Merge remote-tracking branch 'upstream/master' into timespec

22 files changed, 234 insertions, 110 deletions

diff --git a/src/core/channel/census_filter.c b/src/core/census/grpc_filter.c
index d996c3475e..fbedb35661 100644
--- a/src/core/channel/census_filter.c
+++ b/src/core/census/grpc_filter.c
@@ -31,11 +31,13 @@
  *
  */
 
-#include "src/core/channel/census_filter.h"
+#include "src/core/census/grpc_filter.h"
 
 #include <stdio.h>
 #include <string.h>
 
+#include "include/grpc/census.h"
+#include "src/core/census/rpc_stat_id.h"
 #include "src/core/channel/channel_stack.h"
 #include "src/core/channel/noop_filter.h"
 #include "src/core/statistics/census_interface.h"
@@ -47,24 +49,19 @@
 
 typedef struct call_data {
   census_op_id op_id;
-  census_rpc_stats stats;
+  census_context* ctxt;
   gpr_timespec start_ts;
+  int error;
 
   /* recv callback */
   grpc_stream_op_buffer* recv_ops;
-  void (*on_done_recv)(void* user_data, int success);
-  void* recv_user_data;
+  grpc_iomgr_closure* on_done_recv;
 } call_data;
 
 typedef struct channel_data {
   grpc_mdstr* path_str; /* pointer to meta data str with key == ":path" */
 } channel_data;
 
-static void init_rpc_stats(census_rpc_stats* stats) {
-  memset(stats, 0, sizeof(census_rpc_stats));
-  stats->cnt = 1;
-}
-
 static void extract_and_annotate_method_tag(grpc_stream_op_buffer* sopb,
                                             call_data* calld,
                                             channel_data* chand) {
@@ -77,8 +74,7 @@ static void extract_and_annotate_method_tag(grpc_stream_op_buffer* sopb,
       if (m->md->key == chand->path_str) {
         gpr_log(GPR_DEBUG, "%s",
                 (const char*)GPR_SLICE_START_PTR(m->md->value->slice));
-        census_add_method_tag(calld->op_id, (const char*)GPR_SLICE_START_PTR(
-                                                m->md->value->slice));
+        /* Add method tag here */
       }
     }
   }
@@ -95,8 +91,6 @@ static void client_mutate_op(grpc_call_element* elem,
 
 static void client_start_transport_op(grpc_call_element* elem,
                                       grpc_transport_stream_op* op) {
-  call_data* calld = elem->call_data;
-  GPR_ASSERT((calld->op_id.upper != 0) || (calld->op_id.lower != 0));
   client_mutate_op(elem, op);
   grpc_call_next_op(elem, op);
 }
@@ -108,7 +102,7 @@ static void server_on_done_recv(void* ptr, int success) {
   if (success) {
     extract_and_annotate_method_tag(calld->recv_ops, calld, chand);
   }
-  calld->on_done_recv(calld->recv_user_data, success);
+  calld->on_done_recv->cb(calld->on_done_recv->cb_arg, success);
 }
 
 static void server_mutate_op(grpc_call_element* elem,
@@ -118,9 +112,7 @@ static void server_mutate_op(grpc_call_element* elem,
     /* substitute our callback for the op callback */
     calld->recv_ops = op->recv_ops;
     calld->on_done_recv = op->on_done_recv;
-    calld->recv_user_data = op->recv_user_data;
-    op->on_done_recv = server_on_done_recv;
-    op->recv_user_data = elem;
+    op->on_done_recv = calld->on_done_recv;
   }
 }
 
@@ -132,35 +124,19 @@ static void server_start_transport_op(grpc_call_element* elem,
   grpc_call_next_op(elem, op);
 }
 
-static void channel_op(grpc_channel_element* elem,
-                       grpc_channel_element* from_elem, grpc_channel_op* op) {
-  switch (op->type) {
-    case GRPC_TRANSPORT_CLOSED:
-      /* TODO(hongyu): Annotate trace information for all calls of the channel
-       */
-      break;
-    default:
-      break;
-  }
-  grpc_channel_next_op(elem, op);
-}
-
 static void client_init_call_elem(grpc_call_element* elem,
                                   const void* server_transport_data,
                                   grpc_transport_stream_op* initial_op) {
   call_data* d = elem->call_data;
   GPR_ASSERT(d != NULL);
-  init_rpc_stats(&d->stats);
   d->start_ts = gpr_now(GPR_CLOCK_REALTIME);
-  d->op_id = census_tracing_start_op();
   if (initial_op) client_mutate_op(elem, initial_op);
 }
 
 static void client_destroy_call_elem(grpc_call_element* elem) {
   call_data* d = elem->call_data;
   GPR_ASSERT(d != NULL);
-  census_record_rpc_client_stats(d->op_id, &d->stats);
-  census_tracing_end_op(d->op_id);
+  /* TODO(hongyu): record rpc client stats and census_rpc_end_op here */
 }
 
 static void server_init_call_elem(grpc_call_element* elem,
@@ -168,29 +144,24 @@ static void server_init_call_elem(grpc_call_element* elem,
                                   grpc_transport_stream_op* initial_op) {
   call_data* d = elem->call_data;
   GPR_ASSERT(d != NULL);
-  init_rpc_stats(&d->stats);
   d->start_ts = gpr_now(GPR_CLOCK_REALTIME);
-  d->op_id = census_tracing_start_op();
+  /* TODO(hongyu): call census_tracing_start_op here. */
+  grpc_iomgr_closure_init(d->on_done_recv, server_on_done_recv, elem);
   if (initial_op) server_mutate_op(elem, initial_op);
 }
 
 static void server_destroy_call_elem(grpc_call_element* elem) {
   call_data* d = elem->call_data;
   GPR_ASSERT(d != NULL);
-  d->stats.elapsed_time_ms = gpr_timespec_to_micros(
-      gpr_time_sub(gpr_now(GPR_CLOCK_REALTIME), d->start_ts));
-  census_record_rpc_server_stats(d->op_id, &d->stats);
-  census_tracing_end_op(d->op_id);
+  /* TODO(hongyu): record rpc server stats and census_tracing_end_op here */
 }
 
-static void init_channel_elem(grpc_channel_element* elem,
+static void init_channel_elem(grpc_channel_element* elem, grpc_channel* master,
                               const grpc_channel_args* args, grpc_mdctx* mdctx,
                               int is_first, int is_last) {
   channel_data* chand = elem->channel_data;
   GPR_ASSERT(chand != NULL);
-  GPR_ASSERT(!is_first);
-  GPR_ASSERT(!is_last);
-  chand->path_str = grpc_mdstr_from_string(mdctx, ":path");
+  chand->path_str = grpc_mdstr_from_string(mdctx, ":path", 0);
 }
 
 static void destroy_channel_elem(grpc_channel_element* elem) {
@@ -203,22 +174,24 @@ static void destroy_channel_elem(grpc_channel_element* elem) {
 
 const grpc_channel_filter grpc_client_census_filter = {
     client_start_transport_op,
-    channel_op,
+    grpc_channel_next_op,
     sizeof(call_data),
     client_init_call_elem,
     client_destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
     destroy_channel_elem,
+    grpc_call_next_get_peer,
     "census-client"};
 
 const grpc_channel_filter grpc_server_census_filter = {
     server_start_transport_op,
-    channel_op,
+    grpc_channel_next_op,
     sizeof(call_data),
     server_init_call_elem,
     server_destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
     destroy_channel_elem,
+    grpc_call_next_get_peer,
     "census-server"};
diff --git a/src/core/channel/census_filter.h b/src/core/census/grpc_filter.h
index 1453c05d28..1453c05d28 100644
--- a/src/core/channel/census_filter.h
+++ b/src/core/census/grpc_filter.h
diff --git a/src/core/channel/channel_args.c b/src/core/channel/channel_args.c
index c430b56fa2..54ee75af28 100644
--- a/src/core/channel/channel_args.c
+++ b/src/core/channel/channel_args.c
@@ -37,6 +37,7 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
+#include <grpc/support/useful.h>
 
 #include <string.h>
 
@@ -146,3 +147,65 @@ grpc_channel_args *grpc_channel_args_set_compression_algorithm(
   tmp.value.integer = algorithm;
   return grpc_channel_args_copy_and_add(a, &tmp, 1);
 }
+
+/** Returns 1 if the argument for compression algorithm's enabled states bitset
+ * was found in \a a, returning the arg's value in \a states. Otherwise, returns
+ * 0. */
+static int find_compression_algorithm_states_bitset(
+    const grpc_channel_args *a, int **states_arg) {
+  if (a != NULL) {
+    size_t i;
+    for (i = 0; i < a->num_args; ++i) {
+      if (a->args[i].type == GRPC_ARG_INTEGER &&
+          !strcmp(GRPC_COMPRESSION_ALGORITHM_STATE_ARG, a->args[i].key)) {
+        *states_arg = &a->args[i].value.integer;
+        return 1; /* GPR_TRUE */
+      }
+    }
+  }
+  return 0; /* GPR_FALSE */
+}
+
+grpc_channel_args *grpc_channel_args_compression_algorithm_set_state(
+    grpc_channel_args **a,
+    grpc_compression_algorithm algorithm,
+    int state) {
+  int *states_arg;
+  grpc_channel_args *result = *a;
+  const int states_arg_found =
+      find_compression_algorithm_states_bitset(*a, &states_arg);
+
+  if (states_arg_found) {
+    if (state != 0) {
+      GPR_BITSET(states_arg, algorithm);
+    } else {
+      GPR_BITCLEAR(states_arg, algorithm);
+    }
+  } else {
+    /* create a new arg */
+    grpc_arg tmp;
+    tmp.type = GRPC_ARG_INTEGER;
+    tmp.key = GRPC_COMPRESSION_ALGORITHM_STATE_ARG;
+    /* all enabled by default */
+    tmp.value.integer = (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1;
+    if (state != 0) {
+      GPR_BITSET(&tmp.value.integer, algorithm);
+    } else {
+      GPR_BITCLEAR(&tmp.value.integer, algorithm);
+    }
+    result = grpc_channel_args_copy_and_add(*a, &tmp, 1);
+    grpc_channel_args_destroy(*a);
+    *a = result;
+  }
+  return result;
+}
+
+int grpc_channel_args_compression_algorithm_get_states(
+    const grpc_channel_args *a) {
+  int *states_arg;
+  if (find_compression_algorithm_states_bitset(a, &states_arg)) {
+    return *states_arg;
+  } else {
+    return (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1; /* All algs. enabled */
+  }
+}
diff --git a/src/core/channel/channel_args.h b/src/core/channel/channel_args.h
index 7e6ddd3997..06a6012dee 100644
--- a/src/core/channel/channel_args.h
+++ b/src/core/channel/channel_args.h
@@ -67,4 +67,24 @@ grpc_compression_algorithm grpc_channel_args_get_compression_algorithm(
 grpc_channel_args *grpc_channel_args_set_compression_algorithm(
     grpc_channel_args *a, grpc_compression_algorithm algorithm);
 
+/** Sets the support for the given compression algorithm. By default, all
+ * compression algorithms are enabled. It's an error to disable an algorithm set
+ * by grpc_channel_args_set_compression_algorithm.
+ *
+ * Returns an instance will the updated algorithm states. The \a a pointer is
+ * modified to point to the returned instance (which may be different from the
+ * input value of \a a). */
+grpc_channel_args *grpc_channel_args_compression_algorithm_set_state(
+    grpc_channel_args **a,
+    grpc_compression_algorithm algorithm,
+    int enabled);
+
+/** Returns the bitset representing the support state (true for enabled, false
+ * for disabled) for compression algorithms.
+ *
+ * The i-th bit of the returned bitset corresponds to the i-th entry in the
+ * grpc_compression_algorithm enum. */
+int grpc_channel_args_compression_algorithm_get_states(
+    const grpc_channel_args *a);
+
 #endif /* GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_ARGS_H */
diff --git a/src/core/client_config/resolvers/sockaddr_resolver.c b/src/core/client_config/resolvers/sockaddr_resolver.c
index 74584e7e2c..8419873908 100644
--- a/src/core/client_config/resolvers/sockaddr_resolver.c
+++ b/src/core/client_config/resolvers/sockaddr_resolver.c
@@ -60,9 +60,12 @@ typedef struct {
   grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
                                        size_t num_subchannels);
 
-  /** the address that we've 'resolved' */
-  struct sockaddr_storage addr;
-  int addr_len;
+  /** the addresses that we've 'resolved' */
+  struct sockaddr_storage *addrs;
+  /** the corresponding length of the addresses */
+  int *addrs_len;
+  /** how many elements in \a addrs */
+  size_t num_addrs;
 
   /** mutex guarding the rest of the state */
   gpr_mu mu;
@@ -119,17 +122,22 @@ static void sockaddr_next(grpc_resolver *resolver,
 static void sockaddr_maybe_finish_next_locked(sockaddr_resolver *r) {
   grpc_client_config *cfg;
   grpc_lb_policy *lb_policy;
-  grpc_subchannel *subchannel;
+  grpc_subchannel **subchannels;
   grpc_subchannel_args args;
 
   if (r->next_completion != NULL && !r->published) {
+    size_t i;
     cfg = grpc_client_config_create();
-    memset(&args, 0, sizeof(args));
-    args.addr = (struct sockaddr *)&r->addr;
-    args.addr_len = r->addr_len;
-    subchannel =
-        grpc_subchannel_factory_create_subchannel(r->subchannel_factory, &args);
-    lb_policy = r->lb_policy_factory(&subchannel, 1);
+    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_subchannel_factory_create_subchannel(
+          r->subchannel_factory, &args);
+    }
+    lb_policy = r->lb_policy_factory(subchannels, r->num_addrs);
+    gpr_free(subchannels);
     grpc_client_config_set_lb_policy(cfg, lb_policy);
     GRPC_LB_POLICY_UNREF(lb_policy, "unix");
     r->published = 1;
@@ -143,6 +151,8 @@ static void sockaddr_destroy(grpc_resolver *gr) {
   sockaddr_resolver *r = (sockaddr_resolver *)gr;
   gpr_mu_destroy(&r->mu);
   grpc_subchannel_factory_unref(r->subchannel_factory);
+  gpr_free(r->addrs);
+  gpr_free(r->addrs_len);
   gpr_free(r);
 }
 
@@ -238,13 +248,18 @@ done:
   return result;
 }
 
+static void do_nothing(void *ignored) {}
 static grpc_resolver *sockaddr_create(
     grpc_uri *uri,
     grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
                                          size_t num_subchannels),
     grpc_subchannel_factory *subchannel_factory,
     int parse(grpc_uri *uri, struct sockaddr_storage *dst, int *len)) {
+  size_t i;
+  int errors_found = 0; /* GPR_FALSE */
   sockaddr_resolver *r;
+  gpr_slice path_slice;
+  gpr_slice_buffer path_parts;
 
   if (0 != strcmp(uri->authority, "")) {
     gpr_log(GPR_ERROR, "authority based uri's not supported");
@@ -253,7 +268,29 @@ static grpc_resolver *sockaddr_create(
 
   r = gpr_malloc(sizeof(sockaddr_resolver));
   memset(r, 0, sizeof(*r));
-  if (!parse(uri, &r->addr, &r->addr_len)) {
+
+  path_slice = gpr_slice_new(uri->path, strlen(uri->path), do_nothing);
+  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(int) * r->num_addrs);
+
+  for(i = 0; i < r->num_addrs; i++) {
+    grpc_uri ith_uri = *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])) {
+      errors_found = 1; /* GPR_TRUE */
+    }
+    gpr_free(part_str);
+    if (errors_found) break;
+  }
+
+  gpr_slice_buffer_destroy(&path_parts);
+  gpr_slice_unref(path_slice);
+  if (errors_found) {
     gpr_free(r);
     return NULL;
   }
diff --git a/src/core/iomgr/pollset.h b/src/core/iomgr/pollset.h
index c474e4dbf1..337596cb74 100644
--- a/src/core/iomgr/pollset.h
+++ b/src/core/iomgr/pollset.h
@@ -74,10 +74,9 @@ void grpc_pollset_destroy(grpc_pollset *pollset);
    grpc_pollset_work, and it is guaranteed that GRPC_POLLSET_MU(pollset) will
    not be released by grpc_pollset_work AFTER worker has been destroyed.
 
-   Returns true if some work has been done, and false if the deadline
-   expired. */
-int grpc_pollset_work(grpc_pollset *pollset, grpc_pollset_worker *worker,
-                      gpr_timespec deadline);
+   Tries not to block past deadline. */
+void grpc_pollset_work(grpc_pollset *pollset, grpc_pollset_worker *worker,
+                       gpr_timespec now, gpr_timespec deadline);
 
 /* Break one polling thread out of polling work for this pollset.
    If specific_worker is GRPC_POLLSET_KICK_BROADCAST, kick ALL the workers.
diff --git a/src/core/iomgr/pollset_multipoller_with_epoll.c b/src/core/iomgr/pollset_multipoller_with_epoll.c
index 5ea9dd2101..fe66ebed77 100644
--- a/src/core/iomgr/pollset_multipoller_with_epoll.c
+++ b/src/core/iomgr/pollset_multipoller_with_epoll.c
@@ -181,7 +181,7 @@ static void multipoll_with_epoll_pollset_maybe_work(
   pfds[1].events = POLLIN;
   pfds[1].revents = 0;
 
-  poll_rv = poll(pfds, 2, timeout_ms);
+  poll_rv = grpc_poll_function(pfds, 2, timeout_ms);
 
   if (poll_rv < 0) {
     if (errno != EINTR) {
diff --git a/src/core/iomgr/pollset_multipoller_with_poll_posix.c b/src/core/iomgr/pollset_multipoller_with_poll_posix.c
index 001fcecf76..30ee6e24db 100644
--- a/src/core/iomgr/pollset_multipoller_with_poll_posix.c
+++ b/src/core/iomgr/pollset_multipoller_with_poll_posix.c
@@ -144,7 +144,7 @@ static void multipoll_with_poll_pollset_maybe_work(
                                         POLLOUT, &watchers[i]);
   }
 
-  r = poll(pfds, pfd_count, timeout);
+  r = grpc_poll_function(pfds, pfd_count, timeout);
 
   for (i = 1; i < pfd_count; i++) {
     grpc_fd_end_poll(&watchers[i], pfds[i].revents & POLLIN,
diff --git a/src/core/iomgr/pollset_posix.c b/src/core/iomgr/pollset_posix.c
index a01f9ff727..6bd1b61f24 100644
--- a/src/core/iomgr/pollset_posix.c
+++ b/src/core/iomgr/pollset_posix.c
@@ -38,7 +38,6 @@
 #include "src/core/iomgr/pollset_posix.h"
 
 #include <errno.h>
-#include <poll.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -57,6 +56,8 @@
 GPR_TLS_DECL(g_current_thread_poller);
 GPR_TLS_DECL(g_current_thread_worker);
 
+grpc_poll_function_type grpc_poll_function = poll;
+
 static void remove_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
   worker->prev->next = worker->next;
   worker->next->prev = worker->prev;
@@ -89,6 +90,7 @@ static void push_front_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
 }
 
 void grpc_pollset_kick(grpc_pollset *p, grpc_pollset_worker *specific_worker) {
+  /* pollset->mu already held */
   if (specific_worker != NULL) {
     if (specific_worker == GRPC_POLLSET_KICK_BROADCAST) {
       for (specific_worker = p->root_worker.next;
@@ -168,14 +170,10 @@ static void finish_shutdown(grpc_pollset *pollset) {
   pollset->shutdown_done_cb(pollset->shutdown_done_arg);
 }
 
-int grpc_pollset_work(grpc_pollset *pollset, grpc_pollset_worker *worker,
-                      gpr_timespec deadline) {
+void grpc_pollset_work(grpc_pollset *pollset, grpc_pollset_worker *worker,
+                       gpr_timespec now, gpr_timespec deadline) {
   /* pollset->mu already held */
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
   int added_worker = 0;
-  if (gpr_time_cmp(now, deadline) > 0) {
-    return 0;
-  }
   /* this must happen before we (potentially) drop pollset->mu */
   worker->next = worker->prev = NULL;
   /* TODO(ctiller): pool these */
@@ -217,7 +215,6 @@ done:
       gpr_mu_lock(&pollset->mu);
     }
   }
-  return 1;
 }
 
 void grpc_pollset_shutdown(grpc_pollset *pollset,
@@ -456,7 +453,7 @@ static void basic_pollset_maybe_work(grpc_pollset *pollset,
 
   /* poll fd count (argument 2) is shortened by one if we have no events
      to poll on - such that it only includes the kicker */
-  r = poll(pfd, nfds, timeout);
+  r = grpc_poll_function(pfd, nfds, timeout);
   GRPC_TIMER_MARK(GRPC_PTAG_POLL_FINISHED, r);
 
   if (fd) {
diff --git a/src/core/iomgr/pollset_posix.h b/src/core/iomgr/pollset_posix.h
index a3ea353de6..69bd9cca8c 100644
--- a/src/core/iomgr/pollset_posix.h
+++ b/src/core/iomgr/pollset_posix.h
@@ -34,6 +34,8 @@
 #ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H
 #define GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H
 
+#include <poll.h>
+
 #include <grpc/support/sync.h>
 #include "src/core/iomgr/wakeup_fd_posix.h"
 
@@ -118,4 +120,8 @@ void grpc_poll_become_multipoller(grpc_pollset *pollset, struct grpc_fd **fds,
  * be locked) */
 int grpc_pollset_has_workers(grpc_pollset *pollset);
 
+/* override to allow tests to hook poll() usage */
+typedef int (*grpc_poll_function_type)(struct pollfd *, nfds_t, int);
+extern grpc_poll_function_type grpc_poll_function;
+
 #endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H */
diff --git a/src/core/iomgr/pollset_windows.c b/src/core/iomgr/pollset_windows.c
index 8710395ab3..07522c8a0c 100644
--- a/src/core/iomgr/pollset_windows.c
+++ b/src/core/iomgr/pollset_windows.c
@@ -99,14 +99,9 @@ void grpc_pollset_destroy(grpc_pollset *pollset) {
   gpr_mu_destroy(&pollset->mu);
 }
 
-int grpc_pollset_work(grpc_pollset *pollset, grpc_pollset_worker *worker,
-                      gpr_timespec deadline) {
-  gpr_timespec now;
+void grpc_pollset_work(grpc_pollset *pollset, grpc_pollset_worker *worker, 
+                       gpr_timespec now, gpr_timespec deadline) {
   int added_worker = 0;
-  now = gpr_now(GPR_CLOCK_MONOTONIC);
-  if (gpr_time_cmp(now, deadline) > 0) {
-    return 0 /* GPR_FALSE */;
-  }
   worker->next = worker->prev = NULL;
   gpr_cv_init(&worker->cv);
   if (grpc_maybe_call_delayed_callbacks(&pollset->mu, 1 /* GPR_TRUE */)) {
@@ -127,7 +122,6 @@ done:
   if (added_worker) {
     remove_worker(pollset, worker);
   }
-  return 1 /* GPR_TRUE */;
 }
 
 void grpc_pollset_kick(grpc_pollset *p, grpc_pollset_worker *specific_worker) {
diff --git a/src/core/iomgr/tcp_windows.c b/src/core/iomgr/tcp_windows.c
index 123f46d71d..901793ec43 100644
--- a/src/core/iomgr/tcp_windows.c
+++ b/src/core/iomgr/tcp_windows.c
@@ -152,6 +152,7 @@ static void on_read(void *tcpp, int from_iocp) {
       gpr_log(GPR_ERROR, "ReadFile overlapped error: %s", utf8_message);
       gpr_free(utf8_message);
     }
+    gpr_slice_unref(tcp->read_slice);
     status = GRPC_ENDPOINT_CB_ERROR;
   } else {
     if (info->bytes_transfered != 0) {
diff --git a/src/core/iomgr/udp_server.c b/src/core/iomgr/udp_server.c
index 16482c08f7..6429c38b28 100644
--- a/src/core/iomgr/udp_server.c
+++ b/src/core/iomgr/udp_server.c
@@ -235,8 +235,10 @@ static int prepare_socket(int fd, const struct sockaddr *addr, int addr_len) {
   rc = setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &get_local_ip,
                   sizeof(get_local_ip));
   if (rc == 0 && addr->sa_family == AF_INET6) {
+#if !TARGET_OS_IPHONE
     rc = setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &get_local_ip,
                     sizeof(get_local_ip));
+#endif
   }
 
   if (bind(fd, addr, addr_len) < 0) {
diff --git a/src/core/security/google_default_credentials.c b/src/core/security/google_default_credentials.c
index d6092ece32..3631de867a 100644
--- a/src/core/security/google_default_credentials.c
+++ b/src/core/security/google_default_credentials.c
@@ -115,7 +115,7 @@ static int is_stack_running_on_compute_engine(void) {
   gpr_mu_lock(GRPC_POLLSET_MU(&detector.pollset));
   while (!detector.is_done) {
     grpc_pollset_worker worker;
-    grpc_pollset_work(&detector.pollset, &worker,
+    grpc_pollset_work(&detector.pollset, &worker, gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   gpr_mu_unlock(GRPC_POLLSET_MU(&detector.pollset));
diff --git a/src/core/security/security_connector.c b/src/core/security/security_connector.c
index a354536dcd..ba9ac68c5f 100644
--- a/src/core/security/security_connector.c
+++ b/src/core/security/security_connector.c
@@ -575,6 +575,16 @@ grpc_security_status grpc_ssl_channel_security_connector_create(
   if (!check_request_metadata_creds(request_metadata_creds)) {
     goto error;
   }
+  if (config->pem_root_certs == NULL) {
+    pem_root_certs_size = grpc_get_default_ssl_roots(&pem_root_certs);
+    if (pem_root_certs == NULL || pem_root_certs_size == 0) {
+      gpr_log(GPR_ERROR, "Could not get default pem root certs.");
+      goto error;
+    }
+  } else {
+    pem_root_certs = config->pem_root_certs;
+    pem_root_certs_size = config->pem_root_certs_size;
+  }
 
   c = gpr_malloc(sizeof(grpc_ssl_channel_security_connector));
   memset(c, 0, sizeof(grpc_ssl_channel_security_connector));
@@ -590,16 +600,6 @@ grpc_security_status grpc_ssl_channel_security_connector_create(
   if (overridden_target_name != NULL) {
     c->overridden_target_name = gpr_strdup(overridden_target_name);
   }
-  if (config->pem_root_certs == NULL) {
-    pem_root_certs_size = grpc_get_default_ssl_roots(&pem_root_certs);
-    if (pem_root_certs == NULL || pem_root_certs_size == 0) {
-      gpr_log(GPR_ERROR, "Could not get default pem root certs.");
-      goto error;
-    }
-  } else {
-    pem_root_certs = config->pem_root_certs;
-    pem_root_certs_size = config->pem_root_certs_size;
-  }
   result = tsi_create_ssl_client_handshaker_factory(
       config->pem_private_key, config->pem_private_key_size,
       config->pem_cert_chain, config->pem_cert_chain_size, pem_root_certs,
diff --git a/src/core/security/server_auth_filter.c b/src/core/security/server_auth_filter.c
index 2f42f01f53..6e831431fa 100644
--- a/src/core/security/server_auth_filter.c
+++ b/src/core/security/server_auth_filter.c
@@ -104,24 +104,34 @@ static grpc_mdelem *remove_consumed_md(void *user_data, grpc_mdelem *md) {
   return md;
 }
 
-static void on_md_processing_done(void *user_data,
-                                  const grpc_metadata *consumed_md,
-                                  size_t num_consumed_md, int success) {
+static void on_md_processing_done(
+    void *user_data, const grpc_metadata *consumed_md, size_t num_consumed_md,
+    const grpc_metadata *response_md, size_t num_response_md,
+    grpc_status_code status, const char *error_details) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
 
-  if (success) {
+  /* TODO(jboeuf): Implement support for response_md. */
+  if (response_md != NULL && num_response_md > 0) {
+    gpr_log(GPR_INFO,
+            "response_md in auth metadata processing not supported for now. "
+            "Ignoring...");
+  }
+
+  if (status == GRPC_STATUS_OK) {
     calld->consumed_md = consumed_md;
     calld->num_consumed_md = num_consumed_md;
     grpc_metadata_batch_filter(&calld->md_op->data.metadata, remove_consumed_md,
                                elem);
-    calld->on_done_recv->cb(calld->on_done_recv->cb_arg, success);
+    calld->on_done_recv->cb(calld->on_done_recv->cb_arg, 1);
   } else {
-    gpr_slice message = gpr_slice_from_copied_string(
-        "Authentication metadata processing failed.");
+    gpr_slice message;
+    error_details = error_details != NULL
+                    ? error_details
+                    : "Authentication metadata processing failed.";
+    message = gpr_slice_from_copied_string(error_details);
     grpc_sopb_reset(calld->recv_ops);
-    grpc_transport_stream_op_add_close(&calld->transport_op,
-                                       GRPC_STATUS_UNAUTHENTICATED, &message);
+    grpc_transport_stream_op_add_close(&calld->transport_op, status, &message);
     grpc_call_next_op(elem, &calld->transport_op);
   }
 }
diff --git a/src/core/support/time_precise.h b/src/core/support/time_precise.h
index d40ad12d0c..574ebb8448 100644
--- a/src/core/support/time_precise.h
+++ b/src/core/support/time_precise.h
@@ -63,7 +63,6 @@ static void gpr_precise_clock_init() {
   gpr_precise_clock end_cycle;
   while (time(NULL) == start)
     ;
-  gpr_precise_clock_now();
   gpr_get_cycle_counter(&start_cycle);
   while (time(NULL) == start + 1)
     ;
diff --git a/src/core/surface/channel_create.c b/src/core/surface/channel_create.c
index 82ddfac757..707251da89 100644
--- a/src/core/surface/channel_create.c
+++ b/src/core/surface/channel_create.c
@@ -38,6 +38,7 @@
 
 #include <grpc/support/alloc.h>
 
+#include "src/core/census/grpc_filter.h"
 #include "src/core/channel/channel_args.h"
 #include "src/core/channel/client_channel.h"
 #include "src/core/channel/compress_filter.h"
@@ -165,10 +166,9 @@ grpc_channel *grpc_insecure_channel_create(const char *target,
   grpc_mdctx *mdctx = grpc_mdctx_create();
   int n = 0;
   GPR_ASSERT(!reserved);
-  /* TODO(census)
   if (grpc_channel_args_is_census_enabled(args)) {
     filters[n++] = &grpc_client_census_filter;
-    } */
+  }
   filters[n++] = &grpc_compress_filter;
   filters[n++] = &grpc_client_channel_filter;
   GPR_ASSERT(n <= MAX_FILTERS);
diff --git a/src/core/surface/completion_queue.c b/src/core/surface/completion_queue.c
index 77443a7ae8..b58115a93f 100644
--- a/src/core/surface/completion_queue.c
+++ b/src/core/surface/completion_queue.c
@@ -170,6 +170,9 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
                                       gpr_timespec deadline, void *reserved) {
   grpc_event ret;
   grpc_pollset_worker worker;
+  int first_loop = 1;
+  gpr_timespec now;
+
   GPR_ASSERT(!reserved);
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
@@ -196,12 +199,15 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
       ret.type = GRPC_QUEUE_SHUTDOWN;
       break;
     }
-    if (!grpc_pollset_work(&cc->pollset, &worker, deadline)) {
+    now = gpr_now(GPR_CLOCK_MONOTONIC);
+    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
       gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset));
       memset(&ret, 0, sizeof(ret));
       ret.type = GRPC_QUEUE_TIMEOUT;
       break;
     }
+    first_loop = 0;
+    grpc_pollset_work(&cc->pollset, &worker, now, deadline);
   }
   GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret);
   GRPC_CQ_INTERNAL_UNREF(cc, "next");
@@ -239,6 +245,9 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   grpc_cq_completion *c;
   grpc_cq_completion *prev;
   grpc_pollset_worker worker;
+  gpr_timespec now;
+  int first_loop = 1;
+
   GPR_ASSERT(!reserved);
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
@@ -281,13 +290,16 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
       ret.type = GRPC_QUEUE_TIMEOUT;
       break;
     }
-    if (!grpc_pollset_work(&cc->pollset, &worker, deadline)) {
+    now = gpr_now(GPR_CLOCK_MONOTONIC);
+    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
       del_plucker(cc, tag, &worker);
       gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset));
       memset(&ret, 0, sizeof(ret));
       ret.type = GRPC_QUEUE_TIMEOUT;
       break;
     }
+    first_loop = 0;
+    grpc_pollset_work(&cc->pollset, &worker, now, deadline);
     del_plucker(cc, tag, &worker);
   }
 done:
diff --git a/src/core/surface/secure_channel_create.c b/src/core/surface/secure_channel_create.c
index 5b03ba95a7..eccee24698 100644
--- a/src/core/surface/secure_channel_create.c
+++ b/src/core/surface/secure_channel_create.c
@@ -38,6 +38,7 @@
 
 #include <grpc/support/alloc.h>
 
+#include "src/core/census/grpc_filter.h"
 #include "src/core/channel/channel_args.h"
 #include "src/core/channel/client_channel.h"
 #include "src/core/channel/compress_filter.h"
@@ -217,10 +218,9 @@ grpc_channel *grpc_secure_channel_create(grpc_credentials *creds,
   args_copy = grpc_channel_args_copy_and_add(
       new_args_from_connector != NULL ? new_args_from_connector : args,
       &connector_arg, 1);
-  /* TODO(census)
   if (grpc_channel_args_is_census_enabled(args)) {
     filters[n++] = &grpc_client_census_filter;
-    } */
+  }
   filters[n++] = &grpc_compress_filter;
   filters[n++] = &grpc_client_channel_filter;
   GPR_ASSERT(n <= MAX_FILTERS);
diff --git a/src/core/surface/server.c b/src/core/surface/server.c
index 1c402418e8..292bf6fab8 100644
--- a/src/core/surface/server.c
+++ b/src/core/surface/server.c
@@ -41,7 +41,7 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 
-#include "src/core/channel/census_filter.h"
+#include "src/core/census/grpc_filter.h"
 #include "src/core/channel/channel_args.h"
 #include "src/core/channel/connected_channel.h"
 #include "src/core/iomgr/iomgr.h"
@@ -821,10 +821,9 @@ grpc_server *grpc_server_create_from_filters(
   server->channel_filters =
       gpr_malloc(server->channel_filter_count * sizeof(grpc_channel_filter *));
   server->channel_filters[0] = &server_surface_filter;
-  /* TODO(census): restore this once we rework census filter
   if (census_enabled) {
     server->channel_filters[1] = &grpc_server_census_filter;
-    } */
+  }
   for (i = 0; i < filter_count; i++) {
     server->channel_filters[i + 1 + census_enabled] = filters[i];
   }
diff --git a/src/core/transport/chttp2/stream_encoder.c b/src/core/transport/chttp2/stream_encoder.c
index 0f04169741..1ea697f71e 100644
--- a/src/core/transport/chttp2/stream_encoder.c
+++ b/src/core/transport/chttp2/stream_encoder.c
@@ -66,6 +66,8 @@ typedef struct {
   size_t header_idx;
   /* was the last frame emitted a header? (if yes, we'll need a CONTINUATION */
   gpr_uint8 last_was_header;
+  /* have we seen a regular (non-colon-prefixed) header yet? */
+  gpr_uint8 seen_regular_header;
   /* output stream id */
   gpr_uint32 stream_id;
   gpr_slice_buffer *output;
@@ -361,6 +363,15 @@ static grpc_mdelem *hpack_enc(grpc_chttp2_hpack_compressor *c,
   gpr_uint32 indices_key;
   int should_add_elem;
 
+  GPR_ASSERT (GPR_SLICE_LENGTH(elem->key->slice) > 0);
+  if (GPR_SLICE_START_PTR(elem->key->slice)[0] != ':') { /* regular header */
+    st->seen_regular_header = 1;
+  } else if (st->seen_regular_header != 0) { /* reserved header */
+    gpr_log(GPR_ERROR,
+            "Reserved header (colon-prefixed) happening after regular ones.");
+    abort();
+  }
+
   inc_filter(HASH_FRAGMENT_1(elem_hash), &c->filter_elems_sum, c->filter_elems);
 
   /* is this elem currently in the decoders table? */
@@ -566,6 +577,7 @@ void grpc_chttp2_encode(grpc_stream_op *ops, size_t ops_count, int eof,
 
   st.cur_frame_type = NONE;
   st.last_was_header = 0;
+  st.seen_regular_header = 0;
   st.stream_id = stream_id;
   st.output = output;