Merge branch 'master' of github.com:grpc/grpc into subchannel_factory_create_lb_channel

37 files changed, 160 insertions, 1419 deletions

diff --git a/src/core/lib/client_config/client_channel_factory.c b/src/core/lib/client_config/client_channel_factory.c
index c079ce09dd..795776dcdd 100644
--- a/src/core/lib/client_config/client_channel_factory.c
+++ b/src/core/lib/client_config/client_channel_factory.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/client_channel_factory.h b/src/core/lib/client_config/client_channel_factory.h
index 3dd9dfea12..4975eecb1a 100644
--- a/src/core/lib/client_config/client_channel_factory.h
+++ b/src/core/lib/client_config/client_channel_factory.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/client_config.c b/src/core/lib/client_config/client_config.c
index 82c8d68099..2521023364 100644
--- a/src/core/lib/client_config/client_config.c
+++ b/src/core/lib/client_config/client_config.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/client_config.h b/src/core/lib/client_config/client_config.h
index 404ec0d3a5..8dc2f6b299 100644
--- a/src/core/lib/client_config/client_config.h
+++ b/src/core/lib/client_config/client_config.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/connector.c b/src/core/lib/client_config/connector.c
index f51d862c6d..4c7b823dac 100644
--- a/src/core/lib/client_config/connector.c
+++ b/src/core/lib/client_config/connector.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/connector.h b/src/core/lib/client_config/connector.h
index 21b925aade..39870a261c 100644
--- a/src/core/lib/client_config/connector.h
+++ b/src/core/lib/client_config/connector.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/default_initial_connect_string.c b/src/core/lib/client_config/default_initial_connect_string.c
index 86eb37de77..a70da4a84a 100644
--- a/src/core/lib/client_config/default_initial_connect_string.c
+++ b/src/core/lib/client_config/default_initial_connect_string.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/initial_connect_string.c b/src/core/lib/client_config/initial_connect_string.c
index 95ae728316..4034ea2e87 100644
--- a/src/core/lib/client_config/initial_connect_string.c
+++ b/src/core/lib/client_config/initial_connect_string.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/initial_connect_string.h b/src/core/lib/client_config/initial_connect_string.h
index eec42fa240..51302768c6 100644
--- a/src/core/lib/client_config/initial_connect_string.h
+++ b/src/core/lib/client_config/initial_connect_string.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/lb_policies/load_balancer_api.c b/src/core/lib/client_config/lb_policies/load_balancer_api.c
deleted file mode 100644
index 4cbed200df..0000000000
--- a/src/core/lib/client_config/lb_policies/load_balancer_api.c
+++ /dev/null
@@ -1,163 +0,0 @@
-/*
- *
- * 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/client_config/lb_policies/load_balancer_api.h"
-#include "third_party/nanopb/pb_decode.h"
-#include "third_party/nanopb/pb_encode.h"
-
-#include <grpc/support/alloc.h>
-
-typedef struct decode_serverlist_arg {
-  int first_pass;
-  int i;
-  size_t num_servers;
-  grpc_grpclb_server **servers;
-} decode_serverlist_arg;
-
-/* invoked once for every Server in ServerList */
-static bool decode_serverlist(pb_istream_t *stream, const pb_field_t *field,
-                              void **arg) {
-  decode_serverlist_arg *dec_arg = *arg;
-  if (dec_arg->first_pass != 0) { /* first pass */
-    grpc_grpclb_server server;
-    if (!pb_decode(stream, grpc_lb_v0_Server_fields, &server)) {
-      return false;
-    }
-    dec_arg->num_servers++;
-  } else { /* second pass */
-    grpc_grpclb_server *server = gpr_malloc(sizeof(grpc_grpclb_server));
-    GPR_ASSERT(dec_arg->num_servers > 0);
-    if (dec_arg->i == 0) { /* first iteration of second pass */
-      dec_arg->servers =
-          gpr_malloc(sizeof(grpc_grpclb_server *) * dec_arg->num_servers);
-    }
-    if (!pb_decode(stream, grpc_lb_v0_Server_fields, server)) {
-      return false;
-    }
-    dec_arg->servers[dec_arg->i++] = server;
-  }
-
-  return true;
-}
-
-grpc_grpclb_request *grpc_grpclb_request_create(const char *lb_service_name) {
-  grpc_grpclb_request *req = gpr_malloc(sizeof(grpc_grpclb_request));
-
-  req->has_client_stats = 0; /* TODO(dgq): add support for stats once defined */
-  req->has_initial_request = 1;
-  req->initial_request.has_name = 1;
-  strncpy(req->initial_request.name, lb_service_name,
-          GRPC_GRPCLB_SERVICE_NAME_MAX_LENGTH);
-  return req;
-}
-
-gpr_slice grpc_grpclb_request_encode(const grpc_grpclb_request *request) {
-  size_t encoded_length;
-  pb_ostream_t sizestream;
-  pb_ostream_t outputstream;
-  gpr_slice slice;
-  memset(&sizestream, 0, sizeof(pb_ostream_t));
-  pb_encode(&sizestream, grpc_lb_v0_LoadBalanceRequest_fields, request);
-  encoded_length = sizestream.bytes_written;
-
-  slice = gpr_slice_malloc(encoded_length);
-  outputstream =
-      pb_ostream_from_buffer(GPR_SLICE_START_PTR(slice), encoded_length);
-  GPR_ASSERT(pb_encode(&outputstream, grpc_lb_v0_LoadBalanceRequest_fields,
-                       request) != 0);
-  return slice;
-}
-
-void grpc_grpclb_request_destroy(grpc_grpclb_request *request) {
-  gpr_free(request);
-}
-
-grpc_grpclb_response *grpc_grpclb_response_parse(gpr_slice encoded_response) {
-  bool status;
-  pb_istream_t stream =
-      pb_istream_from_buffer(GPR_SLICE_START_PTR(encoded_response),
-                             GPR_SLICE_LENGTH(encoded_response));
-  grpc_grpclb_response *res = gpr_malloc(sizeof(grpc_grpclb_response));
-  memset(res, 0, sizeof(*res));
-  status = pb_decode(&stream, grpc_lb_v0_LoadBalanceResponse_fields, res);
-  GPR_ASSERT(status == true);
-  return res;
-}
-
-grpc_grpclb_serverlist *grpc_grpclb_response_parse_serverlist(
-    gpr_slice encoded_response) {
-  grpc_grpclb_serverlist *sl = gpr_malloc(sizeof(grpc_grpclb_serverlist));
-  bool status;
-  decode_serverlist_arg arg;
-  pb_istream_t stream =
-      pb_istream_from_buffer(GPR_SLICE_START_PTR(encoded_response),
-                             GPR_SLICE_LENGTH(encoded_response));
-  pb_istream_t stream_at_start = stream;
-  grpc_grpclb_response *res = gpr_malloc(sizeof(grpc_grpclb_response));
-  memset(res, 0, sizeof(*res));
-  memset(&arg, 0, sizeof(decode_serverlist_arg));
-
-  res->server_list.servers.funcs.decode = decode_serverlist;
-  res->server_list.servers.arg = &arg;
-  arg.first_pass = 1;
-  status = pb_decode(&stream, grpc_lb_v0_LoadBalanceResponse_fields, res);
-  GPR_ASSERT(status == true);
-  GPR_ASSERT(arg.num_servers > 0);
-
-  arg.first_pass = 0;
-  status =
-      pb_decode(&stream_at_start, grpc_lb_v0_LoadBalanceResponse_fields, res);
-  GPR_ASSERT(status == true);
-  GPR_ASSERT(arg.servers != NULL);
-
-  sl->num_servers = arg.num_servers;
-  sl->servers = arg.servers;
-  if (res->server_list.has_expiration_interval) {
-    sl->expiration_interval = res->server_list.expiration_interval;
-  }
-  grpc_grpclb_response_destroy(res);
-  return sl;
-}
-
-void grpc_grpclb_destroy_serverlist(grpc_grpclb_serverlist *serverlist) {
-  size_t i;
-  for (i = 0; i < serverlist->num_servers; i++) {
-    gpr_free(serverlist->servers[i]);
-  }
-  gpr_free(serverlist->servers);
-  gpr_free(serverlist);
-}
-
-void grpc_grpclb_response_destroy(grpc_grpclb_response *response) {
-  gpr_free(response);
-}
diff --git a/src/core/lib/client_config/lb_policies/load_balancer_api.h b/src/core/lib/client_config/lb_policies/load_balancer_api.h
deleted file mode 100644
index 83299adfa9..0000000000
--- a/src/core/lib/client_config/lb_policies/load_balancer_api.h
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- *
- * 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_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H
-
-#include <grpc/support/slice_buffer.h>
-
-#include "src/core/lib/client_config/lb_policy_factory.h"
-#include "src/core/lib/proto/grpc/lb/v0/load_balancer.pb.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#define GRPC_GRPCLB_SERVICE_NAME_MAX_LENGTH 128
-
-typedef grpc_lb_v0_LoadBalanceRequest grpc_grpclb_request;
-typedef grpc_lb_v0_LoadBalanceResponse grpc_grpclb_response;
-typedef grpc_lb_v0_Server grpc_grpclb_server;
-typedef grpc_lb_v0_Duration grpc_grpclb_duration;
-typedef struct grpc_grpclb_serverlist {
-  grpc_grpclb_server **servers;
-  size_t num_servers;
-  grpc_grpclb_duration expiration_interval;
-} grpc_grpclb_serverlist;
-
-/** Create a request for a gRPC LB service under \a lb_service_name */
-grpc_grpclb_request *grpc_grpclb_request_create(const char *lb_service_name);
-
-/** Protocol Buffers v3-encode \a request */
-gpr_slice grpc_grpclb_request_encode(const grpc_grpclb_request *request);
-
-/** Destroy \a request */
-void grpc_grpclb_request_destroy(grpc_grpclb_request *request);
-
-/** Parse (ie, decode) the bytes in \a encoded_response as a \a
- * grpc_grpclb_response */
-grpc_grpclb_response *grpc_grpclb_response_parse(gpr_slice encoded_response);
-
-/** Destroy \a serverlist */
-void grpc_grpclb_destroy_serverlist(grpc_grpclb_serverlist *serverlist);
-
-/** Parse the list of servers from an encoded \a grpc_grpclb_response */
-grpc_grpclb_serverlist *grpc_grpclb_response_parse_serverlist(
-    gpr_slice encoded_response);
-
-/** Destroy \a response */
-void grpc_grpclb_response_destroy(grpc_grpclb_response *response);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_LOAD_BALANCER_API_H */
diff --git a/src/core/lib/client_config/lb_policies/pick_first.c b/src/core/lib/client_config/lb_policies/pick_first.c
deleted file mode 100644
index 2e399b73f9..0000000000
--- a/src/core/lib/client_config/lb_policies/pick_first.c
+++ /dev/null
@@ -1,421 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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/client_config/lb_policies/pick_first.h"
-#include "src/core/lib/client_config/lb_policy_factory.h"
-
-#include <string.h>
-
-#include <grpc/support/alloc.h>
-#include "src/core/lib/transport/connectivity_state.h"
-
-typedef struct pending_pick {
-  struct pending_pick *next;
-  grpc_pollset *pollset;
-  grpc_connected_subchannel **target;
-  grpc_closure *on_complete;
-} pending_pick;
-
-typedef struct {
-  /** base policy: must be first */
-  grpc_lb_policy base;
-  /** all our subchannels */
-  grpc_subchannel **subchannels;
-  size_t num_subchannels;
-
-  grpc_closure connectivity_changed;
-
-  /** the selected channel (a grpc_connected_subchannel) */
-  gpr_atm selected;
-
-  /** mutex protecting remaining members */
-  gpr_mu mu;
-  /** have we started picking? */
-  int started_picking;
-  /** are we shut down? */
-  int shutdown;
-  /** which subchannel are we watching? */
-  size_t checking_subchannel;
-  /** what is the connectivity of that channel? */
-  grpc_connectivity_state checking_connectivity;
-  /** list of picks that are waiting on connectivity */
-  pending_pick *pending_picks;
-
-  /** our connectivity state tracker */
-  grpc_connectivity_state_tracker state_tracker;
-} pick_first_lb_policy;
-
-#define GET_SELECTED(p) \
-  ((grpc_connected_subchannel *)gpr_atm_acq_load(&(p)->selected))
-
-void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  grpc_connected_subchannel *selected = GET_SELECTED(p);
-  size_t i;
-  GPR_ASSERT(p->pending_picks == NULL);
-  for (i = 0; i < p->num_subchannels; i++) {
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[i], "pick_first");
-  }
-  if (selected != NULL) {
-    GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, selected, "picked_first");
-  }
-  grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
-  gpr_free(p->subchannels);
-  gpr_mu_destroy(&p->mu);
-  gpr_free(p);
-}
-
-void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  pending_pick *pp;
-  grpc_connected_subchannel *selected;
-  gpr_mu_lock(&p->mu);
-  selected = GET_SELECTED(p);
-  p->shutdown = 1;
-  pp = p->pending_picks;
-  p->pending_picks = NULL;
-  grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                              GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
-  /* cancel subscription */
-  if (selected != NULL) {
-    grpc_connected_subchannel_notify_on_state_change(
-        exec_ctx, selected, NULL, NULL, &p->connectivity_changed);
-  } else {
-    grpc_subchannel_notify_on_state_change(
-        exec_ctx, p->subchannels[p->checking_subchannel], NULL, NULL,
-        &p->connectivity_changed);
-  }
-  gpr_mu_unlock(&p->mu);
-  while (pp != NULL) {
-    pending_pick *next = pp->next;
-    *pp->target = NULL;
-    grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                 pp->pollset);
-    grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
-    gpr_free(pp);
-    pp = next;
-  }
-}
-
-static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                           grpc_connected_subchannel **target) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  pending_pick *pp;
-  gpr_mu_lock(&p->mu);
-  pp = p->pending_picks;
-  p->pending_picks = NULL;
-  while (pp != NULL) {
-    pending_pick *next = pp->next;
-    if (pp->target == target) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
-      *target = NULL;
-      grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
-      gpr_free(pp);
-    } else {
-      pp->next = p->pending_picks;
-      p->pending_picks = pp;
-    }
-    pp = next;
-  }
-  gpr_mu_unlock(&p->mu);
-}
-
-static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) {
-  p->started_picking = 1;
-  p->checking_subchannel = 0;
-  p->checking_connectivity = GRPC_CHANNEL_IDLE;
-  GRPC_LB_POLICY_WEAK_REF(&p->base, "pick_first_connectivity");
-  grpc_subchannel_notify_on_state_change(
-      exec_ctx, p->subchannels[p->checking_subchannel],
-      p->base.interested_parties, &p->checking_connectivity,
-      &p->connectivity_changed);
-}
-
-void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
-  if (!p->started_picking) {
-    start_picking(exec_ctx, p);
-  }
-  gpr_mu_unlock(&p->mu);
-}
-
-int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
-            grpc_metadata_batch *initial_metadata,
-            grpc_connected_subchannel **target, grpc_closure *on_complete) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  pending_pick *pp;
-
-  /* Check atomically for a selected channel */
-  grpc_connected_subchannel *selected = GET_SELECTED(p);
-  if (selected != NULL) {
-    *target = selected;
-    return 1;
-  }
-
-  /* No subchannel selected yet, so acquire lock and then attempt again */
-  gpr_mu_lock(&p->mu);
-  selected = GET_SELECTED(p);
-  if (selected) {
-    gpr_mu_unlock(&p->mu);
-    *target = selected;
-    return 1;
-  } else {
-    if (!p->started_picking) {
-      start_picking(exec_ctx, p);
-    }
-    grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
-    pp = gpr_malloc(sizeof(*pp));
-    pp->next = p->pending_picks;
-    pp->pollset = pollset;
-    pp->target = target;
-    pp->on_complete = on_complete;
-    p->pending_picks = pp;
-    gpr_mu_unlock(&p->mu);
-    return 0;
-  }
-}
-
-static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg,
-                                bool iomgr_success) {
-  pick_first_lb_policy *p = arg;
-  size_t i;
-  size_t num_subchannels = p->num_subchannels;
-  grpc_subchannel **subchannels;
-
-  gpr_mu_lock(&p->mu);
-  subchannels = p->subchannels;
-  p->num_subchannels = 0;
-  p->subchannels = NULL;
-  gpr_mu_unlock(&p->mu);
-  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "destroy_subchannels");
-
-  for (i = 0; i < num_subchannels; i++) {
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "pick_first");
-  }
-
-  gpr_free(subchannels);
-}
-
-static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
-                                    bool iomgr_success) {
-  pick_first_lb_policy *p = arg;
-  grpc_subchannel *selected_subchannel;
-  pending_pick *pp;
-  grpc_connected_subchannel *selected;
-
-  gpr_mu_lock(&p->mu);
-
-  selected = GET_SELECTED(p);
-
-  if (p->shutdown) {
-    gpr_mu_unlock(&p->mu);
-    GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
-    return;
-  } else if (selected != NULL) {
-    if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
-      /* if the selected channel goes bad, we're done */
-      p->checking_connectivity = GRPC_CHANNEL_FATAL_FAILURE;
-    }
-    grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                p->checking_connectivity, "selected_changed");
-    if (p->checking_connectivity != GRPC_CHANNEL_FATAL_FAILURE) {
-      grpc_connected_subchannel_notify_on_state_change(
-          exec_ctx, selected, p->base.interested_parties,
-          &p->checking_connectivity, &p->connectivity_changed);
-    } else {
-      GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pick_first_connectivity");
-    }
-  } else {
-  loop:
-    switch (p->checking_connectivity) {
-      case GRPC_CHANNEL_READY:
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    GRPC_CHANNEL_READY, "connecting_ready");
-        selected_subchannel = p->subchannels[p->checking_subchannel];
-        selected =
-            grpc_subchannel_get_connected_subchannel(selected_subchannel);
-        GPR_ASSERT(selected != NULL);
-        GRPC_CONNECTED_SUBCHANNEL_REF(selected, "picked_first");
-        /* drop the pick list: we are connected now */
-        GRPC_LB_POLICY_WEAK_REF(&p->base, "destroy_subchannels");
-        gpr_atm_rel_store(&p->selected, (gpr_atm)selected);
-        grpc_exec_ctx_enqueue(
-            exec_ctx, grpc_closure_create(destroy_subchannels, p), true, NULL);
-        /* update any calls that were waiting for a pick */
-        while ((pp = p->pending_picks)) {
-          p->pending_picks = pp->next;
-          *pp->target = selected;
-          grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                       pp->pollset);
-          grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
-          gpr_free(pp);
-        }
-        grpc_connected_subchannel_notify_on_state_change(
-            exec_ctx, selected, p->base.interested_parties,
-            &p->checking_connectivity, &p->connectivity_changed);
-        break;
-      case GRPC_CHANNEL_TRANSIENT_FAILURE:
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                    "connecting_transient_failure");
-        p->checking_subchannel =
-            (p->checking_subchannel + 1) % p->num_subchannels;
-        p->checking_connectivity = grpc_subchannel_check_connectivity(
-            p->subchannels[p->checking_subchannel]);
-        if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
-          grpc_subchannel_notify_on_state_change(
-              exec_ctx, p->subchannels[p->checking_subchannel],
-              p->base.interested_parties, &p->checking_connectivity,
-              &p->connectivity_changed);
-        } else {
-          goto loop;
-        }
-        break;
-      case GRPC_CHANNEL_CONNECTING:
-      case GRPC_CHANNEL_IDLE:
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    GRPC_CHANNEL_CONNECTING,
-                                    "connecting_changed");
-        grpc_subchannel_notify_on_state_change(
-            exec_ctx, p->subchannels[p->checking_subchannel],
-            p->base.interested_parties, &p->checking_connectivity,
-            &p->connectivity_changed);
-        break;
-      case GRPC_CHANNEL_FATAL_FAILURE:
-        p->num_subchannels--;
-        GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
-                 p->subchannels[p->num_subchannels]);
-        GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[p->num_subchannels],
-                              "pick_first");
-        if (p->num_subchannels == 0) {
-          grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                      GRPC_CHANNEL_FATAL_FAILURE,
-                                      "no_more_channels");
-          while ((pp = p->pending_picks)) {
-            p->pending_picks = pp->next;
-            *pp->target = NULL;
-            grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
-            gpr_free(pp);
-          }
-          GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base,
-                                    "pick_first_connectivity");
-        } else {
-          grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                      GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                      "subchannel_failed");
-          p->checking_subchannel %= p->num_subchannels;
-          p->checking_connectivity = grpc_subchannel_check_connectivity(
-              p->subchannels[p->checking_subchannel]);
-          goto loop;
-        }
-    }
-  }
-
-  gpr_mu_unlock(&p->mu);
-}
-
-static grpc_connectivity_state pf_check_connectivity(grpc_exec_ctx *exec_ctx,
-                                                     grpc_lb_policy *pol) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  grpc_connectivity_state st;
-  gpr_mu_lock(&p->mu);
-  st = grpc_connectivity_state_check(&p->state_tracker);
-  gpr_mu_unlock(&p->mu);
-  return st;
-}
-
-void pf_notify_on_state_change(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                               grpc_connectivity_state *current,
-                               grpc_closure *notify) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
-  grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker,
-                                                 current, notify);
-  gpr_mu_unlock(&p->mu);
-}
-
-void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                 grpc_closure *closure) {
-  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
-  grpc_connected_subchannel *selected = GET_SELECTED(p);
-  if (selected) {
-    grpc_connected_subchannel_ping(exec_ctx, selected, closure);
-  } else {
-    grpc_exec_ctx_enqueue(exec_ctx, closure, false, NULL);
-  }
-}
-
-static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = {
-    pf_destroy,
-    pf_shutdown,
-    pf_pick,
-    pf_cancel_pick,
-    pf_ping_one,
-    pf_exit_idle,
-    pf_check_connectivity,
-    pf_notify_on_state_change};
-
-static void pick_first_factory_ref(grpc_lb_policy_factory *factory) {}
-
-static void pick_first_factory_unref(grpc_lb_policy_factory *factory) {}
-
-static grpc_lb_policy *create_pick_first(grpc_lb_policy_factory *factory,
-                                         grpc_lb_policy_args *args) {
-  if (args->num_subchannels == 0) return NULL;
-  pick_first_lb_policy *p = gpr_malloc(sizeof(*p));
-  memset(p, 0, sizeof(*p));
-  grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable);
-  p->subchannels =
-      gpr_malloc(sizeof(grpc_subchannel *) * args->num_subchannels);
-  p->num_subchannels = args->num_subchannels;
-  grpc_connectivity_state_init(&p->state_tracker, GRPC_CHANNEL_IDLE,
-                               "pick_first");
-  memcpy(p->subchannels, args->subchannels,
-         sizeof(grpc_subchannel *) * args->num_subchannels);
-  grpc_closure_init(&p->connectivity_changed, pf_connectivity_changed, p);
-  gpr_mu_init(&p->mu);
-  return &p->base;
-}
-
-static const grpc_lb_policy_factory_vtable pick_first_factory_vtable = {
-    pick_first_factory_ref, pick_first_factory_unref, create_pick_first,
-    "pick_first"};
-
-static grpc_lb_policy_factory pick_first_lb_policy_factory = {
-    &pick_first_factory_vtable};
-
-grpc_lb_policy_factory *grpc_pick_first_lb_factory_create() {
-  return &pick_first_lb_policy_factory;
-}
diff --git a/src/core/lib/client_config/lb_policies/pick_first.h b/src/core/lib/client_config/lb_policies/pick_first.h
deleted file mode 100644
index dba86ea7ad..0000000000
--- a/src/core/lib/client_config/lb_policies/pick_first.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H
-
-#include "src/core/lib/client_config/lb_policy_factory.h"
-
-/** Returns a load balancing factory for the pick first policy, which picks up
- * the first subchannel from \a subchannels to succesfully connect */
-grpc_lb_policy_factory *grpc_pick_first_lb_factory_create();
-
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_PICK_FIRST_H */
diff --git a/src/core/lib/client_config/lb_policies/round_robin.c b/src/core/lib/client_config/lb_policies/round_robin.c
deleted file mode 100644
index c904c5f921..0000000000
--- a/src/core/lib/client_config/lb_policies/round_robin.c
+++ /dev/null
@@ -1,542 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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/client_config/lb_policies/round_robin.h"
-
-#include <string.h>
-
-#include <grpc/support/alloc.h>
-#include "src/core/lib/transport/connectivity_state.h"
-
-typedef struct round_robin_lb_policy round_robin_lb_policy;
-
-int grpc_lb_round_robin_trace = 0;
-
-/** List of entities waiting for a pick.
- *
- * Once a pick is available, \a target is updated and \a on_complete called. */
-typedef struct pending_pick {
-  struct pending_pick *next;
-  grpc_pollset *pollset;
-  grpc_connected_subchannel **target;
-  grpc_closure *on_complete;
-} pending_pick;
-
-/** List of subchannels in a connectivity READY state */
-typedef struct ready_list {
-  grpc_subchannel *subchannel;
-  struct ready_list *next;
-  struct ready_list *prev;
-} ready_list;
-
-typedef struct {
-  /** index within policy->subchannels */
-  size_t index;
-  /** backpointer to owning policy */
-  round_robin_lb_policy *policy;
-  /** subchannel itself */
-  grpc_subchannel *subchannel;
-  /** notification that connectivity has changed on subchannel */
-  grpc_closure connectivity_changed_closure;
-  /** this subchannels current position in subchannel->ready_list */
-  ready_list *ready_list_node;
-  /** last observed connectivity */
-  grpc_connectivity_state connectivity_state;
-} subchannel_data;
-
-struct round_robin_lb_policy {
-  /** base policy: must be first */
-  grpc_lb_policy base;
-
-  /** all our subchannels */
-  size_t num_subchannels;
-  subchannel_data **subchannels;
-
-  /** mutex protecting remaining members */
-  gpr_mu mu;
-  /** have we started picking? */
-  int started_picking;
-  /** are we shutting down? */
-  int shutdown;
-  /** List of picks that are waiting on connectivity */
-  pending_pick *pending_picks;
-
-  /** our connectivity state tracker */
-  grpc_connectivity_state_tracker state_tracker;
-
-  /** (Dummy) root of the doubly linked list containing READY subchannels */
-  ready_list ready_list;
-  /** Last pick from the ready list. */
-  ready_list *ready_list_last_pick;
-};
-
-/** Returns the next subchannel from the connected list or NULL if the list is
- * empty.
- *
- * Note that this function does *not* advance p->ready_list_last_pick. Use \a
- * advance_last_picked_locked() for that. */
-static ready_list *peek_next_connected_locked(const round_robin_lb_policy *p) {
-  ready_list *selected;
-  selected = p->ready_list_last_pick->next;
-
-  while (selected != NULL) {
-    if (selected == &p->ready_list) {
-      GPR_ASSERT(selected->subchannel == NULL);
-      /* skip dummy root */
-      selected = selected->next;
-    } else {
-      GPR_ASSERT(selected->subchannel != NULL);
-      return selected;
-    }
-  }
-  return NULL;
-}
-
-/** Advance the \a ready_list picking head. */
-static void advance_last_picked_locked(round_robin_lb_policy *p) {
-  if (p->ready_list_last_pick->next != NULL) { /* non-empty list */
-    p->ready_list_last_pick = p->ready_list_last_pick->next;
-    if (p->ready_list_last_pick == &p->ready_list) {
-      /* skip dummy root */
-      p->ready_list_last_pick = p->ready_list_last_pick->next;
-    }
-  } else { /* should be an empty list */
-    GPR_ASSERT(p->ready_list_last_pick == &p->ready_list);
-  }
-
-  if (grpc_lb_round_robin_trace) {
-    gpr_log(GPR_DEBUG, "[READYLIST] ADVANCED LAST PICK. NOW AT NODE %p (SC %p)",
-            p->ready_list_last_pick, p->ready_list_last_pick->subchannel);
-  }
-}
-
-/** Prepends (relative to the root at p->ready_list) the connected subchannel \a
- * csc to the list of ready subchannels. */
-static ready_list *add_connected_sc_locked(round_robin_lb_policy *p,
-                                           grpc_subchannel *sc) {
-  ready_list *new_elem = gpr_malloc(sizeof(ready_list));
-  new_elem->subchannel = sc;
-  if (p->ready_list.prev == NULL) {
-    /* first element */
-    new_elem->next = &p->ready_list;
-    new_elem->prev = &p->ready_list;
-    p->ready_list.next = new_elem;
-    p->ready_list.prev = new_elem;
-  } else {
-    new_elem->next = &p->ready_list;
-    new_elem->prev = p->ready_list.prev;
-    p->ready_list.prev->next = new_elem;
-    p->ready_list.prev = new_elem;
-  }
-  if (grpc_lb_round_robin_trace) {
-    gpr_log(GPR_DEBUG, "[READYLIST] ADDING NODE %p (SC %p)", new_elem, sc);
-  }
-  return new_elem;
-}
-
-/** Removes \a node from the list of connected subchannels */
-static void remove_disconnected_sc_locked(round_robin_lb_policy *p,
-                                          ready_list *node) {
-  if (node == NULL) {
-    return;
-  }
-  if (node == p->ready_list_last_pick) {
-    /* If removing the lastly picked node, reset the last pick pointer to the
-     * dummy root of the list */
-    p->ready_list_last_pick = &p->ready_list;
-  }
-
-  /* removing last item */
-  if (node->next == &p->ready_list && node->prev == &p->ready_list) {
-    GPR_ASSERT(p->ready_list.next == node);
-    GPR_ASSERT(p->ready_list.prev == node);
-    p->ready_list.next = NULL;
-    p->ready_list.prev = NULL;
-  } else {
-    node->prev->next = node->next;
-    node->next->prev = node->prev;
-  }
-
-  if (grpc_lb_round_robin_trace) {
-    gpr_log(GPR_DEBUG, "[READYLIST] REMOVED NODE %p (SC %p)", node,
-            node->subchannel);
-  }
-
-  node->next = NULL;
-  node->prev = NULL;
-  node->subchannel = NULL;
-
-  gpr_free(node);
-}
-
-void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  size_t i;
-  ready_list *elem;
-  for (i = 0; i < p->num_subchannels; i++) {
-    subchannel_data *sd = p->subchannels[i];
-    GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
-    gpr_free(sd);
-  }
-
-  grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
-  gpr_free(p->subchannels);
-  gpr_mu_destroy(&p->mu);
-
-  elem = p->ready_list.next;
-  while (elem != NULL && elem != &p->ready_list) {
-    ready_list *tmp;
-    tmp = elem->next;
-    elem->next = NULL;
-    elem->prev = NULL;
-    elem->subchannel = NULL;
-    gpr_free(elem);
-    elem = tmp;
-  }
-  gpr_free(p);
-}
-
-void rr_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  pending_pick *pp;
-  size_t i;
-
-  gpr_mu_lock(&p->mu);
-
-  p->shutdown = 1;
-  while ((pp = p->pending_picks)) {
-    p->pending_picks = pp->next;
-    *pp->target = NULL;
-    grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
-    gpr_free(pp);
-  }
-  grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                              GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
-  for (i = 0; i < p->num_subchannels; i++) {
-    subchannel_data *sd = p->subchannels[i];
-    grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, NULL,
-                                           &sd->connectivity_changed_closure);
-  }
-  gpr_mu_unlock(&p->mu);
-}
-
-static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                           grpc_connected_subchannel **target) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  pending_pick *pp;
-  gpr_mu_lock(&p->mu);
-  pp = p->pending_picks;
-  p->pending_picks = NULL;
-  while (pp != NULL) {
-    pending_pick *next = pp->next;
-    if (pp->target == target) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
-      *target = NULL;
-      grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
-      gpr_free(pp);
-    } else {
-      pp->next = p->pending_picks;
-      p->pending_picks = pp;
-    }
-    pp = next;
-  }
-  gpr_mu_unlock(&p->mu);
-}
-
-static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) {
-  size_t i;
-  p->started_picking = 1;
-
-  gpr_log(GPR_DEBUG, "LB_POLICY: p=%p num_subchannels=%d", p,
-          p->num_subchannels);
-
-  for (i = 0; i < p->num_subchannels; i++) {
-    subchannel_data *sd = p->subchannels[i];
-    sd->connectivity_state = GRPC_CHANNEL_IDLE;
-    grpc_subchannel_notify_on_state_change(
-        exec_ctx, sd->subchannel, p->base.interested_parties,
-        &sd->connectivity_state, &sd->connectivity_changed_closure);
-    GRPC_LB_POLICY_WEAK_REF(&p->base, "round_robin_connectivity");
-  }
-}
-
-void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
-  if (!p->started_picking) {
-    start_picking(exec_ctx, p);
-  }
-  gpr_mu_unlock(&p->mu);
-}
-
-int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
-            grpc_metadata_batch *initial_metadata,
-            grpc_connected_subchannel **target, grpc_closure *on_complete) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  pending_pick *pp;
-  ready_list *selected;
-  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);
-    if (grpc_lb_round_robin_trace) {
-      gpr_log(GPR_DEBUG,
-              "[RR PICK] TARGET <-- CONNECTED SUBCHANNEL %p (NODE %p)",
-              selected->subchannel, selected);
-    }
-    /* only advance the last picked pointer if the selection was used */
-    advance_last_picked_locked(p);
-    return 1;
-  } else {
-    if (!p->started_picking) {
-      start_picking(exec_ctx, p);
-    }
-    grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
-    pp = gpr_malloc(sizeof(*pp));
-    pp->next = p->pending_picks;
-    pp->pollset = pollset;
-    pp->target = target;
-    pp->on_complete = on_complete;
-    p->pending_picks = pp;
-    gpr_mu_unlock(&p->mu);
-    return 0;
-  }
-}
-
-static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
-                                    bool iomgr_success) {
-  subchannel_data *sd = arg;
-  round_robin_lb_policy *p = sd->policy;
-  pending_pick *pp;
-  ready_list *selected;
-
-  int unref = 0;
-
-  gpr_mu_lock(&p->mu);
-
-  if (p->shutdown) {
-    unref = 1;
-  } else {
-    switch (sd->connectivity_state) {
-      case GRPC_CHANNEL_READY:
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    GRPC_CHANNEL_READY, "connecting_ready");
-        /* add the newly connected subchannel to the list of connected ones.
-         * Note that it goes to the "end of the line". */
-        sd->ready_list_node = add_connected_sc_locked(p, sd->subchannel);
-        /* at this point we know there's at least one suitable subchannel. Go
-         * ahead and pick one and notify the pending suitors in
-         * p->pending_picks. This preemtively replicates rr_pick()'s actions. */
-        selected = peek_next_connected_locked(p);
-        if (p->pending_picks != NULL) {
-          /* if the selected subchannel is going to be used for the pending
-           * picks, update the last picked pointer */
-          advance_last_picked_locked(p);
-        }
-        while ((pp = p->pending_picks)) {
-          p->pending_picks = pp->next;
-          *pp->target =
-              grpc_subchannel_get_connected_subchannel(selected->subchannel);
-          if (grpc_lb_round_robin_trace) {
-            gpr_log(GPR_DEBUG,
-                    "[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
-                    selected->subchannel, selected);
-          }
-          grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                       pp->pollset);
-          grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
-          gpr_free(pp);
-        }
-        grpc_subchannel_notify_on_state_change(
-            exec_ctx, sd->subchannel, p->base.interested_parties,
-            &sd->connectivity_state, &sd->connectivity_changed_closure);
-        break;
-      case GRPC_CHANNEL_CONNECTING:
-      case GRPC_CHANNEL_IDLE:
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    sd->connectivity_state,
-                                    "connecting_changed");
-        grpc_subchannel_notify_on_state_change(
-            exec_ctx, sd->subchannel, p->base.interested_parties,
-            &sd->connectivity_state, &sd->connectivity_changed_closure);
-        break;
-      case GRPC_CHANNEL_TRANSIENT_FAILURE:
-        /* renew state notification */
-        grpc_subchannel_notify_on_state_change(
-            exec_ctx, sd->subchannel, p->base.interested_parties,
-            &sd->connectivity_state, &sd->connectivity_changed_closure);
-
-        /* remove from ready list if still present */
-        if (sd->ready_list_node != NULL) {
-          remove_disconnected_sc_locked(p, sd->ready_list_node);
-          sd->ready_list_node = NULL;
-        }
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                    "connecting_transient_failure");
-        break;
-      case GRPC_CHANNEL_FATAL_FAILURE:
-        if (sd->ready_list_node != NULL) {
-          remove_disconnected_sc_locked(p, sd->ready_list_node);
-          sd->ready_list_node = NULL;
-        }
-
-        p->num_subchannels--;
-        GPR_SWAP(subchannel_data *, p->subchannels[sd->index],
-                 p->subchannels[p->num_subchannels]);
-        GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
-        p->subchannels[sd->index]->index = sd->index;
-        gpr_free(sd);
-
-        unref = 1;
-        if (p->num_subchannels == 0) {
-          grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                      GRPC_CHANNEL_FATAL_FAILURE,
-                                      "no_more_channels");
-          while ((pp = p->pending_picks)) {
-            p->pending_picks = pp->next;
-            *pp->target = NULL;
-            grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
-            gpr_free(pp);
-          }
-        } else {
-          grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                      GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                      "subchannel_failed");
-        }
-    } /* switch */
-  }   /* !unref */
-
-  gpr_mu_unlock(&p->mu);
-
-  if (unref) {
-    GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "round_robin_connectivity");
-  }
-}
-
-static grpc_connectivity_state rr_check_connectivity(grpc_exec_ctx *exec_ctx,
-                                                     grpc_lb_policy *pol) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  grpc_connectivity_state st;
-  gpr_mu_lock(&p->mu);
-  st = grpc_connectivity_state_check(&p->state_tracker);
-  gpr_mu_unlock(&p->mu);
-  return st;
-}
-
-static void rr_notify_on_state_change(grpc_exec_ctx *exec_ctx,
-                                      grpc_lb_policy *pol,
-                                      grpc_connectivity_state *current,
-                                      grpc_closure *notify) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  gpr_mu_lock(&p->mu);
-  grpc_connectivity_state_notify_on_state_change(exec_ctx, &p->state_tracker,
-                                                 current, notify);
-  gpr_mu_unlock(&p->mu);
-}
-
-static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                        grpc_closure *closure) {
-  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
-  ready_list *selected;
-  grpc_connected_subchannel *target;
-  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);
-    grpc_connected_subchannel_ping(exec_ctx, target, closure);
-  } else {
-    gpr_mu_unlock(&p->mu);
-    grpc_exec_ctx_enqueue(exec_ctx, closure, false, NULL);
-  }
-}
-
-static const grpc_lb_policy_vtable round_robin_lb_policy_vtable = {
-    rr_destroy,
-    rr_shutdown,
-    rr_pick,
-    rr_cancel_pick,
-    rr_ping_one,
-    rr_exit_idle,
-    rr_check_connectivity,
-    rr_notify_on_state_change};
-
-static void round_robin_factory_ref(grpc_lb_policy_factory *factory) {}
-
-static void round_robin_factory_unref(grpc_lb_policy_factory *factory) {}
-
-static grpc_lb_policy *create_round_robin(grpc_lb_policy_factory *factory,
-                                          grpc_lb_policy_args *args) {
-  size_t i;
-  round_robin_lb_policy *p = gpr_malloc(sizeof(*p));
-  GPR_ASSERT(args->num_subchannels > 0);
-  memset(p, 0, sizeof(*p));
-  grpc_lb_policy_init(&p->base, &round_robin_lb_policy_vtable);
-  p->num_subchannels = args->num_subchannels;
-  p->subchannels = gpr_malloc(sizeof(*p->subchannels) * p->num_subchannels);
-  memset(p->subchannels, 0, sizeof(*p->subchannels) * p->num_subchannels);
-  grpc_connectivity_state_init(&p->state_tracker, GRPC_CHANNEL_IDLE,
-                               "round_robin");
-
-  gpr_mu_init(&p->mu);
-  for (i = 0; i < args->num_subchannels; i++) {
-    subchannel_data *sd = gpr_malloc(sizeof(*sd));
-    memset(sd, 0, sizeof(*sd));
-    p->subchannels[i] = sd;
-    sd->policy = p;
-    sd->index = i;
-    sd->subchannel = args->subchannels[i];
-    grpc_closure_init(&sd->connectivity_changed_closure,
-                      rr_connectivity_changed, sd);
-  }
-
-  /* The (dummy node) root of the ready list */
-  p->ready_list.subchannel = NULL;
-  p->ready_list.prev = NULL;
-  p->ready_list.next = NULL;
-  p->ready_list_last_pick = &p->ready_list;
-
-  return &p->base;
-}
-
-static const grpc_lb_policy_factory_vtable round_robin_factory_vtable = {
-    round_robin_factory_ref, round_robin_factory_unref, create_round_robin,
-    "round_robin"};
-
-static grpc_lb_policy_factory round_robin_lb_policy_factory = {
-    &round_robin_factory_vtable};
-
-grpc_lb_policy_factory *grpc_round_robin_lb_factory_create() {
-  return &round_robin_lb_policy_factory;
-}
diff --git a/src/core/lib/client_config/lb_policies/round_robin.h b/src/core/lib/client_config/lb_policies/round_robin.h
deleted file mode 100644
index 52db1caa0c..0000000000
--- a/src/core/lib/client_config/lb_policies/round_robin.h
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H
-
-#include "src/core/lib/client_config/lb_policy.h"
-
-extern int grpc_lb_round_robin_trace;
-
-#include "src/core/lib/client_config/lb_policy_factory.h"
-
-/** Returns a load balancing factory for the round robin policy */
-grpc_lb_policy_factory *grpc_round_robin_lb_factory_create();
-
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICIES_ROUND_ROBIN_H */
diff --git a/src/core/lib/client_config/lb_policy.c b/src/core/lib/client_config/lb_policy.c
index ee20ccd76a..3d23669ec2 100644
--- a/src/core/lib/client_config/lb_policy.c
+++ b/src/core/lib/client_config/lb_policy.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/lb_policy.h b/src/core/lib/client_config/lb_policy.h
index 58a0a04d85..a63e8e68df 100644
--- a/src/core/lib/client_config/lb_policy.h
+++ b/src/core/lib/client_config/lb_policy.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/lb_policy_factory.c b/src/core/lib/client_config/lb_policy_factory.c
index 2ca6f42f89..92e1f5f08b 100644
--- a/src/core/lib/client_config/lb_policy_factory.c
+++ b/src/core/lib/client_config/lb_policy_factory.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,7 +42,8 @@ void grpc_lb_policy_factory_unref(grpc_lb_policy_factory* factory) {
 }
 
 grpc_lb_policy* grpc_lb_policy_factory_create_lb_policy(
-    grpc_lb_policy_factory* factory, grpc_lb_policy_args* args) {
+    grpc_exec_ctx* exec_ctx, grpc_lb_policy_factory* factory,
+    grpc_lb_policy_args* args) {
   if (factory == NULL) return NULL;
-  return factory->vtable->create_lb_policy(factory, args);
+  return factory->vtable->create_lb_policy(exec_ctx, factory, args);
 }
diff --git a/src/core/lib/client_config/lb_policy_factory.h b/src/core/lib/client_config/lb_policy_factory.h
index 36eaf178d9..4931d4df58 100644
--- a/src/core/lib/client_config/lb_policy_factory.h
+++ b/src/core/lib/client_config/lb_policy_factory.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,8 +34,11 @@
 #ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H
 #define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H
 
+#include "src/core/lib/client_config/client_channel_factory.h"
 #include "src/core/lib/client_config/lb_policy.h"
-#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+
+#include "src/core/lib/iomgr/exec_ctx.h"
 
 typedef struct grpc_lb_policy_factory grpc_lb_policy_factory;
 typedef struct grpc_lb_policy_factory_vtable grpc_lb_policy_factory_vtable;
@@ -47,8 +50,8 @@ struct grpc_lb_policy_factory {
 };
 
 typedef struct grpc_lb_policy_args {
-  grpc_subchannel **subchannels;
-  size_t num_subchannels;
+  grpc_resolved_addresses *addresses;
+  grpc_client_channel_factory *client_channel_factory;
 } grpc_lb_policy_args;
 
 struct grpc_lb_policy_factory_vtable {
@@ -56,7 +59,8 @@ struct grpc_lb_policy_factory_vtable {
   void (*unref)(grpc_lb_policy_factory *factory);
 
   /** Implementation of grpc_lb_policy_factory_create_lb_policy */
-  grpc_lb_policy *(*create_lb_policy)(grpc_lb_policy_factory *factory,
+  grpc_lb_policy *(*create_lb_policy)(grpc_exec_ctx *exec_ctx,
+                                      grpc_lb_policy_factory *factory,
                                       grpc_lb_policy_args *args);
 
   /** Name for the LB policy this factory implements */
@@ -68,6 +72,7 @@ void grpc_lb_policy_factory_unref(grpc_lb_policy_factory *factory);
 
 /** Create a lb_policy instance. */
 grpc_lb_policy *grpc_lb_policy_factory_create_lb_policy(
-    grpc_lb_policy_factory *factory, grpc_lb_policy_args *args);
+    grpc_exec_ctx *exec_ctx, grpc_lb_policy_factory *factory,
+    grpc_lb_policy_args *args);
 
 #endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H */
diff --git a/src/core/lib/client_config/lb_policy_registry.c b/src/core/lib/client_config/lb_policy_registry.c
index 13acfe78cd..af396362a1 100644
--- a/src/core/lib/client_config/lb_policy_registry.c
+++ b/src/core/lib/client_config/lb_policy_registry.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -40,12 +40,7 @@
 static grpc_lb_policy_factory *g_all_of_the_lb_policies[MAX_POLICIES];
 static int g_number_of_lb_policies = 0;
 
-static grpc_lb_policy_factory *g_default_lb_policy_factory;
-
-void grpc_lb_policy_registry_init(grpc_lb_policy_factory *default_factory) {
-  g_number_of_lb_policies = 0;
-  g_default_lb_policy_factory = default_factory;
-}
+void grpc_lb_policy_registry_init(void) { g_number_of_lb_policies = 0; }
 
 void grpc_lb_policy_registry_shutdown(void) {
   int i;
@@ -79,10 +74,10 @@ static grpc_lb_policy_factory *lookup_factory(const char *name) {
   return NULL;
 }
 
-grpc_lb_policy *grpc_lb_policy_create(const char *name,
+grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
                                       grpc_lb_policy_args *args) {
   grpc_lb_policy_factory *factory = lookup_factory(name);
   grpc_lb_policy *lb_policy =
-      grpc_lb_policy_factory_create_lb_policy(factory, args);
+      grpc_lb_policy_factory_create_lb_policy(exec_ctx, factory, args);
   return lb_policy;
 }
diff --git a/src/core/lib/client_config/lb_policy_registry.h b/src/core/lib/client_config/lb_policy_registry.h
index c251fd9f08..4b8495d8a1 100644
--- a/src/core/lib/client_config/lb_policy_registry.h
+++ b/src/core/lib/client_config/lb_policy_registry.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -35,10 +35,11 @@
 #define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
 
 #include "src/core/lib/client_config/lb_policy_factory.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
 
 /** Initialize the registry and set \a default_factory as the factory to be
  * returned when no name is provided in a lookup */
-void grpc_lb_policy_registry_init(grpc_lb_policy_factory *default_factory);
+void grpc_lb_policy_registry_init(void);
 void grpc_lb_policy_registry_shutdown(void);
 
 /** Register a LB policy factory. */
@@ -48,7 +49,7 @@ void grpc_register_lb_policy(grpc_lb_policy_factory *factory);
  *
  * If \a name is NULL, the default factory from \a grpc_lb_policy_registry_init
  * will be returned. */
-grpc_lb_policy *grpc_lb_policy_create(const char *name,
+grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
                                       grpc_lb_policy_args *args);
 
 #endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H */
diff --git a/src/core/lib/client_config/resolver.c b/src/core/lib/client_config/resolver.c
index 32f0643adb..b9eef5575f 100644
--- a/src/core/lib/client_config/resolver.c
+++ b/src/core/lib/client_config/resolver.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolver.h b/src/core/lib/client_config/resolver.h
index 1ee879293a..cf0bb2bc7a 100644
--- a/src/core/lib/client_config/resolver.h
+++ b/src/core/lib/client_config/resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolver_factory.c b/src/core/lib/client_config/resolver_factory.c
index 0f76c664fa..001fa28536 100644
--- a/src/core/lib/client_config/resolver_factory.c
+++ b/src/core/lib/client_config/resolver_factory.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolver_factory.h b/src/core/lib/client_config/resolver_factory.h
index 91bdbfe01c..18c7fd7d62 100644
--- a/src/core/lib/client_config/resolver_factory.h
+++ b/src/core/lib/client_config/resolver_factory.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolver_registry.c b/src/core/lib/client_config/resolver_registry.c
index ff03041bc5..5450791a00 100644
--- a/src/core/lib/client_config/resolver_registry.c
+++ b/src/core/lib/client_config/resolver_registry.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolver_registry.h b/src/core/lib/client_config/resolver_registry.h
index eec830bbcb..e7eec6d3a6 100644
--- a/src/core/lib/client_config/resolver_registry.h
+++ b/src/core/lib/client_config/resolver_registry.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolvers/dns_resolver.c b/src/core/lib/client_config/resolvers/dns_resolver.c
index 078fda298a..45401e1281 100644
--- a/src/core/lib/client_config/resolvers/dns_resolver.c
+++ b/src/core/lib/client_config/resolvers/dns_resolver.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -162,39 +162,23 @@ static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
                             grpc_resolved_addresses *addresses) {
   dns_resolver *r = arg;
   grpc_client_config *config = NULL;
-  grpc_subchannel **subchannels;
-  grpc_subchannel_args args;
   grpc_lb_policy *lb_policy;
-  size_t i;
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(r->resolving);
   r->resolving = 0;
   if (addresses != NULL) {
     grpc_lb_policy_args lb_policy_args;
     config = grpc_client_config_create();
-    subchannels = gpr_malloc(sizeof(grpc_subchannel *) * addresses->naddrs);
-    size_t naddrs = 0;
-    for (i = 0; i < addresses->naddrs; i++) {
-      memset(&args, 0, sizeof(args));
-      args.addr = (struct sockaddr *)(addresses->addrs[i].addr);
-      args.addr_len = (size_t)addresses->addrs[i].len;
-      grpc_subchannel *subchannel =
-          grpc_client_channel_factory_create_subchannel(
-              exec_ctx, r->client_channel_factory, &args);
-      if (subchannel != NULL) {
-        subchannels[naddrs++] = subchannel;
-      }
-    }
     memset(&lb_policy_args, 0, sizeof(lb_policy_args));
-    lb_policy_args.subchannels = subchannels;
-    lb_policy_args.num_subchannels = naddrs;
-    lb_policy = grpc_lb_policy_create(r->lb_policy_name, &lb_policy_args);
+    lb_policy_args.addresses = addresses;
+    lb_policy_args.client_channel_factory = r->client_channel_factory;
+    lb_policy =
+        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
     if (lb_policy != NULL) {
       grpc_client_config_set_lb_policy(config, lb_policy);
       GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
     }
     grpc_resolved_addresses_destroy(addresses);
-    gpr_free(subchannels);
   } else {
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
     gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
diff --git a/src/core/lib/client_config/resolvers/dns_resolver.h b/src/core/lib/client_config/resolvers/dns_resolver.h
index eb46e41c77..de41961ea9 100644
--- a/src/core/lib/client_config/resolvers/dns_resolver.h
+++ b/src/core/lib/client_config/resolvers/dns_resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolvers/sockaddr_resolver.c b/src/core/lib/client_config/resolvers/sockaddr_resolver.c
index c2492a44b4..f1f3c782f7 100644
--- a/src/core/lib/client_config/resolvers/sockaddr_resolver.c
+++ b/src/core/lib/client_config/resolvers/sockaddr_resolver.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -58,11 +58,7 @@ typedef struct {
   char *lb_policy_name;
 
   /** the addresses that we've 'resolved' */
-  struct sockaddr_storage *addrs;
-  /** the corresponding length of the addresses */
-  size_t *addrs_len;
-  /** how many elements in \a addrs */
-  size_t num_addrs;
+  grpc_resolved_addresses *addresses;
 
   /** mutex guarding the rest of the state */
   gpr_mu mu;
@@ -125,28 +121,14 @@ static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
 
 static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
                                               sockaddr_resolver *r) {
-  grpc_client_config *cfg;
-  grpc_lb_policy *lb_policy;
-  grpc_lb_policy_args lb_policy_args;
-  grpc_subchannel **subchannels;
-  grpc_subchannel_args args;
-
   if (r->next_completion != NULL && !r->published) {
-    size_t i;
-    cfg = grpc_client_config_create();
-    subchannels = gpr_malloc(sizeof(grpc_subchannel *) * r->num_addrs);
-    for (i = 0; i < r->num_addrs; i++) {
-      memset(&args, 0, sizeof(args));
-      args.addr = (struct sockaddr *)&r->addrs[i];
-      args.addr_len = r->addrs_len[i];
-      subchannels[i] = grpc_client_channel_factory_create_subchannel(
-          exec_ctx, r->client_channel_factory, &args);
-    }
+    grpc_client_config *cfg = grpc_client_config_create();
+    grpc_lb_policy_args lb_policy_args;
     memset(&lb_policy_args, 0, sizeof(lb_policy_args));
-    lb_policy_args.subchannels = subchannels;
-    lb_policy_args.num_subchannels = r->num_addrs;
-    lb_policy = grpc_lb_policy_create(r->lb_policy_name, &lb_policy_args);
-    gpr_free(subchannels);
+    lb_policy_args.addresses = r->addresses;
+    lb_policy_args.client_channel_factory = r->client_channel_factory;
+    grpc_lb_policy *lb_policy =
+        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
     grpc_client_config_set_lb_policy(cfg, lb_policy);
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "sockaddr");
     r->published = 1;
@@ -160,8 +142,7 @@ static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   sockaddr_resolver *r = (sockaddr_resolver *)gr;
   gpr_mu_destroy(&r->mu);
   grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory);
-  gpr_free(r->addrs);
-  gpr_free(r->addrs_len);
+  grpc_resolved_addresses_destroy(r->addresses);
   gpr_free(r->lb_policy_name);
   gpr_free(r);
 }
@@ -269,7 +250,6 @@ static void do_nothing(void *ignored) {}
 static grpc_resolver *sockaddr_create(
     grpc_resolver_args *args, const char *default_lb_policy_name,
     int parse(grpc_uri *uri, struct sockaddr_storage *dst, size_t *len)) {
-  size_t i;
   int errors_found = 0; /* GPR_FALSE */
   sockaddr_resolver *r;
   gpr_slice path_slice;
@@ -309,15 +289,18 @@ static grpc_resolver *sockaddr_create(
   gpr_slice_buffer_init(&path_parts);
 
   gpr_slice_split(path_slice, ",", &path_parts);
-  r->num_addrs = path_parts.count;
-  r->addrs = gpr_malloc(sizeof(struct sockaddr_storage) * r->num_addrs);
-  r->addrs_len = gpr_malloc(sizeof(*r->addrs_len) * r->num_addrs);
+  r->addresses = gpr_malloc(sizeof(grpc_resolved_addresses));
+  r->addresses->naddrs = path_parts.count;
+  r->addresses->addrs =
+      gpr_malloc(sizeof(grpc_resolved_address) * r->addresses->naddrs);
 
-  for (i = 0; i < r->num_addrs; i++) {
+  for (size_t i = 0; i < r->addresses->naddrs; 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, &r->addrs[i], &r->addrs_len[i])) {
+    if (!parse(&ith_uri,
+               (struct sockaddr_storage *)(&r->addresses->addrs[i].addr),
+               &r->addresses->addrs[i].len)) {
       errors_found = 1; /* GPR_TRUE */
     }
     gpr_free(part_str);
@@ -328,8 +311,7 @@ static grpc_resolver *sockaddr_create(
   gpr_slice_unref(path_slice);
   if (errors_found) {
     gpr_free(r->lb_policy_name);
-    gpr_free(r->addrs);
-    gpr_free(r->addrs_len);
+    grpc_resolved_addresses_destroy(r->addresses);
     gpr_free(r);
     return NULL;
   }
diff --git a/src/core/lib/client_config/resolvers/sockaddr_resolver.h b/src/core/lib/client_config/resolvers/sockaddr_resolver.h
index 45c55bd160..a8b208176c 100644
--- a/src/core/lib/client_config/resolvers/sockaddr_resolver.h
+++ b/src/core/lib/client_config/resolvers/sockaddr_resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/resolvers/zookeeper_resolver.c b/src/core/lib/client_config/resolvers/zookeeper_resolver.c
index 4548344611..f158090e67 100644
--- a/src/core/lib/client_config/resolvers/zookeeper_resolver.c
+++ b/src/core/lib/client_config/resolvers/zookeeper_resolver.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -184,28 +184,21 @@ static void zookeeper_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
                                   grpc_resolved_addresses *addresses) {
   zookeeper_resolver *r = arg;
   grpc_client_config *config = NULL;
-  grpc_subchannel **subchannels;
-  grpc_subchannel_args args;
   grpc_lb_policy *lb_policy;
-  size_t i;
+
   if (addresses != NULL) {
     grpc_lb_policy_args lb_policy_args;
     config = grpc_client_config_create();
-    subchannels = gpr_malloc(sizeof(grpc_subchannel *) * addresses->naddrs);
-    for (i = 0; i < addresses->naddrs; i++) {
-      memset(&args, 0, sizeof(args));
-      args.addr = (struct sockaddr *)(addresses->addrs[i].addr);
-      args.addr_len = addresses->addrs[i].len;
-      subchannels[i] = grpc_client_channel_factory_create_subchannel(
-          exec_ctx, r->client_channel_factory, &args);
+    lb_policy_args.addresses = addresses;
+    lb_policy_args.client_channel_factory = r->client_channel_factory;
+    lb_policy =
+        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+
+    if (lb_policy != NULL) {
+      grpc_client_config_set_lb_policy(config, lb_policy);
+      GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
     }
-    lb_policy_args.subchannels = subchannels;
-    lb_policy_args.num_subchannels = addresses->naddrs;
-    lb_policy = grpc_lb_policy_create(r->lb_policy_name, &lb_policy_args);
-    grpc_client_config_set_lb_policy(config, lb_policy);
-    GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
     grpc_resolved_addresses_destroy(addresses);
-    gpr_free(subchannels);
   }
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(r->resolving == 1);
diff --git a/src/core/lib/client_config/resolvers/zookeeper_resolver.h b/src/core/lib/client_config/resolvers/zookeeper_resolver.h
index 7ee7604360..a067bd0bdb 100644
--- a/src/core/lib/client_config/resolvers/zookeeper_resolver.h
+++ b/src/core/lib/client_config/resolvers/zookeeper_resolver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/subchannel.c b/src/core/lib/client_config/subchannel.c
index 41242f0dd7..47c53a16ba 100644
--- a/src/core/lib/client_config/subchannel.c
+++ b/src/core/lib/client_config/subchannel.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/subchannel.h b/src/core/lib/client_config/subchannel.h
index b4f545be52..68aeff39a1 100644
--- a/src/core/lib/client_config/subchannel.h
+++ b/src/core/lib/client_config/subchannel.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/client_config/uri_parser.c b/src/core/lib/client_config/uri_parser.c
index d3228dec5f..6bec70da2d 100644
--- a/src/core/lib/client_config/uri_parser.c
+++ b/src/core/lib/client_config/uri_parser.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -38,8 +38,12 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/port_platform.h>
+#include <grpc/support/slice.h>
+#include <grpc/support/slice_buffer.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/support/string.h"
+
 /** a size_t default value... maps to all 1's */
 #define NOT_SET (~(size_t)0)
 
@@ -133,6 +137,51 @@ static int parse_fragment_or_query(const char *uri_text, size_t *i) {
   return 1;
 }
 
+static void do_nothing(void *ignored) {}
+static void parse_query_parts(grpc_uri *uri) {
+  static const char *QUERY_PARTS_SEPARATOR = "&";
+  static const char *QUERY_PARTS_VALUE_SEPARATOR = "=";
+  GPR_ASSERT(uri->query != NULL);
+  if (uri->query[0] == '\0') {
+    uri->query_parts = NULL;
+    uri->query_parts_values = NULL;
+    uri->num_query_parts = 0;
+    return;
+  }
+  gpr_slice query_slice =
+      gpr_slice_new(uri->query, strlen(uri->query), do_nothing);
+  gpr_slice_buffer query_parts; /* the &-separated elements of the query */
+  gpr_slice_buffer query_param_parts; /* the =-separated subelements */
+
+  gpr_slice_buffer_init(&query_parts);
+  gpr_slice_buffer_init(&query_param_parts);
+
+  gpr_slice_split(query_slice, QUERY_PARTS_SEPARATOR, &query_parts);
+  uri->query_parts = gpr_malloc(query_parts.count * sizeof(char *));
+  uri->query_parts_values = gpr_malloc(query_parts.count * sizeof(char *));
+  uri->num_query_parts = query_parts.count;
+  for (size_t i = 0; i < query_parts.count; i++) {
+    gpr_slice_split(query_parts.slices[i], QUERY_PARTS_VALUE_SEPARATOR,
+                    &query_param_parts);
+    GPR_ASSERT(query_param_parts.count > 0);
+    uri->query_parts[i] =
+        gpr_dump_slice(query_param_parts.slices[0], GPR_DUMP_ASCII);
+    if (query_param_parts.count > 1) {
+      /* TODO(dgq): only the first value after the separator is considered.
+       * Perhaps all chars after the first separator for the query part should
+       * be included, even if they include the separator. */
+      uri->query_parts_values[i] =
+          gpr_dump_slice(query_param_parts.slices[1], GPR_DUMP_ASCII);
+    } else {
+      uri->query_parts_values[i] = NULL;
+    }
+    gpr_slice_buffer_reset_and_unref(&query_param_parts);
+  }
+  gpr_slice_buffer_destroy(&query_parts);
+  gpr_slice_buffer_destroy(&query_param_parts);
+  gpr_slice_unref(query_slice);
+}
+
 grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors) {
   grpc_uri *uri;
   size_t scheme_begin = 0;
@@ -227,16 +276,35 @@ grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors) {
   uri->path = copy_component(uri_text, path_begin, path_end);
   uri->query = copy_component(uri_text, query_begin, query_end);
   uri->fragment = copy_component(uri_text, fragment_begin, fragment_end);
+  parse_query_parts(uri);
 
   return uri;
 }
 
+const char *grpc_uri_get_query_arg(const grpc_uri *uri, const char *key) {
+  GPR_ASSERT(key != NULL);
+  if (key[0] == '\0') return NULL;
+
+  for (size_t i = 0; i < uri->num_query_parts; ++i) {
+    if (0 == strcmp(key, uri->query_parts[i])) {
+      return uri->query_parts_values[i];
+    }
+  }
+  return NULL;
+}
+
 void grpc_uri_destroy(grpc_uri *uri) {
   if (!uri) return;
   gpr_free(uri->scheme);
   gpr_free(uri->authority);
   gpr_free(uri->path);
   gpr_free(uri->query);
+  for (size_t i = 0; i < uri->num_query_parts; ++i) {
+    gpr_free(uri->query_parts[i]);
+    gpr_free(uri->query_parts_values[i]);
+  }
+  gpr_free(uri->query_parts);
+  gpr_free(uri->query_parts_values);
   gpr_free(uri->fragment);
   gpr_free(uri);
 }
diff --git a/src/core/lib/client_config/uri_parser.h b/src/core/lib/client_config/uri_parser.h
index d70d451e60..5d6785d293 100644
--- a/src/core/lib/client_config/uri_parser.h
+++ b/src/core/lib/client_config/uri_parser.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,17 +34,29 @@
 #ifndef GRPC_CORE_LIB_CLIENT_CONFIG_URI_PARSER_H
 #define GRPC_CORE_LIB_CLIENT_CONFIG_URI_PARSER_H
 
+#include <stddef.h>
+
 typedef struct {
   char *scheme;
   char *authority;
   char *path;
   char *query;
+  /** Query substrings separated by '&' */
+  char **query_parts;
+  /** Number of elements in \a query_parts and \a query_parts_values */
+  size_t num_query_parts;
+  /** Split each query part by '='. NULL if not present. */
+  char **query_parts_values;
   char *fragment;
 } grpc_uri;
 
 /** parse a uri, return NULL on failure */
 grpc_uri *grpc_uri_parse(const char *uri_text, int suppress_errors);
 
+/** return the part of a query string after the '=' in "?key=xxx&...", or NULL
+ * if key is not present */
+const char *grpc_uri_get_query_arg(const grpc_uri *uri, const char *key);
+
 /** destroy a uri */
 void grpc_uri_destroy(grpc_uri *uri);