATION) &&
       rulist_empty(resource_user->resource_quota,
@@ -338,9 +340,9 @@ static void ru_add_to_free_pool(grpc_exec_ctx *exec_ctx, void *bu,
   rulist_add_tail(resource_user, GRPC_RULIST_NON_EMPTY_FREE_POOL);
 }
 
-static void ru_post_benign_reclaimer(grpc_exec_ctx *exec_ctx, void *bu,
+static void ru_post_benign_reclaimer(grpc_exec_ctx *exec_ctx, void *ru,
                                      grpc_error *error) {
-  grpc_resource_user *resource_user = bu;
+  grpc_resource_user *resource_user = ru;
   if (!rulist_empty(resource_user->resource_quota,
                     GRPC_RULIST_AWAITING_ALLOCATION) &&
       rulist_empty(resource_user->resource_quota,
@@ -352,9 +354,9 @@ static void ru_post_benign_reclaimer(grpc_exec_ctx *exec_ctx, void *bu,
   rulist_add_tail(resource_user, GRPC_RULIST_RECLAIMER_BENIGN);
 }
 
-static void ru_post_destructive_reclaimer(grpc_exec_ctx *exec_ctx, void *bu,
+static void ru_post_destructive_reclaimer(grpc_exec_ctx *exec_ctx, void *ru,
                                           grpc_error *error) {
-  grpc_resource_user *resource_user = bu;
+  grpc_resource_user *resource_user = ru;
   if (!rulist_empty(resource_user->resource_quota,
                     GRPC_RULIST_AWAITING_ALLOCATION) &&
       rulist_empty(resource_user->resource_quota,
@@ -368,8 +370,8 @@ static void ru_post_destructive_reclaimer(grpc_exec_ctx *exec_ctx, void *bu,
   rulist_add_tail(resource_user, GRPC_RULIST_RECLAIMER_DESTRUCTIVE);
 }
 
-static void ru_destroy(grpc_exec_ctx *exec_ctx, void *bu, grpc_error *error) {
-  grpc_resource_user *resource_user = bu;
+static void ru_destroy(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
+  grpc_resource_user *resource_user = ru;
   GPR_ASSERT(resource_user->allocated == 0);
   for (int i = 0; i < GRPC_RULIST_COUNT; i++) {
     rulist_remove(resource_user, (grpc_rulist)i);
@@ -387,9 +389,9 @@ static void ru_destroy(grpc_exec_ctx *exec_ctx, void *bu, grpc_error *error) {
   }
 }
 
-static void ru_allocated_slices(grpc_exec_ctx *exec_ctx, void *ts,
+static void ru_allocated_slices(grpc_exec_ctx *exec_ctx, void *arg,
                                 grpc_error *error) {
-  grpc_resource_user_slice_allocator *slice_allocator = ts;
+  grpc_resource_user_slice_allocator *slice_allocator = arg;
   if (error == GRPC_ERROR_NONE) {
     for (size_t i = 0; i < slice_allocator->count; i++) {
       gpr_slice_buffer_add_indexed(
@@ -400,6 +402,11 @@ static void ru_allocated_slices(grpc_exec_ctx *exec_ctx, void *ts,
   grpc_closure_run(exec_ctx, &slice_allocator->on_done, GRPC_ERROR_REF(error));
 }
 
+/*******************************************************************************
+ * grpc_resource_quota internal implementation: quota manipulation under the
+ * combiner
+ */
+
 typedef struct {
   int64_t size;
   grpc_resource_quota *resource_quota;
@@ -411,20 +418,14 @@ static void rq_resize(grpc_exec_ctx *exec_ctx, void *args, grpc_error *error) {
   int64_t delta = a->size - a->resource_quota->size;
   a->resource_quota->size += delta;
   a->resource_quota->free_pool += delta;
-  if (delta < 0 && a->resource_quota->free_pool < 0) {
-    rq_step_sched(exec_ctx, a->resource_quota);
-  } else if (delta > 0 &&
-             !rulist_empty(a->resource_quota,
-                           GRPC_RULIST_AWAITING_ALLOCATION)) {
-    rq_step_sched(exec_ctx, a->resource_quota);
-  }
+  rq_step_sched(exec_ctx, a->resource_quota);
   grpc_resource_quota_internal_unref(exec_ctx, a->resource_quota);
   gpr_free(a);
 }
 
-static void rq_reclamation_done(grpc_exec_ctx *exec_ctx, void *bp,
+static void rq_reclamation_done(grpc_exec_ctx *exec_ctx, void *rq,
                                 grpc_error *error) {
-  grpc_resource_quota *resource_quota = bp;
+  grpc_resource_quota *resource_quota = rq;
   resource_quota->reclaiming = false;
   rq_step_sched(exec_ctx, resource_quota);
   grpc_resource_quota_internal_unref(exec_ctx, resource_quota);
@@ -434,6 +435,7 @@ static void rq_reclamation_done(grpc_exec_ctx *exec_ctx, void *bp,
  * grpc_resource_quota api
  */
 
+/* Public API */
 grpc_resource_quota *grpc_resource_quota_create(const char *name) {
   grpc_resource_quota *resource_quota = gpr_malloc(sizeof(*resource_quota));
   gpr_ref_init(&resource_quota->refs, 1);
@@ -466,6 +468,7 @@ void grpc_resource_quota_internal_unref(grpc_exec_ctx *exec_ctx,
   }
 }
 
+/* Public API */
 void grpc_resource_quota_unref(grpc_resource_quota *resource_quota) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_resource_quota_internal_unref(&exec_ctx, resource_quota);
@@ -478,10 +481,12 @@ grpc_resource_quota *grpc_resource_quota_internal_ref(
   return resource_quota;
 }
 
+/* Public API */
 void grpc_resource_quota_ref(grpc_resource_quota *resource_quota) {
   grpc_resource_quota_internal_ref(resource_quota);
 }
 
+/* Public API */
 void grpc_resource_quota_resize(grpc_resource_quota *resource_quota,
                                 size_t size) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
@@ -513,12 +518,12 @@ grpc_resource_quota *grpc_resource_quota_from_channel_args(
   return grpc_resource_quota_create(NULL);
 }
 
-static void *rq_copy(void *bp) {
-  grpc_resource_quota_ref(bp);
-  return bp;
+static void *rq_copy(void *rq) {
+  grpc_resource_quota_ref(rq);
+  return rq;
 }
 
-static void rq_destroy(void *bp) { grpc_resource_quota_unref(bp); }
+static void rq_destroy(void *rq) { grpc_resource_quota_unref(rq); }
 
 static int rq_cmp(void *a, void *b) { return GPR_ICMP(a, b); }
 
@@ -558,9 +563,6 @@ void grpc_resource_user_init(grpc_resource_user *resource_user,
   for (int i = 0; i < GRPC_RULIST_COUNT; i++) {
     resource_user->links[i].next = resource_user->links[i].prev = NULL;
   }
-#ifndef NDEBUG
-  resource_user->asan_canary = gpr_malloc(1);
-#endif
   if (name != NULL) {
     resource_user->name = gpr_strdup(name);
   } else {
@@ -587,9 +589,6 @@ void grpc_resource_user_shutdown(grpc_exec_ctx *exec_ctx,
 
 void grpc_resource_user_destroy(grpc_exec_ctx *exec_ctx,
                                 grpc_resource_user *resource_user) {
-#ifndef NDEBUG
-  gpr_free(resource_user->asan_canary);
-#endif
   grpc_resource_quota_internal_unref(exec_ctx, resource_user->resource_quota);
   gpr_mu_destroy(&resource_user->mu);
   gpr_free(resource_user->name);
@@ -604,7 +603,7 @@ void grpc_resource_user_alloc(grpc_exec_ctx *exec_ctx,
   if (on_done_destroy != NULL) {
     /* already shutdown */
     if (grpc_resource_quota_trace) {
-      gpr_log(GPR_DEBUG, "BP %s %s: alloc %" PRIdPTR " after shutdown",
+      gpr_log(GPR_DEBUG, "RQ %s %s: alloc %" PRIdPTR " after shutdown",
               resource_user->resource_quota->name, resource_user->name, size);
     }
     grpc_exec_ctx_sched(
@@ -616,7 +615,7 @@ void grpc_resource_user_alloc(grpc_exec_ctx *exec_ctx,
   resource_user->allocated += (int64_t)size;
   resource_user->free_pool -= (int64_t)size;
   if (grpc_resource_quota_trace) {
-    gpr_log(GPR_DEBUG, "BP %s %s: alloc %" PRIdPTR "; allocated -> %" PRId64
+    gpr_log(GPR_DEBUG, "RQ %s %s: alloc %" PRIdPTR "; allocated -> %" PRId64
                        ", free_pool -> %" PRId64,
             resource_user->resource_quota->name, resource_user->name, size,
             resource_user->allocated, resource_user->free_pool);
@@ -644,7 +643,7 @@ void grpc_resource_user_free(grpc_exec_ctx *exec_ctx,
   resource_user->free_pool += (int64_t)size;
   resource_user->allocated -= (int64_t)size;
   if (grpc_resource_quota_trace) {
-    gpr_log(GPR_DEBUG, "BP %s %s: free %" PRIdPTR "; allocated -> %" PRId64
+    gpr_log(GPR_DEBUG, "RQ %s %s: free %" PRIdPTR "; allocated -> %" PRId64
                        ", free_pool -> %" PRId64,
             resource_user->resource_quota->name, resource_user->name, size,
             resource_user->allocated, resource_user->free_pool);
@@ -685,7 +684,7 @@ void grpc_resource_user_post_reclaimer(grpc_exec_ctx *exec_ctx,
 void grpc_resource_user_finish_reclamation(grpc_exec_ctx *exec_ctx,
                                            grpc_resource_user *resource_user) {
   if (grpc_resource_quota_trace) {
-    gpr_log(GPR_DEBUG, "BP %s %s: reclamation complete",
+    gpr_log(GPR_DEBUG, "RQ %s %s: reclamation complete",
             resource_user->resource_quota->name, resource_user->name);
   }
   grpc_combiner_execute(
diff --git a/src/core/lib/iomgr/resource_quota.h b/src/core/lib/iomgr/resource_quota.h
index af94a19911..6dfac55f88 100644
--- a/src/core/lib/iomgr/resource_quota.h
+++ b/src/core/lib/iomgr/resource_quota.h
@@ -49,7 +49,8 @@
     resource constrained, grpc_resource_user instances are asked (in turn) to
     free up whatever they can so that the system as a whole can make progress.
 
-    There are three kinds of reclamation that take place:
+    There are three kinds of reclamation that take place, in order of increasing
+    invasiveness:
     - an internal reclamation, where cached resource at the resource user level
       is returned to the quota
     - a benign reclamation phase, whereby resources that are in use but are not
@@ -58,9 +59,14 @@
       make progress may be enacted so that at least one part of the system can
       complete.
 
-    These reclamations are tried in priority order, and only one reclamation
-    is outstanding for a quota at any given time (meaning that if a destructive
-    reclamation makes progress, we may follow up with a benign reclamation).
+    Only one reclamation will be outstanding for a given quota at a given time.
+    On each reclamation attempt, the kinds of reclamation are tried in order of
+    increasing invasiveness, stopping at the first one that succeeds. Thus, on a
+    given reclamation attempt, if internal and benign reclamation both fail, it
+    will wind up doing a destructive reclamation. However, the next reclamation
+    attempt may then be able to get what it needs via internal or benign
+    reclamation, due to resources that may have been freed up by the destructive
+    reclamation in the previous attempt.
 
     Future work will be to expose the current resource pressure so that back
     pressure can be applied to avoid reclamation phases starting.
@@ -106,24 +112,20 @@ struct grpc_resource_user {
   /* The quota this resource user consumes from */
   grpc_resource_quota *resource_quota;
 
-  /* Closure to schedule an allocation onder the resource quota combiner lock */
+  /* Closure to schedule an allocation under the resource quota combiner lock */
   grpc_closure allocate_closure;
   /* Closure to publish a non empty free pool under the resource quota combiner
      lock */
   grpc_closure add_to_free_pool_closure;
 
-#ifndef NDEBUG
-  /* Canary object to detect leaked resource users with ASAN */
-  void *asan_canary;
-#endif
-
   gpr_mu mu;
-  /* Total allocated memory outstanding by this resource user;
+  /* Total allocated memory outstanding by this resource user in bytes;
      always positive */
   int64_t allocated;
-  /* The amount of memory this user has cached for its own use: to avoid quota
-     contention, each resource user can keep some memory aside from the quota,
-     and the quota can pull it back under memory pressure.
+  /* The amount of memory (in bytes) this user has cached for its own use: to
+     avoid quota contention, each resource user can keep some memory in
+     addition to what it is immediately using (e.g., for caching), and the quota
+     can pull it back under memory pressure.
      This value can become negative if more memory has been requested than
      existed in the free pool, at which point the quota is consulted to bring
      this value non-negative (asynchronously). */
@@ -148,7 +150,8 @@ struct grpc_resource_user {
      resource user */
   grpc_closure destroy_closure;
   /* User supplied closure to call once the user has finished shutting down AND
-     all outstanding allocations have been freed */
+     all outstanding allocations have been freed. Real type is grpc_closure*,
+     but it's stored as an atomic to avoid a mutex on some fast paths. */
   gpr_atm on_done_destroy_closure;
 
   /* Links in the various grpc_rulist lists */
@@ -167,7 +170,7 @@ void grpc_resource_user_shutdown(grpc_exec_ctx *exec_ctx,
 void grpc_resource_user_destroy(grpc_exec_ctx *exec_ctx,
                                 grpc_resource_user *resource_user);
 
-/* Allocate from the resource user (and it's quota).
+/* Allocate from the resource user (and its quota).
    If optional_on_done is NULL, then allocate immediately. This may push the
    quota over-limit, at which point reclamation will kick in.
    If optional_on_done is non-NULL, it will be scheduled when the allocation has
@@ -191,20 +194,28 @@ void grpc_resource_user_finish_reclamation(grpc_exec_ctx *exec_ctx,
 
 /* Helper to allocate slices from a resource user */
 typedef struct grpc_resource_user_slice_allocator {
+  /* Closure for when a resource user allocation completes */
   grpc_closure on_allocated;
+  /* Closure to call when slices have been allocated */
   grpc_closure on_done;
+  /* Length of slices to allocate on the current request */
   size_t length;
+  /* Number of slices to allocate on the current request */
   size_t count;
+  /* Destination for slices to allocate on the current request */
   gpr_slice_buffer *dest;
+  /* Parent resource user */
   grpc_resource_user *resource_user;
 } grpc_resource_user_slice_allocator;
 
-/* Initialize a slice allocator */
+/* Initialize a slice allocator.
+   When an allocation is completed, calls \a cb with arg \p. */
 void grpc_resource_user_slice_allocator_init(
     grpc_resource_user_slice_allocator *slice_allocator,
     grpc_resource_user *resource_user, grpc_iomgr_cb_func cb, void *p);
 
-/* Allocate \a count slices of length \a length into \a dest. */
+/* Allocate \a count slices of length \a length into \a dest. Only one request
+   can be outstanding at a time. */
 void grpc_resource_user_alloc_slices(
     grpc_exec_ctx *exec_ctx,
     grpc_resource_user_slice_allocator *slice_allocator, size_t length,
diff --git a/src/core/lib/iomgr/sockaddr.h b/src/core/lib/iomgr/sockaddr.h
index 5563d0b8a6..52b504390d 100644
--- a/src/core/lib/iomgr/sockaddr.h
+++ b/src/core/lib/iomgr/sockaddr.h
@@ -31,16 +31,24 @@
  *
  */
 
+/* This header transitively includes other headers that care about include
+ * order, so it should be included first. As a consequence, it should not be
+ * included in any other header. */
+
 #ifndef GRPC_CORE_LIB_IOMGR_SOCKADDR_H
 #define GRPC_CORE_LIB_IOMGR_SOCKADDR_H
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+#include <uv.h>
+#endif
 
 #ifdef GPR_WINDOWS
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 #endif
 
-#ifdef GPR_POSIX_SOCKETADDR
+#ifdef GRPC_POSIX_SOCKETADDR
 #include "src/core/lib/iomgr/sockaddr_posix.h"
 #endif
 
diff --git a/src/core/lib/iomgr/sockaddr_utils.c b/src/core/lib/iomgr/sockaddr_utils.c
index 127d95c618..44bc2f968b 100644
--- a/src/core/lib/iomgr/sockaddr_utils.c
+++ b/src/core/lib/iomgr/sockaddr_utils.c
@@ -42,26 +42,32 @@
 #include <grpc/support/port_platform.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/socket_utils.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/support/string.h"
 
 static const uint8_t kV4MappedPrefix[] = {0, 0, 0, 0, 0,    0,
                                           0, 0, 0, 0, 0xff, 0xff};
 
-int grpc_sockaddr_is_v4mapped(const struct sockaddr *addr,
-                              struct sockaddr_in *addr4_out) {
-  GPR_ASSERT(addr != (struct sockaddr *)addr4_out);
+int grpc_sockaddr_is_v4mapped(const grpc_resolved_address *resolved_addr,
+                              grpc_resolved_address *resolved_addr4_out) {
+  GPR_ASSERT(resolved_addr != resolved_addr4_out);
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
+  struct sockaddr_in *addr4_out =
+      (struct sockaddr_in *)resolved_addr4_out->addr;
   if (addr->sa_family == AF_INET6) {
     const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr;
     if (memcmp(addr6->sin6_addr.s6_addr, kV4MappedPrefix,
                sizeof(kV4MappedPrefix)) == 0) {
-      if (addr4_out != NULL) {
+      if (resolved_addr4_out != NULL) {
         /* Normalize ::ffff:0.0.0.0/96 to IPv4. */
-        memset(addr4_out, 0, sizeof(*addr4_out));
+        memset(resolved_addr4_out, 0, sizeof(*resolved_addr4_out));
         addr4_out->sin_family = AF_INET;
         /* s6_addr32 would be nice, but it's non-standard. */
         memcpy(&addr4_out->sin_addr, &addr6->sin6_addr.s6_addr[12], 4);
         addr4_out->sin_port = addr6->sin6_port;
+        resolved_addr4_out->len = sizeof(struct sockaddr_in);
       }
       return 1;
     }
@@ -69,26 +75,33 @@ int grpc_sockaddr_is_v4mapped(const struct sockaddr *addr,
   return 0;
 }
 
-int grpc_sockaddr_to_v4mapped(const struct sockaddr *addr,
-                              struct sockaddr_in6 *addr6_out) {
-  GPR_ASSERT(addr != (struct sockaddr *)addr6_out);
+int grpc_sockaddr_to_v4mapped(const grpc_resolved_address *resolved_addr,
+                              grpc_resolved_address *resolved_addr6_out) {
+  GPR_ASSERT(resolved_addr != resolved_addr6_out);
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
+  struct sockaddr_in6 *addr6_out =
+      (struct sockaddr_in6 *)resolved_addr6_out->addr;
   if (addr->sa_family == AF_INET) {
     const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;
-    memset(addr6_out, 0, sizeof(*addr6_out));
+    memset(resolved_addr6_out, 0, sizeof(*resolved_addr6_out));
     addr6_out->sin6_family = AF_INET6;
     memcpy(&addr6_out->sin6_addr.s6_addr[0], kV4MappedPrefix, 12);
     memcpy(&addr6_out->sin6_addr.s6_addr[12], &addr4->sin_addr, 4);
     addr6_out->sin6_port = addr4->sin_port;
+    resolved_addr6_out->len = sizeof(struct sockaddr_in6);
     return 1;
   }
   return 0;
 }
 
-int grpc_sockaddr_is_wildcard(const struct sockaddr *addr, int *port_out) {
-  struct sockaddr_in addr4_normalized;
-  if (grpc_sockaddr_is_v4mapped(addr, &addr4_normalized)) {
-    addr = (struct sockaddr *)&addr4_normalized;
+int grpc_sockaddr_is_wildcard(const grpc_resolved_address *resolved_addr,
+                              int *port_out) {
+  const struct sockaddr *addr;
+  grpc_resolved_address addr4_normalized;
+  if (grpc_sockaddr_is_v4mapped(resolved_addr, &addr4_normalized)) {
+    resolved_addr = &addr4_normalized;
   }
+  addr = (const struct sockaddr *)resolved_addr->addr;
   if (addr->sa_family == AF_INET) {
     /* Check for 0.0.0.0 */
     const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;
@@ -113,39 +126,49 @@ int grpc_sockaddr_is_wildcard(const struct sockaddr *addr, int *port_out) {
   }
 }
 
-void grpc_sockaddr_make_wildcards(int port, struct sockaddr_in *wild4_out,
-                                  struct sockaddr_in6 *wild6_out) {
+void grpc_sockaddr_make_wildcards(int port, grpc_resolved_address *wild4_out,
+                                  grpc_resolved_address *wild6_out) {
   grpc_sockaddr_make_wildcard4(port, wild4_out);
   grpc_sockaddr_make_wildcard6(port, wild6_out);
 }
 
-void grpc_sockaddr_make_wildcard4(int port, struct sockaddr_in *wild_out) {
+void grpc_sockaddr_make_wildcard4(int port,
+                                  grpc_resolved_address *resolved_wild_out) {
+  struct sockaddr_in *wild_out = (struct sockaddr_in *)resolved_wild_out->addr;
   GPR_ASSERT(port >= 0 && port < 65536);
-  memset(wild_out, 0, sizeof(*wild_out));
+  memset(resolved_wild_out, 0, sizeof(*resolved_wild_out));
   wild_out->sin_family = AF_INET;
   wild_out->sin_port = htons((uint16_t)port);
+  resolved_wild_out->len = sizeof(struct sockaddr_in);
 }
 
-void grpc_sockaddr_make_wildcard6(int port, struct sockaddr_in6 *wild_out) {
+void grpc_sockaddr_make_wildcard6(int port,
+                                  grpc_resolved_address *resolved_wild_out) {
+  struct sockaddr_in6 *wild_out =
+      (struct sockaddr_in6 *)resolved_wild_out->addr;
   GPR_ASSERT(port >= 0 && port < 65536);
-  memset(wild_out, 0, sizeof(*wild_out));
+  memset(resolved_wild_out, 0, sizeof(*resolved_wild_out));
   wild_out->sin6_family = AF_INET6;
   wild_out->sin6_port = htons((uint16_t)port);
+  resolved_wild_out->len = sizeof(struct sockaddr_in6);
 }
 
-int grpc_sockaddr_to_string(char **out, const struct sockaddr *addr,
+int grpc_sockaddr_to_string(char **out,
+                            const grpc_resolved_address *resolved_addr,
                             int normalize) {
+  const struct sockaddr *addr;
   const int save_errno = errno;
-  struct sockaddr_in addr_normalized;
+  grpc_resolved_address addr_normalized;
   char ntop_buf[INET6_ADDRSTRLEN];
   const void *ip = NULL;
   int port;
   int ret;
 
   *out = NULL;
-  if (normalize && grpc_sockaddr_is_v4mapped(addr, &addr_normalized)) {
-    addr = (const struct sockaddr *)&addr_normalized;
+  if (normalize && grpc_sockaddr_is_v4mapped(resolved_addr, &addr_normalized)) {
+    resolved_addr = &addr_normalized;
   }
+  addr = (const struct sockaddr *)resolved_addr->addr;
   if (addr->sa_family == AF_INET) {
     const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;
     ip = &addr4->sin_addr;
@@ -155,10 +178,8 @@ int grpc_sockaddr_to_string(char **out, const struct sockaddr *addr,
     ip = &addr6->sin6_addr;
     port = ntohs(addr6->sin6_port);
   }
-  /* Windows inet_ntop wants a mutable ip pointer */
   if (ip != NULL &&
-      inet_ntop(addr->sa_family, (void *)ip, ntop_buf, sizeof(ntop_buf)) !=
-          NULL) {
+      grpc_inet_ntop(addr->sa_family, ip, ntop_buf, sizeof(ntop_buf)) != NULL) {
     ret = gpr_join_host_port(out, ntop_buf, port);
   } else {
     ret = gpr_asprintf(out, "(sockaddr family=%d)", addr->sa_family);
@@ -168,39 +189,43 @@ int grpc_sockaddr_to_string(char **out, const struct sockaddr *addr,
   return ret;
 }
 
-char *grpc_sockaddr_to_uri(const struct sockaddr *addr) {
+char *grpc_sockaddr_to_uri(const grpc_resolved_address *resolved_addr) {
   char *temp;
   char *result;
-  struct sockaddr_in addr_normalized;
+  grpc_resolved_address addr_normalized;
+  const struct sockaddr *addr;
 
-  if (grpc_sockaddr_is_v4mapped(addr, &addr_normalized)) {
-    addr = (const struct sockaddr *)&addr_normalized;
+  if (grpc_sockaddr_is_v4mapped(resolved_addr, &addr_normalized)) {
+    resolved_addr = &addr_normalized;
   }
 
+  addr = (const struct sockaddr *)resolved_addr->addr;
+
   switch (addr->sa_family) {
     case AF_INET:
-      grpc_sockaddr_to_string(&temp, addr, 0);
+      grpc_sockaddr_to_string(&temp, resolved_addr, 0);
       gpr_asprintf(&result, "ipv4:%s", temp);
       gpr_free(temp);
       return result;
     case AF_INET6:
-      grpc_sockaddr_to_string(&temp, addr, 0);
+      grpc_sockaddr_to_string(&temp, resolved_addr, 0);
       gpr_asprintf(&result, "ipv6:%s", temp);
       gpr_free(temp);
       return result;
     default:
-      return grpc_sockaddr_to_uri_unix_if_possible(addr);
+      return grpc_sockaddr_to_uri_unix_if_possible(resolved_addr);
   }
 }
 
-int grpc_sockaddr_get_port(const struct sockaddr *addr) {
+int grpc_sockaddr_get_port(const grpc_resolved_address *resolved_addr) {
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
   switch (addr->sa_family) {
     case AF_INET:
       return ntohs(((struct sockaddr_in *)addr)->sin_port);
     case AF_INET6:
       return ntohs(((struct sockaddr_in6 *)addr)->sin6_port);
     default:
-      if (grpc_is_unix_socket(addr)) {
+      if (grpc_is_unix_socket(resolved_addr)) {
         return 1;
       }
       gpr_log(GPR_ERROR, "Unknown socket family %d in grpc_sockaddr_get_port",
@@ -209,7 +234,9 @@ int grpc_sockaddr_get_port(const struct sockaddr *addr) {
   }
 }
 
-int grpc_sockaddr_set_port(const struct sockaddr *addr, int port) {
+int grpc_sockaddr_set_port(const grpc_resolved_address *resolved_addr,
+                           int port) {
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
   switch (addr->sa_family) {
     case AF_INET:
       GPR_ASSERT(port >= 0 && port < 65536);
diff --git a/src/core/lib/iomgr/sockaddr_utils.h b/src/core/lib/iomgr/sockaddr_utils.h
index 9f81992e6b..5371e360c5 100644
--- a/src/core/lib/iomgr/sockaddr_utils.h
+++ b/src/core/lib/iomgr/sockaddr_utils.h
@@ -34,40 +34,40 @@
 #ifndef GRPC_CORE_LIB_IOMGR_SOCKADDR_UTILS_H
 #define GRPC_CORE_LIB_IOMGR_SOCKADDR_UTILS_H
 
-#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 
 /* Returns true if addr is an IPv4-mapped IPv6 address within the
    ::ffff:0.0.0.0/96 range, or false otherwise.
 
    If addr4_out is non-NULL, the inner IPv4 address will be copied here when
    returning true. */
-int grpc_sockaddr_is_v4mapped(const struct sockaddr *addr,
-                              struct sockaddr_in *addr4_out);
+int grpc_sockaddr_is_v4mapped(const grpc_resolved_address *addr,
+                              grpc_resolved_address *addr4_out);
 
 /* If addr is an AF_INET address, writes the corresponding ::ffff:0.0.0.0/96
    address to addr6_out and returns true.  Otherwise returns false. */
-int grpc_sockaddr_to_v4mapped(const struct sockaddr *addr,
-                              struct sockaddr_in6 *addr6_out);
+int grpc_sockaddr_to_v4mapped(const grpc_resolved_address *addr,
+                              grpc_resolved_address *addr6_out);
 
 /* If addr is ::, 0.0.0.0, or ::ffff:0.0.0.0, writes the port number to
    *port_out (if not NULL) and returns true, otherwise returns false. */
-int grpc_sockaddr_is_wildcard(const struct sockaddr *addr, int *port_out);
+int grpc_sockaddr_is_wildcard(const grpc_resolved_address *addr, int *port_out);
 
 /* Writes 0.0.0.0:port and [::]:port to separate sockaddrs. */
-void grpc_sockaddr_make_wildcards(int port, struct sockaddr_in *wild4_out,
-                                  struct sockaddr_in6 *wild6_out);
+void grpc_sockaddr_make_wildcards(int port, grpc_resolved_address *wild4_out,
+                                  grpc_resolved_address *wild6_out);
 
 /* Writes 0.0.0.0:port. */
-void grpc_sockaddr_make_wildcard4(int port, struct sockaddr_in *wild_out);
+void grpc_sockaddr_make_wildcard4(int port, grpc_resolved_address *wild_out);
 
 /* Writes [::]:port. */
-void grpc_sockaddr_make_wildcard6(int port, struct sockaddr_in6 *wild_out);
+void grpc_sockaddr_make_wildcard6(int port, grpc_resolved_address *wild_out);
 
 /* Return the IP port number of a sockaddr */
-int grpc_sockaddr_get_port(const struct sockaddr *addr);
+int grpc_sockaddr_get_port(const grpc_resolved_address *addr);
 
 /* Set IP port number of a sockaddr */
-int grpc_sockaddr_set_port(const struct sockaddr *addr, int port);
+int grpc_sockaddr_set_port(const grpc_resolved_address *addr, int port);
 
 /* Converts a sockaddr into a newly-allocated human-readable string.
 
@@ -81,9 +81,9 @@ int grpc_sockaddr_set_port(const struct sockaddr *addr, int port);
 
    In the unlikely event of an error, returns -1 and sets *out to NULL.
    The existing value of errno is always preserved. */
-int grpc_sockaddr_to_string(char **out, const struct sockaddr *addr,
+int grpc_sockaddr_to_string(char **out, const grpc_resolved_address *addr,
                             int normalize);
 
-char *grpc_sockaddr_to_uri(const struct sockaddr *addr);
+char *grpc_sockaddr_to_uri(const grpc_resolved_address *addr);
 
 #endif /* GRPC_CORE_LIB_IOMGR_SOCKADDR_UTILS_H */
diff --git a/src/core/lib/iomgr/socket_utils.h b/src/core/lib/iomgr/socket_utils.h
new file mode 100644
index 0000000000..cc3ee2e30c
--- /dev/null
+++ b/src/core/lib/iomgr/socket_utils.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_H
+#define GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_H
+
+#include <stddef.h>
+
+/* A wrapper for inet_ntop on POSIX systems and InetNtop on Windows systems */
+const char *grpc_inet_ntop(int af, const void *src, char *dst, size_t size);
+
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_H */
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.c b/src/core/lib/iomgr/socket_utils_common_posix.c
index d2f6261e2a..bc28bbe316 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.c
+++ b/src/core/lib/iomgr/socket_utils_common_posix.c
@@ -31,10 +31,11 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
+#include "src/core/lib/iomgr/socket_utils.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 
 #include <arpa/inet.h>
@@ -78,7 +79,7 @@ grpc_error *grpc_set_socket_nonblocking(int fd, int non_blocking) {
 }
 
 grpc_error *grpc_set_socket_no_sigpipe_if_possible(int fd) {
-#ifdef GPR_HAVE_SO_NOSIGPIPE
+#ifdef GRPC_HAVE_SO_NOSIGPIPE
   int val = 1;
   int newval;
   socklen_t intlen = sizeof(newval);
@@ -96,7 +97,7 @@ grpc_error *grpc_set_socket_no_sigpipe_if_possible(int fd) {
 }
 
 grpc_error *grpc_set_socket_ip_pktinfo_if_possible(int fd) {
-#ifdef GPR_HAVE_IP_PKTINFO
+#ifdef GRPC_HAVE_IP_PKTINFO
   int get_local_ip = 1;
   if (0 != setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &get_local_ip,
                       sizeof(get_local_ip))) {
@@ -107,7 +108,7 @@ grpc_error *grpc_set_socket_ip_pktinfo_if_possible(int fd) {
 }
 
 grpc_error *grpc_set_socket_ipv6_recvpktinfo_if_possible(int fd) {
-#ifdef GPR_HAVE_IPV6_RECVPKTINFO
+#ifdef GRPC_HAVE_IPV6_RECVPKTINFO
   int get_local_ip = 1;
   if (0 != setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &get_local_ip,
                       sizeof(get_local_ip))) {
@@ -253,7 +254,7 @@ static int set_socket_dualstack(int fd) {
   }
 }
 
-static grpc_error *error_for_fd(int fd, const struct sockaddr *addr) {
+static grpc_error *error_for_fd(int fd, const grpc_resolved_address *addr) {
   if (fd >= 0) return GRPC_ERROR_NONE;
   char *addr_str;
   grpc_sockaddr_to_string(&addr_str, addr, 0);
@@ -263,10 +264,10 @@ static grpc_error *error_for_fd(int fd, const struct sockaddr *addr) {
   return err;
 }
 
-grpc_error *grpc_create_dualstack_socket(const struct sockaddr *addr, int type,
-                                         int protocol,
-                                         grpc_dualstack_mode *dsmode,
-                                         int *newfd) {
+grpc_error *grpc_create_dualstack_socket(
+    const grpc_resolved_address *resolved_addr, int type, int protocol,
+    grpc_dualstack_mode *dsmode, int *newfd) {
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
   int family = addr->sa_family;
   if (family == AF_INET6) {
     if (grpc_ipv6_loopback_available()) {
@@ -281,9 +282,9 @@ grpc_error *grpc_create_dualstack_socket(const struct sockaddr *addr, int type,
       return GRPC_ERROR_NONE;
     }
     /* If this isn't an IPv4 address, then return whatever we've got. */
-    if (!grpc_sockaddr_is_v4mapped(addr, NULL)) {
+    if (!grpc_sockaddr_is_v4mapped(resolved_addr, NULL)) {
       *dsmode = GRPC_DSMODE_IPV6;
-      return error_for_fd(*newfd, addr);
+      return error_for_fd(*newfd, resolved_addr);
     }
     /* Fall back to AF_INET. */
     if (*newfd >= 0) {
@@ -293,7 +294,12 @@ grpc_error *grpc_create_dualstack_socket(const struct sockaddr *addr, int type,
   }
   *dsmode = family == AF_INET ? GRPC_DSMODE_IPV4 : GRPC_DSMODE_NONE;
   *newfd = socket(family, type, protocol);
-  return error_for_fd(*newfd, addr);
+  return error_for_fd(*newfd, resolved_addr);
+}
+
+const char *grpc_inet_ntop(int af, const void *src, char *dst, size_t size) {
+  GPR_ASSERT(size <= (socklen_t)-1);
+  return inet_ntop(af, src, dst, (socklen_t)size);
 }
 
 #endif
diff --git a/src/core/lib/iomgr/socket_utils_linux.c b/src/core/lib/iomgr/socket_utils_linux.c
index 144e3110c8..bf6e9e4f55 100644
--- a/src/core/lib/iomgr/socket_utils_linux.c
+++ b/src/core/lib/iomgr/socket_utils_linux.c
@@ -31,21 +31,27 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_LINUX_SOCKETUTILS
+#ifdef GRPC_LINUX_SOCKETUTILS
 
+#include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 
+#include <grpc/support/log.h>
+
 #include <sys/socket.h>
 #include <sys/types.h>
 
-int grpc_accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
-                 int nonblock, int cloexec) {
+int grpc_accept4(int sockfd, grpc_resolved_address *resolved_addr, int nonblock,
+                 int cloexec) {
   int flags = 0;
+  GPR_ASSERT(sizeof(socklen_t) <= sizeof(size_t));
+  GPR_ASSERT(resolved_addr->len <= (socklen_t)-1);
   flags |= nonblock ? SOCK_NONBLOCK : 0;
   flags |= cloexec ? SOCK_CLOEXEC : 0;
-  return accept4(sockfd, addr, addrlen, flags);
+  return accept4(sockfd, (struct sockaddr *)resolved_addr->addr,
+                 (socklen_t *)&resolved_addr->len, flags);
 }
 
 #endif
diff --git a/src/core/lib/iomgr/socket_utils_posix.c b/src/core/lib/iomgr/socket_utils_posix.c
index 57ae64c103..9dea0c0cd8 100644
--- a/src/core/lib/iomgr/socket_utils_posix.c
+++ b/src/core/lib/iomgr/socket_utils_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKETUTILS
+#ifdef GRPC_POSIX_SOCKETUTILS
 
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 
@@ -42,12 +42,15 @@
 #include <unistd.h>
 
 #include <grpc/support/log.h>
+#include "src/core/lib/iomgr/sockaddr.h"
 
-int grpc_accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
-                 int nonblock, int cloexec) {
+int grpc_accept4(int sockfd, grpc_resolved_address *resolved_addr, int nonblock,
+                 int cloexec) {
   int fd, flags;
-
-  fd = accept(sockfd, addr, addrlen);
+  GPR_ASSERT(sizeof(socklen_t) <= sizeof(size_t));
+  GPR_ASSERT(resolved_addr->len <= (socklen_t)-1);
+  fd = accept(sockfd, (struct sockaddr *)resolved_addr->addr,
+              (socklen_t *)&resolved_addr->len);
   if (fd >= 0) {
     if (nonblock) {
       flags = fcntl(fd, F_GETFL, 0);
@@ -67,4 +70,4 @@ close_and_error:
   return -1;
 }
 
-#endif /* GPR_POSIX_SOCKETUTILS */
+#endif /* GRPC_POSIX_SOCKETUTILS */
diff --git a/src/core/lib/iomgr/socket_utils_posix.h b/src/core/lib/iomgr/socket_utils_posix.h
index 7bcc2219ae..175fb2b717 100644
--- a/src/core/lib/iomgr/socket_utils_posix.h
+++ b/src/core/lib/iomgr/socket_utils_posix.h
@@ -34,14 +34,16 @@
 #ifndef GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_POSIX_H
 #define GRPC_CORE_LIB_IOMGR_SOCKET_UTILS_POSIX_H
 
+#include "src/core/lib/iomgr/resolve_address.h"
+
 #include <sys/socket.h>
 #include <unistd.h>
 
 #include "src/core/lib/iomgr/error.h"
 
 /* a wrapper for accept or accept4 */
-int grpc_accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
-                 int nonblock, int cloexec);
+int grpc_accept4(int sockfd, grpc_resolved_address *resolved_addr, int nonblock,
+                 int cloexec);
 
 /* set a socket to non blocking mode */
 grpc_error *grpc_set_socket_nonblocking(int fd, int non_blocking);
@@ -125,8 +127,8 @@ extern int grpc_forbid_dualstack_sockets_for_testing;
      IPv4, so that bind() or connect() see the correct family.
    Also, it's important to distinguish between DUALSTACK and IPV6 when
    listening on the [::] wildcard address. */
-grpc_error *grpc_create_dualstack_socket(const struct sockaddr *addr, int type,
-                                         int protocol,
+grpc_error *grpc_create_dualstack_socket(const grpc_resolved_address *addr,
+                                         int type, int protocol,
                                          grpc_dualstack_mode *dsmode,
                                          int *newfd);
 
diff --git a/src/core/lib/iomgr/socket_utils_uv.c b/src/core/lib/iomgr/socket_utils_uv.c
new file mode 100644
index 0000000000..741bf28969
--- /dev/null
+++ b/src/core/lib/iomgr/socket_utils_uv.c
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include <uv.h>
+
+#include "src/core/lib/iomgr/socket_utils.h"
+
+#include <grpc/support/log.h>
+
+const char *grpc_inet_ntop(int af, const void *src, char *dst, size_t size) {
+  uv_inet_ntop(af, src, dst, size);
+  return dst;
+}
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/socket_utils_windows.c b/src/core/lib/iomgr/socket_utils_windows.c
new file mode 100644
index 0000000000..628ad4a45b
--- /dev/null
+++ b/src/core/lib/iomgr/socket_utils_windows.c
@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_WINDOWS_SOCKETUTILS
+
+#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/socket_utils.h"
+
+#include <grpc/support/log.h>
+
+const char *grpc_inet_ntop(int af, const void *src, char *dst, size_t size) {
+  /* Windows InetNtopA wants a mutable ip pointer */
+  return InetNtopA(af, (void *)src, dst, size);
+}
+
+#endif /* GRPC_WINDOWS_SOCKETUTILS */
diff --git a/src/core/lib/iomgr/socket_windows.c b/src/core/lib/iomgr/socket_windows.c
index 78ef46d042..35f23300dc 100644
--- a/src/core/lib/iomgr/socket_windows.c
+++ b/src/core/lib/iomgr/socket_windows.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <winsock2.h>
 
@@ -156,4 +156,4 @@ void grpc_socket_become_ready(grpc_exec_ctx *exec_ctx, grpc_winsocket *socket,
   if (should_destroy) destroy(socket);
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/tcp_client.h b/src/core/lib/iomgr/tcp_client.h
index d1b0e9cd19..18e6e60ebc 100644
--- a/src/core/lib/iomgr/tcp_client.h
+++ b/src/core/lib/iomgr/tcp_client.h
@@ -37,7 +37,7 @@
 #include <grpc/support/time.h>
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/pollset_set.h"
-#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 
 /* Channel arg (integer) setting how large a slice to try and read from the wire
    each time recvmsg (or equivalent) is called */
@@ -52,7 +52,7 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *on_connect,
                              grpc_endpoint **endpoint,
                              grpc_pollset_set *interested_parties,
                              const grpc_channel_args *channel_args,
-                             const struct sockaddr *addr, size_t addr_len,
+                             const grpc_resolved_address *addr,
                              gpr_timespec deadline);
 
 #endif /* GRPC_CORE_LIB_IOMGR_TCP_CLIENT_H */
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index 500c988146..bc08c94ee0 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/tcp_client_posix.h"
 
@@ -73,7 +73,7 @@ typedef struct {
   grpc_channel_args *channel_args;
 } async_connect;
 
-static grpc_error *prepare_socket(const struct sockaddr *addr, int fd) {
+static grpc_error *prepare_socket(const grpc_resolved_address *addr, int fd) {
   grpc_error *err = GRPC_ERROR_NONE;
 
   GPR_ASSERT(fd >= 0);
@@ -257,14 +257,14 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
                                     grpc_closure *closure, grpc_endpoint **ep,
                                     grpc_pollset_set *interested_parties,
                                     const grpc_channel_args *channel_args,
-                                    const struct sockaddr *addr,
-                                    size_t addr_len, gpr_timespec deadline) {
+                                    const grpc_resolved_address *addr,
+                                    gpr_timespec deadline) {
   int fd;
   grpc_dualstack_mode dsmode;
   int err;
   async_connect *ac;
-  struct sockaddr_in6 addr6_v4mapped;
-  struct sockaddr_in addr4_copy;
+  grpc_resolved_address addr6_v4mapped;
+  grpc_resolved_address addr4_copy;
   grpc_fd *fdobj;
   char *name;
   char *addr_str;
@@ -274,8 +274,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
 
   /* Use dualstack sockets where available. */
   if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
-    addr = (const struct sockaddr *)&addr6_v4mapped;
-    addr_len = sizeof(addr6_v4mapped);
+    addr = &addr6_v4mapped;
   }
 
   error = grpc_create_dualstack_socket(addr, SOCK_STREAM, 0, &dsmode, &fd);
@@ -286,8 +285,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
   if (dsmode == GRPC_DSMODE_IPV4) {
     /* If we got an AF_INET socket, map the address back to IPv4. */
     GPR_ASSERT(grpc_sockaddr_is_v4mapped(addr, &addr4_copy));
-    addr = (struct sockaddr *)&addr4_copy;
-    addr_len = sizeof(addr4_copy);
+    addr = &addr4_copy;
   }
   if ((error = prepare_socket(addr, fd)) != GRPC_ERROR_NONE) {
     grpc_exec_ctx_sched(exec_ctx, closure, error, NULL);
@@ -295,8 +293,9 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
   }
 
   do {
-    GPR_ASSERT(addr_len < ~(socklen_t)0);
-    err = connect(fd, addr, (socklen_t)addr_len);
+    GPR_ASSERT(addr->len < ~(socklen_t)0);
+    err =
+        connect(fd, (const struct sockaddr *)addr->addr, (socklen_t)addr->len);
   } while (err < 0 && errno == EINTR);
 
   addr_str = grpc_sockaddr_to_uri(addr);
@@ -354,17 +353,17 @@ done:
 void (*grpc_tcp_client_connect_impl)(
     grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_endpoint **ep,
     grpc_pollset_set *interested_parties, const grpc_channel_args *channel_args,
-    const struct sockaddr *addr, size_t addr_len,
+    const grpc_resolved_address *addr,
     gpr_timespec deadline) = tcp_client_connect_impl;
 
 void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
                              grpc_endpoint **ep,
                              grpc_pollset_set *interested_parties,
                              const grpc_channel_args *channel_args,
-                             const struct sockaddr *addr, size_t addr_len,
+                             const grpc_resolved_address *addr,
                              gpr_timespec deadline) {
   grpc_tcp_client_connect_impl(exec_ctx, closure, ep, interested_parties,
-                               channel_args, addr, addr_len, deadline);
+                               channel_args, addr, deadline);
 }
 
 #endif
diff --git a/src/core/lib/iomgr/tcp_client_uv.c b/src/core/lib/iomgr/tcp_client_uv.c
new file mode 100644
index 0000000000..6274667042
--- /dev/null
+++ b/src/core/lib/iomgr/tcp_client_uv.c
@@ -0,0 +1,153 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/iomgr/tcp_client.h"
+#include "src/core/lib/iomgr/tcp_uv.h"
+#include "src/core/lib/iomgr/timer.h"
+
+typedef struct grpc_uv_tcp_connect {
+  uv_connect_t connect_req;
+  grpc_timer alarm;
+  uv_tcp_t *tcp_handle;
+  grpc_closure *closure;
+  grpc_endpoint **endpoint;
+  int refs;
+  char *addr_name;
+} grpc_uv_tcp_connect;
+
+static void uv_tcp_connect_cleanup(grpc_uv_tcp_connect *connect) {
+  gpr_free(connect);
+}
+
+static void tcp_close_callback(uv_handle_t *handle) { gpr_free(handle); }
+
+static void uv_tc_on_alarm(grpc_exec_ctx *exec_ctx, void *acp,
+                           grpc_error *error) {
+  int done;
+  grpc_uv_tcp_connect *connect = acp;
+  if (error == GRPC_ERROR_NONE) {
+    /* error == NONE implies that the timer ran out, and wasn't cancelled. If
+       it was cancelled, then the handler that cancelled it also should close
+       the handle, if applicable */
+    uv_close((uv_handle_t *)connect->tcp_handle, tcp_close_callback);
+  }
+  done = (--connect->refs == 0);
+  if (done) {
+    uv_tcp_connect_cleanup(connect);
+  }
+}
+
+static void uv_tc_on_connect(uv_connect_t *req, int status) {
+  grpc_uv_tcp_connect *connect = req->data;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_error *error = GRPC_ERROR_NONE;
+  int done;
+  grpc_closure *closure = connect->closure;
+  grpc_timer_cancel(&exec_ctx, &connect->alarm);
+  if (status == 0) {
+    *connect->endpoint =
+        grpc_tcp_create(connect->tcp_handle, connect->addr_name);
+  } else {
+    error = GRPC_ERROR_CREATE("Failed to connect to remote host");
+    error = grpc_error_set_int(error, GRPC_ERROR_INT_ERRNO, -status);
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR, uv_strerror(status));
+    if (status == UV_ECANCELED) {
+      error = grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR,
+                                 "Timeout occurred");
+      // This should only happen if the handle is already closed
+    } else {
+      error = grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR,
+                                 uv_strerror(status));
+      uv_close((uv_handle_t *)connect->tcp_handle, tcp_close_callback);
+    }
+  }
+  done = (--connect->refs == 0);
+  if (done) {
+    uv_tcp_connect_cleanup(connect);
+  }
+  grpc_exec_ctx_sched(&exec_ctx, closure, error, NULL);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
+                                    grpc_closure *closure, grpc_endpoint **ep,
+                                    grpc_pollset_set *interested_parties,
+                                    const grpc_resolved_address *resolved_addr,
+                                    gpr_timespec deadline) {
+  grpc_uv_tcp_connect *connect;
+  (void)interested_parties;
+  connect = gpr_malloc(sizeof(grpc_uv_tcp_connect));
+  memset(connect, 0, sizeof(grpc_uv_tcp_connect));
+  connect->closure = closure;
+  connect->endpoint = ep;
+  connect->tcp_handle = gpr_malloc(sizeof(uv_tcp_t));
+  connect->addr_name = grpc_sockaddr_to_uri(resolved_addr);
+  uv_tcp_init(uv_default_loop(), connect->tcp_handle);
+  connect->connect_req.data = connect;
+  // TODO(murgatroid99): figure out what the return value here means
+  uv_tcp_connect(&connect->connect_req, connect->tcp_handle,
+                 (const struct sockaddr *)resolved_addr->addr,
+                 uv_tc_on_connect);
+  grpc_timer_init(exec_ctx, &connect->alarm,
+                  gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
+                  uv_tc_on_alarm, connect, gpr_now(GPR_CLOCK_MONOTONIC));
+}
+
+// overridden by api_fuzzer.c
+void (*grpc_tcp_client_connect_impl)(
+    grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_endpoint **ep,
+    grpc_pollset_set *interested_parties, const grpc_resolved_address *addr,
+    gpr_timespec deadline) = tcp_client_connect_impl;
+
+void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
+                             grpc_endpoint **ep,
+                             grpc_pollset_set *interested_parties,
+                             const grpc_resolved_address *addr,
+                             gpr_timespec deadline) {
+  grpc_tcp_client_connect_impl(exec_ctx, closure, ep, interested_parties, addr,
+                               deadline);
+}
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/tcp_client_windows.c b/src/core/lib/iomgr/tcp_client_windows.c
index 562cb9c6bf..fdd8c1a1f8 100644
--- a/src/core/lib/iomgr/tcp_client_windows.c
+++ b/src/core/lib/iomgr/tcp_client_windows.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 
@@ -129,13 +129,13 @@ static void on_connect(grpc_exec_ctx *exec_ctx, void *acp, grpc_error *error) {
 void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *on_done,
                              grpc_endpoint **endpoint,
                              grpc_pollset_set *interested_parties,
-                             const struct sockaddr *addr, size_t addr_len,
+                             const grpc_resolved_address *addr,
                              gpr_timespec deadline) {
   SOCKET sock = INVALID_SOCKET;
   BOOL success;
   int status;
-  struct sockaddr_in6 addr6_v4mapped;
-  struct sockaddr_in6 local_address;
+  grpc_resolved_address addr6_v4mapped;
+  grpc_resolved_address local_address;
   async_connect *ac;
   grpc_winsocket *socket = NULL;
   LPFN_CONNECTEX ConnectEx;
@@ -148,8 +148,7 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *on_done,
 
   /* Use dualstack sockets where available. */
   if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
-    addr = (const struct sockaddr *)&addr6_v4mapped;
-    addr_len = sizeof(addr6_v4mapped);
+    addr = &addr6_v4mapped;
   }
 
   sock = WSASocket(AF_INET6, SOCK_STREAM, IPPROTO_TCP, NULL, 0,
@@ -178,7 +177,8 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *on_done,
 
   grpc_sockaddr_make_wildcard6(0, &local_address);
 
-  status = bind(sock, (struct sockaddr *)&local_address, sizeof(local_address));
+  status =
+      bind(sock, (struct sockaddr *)&local_address.addr, local_address.len);
   if (status != 0) {
     error = GRPC_WSA_ERROR(WSAGetLastError(), "bind");
     goto failure;
@@ -186,8 +186,8 @@ void grpc_tcp_client_connect(grpc_exec_ctx *exec_ctx, grpc_closure *on_done,
 
   socket = grpc_winsocket_create(sock, "client");
   info = &socket->write_info;
-  success =
-      ConnectEx(sock, addr, (int)addr_len, NULL, 0, NULL, &info->overlapped);
+  success = ConnectEx(sock, (struct sockaddr *)&addr->addr, (int)addr->len,
+                      NULL, 0, NULL, &info->overlapped);
 
   /* It wouldn't be unusual to get a success immediately. But we'll still get
      an IOCP notification, so let's ignore it. */
@@ -228,4 +228,4 @@ failure:
   grpc_exec_ctx_sched(exec_ctx, on_done, final_error, NULL);
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 27b6677545..880af93ee1 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
@@ -58,14 +58,14 @@
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/string.h"
 
-#ifdef GPR_HAVE_MSG_NOSIGNAL
+#ifdef GRPC_HAVE_MSG_NOSIGNAL
 #define SENDMSG_FLAGS MSG_NOSIGNAL
 #else
 #define SENDMSG_FLAGS 0
 #endif
 
-#ifdef GPR_MSG_IOVLEN_TYPE
-typedef GPR_MSG_IOVLEN_TYPE msg_iovlen_type;
+#ifdef GRPC_MSG_IOVLEN_TYPE
+typedef GRPC_MSG_IOVLEN_TYPE msg_iovlen_type;
 #else
 typedef size_t msg_iovlen_type;
 #endif
diff --git a/src/core/lib/iomgr/tcp_server.h b/src/core/lib/iomgr/tcp_server.h
index 2568d7d836..6eba8c4057 100644
--- a/src/core/lib/iomgr/tcp_server.h
+++ b/src/core/lib/iomgr/tcp_server.h
@@ -38,6 +38,7 @@
 
 #include "src/core/lib/iomgr/closure.h"
 #include "src/core/lib/iomgr/endpoint.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 
 /* Forward decl of grpc_tcp_server */
 typedef struct grpc_tcp_server grpc_tcp_server;
@@ -79,8 +80,9 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *server,
    but not dualstack sockets. */
 /* TODO(ctiller): deprecate this, and make grpc_tcp_server_add_ports to handle
                   all of the multiple socket port matching logic in one place */
-grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
-                                     size_t addr_len, int *out_port);
+grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s,
+                                     const grpc_resolved_address *addr,
+                                     int *out_port);
 
 /* Number of fds at the given port_index, or 0 if port_index is out of
    bounds. */
diff --git a/src/core/lib/iomgr/tcp_server_posix.c b/src/core/lib/iomgr/tcp_server_posix.c
index 648736caa9..b6fc1e4ca2 100644
--- a/src/core/lib/iomgr/tcp_server_posix.c
+++ b/src/core/lib/iomgr/tcp_server_posix.c
@@ -36,9 +36,9 @@
 #define _GNU_SOURCE
 #endif
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/tcp_server.h"
 
@@ -62,6 +62,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
@@ -79,11 +80,7 @@ struct grpc_tcp_listener {
   int fd;
   grpc_fd *emfd;
   grpc_tcp_server *server;
-  union {
-    uint8_t untyped[GRPC_MAX_SOCKADDR_SIZE];
-    struct sockaddr sockaddr;
-  } addr;
-  size_t addr_len;
+  grpc_resolved_address addr;
   int port;
   unsigned port_index;
   unsigned fd_index;
@@ -256,7 +253,7 @@ static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
   if (s->head) {
     grpc_tcp_listener *sp;
     for (sp = s->head; sp; sp = sp->next) {
-      grpc_unlink_if_unix_domain_socket(&sp->addr.sockaddr);
+      grpc_unlink_if_unix_domain_socket(&sp->addr);
       sp->destroyed_closure.cb = destroyed_port;
       sp->destroyed_closure.cb_arg = s;
       grpc_fd_orphan(exec_ctx, sp->emfd, &sp->destroyed_closure, NULL,
@@ -322,11 +319,9 @@ static int get_max_accept_queue_size(void) {
 }
 
 /* Prepare a recently-created socket for listening. */
-static grpc_error *prepare_socket(int fd, const struct sockaddr *addr,
-                                  size_t addr_len, bool so_reuseport,
-                                  int *port) {
-  struct sockaddr_storage sockname_temp;
-  socklen_t sockname_len;
+static grpc_error *prepare_socket(int fd, const grpc_resolved_address *addr,
+                                  bool so_reuseport, int *port) {
+  grpc_resolved_address sockname_temp;
   grpc_error *err = GRPC_ERROR_NONE;
 
   GPR_ASSERT(fd >= 0);
@@ -349,8 +344,8 @@ static grpc_error *prepare_socket(int fd, const struct sockaddr *addr,
   err = grpc_set_socket_no_sigpipe_if_possible(fd);
   if (err != GRPC_ERROR_NONE) goto error;
 
-  GPR_ASSERT(addr_len < ~(socklen_t)0);
-  if (bind(fd, addr, (socklen_t)addr_len) < 0) {
+  GPR_ASSERT(addr->len < ~(socklen_t)0);
+  if (bind(fd, (struct sockaddr *)addr->addr, (socklen_t)addr->len) < 0) {
     err = GRPC_OS_ERROR(errno, "bind");
     goto error;
   }
@@ -360,13 +355,15 @@ static grpc_error *prepare_socket(int fd, const struct sockaddr *addr,
     goto error;
   }
 
-  sockname_len = sizeof(sockname_temp);
-  if (getsockname(fd, (struct sockaddr *)&sockname_temp, &sockname_len) < 0) {
+  sockname_temp.len = sizeof(struct sockaddr_storage);
+
+  if (getsockname(fd, (struct sockaddr *)sockname_temp.addr,
+                  (socklen_t *)&sockname_temp.len) < 0) {
     err = GRPC_OS_ERROR(errno, "getsockname");
     goto error;
   }
 
-  *port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+  *port = grpc_sockaddr_get_port(&sockname_temp);
   return GRPC_ERROR_NONE;
 
 error:
@@ -400,13 +397,13 @@ static void on_read(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *err) {
 
   /* loop until accept4 returns EAGAIN, and then re-arm notification */
   for (;;) {
-    struct sockaddr_storage addr;
-    socklen_t addrlen = sizeof(addr);
+    grpc_resolved_address addr;
     char *addr_str;
     char *name;
+    addr.len = sizeof(struct sockaddr_storage);
     /* Note: If we ever decide to return this address to the user, remember to
        strip off the ::ffff:0.0.0.0/96 prefix first. */
-    int fd = grpc_accept4(sp->fd, (struct sockaddr *)&addr, &addrlen, 1, 1);
+    int fd = grpc_accept4(sp->fd, &addr, 1, 1);
     if (fd < 0) {
       switch (errno) {
         case EINTR:
@@ -422,7 +419,7 @@ static void on_read(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *err) {
 
     grpc_set_socket_no_sigpipe_if_possible(fd);
 
-    addr_str = grpc_sockaddr_to_uri((struct sockaddr *)&addr);
+    addr_str = grpc_sockaddr_to_uri(&addr);
     gpr_asprintf(&name, "tcp-server-connection:%s", addr_str);
 
     if (grpc_tcp_trace) {
@@ -461,19 +458,18 @@ error:
 }
 
 static grpc_error *add_socket_to_server(grpc_tcp_server *s, int fd,
-                                        const struct sockaddr *addr,
-                                        size_t addr_len, unsigned port_index,
-                                        unsigned fd_index,
+                                        const grpc_resolved_address *addr,
+                                        unsigned port_index, unsigned fd_index,
                                         grpc_tcp_listener **listener) {
   grpc_tcp_listener *sp = NULL;
   int port = -1;
   char *addr_str;
   char *name;
 
-  grpc_error *err = prepare_socket(fd, addr, addr_len, s->so_reuseport, &port);
+  grpc_error *err = prepare_socket(fd, addr, s->so_reuseport, &port);
   if (err == GRPC_ERROR_NONE) {
     GPR_ASSERT(port > 0);
-    grpc_sockaddr_to_string(&addr_str, (struct sockaddr *)&addr, 1);
+    grpc_sockaddr_to_string(&addr_str, addr, 1);
     gpr_asprintf(&name, "tcp-server-listener:%s", addr_str);
     gpr_mu_lock(&s->mu);
     s->nports++;
@@ -489,8 +485,7 @@ static grpc_error *add_socket_to_server(grpc_tcp_server *s, int fd,
     sp->server = s;
     sp->fd = fd;
     sp->emfd = grpc_fd_create(fd, name);
-    memcpy(sp->addr.untyped, addr, addr_len);
-    sp->addr_len = addr_len;
+    memcpy(&sp->addr, addr, sizeof(grpc_resolved_address));
     sp->port = port;
     sp->port_index = port_index;
     sp->fd_index = fd_index;
@@ -523,14 +518,13 @@ static grpc_error *clone_port(grpc_tcp_listener *listener, unsigned count) {
     int fd = -1;
     int port = -1;
     grpc_dualstack_mode dsmode;
-    err = grpc_create_dualstack_socket(&listener->addr.sockaddr, SOCK_STREAM, 0,
-                                       &dsmode, &fd);
+    err = grpc_create_dualstack_socket(&listener->addr, SOCK_STREAM, 0, &dsmode,
+                                       &fd);
     if (err != GRPC_ERROR_NONE) return err;
-    err = prepare_socket(fd, &listener->addr.sockaddr, listener->addr_len, true,
-                         &port);
+    err = prepare_socket(fd, &listener->addr, true, &port);
     if (err != GRPC_ERROR_NONE) return err;
     listener->server->nports++;
-    grpc_sockaddr_to_string(&addr_str, &listener->addr.sockaddr, 1);
+    grpc_sockaddr_to_string(&addr_str, &listener->addr, 1);
     gpr_asprintf(&name, "tcp-server-listener:%s/clone-%d", addr_str, i);
     sp = gpr_malloc(sizeof(grpc_tcp_listener));
     sp->next = listener->next;
@@ -543,8 +537,7 @@ static grpc_error *clone_port(grpc_tcp_listener *listener, unsigned count) {
     sp->server = listener->server;
     sp->fd = fd;
     sp->emfd = grpc_fd_create(fd, name);
-    memcpy(sp->addr.untyped, listener->addr.untyped, listener->addr_len);
-    sp->addr_len = listener->addr_len;
+    memcpy(&sp->addr, &listener->addr, sizeof(grpc_resolved_address));
     sp->port = port;
     sp->port_index = listener->port_index;
     sp->fd_index = listener->fd_index + count - i;
@@ -559,19 +552,19 @@ static grpc_error *clone_port(grpc_tcp_listener *listener, unsigned count) {
   return GRPC_ERROR_NONE;
 }
 
-grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
-                                     size_t addr_len, int *out_port) {
+grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s,
+                                     const grpc_resolved_address *addr,
+                                     int *out_port) {
   grpc_tcp_listener *sp;
   grpc_tcp_listener *sp2 = NULL;
   int fd;
   grpc_dualstack_mode dsmode;
-  struct sockaddr_in6 addr6_v4mapped;
-  struct sockaddr_in wild4;
-  struct sockaddr_in6 wild6;
-  struct sockaddr_in addr4_copy;
-  struct sockaddr *allocated_addr = NULL;
-  struct sockaddr_storage sockname_temp;
-  socklen_t sockname_len;
+  grpc_resolved_address addr6_v4mapped;
+  grpc_resolved_address wild4;
+  grpc_resolved_address wild6;
+  grpc_resolved_address addr4_copy;
+  grpc_resolved_address *allocated_addr = NULL;
+  grpc_resolved_address sockname_temp;
   int port;
   unsigned port_index = 0;
   unsigned fd_index = 0;
@@ -579,19 +572,19 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
   if (s->tail != NULL) {
     port_index = s->tail->port_index + 1;
   }
-  grpc_unlink_if_unix_domain_socket((struct sockaddr *)addr);
+  grpc_unlink_if_unix_domain_socket(addr);
 
   /* Check if this is a wildcard port, and if so, try to keep the port the same
      as some previously created listener. */
   if (grpc_sockaddr_get_port(addr) == 0) {
     for (sp = s->head; sp; sp = sp->next) {
-      sockname_len = sizeof(sockname_temp);
-      if (0 == getsockname(sp->fd, (struct sockaddr *)&sockname_temp,
-                           &sockname_len)) {
-        port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+      sockname_temp.len = sizeof(struct sockaddr_storage);
+      if (0 == getsockname(sp->fd, (struct sockaddr *)sockname_temp.addr,
+                           (socklen_t *)&sockname_temp.len)) {
+        port = grpc_sockaddr_get_port(&sockname_temp);
         if (port > 0) {
-          allocated_addr = gpr_malloc(addr_len);
-          memcpy(allocated_addr, addr, addr_len);
+          allocated_addr = gpr_malloc(sizeof(grpc_resolved_address));
+          memcpy(allocated_addr, addr, addr->len);
           grpc_sockaddr_set_port(allocated_addr, port);
           addr = allocated_addr;
           break;
@@ -603,8 +596,7 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
   sp = NULL;
 
   if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
-    addr = (const struct sockaddr *)&addr6_v4mapped;
-    addr_len = sizeof(addr6_v4mapped);
+    addr = &addr6_v4mapped;
   }
 
   /* Treat :: or 0.0.0.0 as a family-agnostic wildcard. */
@@ -612,12 +604,10 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
     grpc_sockaddr_make_wildcards(port, &wild4, &wild6);
 
     /* Try listening on IPv6 first. */
-    addr = (struct sockaddr *)&wild6;
-    addr_len = sizeof(wild6);
+    addr = &wild6;
     errs[0] = grpc_create_dualstack_socket(addr, SOCK_STREAM, 0, &dsmode, &fd);
     if (errs[0] == GRPC_ERROR_NONE) {
-      errs[0] = add_socket_to_server(s, fd, addr, addr_len, port_index,
-                                     fd_index, &sp);
+      errs[0] = add_socket_to_server(s, fd, addr, port_index, fd_index, &sp);
       if (fd >= 0 && dsmode == GRPC_DSMODE_DUALSTACK) {
         goto done;
       }
@@ -626,23 +616,20 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
       }
       /* If we didn't get a dualstack socket, also listen on 0.0.0.0. */
       if (port == 0 && sp != NULL) {
-        grpc_sockaddr_set_port((struct sockaddr *)&wild4, sp->port);
+        grpc_sockaddr_set_port(&wild4, sp->port);
       }
     }
-    addr = (struct sockaddr *)&wild4;
-    addr_len = sizeof(wild4);
+    addr = &wild4;
   }
 
   errs[1] = grpc_create_dualstack_socket(addr, SOCK_STREAM, 0, &dsmode, &fd);
   if (errs[1] == GRPC_ERROR_NONE) {
     if (dsmode == GRPC_DSMODE_IPV4 &&
         grpc_sockaddr_is_v4mapped(addr, &addr4_copy)) {
-      addr = (struct sockaddr *)&addr4_copy;
-      addr_len = sizeof(addr4_copy);
+      addr = &addr4_copy;
     }
     sp2 = sp;
-    errs[1] =
-        add_socket_to_server(s, fd, addr, addr_len, port_index, fd_index, &sp);
+    errs[1] = add_socket_to_server(s, fd, addr, port_index, fd_index, &sp);
     if (sp2 != NULL && sp != NULL) {
       sp2->sibling = sp;
       sp->is_sibling = 1;
@@ -723,7 +710,7 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
   s->pollset_count = pollset_count;
   sp = s->head;
   while (sp != NULL) {
-    if (s->so_reuseport && !grpc_is_unix_socket(&sp->addr.sockaddr) &&
+    if (s->so_reuseport && !grpc_is_unix_socket(&sp->addr) &&
         pollset_count > 1) {
       GPR_ASSERT(GRPC_LOG_IF_ERROR(
           "clone_port", clone_port(sp, (unsigned)(pollset_count - 1))));
diff --git a/src/core/lib/iomgr/tcp_server_uv.c b/src/core/lib/iomgr/tcp_server_uv.c
new file mode 100644
index 0000000000..73e4db3d65
--- /dev/null
+++ b/src/core/lib/iomgr/tcp_server_uv.c
@@ -0,0 +1,365 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/sockaddr.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/iomgr/tcp_server.h"
+#include "src/core/lib/iomgr/tcp_uv.h"
+
+/* one listening port */
+typedef struct grpc_tcp_listener grpc_tcp_listener;
+struct grpc_tcp_listener {
+  uv_tcp_t *handle;
+  grpc_tcp_server *server;
+  unsigned port_index;
+  int port;
+  /* linked list */
+  struct grpc_tcp_listener *next;
+};
+
+struct grpc_tcp_server {
+  gpr_refcount refs;
+
+  /* Called whenever accept() succeeds on a server port. */
+  grpc_tcp_server_cb on_accept_cb;
+  void *on_accept_cb_arg;
+
+  int open_ports;
+
+  /* linked list of server ports */
+  grpc_tcp_listener *head;
+  grpc_tcp_listener *tail;
+
+  /* List of closures passed to shutdown_starting_add(). */
+  grpc_closure_list shutdown_starting;
+
+  /* shutdown callback */
+  grpc_closure *shutdown_complete;
+};
+
+grpc_error *grpc_tcp_server_create(grpc_closure *shutdown_complete,
+                                   const grpc_channel_args *args,
+                                   grpc_tcp_server **server) {
+  grpc_tcp_server *s = gpr_malloc(sizeof(grpc_tcp_server));
+  (void)args;
+  gpr_ref_init(&s->refs, 1);
+  s->on_accept_cb = NULL;
+  s->on_accept_cb_arg = NULL;
+  s->open_ports = 0;
+  s->head = NULL;
+  s->tail = NULL;
+  s->shutdown_starting.head = NULL;
+  s->shutdown_starting.tail = NULL;
+  s->shutdown_complete = shutdown_complete;
+  *server = s;
+  return GRPC_ERROR_NONE;
+}
+
+grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s) {
+  gpr_ref(&s->refs);
+  return s;
+}
+
+void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
+                                           grpc_closure *shutdown_starting) {
+  grpc_closure_list_append(&s->shutdown_starting, shutdown_starting,
+                           GRPC_ERROR_NONE);
+}
+
+static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  if (s->shutdown_complete != NULL) {
+    grpc_exec_ctx_sched(exec_ctx, s->shutdown_complete, GRPC_ERROR_NONE, NULL);
+  }
+
+  while (s->head) {
+    grpc_tcp_listener *sp = s->head;
+    s->head = sp->next;
+    sp->next = NULL;
+    gpr_free(sp->handle);
+    gpr_free(sp);
+  }
+  gpr_free(s);
+}
+
+static void handle_close_callback(uv_handle_t *handle) {
+  grpc_tcp_listener *sp = (grpc_tcp_listener *)handle->data;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  sp->server->open_ports--;
+  if (sp->server->open_ports == 0) {
+    finish_shutdown(&exec_ctx, sp->server);
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  int immediately_done = 0;
+  grpc_tcp_listener *sp;
+
+  if (s->open_ports == 0) {
+    immediately_done = 1;
+  }
+  for (sp = s->head; sp; sp = sp->next) {
+    uv_close((uv_handle_t *)sp->handle, handle_close_callback);
+  }
+
+  if (immediately_done) {
+    finish_shutdown(exec_ctx, s);
+  }
+}
+
+void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  if (gpr_unref(&s->refs)) {
+    /* Complete shutdown_starting work before destroying. */
+    grpc_exec_ctx local_exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_exec_ctx_enqueue_list(&local_exec_ctx, &s->shutdown_starting, NULL);
+    if (exec_ctx == NULL) {
+      grpc_exec_ctx_flush(&local_exec_ctx);
+      tcp_server_destroy(&local_exec_ctx, s);
+      grpc_exec_ctx_finish(&local_exec_ctx);
+    } else {
+      grpc_exec_ctx_finish(&local_exec_ctx);
+      tcp_server_destroy(exec_ctx, s);
+    }
+  }
+}
+
+static void accepted_connection_close_cb(uv_handle_t *handle) {
+  gpr_free(handle);
+}
+
+static void on_connect(uv_stream_t *server, int status) {
+  grpc_tcp_listener *sp = (grpc_tcp_listener *)server->data;
+  grpc_tcp_server_acceptor acceptor = {sp->server, sp->port_index, 0};
+  uv_tcp_t *client;
+  grpc_endpoint *ep = NULL;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_resolved_address peer_name;
+  char *peer_name_string;
+  int err;
+
+  if (status < 0) {
+    gpr_log(GPR_INFO, "Skipping on_accept due to error: %s",
+            uv_strerror(status));
+    return;
+  }
+  client = gpr_malloc(sizeof(uv_tcp_t));
+  uv_tcp_init(uv_default_loop(), client);
+  // UV documentation says this is guaranteed to succeed
+  uv_accept((uv_stream_t *)server, (uv_stream_t *)client);
+  // If the server has not been started, we discard incoming connections
+  if (sp->server->on_accept_cb == NULL) {
+    uv_close((uv_handle_t *)client, accepted_connection_close_cb);
+  } else {
+    peer_name_string = NULL;
+    memset(&peer_name, 0, sizeof(grpc_resolved_address));
+    peer_name.len = sizeof(struct sockaddr_storage);
+    err = uv_tcp_getpeername(client, (struct sockaddr *)&peer_name.addr,
+                             (int *)&peer_name.len);
+    if (err == 0) {
+      peer_name_string = grpc_sockaddr_to_uri(&peer_name);
+    } else {
+      gpr_log(GPR_INFO, "uv_tcp_getpeername error: %s", uv_strerror(status));
+    }
+    ep = grpc_tcp_create(client, peer_name_string);
+    sp->server->on_accept_cb(&exec_ctx, sp->server->on_accept_cb_arg, ep, NULL,
+                             &acceptor);
+    grpc_exec_ctx_finish(&exec_ctx);
+  }
+}
+
+static grpc_error *add_socket_to_server(grpc_tcp_server *s, uv_tcp_t *handle,
+                                        const grpc_resolved_address *addr,
+                                        unsigned port_index,
+                                        grpc_tcp_listener **listener) {
+  grpc_tcp_listener *sp = NULL;
+  int port = -1;
+  int status;
+  grpc_error *error;
+  grpc_resolved_address sockname_temp;
+
+  // The last argument to uv_tcp_bind is flags
+  status = uv_tcp_bind(handle, (struct sockaddr *)addr->addr, 0);
+  if (status != 0) {
+    error = GRPC_ERROR_CREATE("Failed to bind to port");
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR, uv_strerror(status));
+    return error;
+  }
+
+  status = uv_listen((uv_stream_t *)handle, SOMAXCONN, on_connect);
+  if (status != 0) {
+    error = GRPC_ERROR_CREATE("Failed to listen to port");
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR, uv_strerror(status));
+    return error;
+  }
+
+  sockname_temp.len = (int)sizeof(struct sockaddr_storage);
+  status = uv_tcp_getsockname(handle, (struct sockaddr *)&sockname_temp.addr,
+                              (int *)&sockname_temp.len);
+  if (status != 0) {
+    error = GRPC_ERROR_CREATE("getsockname failed");
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR, uv_strerror(status));
+    return error;
+  }
+
+  port = grpc_sockaddr_get_port(&sockname_temp);
+
+  GPR_ASSERT(port >= 0);
+  GPR_ASSERT(!s->on_accept_cb && "must add ports before starting server");
+  sp = gpr_malloc(sizeof(grpc_tcp_listener));
+  sp->next = NULL;
+  if (s->head == NULL) {
+    s->head = sp;
+  } else {
+    s->tail->next = sp;
+  }
+  s->tail = sp;
+  sp->server = s;
+  sp->handle = handle;
+  sp->port = port;
+  sp->port_index = port_index;
+  handle->data = sp;
+  s->open_ports++;
+  GPR_ASSERT(sp->handle);
+  *listener = sp;
+
+  return GRPC_ERROR_NONE;
+}
+
+grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s,
+                                     const grpc_resolved_address *addr,
+                                     int *port) {
+  // This function is mostly copied from tcp_server_windows.c
+  grpc_tcp_listener *sp = NULL;
+  uv_tcp_t *handle;
+  grpc_resolved_address addr6_v4mapped;
+  grpc_resolved_address wildcard;
+  grpc_resolved_address *allocated_addr = NULL;
+  grpc_resolved_address sockname_temp;
+  unsigned port_index = 0;
+  int status;
+  grpc_error *error = GRPC_ERROR_NONE;
+
+  if (s->tail != NULL) {
+    port_index = s->tail->port_index + 1;
+  }
+
+  /* Check if this is a wildcard port, and if so, try to keep the port the same
+     as some previously created listener. */
+  if (grpc_sockaddr_get_port(addr) == 0) {
+    for (sp = s->head; sp; sp = sp->next) {
+      sockname_temp.len = sizeof(struct sockaddr_storage);
+      if (0 == uv_tcp_getsockname(sp->handle,
+                                  (struct sockaddr *)&sockname_temp.addr,
+                                  (int *)&sockname_temp.len)) {
+        *port = grpc_sockaddr_get_port(&sockname_temp);
+        if (*port > 0) {
+          allocated_addr = gpr_malloc(sizeof(grpc_resolved_address));
+          memcpy(allocated_addr, addr, sizeof(grpc_resolved_address));
+          grpc_sockaddr_set_port(allocated_addr, *port);
+          addr = allocated_addr;
+          break;
+        }
+      }
+    }
+  }
+
+  if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
+    addr = &addr6_v4mapped;
+  }
+
+  /* Treat :: or 0.0.0.0 as a family-agnostic wildcard. */
+  if (grpc_sockaddr_is_wildcard(addr, port)) {
+    grpc_sockaddr_make_wildcard6(*port, &wildcard);
+
+    addr = &wildcard;
+  }
+
+  handle = gpr_malloc(sizeof(uv_tcp_t));
+  status = uv_tcp_init(uv_default_loop(), handle);
+  if (status == 0) {
+    error = add_socket_to_server(s, handle, addr, port_index, &sp);
+  } else {
+    error = GRPC_ERROR_CREATE("Failed to initialize UV tcp handle");
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR, uv_strerror(status));
+  }
+
+  gpr_free(allocated_addr);
+
+  if (error != GRPC_ERROR_NONE) {
+    grpc_error *error_out = GRPC_ERROR_CREATE_REFERENCING(
+        "Failed to add port to server", &error, 1);
+    GRPC_ERROR_UNREF(error);
+    error = error_out;
+    *port = -1;
+  } else {
+    GPR_ASSERT(sp != NULL);
+    *port = sp->port;
+  }
+  return error;
+}
+
+void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *server,
+                           grpc_pollset **pollsets, size_t pollset_count,
+                           grpc_tcp_server_cb on_accept_cb, void *cb_arg) {
+  grpc_tcp_listener *sp;
+  (void)pollsets;
+  (void)pollset_count;
+  GPR_ASSERT(on_accept_cb);
+  GPR_ASSERT(!server->on_accept_cb);
+  server->on_accept_cb = on_accept_cb;
+  server->on_accept_cb_arg = cb_arg;
+  for (sp = server->head; sp; sp = sp->next) {
+    GPR_ASSERT(uv_listen((uv_stream_t *)sp->handle, SOMAXCONN, on_connect) ==
+               0);
+  }
+}
+
+void grpc_tcp_server_shutdown_listeners(grpc_exec_ctx *exec_ctx,
+                                        grpc_tcp_server *s) {}
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index 4ff05601fa..ad6769a6ba 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -31,13 +31,13 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
-#include <io.h>
+#include "src/core/lib/iomgr/sockaddr.h"
 
-#include "src/core/lib/iomgr/sockaddr_utils.h"
+#include <io.h>
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
@@ -48,6 +48,8 @@
 
 #include "src/core/lib/iomgr/iocp_windows.h"
 #include "src/core/lib/iomgr/pollset_windows.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/socket_windows.h"
 #include "src/core/lib/iomgr/tcp_server.h"
 #include "src/core/lib/iomgr/tcp_windows.h"
@@ -183,10 +185,10 @@ void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
 }
 
 /* Prepare (bind) a recently-created socket for listening. */
-static grpc_error *prepare_socket(SOCKET sock, const struct sockaddr *addr,
-                                  size_t addr_len, int *port) {
-  struct sockaddr_storage sockname_temp;
-  socklen_t sockname_len;
+static grpc_error *prepare_socket(SOCKET sock,
+                                  const grpc_resolved_address *addr,
+                                  int *port) {
+  grpc_resolved_address sockname_temp;
   grpc_error *error = GRPC_ERROR_NONE;
 
   error = grpc_tcp_prepare_socket(sock);
@@ -194,7 +196,8 @@ static grpc_error *prepare_socket(SOCKET sock, const struct sockaddr *addr,
     goto failure;
   }
 
-  if (bind(sock, addr, (int)addr_len) == SOCKET_ERROR) {
+  if (bind(sock, (const struct sockaddr *)addr->addr, (int)addr->len) ==
+      SOCKET_ERROR) {
     error = GRPC_WSA_ERROR(WSAGetLastError(), "bind");
     goto failure;
   }
@@ -204,14 +207,14 @@ static grpc_error *prepare_socket(SOCKET sock, const struct sockaddr *addr,
     goto failure;
   }
 
-  sockname_len = sizeof(sockname_temp);
-  if (getsockname(sock, (struct sockaddr *)&sockname_temp, &sockname_len) ==
-      SOCKET_ERROR) {
+  sockname_temp.len = sizeof(struct sockaddr_storage);
+  if (getsockname(sock, (struct sockaddr *)sockname_temp.addr,
+                  &sockname_temp.len) == SOCKET_ERROR) {
     error = GRPC_WSA_ERROR(WSAGetLastError(), "getsockname");
     goto failure;
   }
 
-  *port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+  *port = grpc_sockaddr_get_port(&sockname_temp);
   return GRPC_ERROR_NONE;
 
 failure:
@@ -307,15 +310,16 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
   SOCKET sock = sp->new_socket;
   grpc_winsocket_callback_info *info = &sp->socket->read_info;
   grpc_endpoint *ep = NULL;
-  struct sockaddr_storage peer_name;
+  grpc_resolved_address peer_name;
   char *peer_name_string;
   char *fd_name;
-  int peer_name_len = sizeof(peer_name);
   DWORD transfered_bytes;
   DWORD flags;
   BOOL wsa_success;
   int err;
 
+  peer_name.len = sizeof(struct sockaddr_storage);
+
   /* The general mechanism for shutting down is to queue abortion calls. While
      this is necessary in the read/write case, it's useless for the accept
      case. We only need to adjust the pending callback count */
@@ -353,9 +357,10 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
         gpr_log(GPR_ERROR, "setsockopt error: %s", utf8_message);
         gpr_free(utf8_message);
       }
-      err = getpeername(sock, (struct sockaddr *)&peer_name, &peer_name_len);
+      err =
+          getpeername(sock, (struct sockaddr *)peer_name.addr, &peer_name.len);
       if (!err) {
-        peer_name_string = grpc_sockaddr_to_uri((struct sockaddr *)&peer_name);
+        peer_name_string = grpc_sockaddr_to_uri(&peer_name);
       } else {
         char *utf8_message = gpr_format_message(WSAGetLastError());
         gpr_log(GPR_ERROR, "getpeername error: %s", utf8_message);
@@ -385,8 +390,8 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
 }
 
 static grpc_error *add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
-                                        const struct sockaddr *addr,
-                                        size_t addr_len, unsigned port_index,
+                                        const grpc_resolved_address *addr,
+                                        unsigned port_index,
                                         grpc_tcp_listener **listener) {
   grpc_tcp_listener *sp = NULL;
   int port = -1;
@@ -410,7 +415,7 @@ static grpc_error *add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
     return NULL;
   }
 
-  error = prepare_socket(sock, addr, addr_len, &port);
+  error = prepare_socket(sock, addr, &port);
   if (error != GRPC_ERROR_NONE) {
     return error;
   }
@@ -441,15 +446,15 @@ static grpc_error *add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
   return GRPC_ERROR_NONE;
 }
 
-grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
-                                     size_t addr_len, int *port) {
+grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s,
+                                     const grpc_resolved_address *addr,
+                                     int *port) {
   grpc_tcp_listener *sp = NULL;
   SOCKET sock;
-  struct sockaddr_in6 addr6_v4mapped;
-  struct sockaddr_in6 wildcard;
-  struct sockaddr *allocated_addr = NULL;
-  struct sockaddr_storage sockname_temp;
-  socklen_t sockname_len;
+  grpc_resolved_address addr6_v4mapped;
+  grpc_resolved_address wildcard;
+  grpc_resolved_address *allocated_addr = NULL;
+  grpc_resolved_address sockname_temp;
   unsigned port_index = 0;
   grpc_error *error = GRPC_ERROR_NONE;
 
@@ -461,13 +466,14 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
      as some previously created listener. */
   if (grpc_sockaddr_get_port(addr) == 0) {
     for (sp = s->head; sp; sp = sp->next) {
-      sockname_len = sizeof(sockname_temp);
+      sockname_temp.len = sizeof(struct sockaddr_storage);
       if (0 == getsockname(sp->socket->socket,
-                           (struct sockaddr *)&sockname_temp, &sockname_len)) {
-        *port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+                           (struct sockaddr *)sockname_temp.addr,
+                           &sockname_temp.len)) {
+        *port = grpc_sockaddr_get_port(&sockname_temp);
         if (*port > 0) {
-          allocated_addr = gpr_malloc(addr_len);
-          memcpy(allocated_addr, addr, addr_len);
+          allocated_addr = gpr_malloc(sizeof(grpc_resolved_address));
+          memcpy(allocated_addr, addr, sizeof(grpc_resolved_address));
           grpc_sockaddr_set_port(allocated_addr, *port);
           addr = allocated_addr;
           break;
@@ -477,16 +483,14 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
   }
 
   if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
-    addr = (const struct sockaddr *)&addr6_v4mapped;
-    addr_len = sizeof(addr6_v4mapped);
+    addr = &addr6_v4mapped;
   }
 
   /* Treat :: or 0.0.0.0 as a family-agnostic wildcard. */
   if (grpc_sockaddr_is_wildcard(addr, port)) {
     grpc_sockaddr_make_wildcard6(*port, &wildcard);
 
-    addr = (struct sockaddr *)&wildcard;
-    addr_len = sizeof(wildcard);
+    addr = &wildcard;
   }
 
   sock = WSASocket(AF_INET6, SOCK_STREAM, IPPROTO_TCP, NULL, 0,
@@ -496,7 +500,7 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
     goto done;
   }
 
-  error = add_socket_to_server(s, sock, addr, addr_len, port_index, &sp);
+  error = add_socket_to_server(s, sock, addr, port_index, &sp);
 
 done:
   gpr_free(allocated_addr);
@@ -535,4 +539,4 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
 void grpc_tcp_server_shutdown_listeners(grpc_exec_ctx *exec_ctx,
                                         grpc_tcp_server *s) {}
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/tcp_uv.c b/src/core/lib/iomgr/tcp_uv.c
new file mode 100644
index 0000000000..3860fe3e9b
--- /dev/null
+++ b/src/core/lib/iomgr/tcp_uv.c
@@ -0,0 +1,338 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include <limits.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/slice_buffer.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/network_status_tracker.h"
+#include "src/core/lib/iomgr/tcp_uv.h"
+#include "src/core/lib/support/string.h"
+
+int grpc_tcp_trace = 0;
+
+typedef struct {
+  grpc_endpoint base;
+  gpr_refcount refcount;
+
+  uv_tcp_t *handle;
+
+  grpc_closure *read_cb;
+  grpc_closure *write_cb;
+
+  gpr_slice read_slice;
+  gpr_slice_buffer *read_slices;
+  gpr_slice_buffer *write_slices;
+  uv_buf_t *write_buffers;
+
+  bool shutting_down;
+  char *peer_string;
+  grpc_pollset *pollset;
+} grpc_tcp;
+
+static void uv_close_callback(uv_handle_t *handle) { gpr_free(handle); }
+
+static void tcp_free(grpc_tcp *tcp) { gpr_free(tcp); }
+
+/*#define GRPC_TCP_REFCOUNT_DEBUG*/
+#ifdef GRPC_TCP_REFCOUNT_DEBUG
+#define TCP_UNREF(tcp, reason) tcp_unref((tcp), (reason), __FILE__, __LINE__)
+#define TCP_REF(tcp, reason) tcp_ref((tcp), (reason), __FILE__, __LINE__)
+static void tcp_unref(grpc_tcp *tcp, const char *reason, const char *file,
+                      int line) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "TCP unref %p : %s %d -> %d", tcp,
+          reason, tcp->refcount.count, tcp->refcount.count - 1);
+  if (gpr_unref(&tcp->refcount)) {
+    tcp_free(tcp);
+  }
+}
+
+static void tcp_ref(grpc_tcp *tcp, const char *reason, const char *file,
+                    int line) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "TCP   ref %p : %s %d -> %d", tcp,
+          reason, tcp->refcount.count, tcp->refcount.count + 1);
+  gpr_ref(&tcp->refcount);
+}
+#else
+#define TCP_UNREF(tcp, reason) tcp_unref((tcp))
+#define TCP_REF(tcp, reason) tcp_ref((tcp))
+static void tcp_unref(grpc_tcp *tcp) {
+  if (gpr_unref(&tcp->refcount)) {
+    tcp_free(tcp);
+  }
+}
+
+static void tcp_ref(grpc_tcp *tcp) { gpr_ref(&tcp->refcount); }
+#endif
+
+static void alloc_uv_buf(uv_handle_t *handle, size_t suggested_size,
+                         uv_buf_t *buf) {
+  grpc_tcp *tcp = handle->data;
+  (void)suggested_size;
+  tcp->read_slice = gpr_slice_malloc(GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
+  buf->base = (char *)GPR_SLICE_START_PTR(tcp->read_slice);
+  buf->len = GPR_SLICE_LENGTH(tcp->read_slice);
+}
+
+static void read_callback(uv_stream_t *stream, ssize_t nread,
+                          const uv_buf_t *buf) {
+  gpr_slice sub;
+  grpc_error *error;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_tcp *tcp = stream->data;
+  grpc_closure *cb = tcp->read_cb;
+  if (nread == 0) {
+    // Nothing happened. Wait for the next callback
+    return;
+  }
+  TCP_UNREF(tcp, "read");
+  tcp->read_cb = NULL;
+  // TODO(murgatroid99): figure out what the return value here means
+  uv_read_stop(stream);
+  if (nread == UV_EOF) {
+    error = GRPC_ERROR_CREATE("EOF");
+  } else if (nread > 0) {
+    // Successful read
+    sub = gpr_slice_sub_no_ref(tcp->read_slice, 0, (size_t)nread);
+    gpr_slice_buffer_add(tcp->read_slices, sub);
+    error = GRPC_ERROR_NONE;
+    if (grpc_tcp_trace) {
+      size_t i;
+      const char *str = grpc_error_string(error);
+      gpr_log(GPR_DEBUG, "read: error=%s", str);
+      grpc_error_free_string(str);
+      for (i = 0; i < tcp->read_slices->count; i++) {
+        char *dump = gpr_dump_slice(tcp->read_slices->slices[i],
+                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
+        gpr_log(GPR_DEBUG, "READ %p (peer=%s): %s", tcp, tcp->peer_string,
+                dump);
+        gpr_free(dump);
+      }
+    }
+  } else {
+    // nread < 0: Error
+    error = GRPC_ERROR_CREATE("TCP Read failed");
+  }
+  grpc_exec_ctx_sched(&exec_ctx, cb, error, NULL);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void uv_endpoint_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                             gpr_slice_buffer *read_slices, grpc_closure *cb) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  int status;
+  grpc_error *error = GRPC_ERROR_NONE;
+  GPR_ASSERT(tcp->read_cb == NULL);
+  tcp->read_cb = cb;
+  tcp->read_slices = read_slices;
+  gpr_slice_buffer_reset_and_unref(read_slices);
+  TCP_REF(tcp, "read");
+  // TODO(murgatroid99): figure out what the return value here means
+  status =
+      uv_read_start((uv_stream_t *)tcp->handle, alloc_uv_buf, read_callback);
+  if (status != 0) {
+    error = GRPC_ERROR_CREATE("TCP Read failed at start");
+    error =
+        grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR, uv_strerror(status));
+    grpc_exec_ctx_sched(exec_ctx, cb, error, NULL);
+  }
+  if (grpc_tcp_trace) {
+    const char *str = grpc_error_string(error);
+    gpr_log(GPR_DEBUG, "Initiating read on %p: error=%s", tcp, str);
+  }
+}
+
+static void write_callback(uv_write_t *req, int status) {
+  grpc_tcp *tcp = req->data;
+  grpc_error *error;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_closure *cb = tcp->write_cb;
+  tcp->write_cb = NULL;
+  TCP_UNREF(tcp, "write");
+  if (status == 0) {
+    error = GRPC_ERROR_NONE;
+  } else {
+    error = GRPC_ERROR_CREATE("TCP Write failed");
+  }
+  if (grpc_tcp_trace) {
+    const char *str = grpc_error_string(error);
+    gpr_log(GPR_DEBUG, "write complete on %p: error=%s", tcp, str);
+  }
+  gpr_free(tcp->write_buffers);
+  gpr_free(req);
+  grpc_exec_ctx_sched(&exec_ctx, cb, error, NULL);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void uv_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                              gpr_slice_buffer *write_slices,
+                              grpc_closure *cb) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  uv_buf_t *buffers;
+  unsigned int buffer_count;
+  unsigned int i;
+  gpr_slice *slice;
+  uv_write_t *write_req;
+
+  if (grpc_tcp_trace) {
+    size_t j;
+
+    for (j = 0; j < write_slices->count; j++) {
+      char *data = gpr_dump_slice(write_slices->slices[j],
+                                  GPR_DUMP_HEX | GPR_DUMP_ASCII);
+      gpr_log(GPR_DEBUG, "WRITE %p (peer=%s): %s", tcp, tcp->peer_string, data);
+      gpr_free(data);
+    }
+  }
+
+  if (tcp->shutting_down) {
+    grpc_exec_ctx_sched(exec_ctx, cb,
+                        GRPC_ERROR_CREATE("TCP socket is shutting down"), NULL);
+    return;
+  }
+
+  GPR_ASSERT(tcp->write_cb == NULL);
+  tcp->write_slices = write_slices;
+  GPR_ASSERT(tcp->write_slices->count <= UINT_MAX);
+  if (tcp->write_slices->count == 0) {
+    // No slices means we don't have to do anything,
+    // and libuv doesn't like empty writes
+    grpc_exec_ctx_sched(exec_ctx, cb, GRPC_ERROR_NONE, NULL);
+    return;
+  }
+
+  tcp->write_cb = cb;
+  buffer_count = (unsigned int)tcp->write_slices->count;
+  buffers = gpr_malloc(sizeof(uv_buf_t) * buffer_count);
+  for (i = 0; i < buffer_count; i++) {
+    slice = &tcp->write_slices->slices[i];
+    buffers[i].base = (char *)GPR_SLICE_START_PTR(*slice);
+    buffers[i].len = GPR_SLICE_LENGTH(*slice);
+  }
+  write_req = gpr_malloc(sizeof(uv_write_t));
+  write_req->data = tcp;
+  TCP_REF(tcp, "write");
+  // TODO(murgatroid99): figure out what the return value here means
+  uv_write(write_req, (uv_stream_t *)tcp->handle, buffers, buffer_count,
+           write_callback);
+}
+
+static void uv_add_to_pollset(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                              grpc_pollset *pollset) {
+  // No-op. We're ignoring pollsets currently
+  (void)exec_ctx;
+  (void)ep;
+  (void)pollset;
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  tcp->pollset = pollset;
+}
+
+static void uv_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                                  grpc_pollset_set *pollset) {
+  // No-op. We're ignoring pollsets currently
+  (void)exec_ctx;
+  (void)ep;
+  (void)pollset;
+}
+
+static void shutdown_callback(uv_shutdown_t *req, int status) { gpr_free(req); }
+
+static void uv_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  if (!tcp->shutting_down) {
+    tcp->shutting_down = true;
+    uv_shutdown_t *req = gpr_malloc(sizeof(uv_shutdown_t));
+    uv_shutdown(req, (uv_stream_t *)tcp->handle, shutdown_callback);
+  }
+}
+
+static void uv_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+  grpc_network_status_unregister_endpoint(ep);
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  uv_close((uv_handle_t *)tcp->handle, uv_close_callback);
+  TCP_UNREF(tcp, "destroy");
+}
+
+static char *uv_get_peer(grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  return gpr_strdup(tcp->peer_string);
+}
+
+static grpc_workqueue *uv_get_workqueue(grpc_endpoint *ep) { return NULL; }
+
+static grpc_endpoint_vtable vtable = {uv_endpoint_read,
+                                      uv_endpoint_write,
+                                      uv_get_workqueue,
+                                      uv_add_to_pollset,
+                                      uv_add_to_pollset_set,
+                                      uv_endpoint_shutdown,
+                                      uv_destroy,
+                                      uv_get_peer};
+
+grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle, char *peer_string) {
+  grpc_tcp *tcp = (grpc_tcp *)gpr_malloc(sizeof(grpc_tcp));
+
+  if (grpc_tcp_trace) {
+    gpr_log(GPR_DEBUG, "Creating TCP endpoint %p", tcp);
+  }
+
+  /* Disable Nagle's Algorithm */
+  uv_tcp_nodelay(handle, 1);
+
+  memset(tcp, 0, sizeof(grpc_tcp));
+  tcp->base.vtable = &vtable;
+  tcp->handle = handle;
+  handle->data = tcp;
+  gpr_ref_init(&tcp->refcount, 1);
+  tcp->peer_string = gpr_strdup(peer_string);
+  tcp->shutting_down = false;
+  /* Tell network status tracking code about the new endpoint */
+  grpc_network_status_register_endpoint(&tcp->base);
+
+#ifndef GRPC_UV_TCP_HOLD_LOOP
+  uv_unref((uv_handle_t *)handle);
+#endif
+
+  return &tcp->base;
+}
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/tcp_uv.h b/src/core/lib/iomgr/tcp_uv.h
new file mode 100644
index 0000000000..eed41151ea
--- /dev/null
+++ b/src/core/lib/iomgr/tcp_uv.h
@@ -0,0 +1,57 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_TCP_UV_H
+#define GRPC_CORE_LIB_IOMGR_TCP_UV_H
+/*
+   Low level TCP "bottom half" implementation, for use by transports built on
+   top of a TCP connection.
+
+   Note that this file does not (yet) include APIs for creating the socket in
+   the first place.
+
+   All calls passing slice transfer ownership of a slice refcount unless
+   otherwise specified.
+*/
+
+#include "src/core/lib/iomgr/endpoint.h"
+
+#include <uv.h>
+
+extern int grpc_tcp_trace;
+
+#define GRPC_TCP_DEFAULT_READ_SLICE_SIZE 8192
+
+grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle, char *peer_string);
+
+#endif /* GRPC_CORE_LIB_IOMGR_TCP_UV_H */
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index 448a72671c..a5f508a2c3 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <limits.h>
 
@@ -417,4 +417,4 @@ grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket, char *peer_string) {
   return &tcp->base;
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/timer.h b/src/core/lib/iomgr/timer.h
index 5a9a177963..20fe98c4a7 100644
--- a/src/core/lib/iomgr/timer.h
+++ b/src/core/lib/iomgr/timer.h
@@ -34,19 +34,20 @@
 #ifndef GRPC_CORE_LIB_IOMGR_TIMER_H
 #define GRPC_CORE_LIB_IOMGR_TIMER_H
 
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+#include "src/core/lib/iomgr/timer_uv.h"
+#else
+#include "src/core/lib/iomgr/timer_generic.h"
+#endif /* GRPC_UV */
+
 #include <grpc/support/port_platform.h>
 #include <grpc/support/time.h>
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/iomgr.h"
 
-typedef struct grpc_timer {
-  gpr_timespec deadline;
-  uint32_t heap_index; /* INVALID_HEAP_INDEX if not in heap */
-  int triggered;
-  struct grpc_timer *next;
-  struct grpc_timer *prev;
-  grpc_closure closure;
-} grpc_timer;
+typedef struct grpc_timer grpc_timer;
 
 /* Initialize *timer. When expired or canceled, timer_cb will be called with
    *timer_cb_arg and error set to indicate if it expired (GRPC_ERROR_NONE) or
diff --git a/src/core/lib/iomgr/timer.c b/src/core/lib/iomgr/timer_generic.c
index 9975fa1671..00058f9d86 100644
--- a/src/core/lib/iomgr/timer.c
+++ b/src/core/lib/iomgr/timer_generic.c
@@ -31,6 +31,10 @@
  *
  */
 
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_TIMER_USE_GENERIC
+
 #include "src/core/lib/iomgr/timer.h"
 
 #include <grpc/support/log.h>
@@ -382,3 +386,5 @@ bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
           ? GRPC_ERROR_NONE
           : GRPC_ERROR_CREATE("Shutting down timer system"));
 }
+
+#endif /* GRPC_TIMER_USE_GENERIC */
diff --git a/src/core/lib/iomgr/timer_generic.h b/src/core/lib/iomgr/timer_generic.h
new file mode 100644
index 0000000000..e4494adb5f
--- /dev/null
+++ b/src/core/lib/iomgr/timer_generic.h
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_TIMER_GENERIC_H
+#define GRPC_CORE_LIB_IOMGR_TIMER_GENERIC_H
+
+#include <grpc/support/time.h>
+#include "src/core/lib/iomgr/exec_ctx.h"
+
+struct grpc_timer {
+  gpr_timespec deadline;
+  uint32_t heap_index; /* INVALID_HEAP_INDEX if not in heap */
+  int triggered;
+  struct grpc_timer *next;
+  struct grpc_timer *prev;
+  grpc_closure closure;
+};
+
+#endif /* GRPC_CORE_LIB_IOMGR_TIMER_GENERIC_H */
diff --git a/src/core/lib/iomgr/timer_heap.c b/src/core/lib/iomgr/timer_heap.c
index 2ad9bb9cd2..f736d335e6 100644
--- a/src/core/lib/iomgr/timer_heap.c
+++ b/src/core/lib/iomgr/timer_heap.c
@@ -31,6 +31,10 @@
  *
  */
 
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_TIMER_USE_GENERIC
+
 #include "src/core/lib/iomgr/timer_heap.h"
 
 #include <string.h>
@@ -144,3 +148,5 @@ grpc_timer *grpc_timer_heap_top(grpc_timer_heap *heap) {
 void grpc_timer_heap_pop(grpc_timer_heap *heap) {
   grpc_timer_heap_remove(heap, grpc_timer_heap_top(heap));
 }
+
+#endif /* GRPC_TIMER_USE_GENERIC */
diff --git a/src/core/lib/iomgr/timer_uv.c b/src/core/lib/iomgr/timer_uv.c
new file mode 100644
index 0000000000..cfcb89268b
--- /dev/null
+++ b/src/core/lib/iomgr/timer_uv.c
@@ -0,0 +1,99 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#if GRPC_UV
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/iomgr/timer.h"
+
+#include <uv.h>
+
+static void timer_close_callback(uv_handle_t *handle) { gpr_free(handle); }
+
+static void stop_uv_timer(uv_timer_t *handle) {
+  uv_timer_stop(handle);
+  uv_unref((uv_handle_t *)handle);
+  uv_close((uv_handle_t *)handle, timer_close_callback);
+}
+
+void run_expired_timer(uv_timer_t *handle) {
+  grpc_timer *timer = (grpc_timer *)handle->data;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GPR_ASSERT(!timer->triggered);
+  timer->triggered = 1;
+  grpc_exec_ctx_sched(&exec_ctx, &timer->closure, GRPC_ERROR_NONE, NULL);
+  stop_uv_timer(handle);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer,
+                     gpr_timespec deadline, grpc_iomgr_cb_func timer_cb,
+                     void *timer_cb_arg, gpr_timespec now) {
+  uint64_t timeout;
+  uv_timer_t *uv_timer;
+  grpc_closure_init(&timer->closure, timer_cb, timer_cb_arg);
+  if (gpr_time_cmp(deadline, now) <= 0) {
+    timer->triggered = 1;
+    grpc_exec_ctx_sched(exec_ctx, &timer->closure, GRPC_ERROR_NONE, NULL);
+    return;
+  }
+  timer->triggered = 0;
+  timeout = (uint64_t)gpr_time_to_millis(gpr_time_sub(deadline, now));
+  uv_timer = gpr_malloc(sizeof(uv_timer_t));
+  uv_timer_init(uv_default_loop(), uv_timer);
+  uv_timer->data = timer;
+  timer->uv_timer = uv_timer;
+  uv_timer_start(uv_timer, run_expired_timer, timeout, 0);
+}
+
+void grpc_timer_cancel(grpc_exec_ctx *exec_ctx, grpc_timer *timer) {
+  if (!timer->triggered) {
+    timer->triggered = 1;
+    grpc_exec_ctx_sched(exec_ctx, &timer->closure, GRPC_ERROR_CANCELLED, NULL);
+    stop_uv_timer((uv_timer_t *)timer->uv_timer);
+  }
+}
+
+bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
+                      gpr_timespec *next) {
+  return false;
+}
+
+void grpc_timer_list_init(gpr_timespec now) {}
+void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx) {}
+
+#endif /* GRPC_UV */
diff --git a/src/core/lib/iomgr/timer_uv.h b/src/core/lib/iomgr/timer_uv.h
new file mode 100644
index 0000000000..3de383ebd5
--- /dev/null
+++ b/src/core/lib/iomgr/timer_uv.h
@@ -0,0 +1,47 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_TIMER_UV_H
+#define GRPC_CORE_LIB_IOMGR_TIMER_UV_H
+
+#include "src/core/lib/iomgr/exec_ctx.h"
+
+struct grpc_timer {
+  grpc_closure closure;
+  /* This is actually a uv_timer_t*, but we want to keep platform-specific
+     types out of headers */
+  void *uv_timer;
+  int triggered;
+};
+
+#endif /* GRPC_CORE_LIB_IOMGR_TIMER_UV_H */
diff --git a/src/core/lib/iomgr/udp_server.c b/src/core/lib/iomgr/udp_server.c
index edf7b133e9..fd0c7a0f9d 100644
--- a/src/core/lib/iomgr/udp_server.c
+++ b/src/core/lib/iomgr/udp_server.c
@@ -36,9 +36,9 @@
 #define _GNU_SOURCE
 #endif
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/udp_server.h"
 
@@ -62,32 +62,30 @@
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
+#include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/support/string.h"
 
-#define INIT_PORT_CAP 2
-
 /* one listening port */
-typedef struct {
+typedef struct grpc_udp_listener grpc_udp_listener;
+struct grpc_udp_listener {
   int fd;
   grpc_fd *emfd;
   grpc_udp_server *server;
-  union {
-    uint8_t untyped[GRPC_MAX_SOCKADDR_SIZE];
-    struct sockaddr sockaddr;
-  } addr;
-  size_t addr_len;
+  grpc_resolved_address addr;
   grpc_closure read_closure;
   grpc_closure destroyed_closure;
   grpc_udp_server_read_cb read_cb;
   grpc_udp_server_orphan_cb orphan_cb;
-} server_port;
+
+  struct grpc_udp_listener *next;
+};
 
 /* the overall server */
 struct grpc_udp_server {
   gpr_mu mu;
-  gpr_cv cv;
 
   /* active port count: how many ports are actually still listening */
   size_t active_ports;
@@ -97,10 +95,10 @@ struct grpc_udp_server {
   /* is this server shutting down? (boolean) */
   int shutdown;
 
-  /* all listening ports */
-  server_port *ports;
-  size_t nports;
-  size_t port_capacity;
+  /* linked list of server ports */
+  grpc_udp_listener *head;
+  grpc_udp_listener *tail;
+  unsigned nports;
 
   /* shutdown callback */
   grpc_closure *shutdown_complete;
@@ -116,24 +114,29 @@ struct grpc_udp_server {
 grpc_udp_server *grpc_udp_server_create(void) {
   grpc_udp_server *s = gpr_malloc(sizeof(grpc_udp_server));
   gpr_mu_init(&s->mu);
-  gpr_cv_init(&s->cv);
   s->active_ports = 0;
   s->destroyed_ports = 0;
   s->shutdown = 0;
-  s->ports = gpr_malloc(sizeof(server_port) * INIT_PORT_CAP);
+  s->head = NULL;
+  s->tail = NULL;
   s->nports = 0;
-  s->port_capacity = INIT_PORT_CAP;
 
   return s;
 }
 
 static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_udp_server *s) {
-  grpc_exec_ctx_sched(exec_ctx, s->shutdown_complete, GRPC_ERROR_NONE, NULL);
+  if (s->shutdown_complete != NULL) {
+    grpc_exec_ctx_sched(exec_ctx, s->shutdown_complete, GRPC_ERROR_NONE, NULL);
+  }
 
   gpr_mu_destroy(&s->mu);
-  gpr_cv_destroy(&s->cv);
 
-  gpr_free(s->ports);
+  while (s->head) {
+    grpc_udp_listener *sp = s->head;
+    s->head = sp->next;
+    gpr_free(sp);
+  }
+
   gpr_free(s);
 }
 
@@ -154,8 +157,6 @@ static void destroyed_port(grpc_exec_ctx *exec_ctx, void *server,
    events will be received on them - at this point it's safe to destroy
    things */
 static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_udp_server *s) {
-  size_t i;
-
   /* delete ALL the things */
   gpr_mu_lock(&s->mu);
 
@@ -164,9 +165,11 @@ static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_udp_server *s) {
     return;
   }
 
-  if (s->nports) {
-    for (i = 0; i < s->nports; i++) {
-      server_port *sp = &s->ports[i];
+  if (s->head) {
+    grpc_udp_listener *sp;
+    for (sp = s->head; sp; sp = sp->next) {
+      grpc_unlink_if_unix_domain_socket(&sp->addr);
+
       sp->destroyed_closure.cb = destroyed_port;
       sp->destroyed_closure.cb_arg = s;
 
@@ -187,7 +190,7 @@ static void deactivated_all_ports(grpc_exec_ctx *exec_ctx, grpc_udp_server *s) {
 
 void grpc_udp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_udp_server *s,
                              grpc_closure *on_done) {
-  size_t i;
+  grpc_udp_listener *sp;
   gpr_mu_lock(&s->mu);
 
   GPR_ASSERT(!s->shutdown);
@@ -197,14 +200,10 @@ void grpc_udp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_udp_server *s,
 
   /* shutdown all fd's */
   if (s->active_ports) {
-    for (i = 0; i < s->nports; i++) {
-      server_port *sp = &s->ports[i];
-      /* Call the orphan_cb to signal that the FD is about to be closed and
-       * should no longer be used. */
+    for (sp = s->head; sp; sp = sp->next) {
       GPR_ASSERT(sp->orphan_cb);
       sp->orphan_cb(sp->emfd);
-
-      grpc_fd_shutdown(exec_ctx, s->ports[i].emfd);
+      grpc_fd_shutdown(exec_ctx, sp->emfd);
     }
     gpr_mu_unlock(&s->mu);
   } else {
@@ -214,10 +213,9 @@ void grpc_udp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_udp_server *s,
 }
 
 /* Prepare a recently-created socket for listening. */
-static int prepare_socket(int fd, const struct sockaddr *addr,
-                          size_t addr_len) {
-  struct sockaddr_storage sockname_temp;
-  socklen_t sockname_len;
+static int prepare_socket(int fd, const grpc_resolved_address *addr) {
+  grpc_resolved_address sockname_temp;
+  struct sockaddr *addr_ptr = (struct sockaddr *)addr->addr;
   /* Set send/receive socket buffers to 1 MB */
   int buffer_size_bytes = 1024 * 1024;
 
@@ -237,15 +235,15 @@ static int prepare_socket(int fd, const struct sockaddr *addr,
   if (grpc_set_socket_ip_pktinfo_if_possible(fd) != GRPC_ERROR_NONE) {
     gpr_log(GPR_ERROR, "Unable to set ip_pktinfo.");
     goto error;
-  } else if (addr->sa_family == AF_INET6) {
+  } else if (addr_ptr->sa_family == AF_INET6) {
     if (grpc_set_socket_ipv6_recvpktinfo_if_possible(fd) != GRPC_ERROR_NONE) {
       gpr_log(GPR_ERROR, "Unable to set ipv6_recvpktinfo.");
       goto error;
     }
   }
 
-  GPR_ASSERT(addr_len < ~(socklen_t)0);
-  if (bind(fd, addr, (socklen_t)addr_len) < 0) {
+  GPR_ASSERT(addr->len < ~(socklen_t)0);
+  if (bind(fd, (struct sockaddr *)addr, (socklen_t)addr->len) < 0) {
     char *addr_str;
     grpc_sockaddr_to_string(&addr_str, addr, 0);
     gpr_log(GPR_ERROR, "bind addr=%s: %s", addr_str, strerror(errno));
@@ -253,8 +251,10 @@ static int prepare_socket(int fd, const struct sockaddr *addr,
     goto error;
   }
 
-  sockname_len = sizeof(sockname_temp);
-  if (getsockname(fd, (struct sockaddr *)&sockname_temp, &sockname_len) < 0) {
+  sockname_temp.len = sizeof(struct sockaddr_storage);
+
+  if (getsockname(fd, (struct sockaddr *)sockname_temp.addr,
+                  (socklen_t *)&sockname_temp.len) < 0) {
     goto error;
   }
 
@@ -270,7 +270,7 @@ static int prepare_socket(int fd, const struct sockaddr *addr,
     goto error;
   }
 
-  return grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+  return grpc_sockaddr_get_port(&sockname_temp);
 
 error:
   if (fd >= 0) {
@@ -281,10 +281,10 @@ error:
 
 /* event manager callback when reads are ready */
 static void on_read(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
-  server_port *sp = arg;
+  grpc_udp_listener *sp = arg;
 
+  gpr_mu_lock(&sp->server->mu);
   if (error != GRPC_ERROR_NONE) {
-    gpr_mu_lock(&sp->server->mu);
     if (0 == --sp->server->active_ports) {
       gpr_mu_unlock(&sp->server->mu);
       deactivated_all_ports(exec_ctx, sp->server);
@@ -300,34 +300,37 @@ static void on_read(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
 
   /* Re-arm the notification event so we get another chance to read. */
   grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
+  gpr_mu_unlock(&sp->server->mu);
 }
 
 static int add_socket_to_server(grpc_udp_server *s, int fd,
-                                const struct sockaddr *addr, size_t addr_len,
+                                const grpc_resolved_address *addr,
                                 grpc_udp_server_read_cb read_cb,
                                 grpc_udp_server_orphan_cb orphan_cb) {
-  server_port *sp;
+  grpc_udp_listener *sp;
   int port;
   char *addr_str;
   char *name;
 
-  port = prepare_socket(fd, addr, addr_len);
+  port = prepare_socket(fd, addr);
   if (port >= 0) {
-    grpc_sockaddr_to_string(&addr_str, (struct sockaddr *)&addr, 1);
+    grpc_sockaddr_to_string(&addr_str, addr, 1);
     gpr_asprintf(&name, "udp-server-listener:%s", addr_str);
     gpr_free(addr_str);
     gpr_mu_lock(&s->mu);
-    /* append it to the list under a lock */
-    if (s->nports == s->port_capacity) {
-      s->port_capacity *= 2;
-      s->ports = gpr_realloc(s->ports, sizeof(server_port) * s->port_capacity);
+    s->nports++;
+    sp = gpr_malloc(sizeof(grpc_udp_listener));
+    sp->next = NULL;
+    if (s->head == NULL) {
+      s->head = sp;
+    } else {
+      s->tail->next = sp;
     }
-    sp = &s->ports[s->nports++];
+    s->tail = sp;
     sp->server = s;
     sp->fd = fd;
     sp->emfd = grpc_fd_create(fd, name);
-    memcpy(sp->addr.untyped, addr, addr_len);
-    sp->addr_len = addr_len;
+    memcpy(&sp->addr, addr, sizeof(grpc_resolved_address));
     sp->read_cb = read_cb;
     sp->orphan_cb = orphan_cb;
     GPR_ASSERT(sp->emfd);
@@ -338,34 +341,34 @@ static int add_socket_to_server(grpc_udp_server *s, int fd,
   return port;
 }
 
-int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
-                             size_t addr_len, grpc_udp_server_read_cb read_cb,
+int grpc_udp_server_add_port(grpc_udp_server *s,
+                             const grpc_resolved_address *addr,
+                             grpc_udp_server_read_cb read_cb,
                              grpc_udp_server_orphan_cb orphan_cb) {
+  grpc_udp_listener *sp;
   int allocated_port1 = -1;
   int allocated_port2 = -1;
-  unsigned i;
   int fd;
   grpc_dualstack_mode dsmode;
-  struct sockaddr_in6 addr6_v4mapped;
-  struct sockaddr_in wild4;
-  struct sockaddr_in6 wild6;
-  struct sockaddr_in addr4_copy;
-  struct sockaddr *allocated_addr = NULL;
-  struct sockaddr_storage sockname_temp;
-  socklen_t sockname_len;
+  grpc_resolved_address addr6_v4mapped;
+  grpc_resolved_address wild4;
+  grpc_resolved_address wild6;
+  grpc_resolved_address addr4_copy;
+  grpc_resolved_address *allocated_addr = NULL;
+  grpc_resolved_address sockname_temp;
   int port;
 
   /* Check if this is a wildcard port, and if so, try to keep the port the same
      as some previously created listener. */
   if (grpc_sockaddr_get_port(addr) == 0) {
-    for (i = 0; i < s->nports; i++) {
-      sockname_len = sizeof(sockname_temp);
-      if (0 == getsockname(s->ports[i].fd, (struct sockaddr *)&sockname_temp,
-                           &sockname_len)) {
-        port = grpc_sockaddr_get_port((struct sockaddr *)&sockname_temp);
+    for (sp = s->head; sp; sp = sp->next) {
+      sockname_temp.len = sizeof(struct sockaddr_storage);
+      if (0 == getsockname(sp->fd, (struct sockaddr *)sockname_temp.addr,
+                           (socklen_t *)&sockname_temp.len)) {
+        port = grpc_sockaddr_get_port(&sockname_temp);
         if (port > 0) {
-          allocated_addr = gpr_malloc(addr_len);
-          memcpy(allocated_addr, addr, addr_len);
+          allocated_addr = gpr_malloc(sizeof(grpc_resolved_address));
+          memcpy(allocated_addr, addr, sizeof(grpc_resolved_address));
           grpc_sockaddr_set_port(allocated_addr, port);
           addr = allocated_addr;
           break;
@@ -375,8 +378,7 @@ int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
   }
 
   if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
-    addr = (const struct sockaddr *)&addr6_v4mapped;
-    addr_len = sizeof(addr6_v4mapped);
+    addr = &addr6_v4mapped;
   }
 
   /* Treat :: or 0.0.0.0 as a family-agnostic wildcard. */
@@ -384,22 +386,19 @@ int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
     grpc_sockaddr_make_wildcards(port, &wild4, &wild6);
 
     /* Try listening on IPv6 first. */
-    addr = (struct sockaddr *)&wild6;
-    addr_len = sizeof(wild6);
+    addr = &wild6;
     // TODO(rjshade): Test and propagate the returned grpc_error*:
     grpc_create_dualstack_socket(addr, SOCK_DGRAM, IPPROTO_UDP, &dsmode, &fd);
-    allocated_port1 =
-        add_socket_to_server(s, fd, addr, addr_len, read_cb, orphan_cb);
+    allocated_port1 = add_socket_to_server(s, fd, addr, read_cb, orphan_cb);
     if (fd >= 0 && dsmode == GRPC_DSMODE_DUALSTACK) {
       goto done;
     }
 
     /* If we didn't get a dualstack socket, also listen on 0.0.0.0. */
     if (port == 0 && allocated_port1 > 0) {
-      grpc_sockaddr_set_port((struct sockaddr *)&wild4, allocated_port1);
+      grpc_sockaddr_set_port(&wild4, allocated_port1);
     }
-    addr = (struct sockaddr *)&wild4;
-    addr_len = sizeof(wild4);
+    addr = &wild4;
   }
 
   // TODO(rjshade): Test and propagate the returned grpc_error*:
@@ -409,11 +408,9 @@ int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
   }
   if (dsmode == GRPC_DSMODE_IPV4 &&
       grpc_sockaddr_is_v4mapped(addr, &addr4_copy)) {
-    addr = (struct sockaddr *)&addr4_copy;
-    addr_len = sizeof(addr4_copy);
+    addr = &addr4_copy;
   }
-  allocated_port2 =
-      add_socket_to_server(s, fd, addr, addr_len, read_cb, orphan_cb);
+  allocated_port2 = add_socket_to_server(s, fd, addr, read_cb, orphan_cb);
 
 done:
   gpr_free(allocated_addr);
@@ -421,27 +418,40 @@ done:
 }
 
 int grpc_udp_server_get_fd(grpc_udp_server *s, unsigned port_index) {
-  return (port_index < s->nports) ? s->ports[port_index].fd : -1;
+  grpc_udp_listener *sp;
+  if (port_index >= s->nports) {
+    return -1;
+  }
+
+  for (sp = s->head; sp && port_index != 0; sp = sp->next) {
+    --port_index;
+  }
+  return sp->fd;
 }
 
 void grpc_udp_server_start(grpc_exec_ctx *exec_ctx, grpc_udp_server *s,
                            grpc_pollset **pollsets, size_t pollset_count,
                            grpc_server *server) {
-  size_t i, j;
+  size_t i;
   gpr_mu_lock(&s->mu);
+  grpc_udp_listener *sp;
   GPR_ASSERT(s->active_ports == 0);
   s->pollsets = pollsets;
   s->grpc_server = server;
-  for (i = 0; i < s->nports; i++) {
-    for (j = 0; j < pollset_count; j++) {
-      grpc_pollset_add_fd(exec_ctx, pollsets[j], s->ports[i].emfd);
+
+  sp = s->head;
+  while (sp != NULL) {
+    for (i = 0; i < pollset_count; i++) {
+      grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
     }
-    s->ports[i].read_closure.cb = on_read;
-    s->ports[i].read_closure.cb_arg = &s->ports[i];
-    grpc_fd_notify_on_read(exec_ctx, s->ports[i].emfd,
-                           &s->ports[i].read_closure);
+    sp->read_closure.cb = on_read;
+    sp->read_closure.cb_arg = sp;
+    grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
+
     s->active_ports++;
+    sp = sp->next;
   }
+
   gpr_mu_unlock(&s->mu);
 }
 
diff --git a/src/core/lib/iomgr/udp_server.h b/src/core/lib/iomgr/udp_server.h
index 33c5ce11cd..f3c466a031 100644
--- a/src/core/lib/iomgr/udp_server.h
+++ b/src/core/lib/iomgr/udp_server.h
@@ -36,6 +36,7 @@
 
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/ev_posix.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 
 /* Forward decl of struct grpc_server */
 /* This is not typedef'ed to avoid a typedef-redefinition error */
@@ -59,7 +60,7 @@ void grpc_udp_server_start(grpc_exec_ctx *exec_ctx, grpc_udp_server *udp_server,
                            grpc_pollset **pollsets, size_t pollset_count,
                            struct grpc_server *server);
 
-int grpc_udp_server_get_fd(grpc_udp_server *s, unsigned index);
+int grpc_udp_server_get_fd(grpc_udp_server *s, unsigned port_index);
 
 /* Add a port to the server, returning port number on success, or negative
    on failure.
@@ -71,8 +72,9 @@ int grpc_udp_server_get_fd(grpc_udp_server *s, unsigned index);
 
 /* TODO(ctiller): deprecate this, and make grpc_udp_server_add_ports to handle
                   all of the multiple socket port matching logic in one place */
-int grpc_udp_server_add_port(grpc_udp_server *s, const void *addr,
-                             size_t addr_len, grpc_udp_server_read_cb read_cb,
+int grpc_udp_server_add_port(grpc_udp_server *s,
+                             const grpc_resolved_address *addr,
+                             grpc_udp_server_read_cb read_cb,
                              grpc_udp_server_orphan_cb orphan_cb);
 
 void grpc_udp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_udp_server *server,
diff --git a/src/core/lib/iomgr/unix_sockets_posix.c b/src/core/lib/iomgr/unix_sockets_posix.c
index 0e7670e5a5..030acd9811 100644
--- a/src/core/lib/iomgr/unix_sockets_posix.c
+++ b/src/core/lib/iomgr/unix_sockets_posix.c
@@ -30,16 +30,19 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
+#include "src/core/lib/iomgr/port.h"
 
-#include "src/core/lib/iomgr/unix_sockets_posix.h"
+#ifdef GRPC_HAVE_UNIX_SOCKET
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#include "src/core/lib/iomgr/sockaddr.h"
 
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/un.h>
 
+#include "src/core/lib/iomgr/unix_sockets_posix.h"
+
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
@@ -61,15 +64,18 @@ grpc_error *grpc_resolve_unix_domain_address(const char *name,
   return GRPC_ERROR_NONE;
 }
 
-int grpc_is_unix_socket(const struct sockaddr *addr) {
+int grpc_is_unix_socket(const grpc_resolved_address *resolved_addr) {
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
   return addr->sa_family == AF_UNIX;
 }
 
-void grpc_unlink_if_unix_domain_socket(const struct sockaddr *addr) {
+void grpc_unlink_if_unix_domain_socket(
+    const grpc_resolved_address *resolved_addr) {
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
   if (addr->sa_family != AF_UNIX) {
     return;
   }
-  struct sockaddr_un *un = (struct sockaddr_un *)addr;
+  struct sockaddr_un *un = (struct sockaddr_un *)resolved_addr->addr;
   struct stat st;
 
   if (stat(un->sun_path, &st) == 0 && (st.st_mode & S_IFMT) == S_IFSOCK) {
@@ -77,7 +83,9 @@ void grpc_unlink_if_unix_domain_socket(const struct sockaddr *addr) {
   }
 }
 
-char *grpc_sockaddr_to_uri_unix_if_possible(const struct sockaddr *addr) {
+char *grpc_sockaddr_to_uri_unix_if_possible(
+    const grpc_resolved_address *resolved_addr) {
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
   if (addr->sa_family != AF_UNIX) {
     return NULL;
   }
diff --git a/src/core/lib/iomgr/unix_sockets_posix.h b/src/core/lib/iomgr/unix_sockets_posix.h
index db0516d945..21afd3aa15 100644
--- a/src/core/lib/iomgr/unix_sockets_posix.h
+++ b/src/core/lib/iomgr/unix_sockets_posix.h
@@ -34,22 +34,23 @@
 #ifndef GRPC_CORE_LIB_IOMGR_UNIX_SOCKETS_POSIX_H
 #define GRPC_CORE_LIB_IOMGR_UNIX_SOCKETS_POSIX_H
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/iomgr/resolve_address.h"
-#include "src/core/lib/iomgr/sockaddr.h"
 
 void grpc_create_socketpair_if_unix(int sv[2]);
 
 grpc_error *grpc_resolve_unix_domain_address(
     const char *name, grpc_resolved_addresses **addresses);
 
-int grpc_is_unix_socket(const struct sockaddr *addr);
+int grpc_is_unix_socket(const grpc_resolved_address *resolved_addr);
 
-void grpc_unlink_if_unix_domain_socket(const struct sockaddr *addr);
+void grpc_unlink_if_unix_domain_socket(
+    const grpc_resolved_address *resolved_addr);
 
-char *grpc_sockaddr_to_uri_unix_if_possible(const struct sockaddr *addr);
+char *grpc_sockaddr_to_uri_unix_if_possible(
+    const grpc_resolved_address *resolved_addr);
 
 #endif /* GRPC_CORE_LIB_IOMGR_UNIX_SOCKETS_POSIX_H */
diff --git a/src/core/lib/iomgr/unix_sockets_posix_noop.c b/src/core/lib/iomgr/unix_sockets_posix_noop.c
index 56b47c3daf..1daf5152c1 100644
--- a/src/core/lib/iomgr/unix_sockets_posix_noop.c
+++ b/src/core/lib/iomgr/unix_sockets_posix_noop.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 
-#ifndef GPR_HAVE_UNIX_SOCKET
+#ifndef GRPC_HAVE_UNIX_SOCKET
 
 #include <grpc/support/log.h>
 
@@ -50,11 +50,11 @@ grpc_error *grpc_resolve_unix_domain_address(
   return GRPC_ERROR_CREATE("Unix domain sockets are not supported on Windows");
 }
 
-int grpc_is_unix_socket(const struct sockaddr *addr) { return false; }
+int grpc_is_unix_socket(const grpc_resolved_address *addr) { return false; }
 
-void grpc_unlink_if_unix_domain_socket(const struct sockaddr *addr) {}
+void grpc_unlink_if_unix_domain_socket(const grpc_resolved_address *addr) {}
 
-char *grpc_sockaddr_to_uri_unix_if_possible(const struct sockaddr *addr) {
+char *grpc_sockaddr_to_uri_unix_if_possible(const grpc_resolved_address *addr) {
   return NULL;
 }
 
diff --git a/src/core/lib/iomgr/wakeup_fd_cv.c b/src/core/lib/iomgr/wakeup_fd_cv.c
index b4165208ed..da4c2870cd 100644
--- a/src/core/lib/iomgr/wakeup_fd_cv.c
+++ b/src/core/lib/iomgr/wakeup_fd_cv.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_WAKEUP_FD
+#ifdef GRPC_POSIX_WAKEUP_FD
 
 #include "src/core/lib/iomgr/wakeup_fd_cv.h"
 
@@ -115,4 +115,4 @@ const grpc_wakeup_fd_vtable grpc_cv_wakeup_fd_vtable = {
     cv_fd_init, cv_fd_consume, cv_fd_wakeup, cv_fd_destroy,
     cv_check_availability};
 
-#endif /* GPR_POSIX_WAKUP_FD */
+#endif /* GRPC_POSIX_WAKUP_FD */
diff --git a/src/core/lib/iomgr/wakeup_fd_eventfd.c b/src/core/lib/iomgr/wakeup_fd_eventfd.c
index 95f6102330..373e21d3e1 100644
--- a/src/core/lib/iomgr/wakeup_fd_eventfd.c
+++ b/src/core/lib/iomgr/wakeup_fd_eventfd.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_LINUX_EVENTFD
+#ifdef GRPC_LINUX_EVENTFD
 
 #include <errno.h>
 #include <sys/eventfd.h>
@@ -94,4 +94,4 @@ const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
     eventfd_create, eventfd_consume, eventfd_wakeup, eventfd_destroy,
     eventfd_check_availability};
 
-#endif /* GPR_LINUX_EVENTFD */
+#endif /* GRPC_LINUX_EVENTFD */
diff --git a/src/core/lib/iomgr/wakeup_fd_nospecial.c b/src/core/lib/iomgr/wakeup_fd_nospecial.c
index cb2f707dc5..611bced029 100644
--- a/src/core/lib/iomgr/wakeup_fd_nospecial.c
+++ b/src/core/lib/iomgr/wakeup_fd_nospecial.c
@@ -36,9 +36,9 @@
  * systems without anything better than pipe.
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_NO_SPECIAL_WAKEUP_FD
+#ifdef GRPC_POSIX_NO_SPECIAL_WAKEUP_FD
 
 #include <stddef.h>
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
@@ -48,4 +48,4 @@ static int check_availability_invalid(void) { return 0; }
 const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
     NULL, NULL, NULL, NULL, check_availability_invalid};
 
-#endif /* GPR_POSIX_NO_SPECIAL_WAKEUP_FD */
+#endif /* GRPC_POSIX_NO_SPECIAL_WAKEUP_FD */
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.c b/src/core/lib/iomgr/wakeup_fd_pipe.c
index d0ea216aa0..183f0eb930 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.c
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_WAKEUP_FD
+#ifdef GRPC_POSIX_WAKEUP_FD
 
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.c b/src/core/lib/iomgr/wakeup_fd_posix.c
index 5c894bef37..85526402bd 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.c
+++ b/src/core/lib/iomgr/wakeup_fd_posix.c
@@ -31,9 +31,9 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
+#include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_WAKEUP_FD
+#ifdef GRPC_POSIX_WAKEUP_FD
 
 #include <stddef.h>
 #include "src/core/lib/iomgr/wakeup_fd_cv.h"
@@ -98,4 +98,4 @@ void grpc_wakeup_fd_destroy(grpc_wakeup_fd *fd_info) {
   }
 }
 
-#endif /* GPR_POSIX_WAKEUP_FD */
+#endif /* GRPC_POSIX_WAKEUP_FD */
diff --git a/src/core/lib/iomgr/workqueue.h b/src/core/lib/iomgr/workqueue.h
index 5b96d1d851..73d9849843 100644
--- a/src/core/lib/iomgr/workqueue.h
+++ b/src/core/lib/iomgr/workqueue.h
@@ -39,6 +39,7 @@
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
+#include "src/core/lib/iomgr/port.h"
 
 #ifdef GPR_WINDOWS
 #include "src/core/lib/iomgr/workqueue_windows.h"
diff --git a/src/core/lib/iomgr/workqueue_uv.c b/src/core/lib/iomgr/workqueue_uv.c
new file mode 100644
index 0000000000..e58ca476cc
--- /dev/null
+++ b/src/core/lib/iomgr/workqueue_uv.c
@@ -0,0 +1,66 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_UV
+
+#include "src/core/lib/iomgr/workqueue.h"
+
+// Minimal implementation of grpc_workqueue for libuv
+// Works by directly enqueuing workqueue items onto the current execution
+// context, which is at least correct, if not performant or in the spirit of
+// workqueues.
+
+void grpc_workqueue_flush(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {}
+
+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
+                                   int line, const char *reason) {
+  return workqueue;
+}
+void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                          const char *file, int line, const char *reason) {}
+#else
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue) {
+  return workqueue;
+}
+void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {}
+#endif
+
+void grpc_workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                            grpc_closure *closure, grpc_error *error) {
+  grpc_exec_ctx_sched(exec_ctx, closure, error, NULL);
+}
+
+#endif /* GPR_UV */
diff --git a/src/core/lib/iomgr/workqueue_uv.h b/src/core/lib/iomgr/workqueue_uv.h
new file mode 100644
index 0000000000..be3f8e4d93
--- /dev/null
+++ b/src/core/lib/iomgr/workqueue_uv.h
@@ -0,0 +1,37 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_WORKQUEUE_UV_H
+#define GRPC_CORE_LIB_IOMGR_WORKQUEUE_UV_H
+
+#endif /* GRPC_CORE_LIB_IOMGR_WORKQUEUE_UV_H */
diff --git a/src/core/lib/security/credentials/google_default/credentials_posix.c b/src/core/lib/security/credentials/google_default/credentials_generic.c
index 42c9d7f997..d13d8c5200 100644
--- a/src/core/lib/security/credentials/google_default/credentials_posix.c
+++ b/src/core/lib/security/credentials/google_default/credentials_generic.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,10 +31,6 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
-
-#ifdef GPR_POSIX_FILE
-
 #include "src/core/lib/security/credentials/google_default/google_default_credentials.h"
 
 #include <grpc/support/alloc.h>
@@ -46,16 +42,13 @@
 
 char *grpc_get_well_known_google_credentials_file_path_impl(void) {
   char *result = NULL;
-  char *home = gpr_getenv("HOME");
-  if (home == NULL) {
-    gpr_log(GPR_ERROR, "Could not get HOME environment variable.");
+  char *base = gpr_getenv(GRPC_GOOGLE_CREDENTIALS_PATH_ENV_VAR);
+  if (base == NULL) {
+    gpr_log(GPR_ERROR, "Could not get " GRPC_GOOGLE_CREDENTIALS_ENV_VAR
+                       " environment variable.");
     return NULL;
   }
-  gpr_asprintf(&result, "%s/.config/%s/%s", home,
-               GRPC_GOOGLE_CLOUD_SDK_CONFIG_DIRECTORY,
-               GRPC_GOOGLE_WELL_KNOWN_CREDENTIALS_FILE);
-  gpr_free(home);
+  gpr_asprintf(&result, "%s/%s", base, GRPC_GOOGLE_CREDENTIALS_PATH_SUFFIX);
+  gpr_free(base);
   return result;
 }
-
-#endif /* GPR_POSIX_FILE */
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.h b/src/core/lib/security/credentials/google_default/google_default_credentials.h
index fac4377e2c..b55546ded0 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.h
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.h
@@ -34,12 +34,26 @@
 #ifndef GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_GOOGLE_DEFAULT_CREDENTIALS_H
 #define GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_GOOGLE_DEFAULT_CREDENTIALS_H
 
+#include <grpc/support/port_platform.h>
+
 #include "src/core/lib/security/credentials/credentials.h"
 
 #define GRPC_GOOGLE_CLOUD_SDK_CONFIG_DIRECTORY "gcloud"
 #define GRPC_GOOGLE_WELL_KNOWN_CREDENTIALS_FILE \
   "application_default_credentials.json"
 
+#ifdef GPR_WINDOWS
+#define GRPC_GOOGLE_CREDENTIALS_PATH_ENV_VAR "APPDATA"
+#define GRPC_GOOGLE_CREDENTIALS_PATH_SUFFIX \
+  GRPC_GOOGLE_CLOUD_SDK_CONFIG_DIRECTORY    \
+  "/" GRPC_GOOGLE_WELL_KNOWN_CREDENTIALS_FILE
+#else
+#define GRPC_GOOGLE_CREDENTIALS_PATH_ENV_VAR "HOME"
+#define GRPC_GOOGLE_CREDENTIALS_PATH_SUFFIX         \
+  ".config/" GRPC_GOOGLE_CLOUD_SDK_CONFIG_DIRECTORY \
+  "/" GRPC_GOOGLE_WELL_KNOWN_CREDENTIALS_FILE
+#endif
+
 void grpc_flush_cached_google_default_credentials(void);
 
 #endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_GOOGLE_DEFAULT_CREDENTIALS_H \
diff --git a/src/core/lib/support/thd.c b/src/core/lib/support/thd.c
index 41daeb5d0e..40f53a18e5 100644
--- a/src/core/lib/support/thd.c
+++ b/src/core/lib/support/thd.c
@@ -33,7 +33,7 @@
 
 /* Posix implementation for gpr threads. */
 
-#include <memory.h>
+#include <string.h>
 
 #include <grpc/support/thd.h>
 
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index ee94f274f8..6c25952c0a 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -30,6 +30,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
+
 #include <assert.h>
 #include <limits.h>
 #include <stdio.h>
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
index be16162e7f..3a90308058 100644
--- a/src/core/lib/surface/server.c
+++ b/src/core/lib/surface/server.c
@@ -842,6 +842,7 @@ static void accept_stream(grpc_exec_ctx *exec_ctx, void *cd,
       grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
   if (error != GRPC_ERROR_NONE) {
     got_initial_metadata(exec_ctx, elem, error);
+    GRPC_ERROR_UNREF(error);
     return;
   }
   call_data *calld = elem->call_data;
diff --git a/src/core/ext/client_channel/method_config.c b/src/core/lib/transport/method_config.c
index 4313ad5e0e..57d97700bf 100644
--- a/src/core/ext/client_channel/method_config.c
+++ b/src/core/lib/transport/method_config.c
@@ -29,7 +29,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
-#include "src/core/ext/client_channel/method_config.h"
+#include "src/core/lib/transport/method_config.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_channel/method_config.h b/src/core/lib/transport/method_config.h
index 4cbeee5625..58fedd9436 100644
--- a/src/core/ext/client_channel/method_config.h
+++ b/src/core/lib/transport/method_config.h
@@ -29,8 +29,8 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_METHOD_CONFIG_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_METHOD_CONFIG_H
+#ifndef GRPC_CORE_LIB_TRANSPORT_METHOD_CONFIG_H
+#define GRPC_CORE_LIB_TRANSPORT_METHOD_CONFIG_H
 
 #include <stdbool.h>
 
@@ -133,4 +133,4 @@ grpc_mdstr_hash_table* grpc_method_config_table_convert(
     void* (*convert_value)(const grpc_method_config* method_config),
     const grpc_mdstr_hash_table_vtable* vtable);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_METHOD_CONFIG_H */
+#endif /* GRPC_CORE_LIB_TRANSPORT_METHOD_CONFIG_H */
diff --git a/src/core/lib/tsi/ssl_transport_security.c b/src/core/lib/tsi/ssl_transport_security.c
index e91c6316e7..749b46e19f 100644
--- a/src/core/lib/tsi/ssl_transport_security.c
+++ b/src/core/lib/tsi/ssl_transport_security.c
@@ -31,6 +31,9 @@
  *
  */
 
+#include "src/core/lib/iomgr/sockaddr.h"
+
+#include "src/core/lib/iomgr/socket_utils.h"
 #include "src/core/lib/tsi/ssl_transport_security.h"
 
 #include <grpc/support/port_platform.h>
@@ -38,13 +41,6 @@
 #include <limits.h>
 #include <string.h>
 
-/* TODO(jboeuf): refactor inet_ntop into a portability header. */
-#ifdef GPR_WINSOCK_SOCKET
-#include <ws2tcpip.h>
-#else
-#include <arpa/inet.h>
-#endif
-
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
@@ -353,8 +349,8 @@ static tsi_result add_subject_alt_names_properties_to_peer(
         result = TSI_INTERNAL_ERROR;
         break;
       }
-      const char *name = inet_ntop(af, subject_alt_name->d.iPAddress->data,
-                                   ntop_buf, INET6_ADDRSTRLEN);
+      const char *name = grpc_inet_ntop(af, subject_alt_name->d.iPAddress->data,
+                                        ntop_buf, INET6_ADDRSTRLEN);
       if (name == NULL) {
         gpr_log(GPR_ERROR, "Could not get IP string from asn1 octet.");
         result = TSI_INTERNAL_ERROR;