Merge pull request #2529 from ctiller/prefer-gin-n-tonic

Move alarm subsystem to monotonic time

include/grpc/support/time.h

@@ -83,6 +83,9 @@ void gpr_time_init(void);
 /* Return the current time measured from the given clocks epoch. */
 gpr_timespec gpr_now(gpr_clock_type clock);
 
+/* Convert a timespec from one clock to another */
+gpr_timespec gpr_convert_clock_type(gpr_timespec t, gpr_clock_type target_clock);
+
 /* Return -ve, 0, or +ve according to whether a < b, a == b, or a > b
    respectively.  */
 int gpr_time_cmp(gpr_timespec a, gpr_timespec b);

src/core/client_config/subchannel.c

@@ -300,7 +300,7 @@ static void continue_connect(grpc_subchannel *c) {
 }
 
 static void start_connect(grpc_subchannel *c) {
-  gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
+  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
   c->next_attempt = now;
   c->backoff_delta = gpr_time_from_seconds(1, GPR_TIMESPAN);
 
@@ -585,7 +585,7 @@ static void subchannel_connected(void *arg, int iomgr_success) {
     c->have_alarm = 1;
     c->next_attempt = gpr_time_add(c->next_attempt, c->backoff_delta);
     c->backoff_delta = gpr_time_add(c->backoff_delta, c->backoff_delta);
-    grpc_alarm_init(&c->alarm, c->next_attempt, on_alarm, c, gpr_now(GPR_CLOCK_REALTIME));
+    grpc_alarm_init(&c->alarm, c->next_attempt, on_alarm, c, gpr_now(GPR_CLOCK_MONOTONIC));
     gpr_mu_unlock(&c->mu);
   }
 }

src/core/iomgr/alarm.c

@@ -36,6 +36,7 @@
 #include "src/core/iomgr/alarm_heap.h"
 #include "src/core/iomgr/alarm_internal.h"
 #include "src/core/iomgr/time_averaged_stats.h"
+#include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/useful.h>
 
@@ -67,6 +68,7 @@ typedef struct {
 static gpr_mu g_mu;
 /* Allow only one run_some_expired_alarms at once */
 static gpr_mu g_checker_mu;
+static gpr_clock_type g_clock_type;
 static shard_type g_shards[NUM_SHARDS];
 /* Protected by g_mu */
 static shard_type *g_shard_queue[NUM_SHARDS];
@@ -85,6 +87,7 @@ void grpc_alarm_list_init(gpr_timespec now) {
 
   gpr_mu_init(&g_mu);
   gpr_mu_init(&g_checker_mu);
+  g_clock_type = now.clock_type;
 
   for (i = 0; i < NUM_SHARDS; i++) {
     shard_type *shard = &g_shards[i];
@@ -102,7 +105,7 @@ void grpc_alarm_list_init(gpr_timespec now) {
 
 void grpc_alarm_list_shutdown(void) {
   int i;
-  while (run_some_expired_alarms(NULL, gpr_inf_future(GPR_CLOCK_REALTIME), NULL,
+  while (run_some_expired_alarms(NULL, gpr_inf_future(g_clock_type), NULL,
                                  0))
     ;
   for (i = 0; i < NUM_SHARDS; i++) {
@@ -175,6 +178,8 @@ void grpc_alarm_init(grpc_alarm *alarm, gpr_timespec deadline,
                      gpr_timespec now) {
   int is_first_alarm = 0;
   shard_type *shard = &g_shards[shard_idx(alarm)];
+  GPR_ASSERT(deadline.clock_type == g_clock_type);
+  GPR_ASSERT(now.clock_type == g_clock_type);
   alarm->cb = alarm_cb;
   alarm->cb_arg = alarm_cb_arg;
   alarm->deadline = deadline;
@@ -355,6 +360,7 @@ static int run_some_expired_alarms(gpr_mu *drop_mu, gpr_timespec now,
 }
 
 int grpc_alarm_check(gpr_mu *drop_mu, gpr_timespec now, gpr_timespec *next) {
+  GPR_ASSERT(now.clock_type == g_clock_type);
   return run_some_expired_alarms(drop_mu, now, next, 1);
 }
 

src/core/iomgr/iomgr.c

@@ -57,9 +57,9 @@ static grpc_iomgr_object g_root_object;
 static void background_callback_executor(void *ignored) {
   gpr_mu_lock(&g_mu);
   while (!g_shutdown) {
-    gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+    gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
     gpr_timespec short_deadline = gpr_time_add(
-        gpr_now(GPR_CLOCK_REALTIME), gpr_time_from_millis(100, GPR_TIMESPAN));
+        gpr_now(GPR_CLOCK_MONOTONIC), gpr_time_from_millis(100, GPR_TIMESPAN));
     if (g_cbs_head) {
       grpc_iomgr_closure *closure = g_cbs_head;
       g_cbs_head = closure->next;
@@ -67,7 +67,7 @@ static void background_callback_executor(void *ignored) {
       gpr_mu_unlock(&g_mu);
       closure->cb(closure->cb_arg, closure->success);
       gpr_mu_lock(&g_mu);
-    } else if (grpc_alarm_check(&g_mu, gpr_now(GPR_CLOCK_REALTIME),
+    } else if (grpc_alarm_check(&g_mu, gpr_now(GPR_CLOCK_MONOTONIC),
                                 &deadline)) {
     } else {
       gpr_mu_unlock(&g_mu);
@@ -90,7 +90,7 @@ void grpc_iomgr_init(void) {
   gpr_thd_id id;
   gpr_mu_init(&g_mu);
   gpr_cv_init(&g_rcv);
-  grpc_alarm_list_init(gpr_now(GPR_CLOCK_REALTIME));
+  grpc_alarm_list_init(gpr_now(GPR_CLOCK_MONOTONIC));
   g_root_object.next = g_root_object.prev = &g_root_object;
   g_root_object.name = "root";
   grpc_iomgr_platform_init();
@@ -145,7 +145,7 @@ void grpc_iomgr_shutdown(void) {
       } while (g_cbs_head);
       continue;
     }
-    if (grpc_alarm_check(&g_mu, gpr_inf_future(GPR_CLOCK_REALTIME), NULL)) {
+    if (grpc_alarm_check(&g_mu, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL)) {
       gpr_log(GPR_DEBUG, "got late alarm");
       continue;
     }

src/core/iomgr/pollset_posix.c

@@ -136,7 +136,7 @@ static void finish_shutdown(grpc_pollset *pollset) {
 
 int grpc_pollset_work(grpc_pollset *pollset, gpr_timespec deadline) {
   /* pollset->mu already held */
-  gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
+  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
   if (gpr_time_cmp(now, deadline) > 0) {
     return 0;
   }
@@ -205,7 +205,7 @@ int grpc_poll_deadline_to_millis_timeout(gpr_timespec deadline,
                                          gpr_timespec now) {
   gpr_timespec timeout;
   static const int max_spin_polling_us = 10;
-  if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_REALTIME)) == 0) {
+  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
     return -1;
   }
   if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(

src/core/iomgr/pollset_windows.c

@@ -70,7 +70,7 @@ void grpc_pollset_destroy(grpc_pollset *pollset) {
 
 int grpc_pollset_work(grpc_pollset *pollset, gpr_timespec deadline) {
   gpr_timespec now;
-  now = gpr_now(GPR_CLOCK_REALTIME);
+  now = gpr_now(GPR_CLOCK_MONOTONIC);
   if (gpr_time_cmp(now, deadline) > 0) {
     return 0 /* GPR_FALSE */;
   }

src/core/iomgr/tcp_client_posix.c

@@ -253,8 +253,8 @@ void grpc_tcp_client_connect(void (*cb)(void *arg, grpc_endpoint *ep),
   ac->write_closure.cb_arg = ac;
 
   gpr_mu_lock(&ac->mu);
-  grpc_alarm_init(&ac->alarm, deadline, on_alarm, ac,
+  grpc_alarm_init(&ac->alarm, gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC), 
-                  gpr_now(GPR_CLOCK_REALTIME));
+                  on_alarm, ac, gpr_now(GPR_CLOCK_MONOTONIC));
   grpc_fd_notify_on_write(ac->fd, &ac->write_closure);
   gpr_mu_unlock(&ac->mu);
 

src/core/iomgr/tcp_client_windows.c

@@ -216,7 +216,7 @@ void grpc_tcp_client_connect(void (*cb)(void *arg, grpc_endpoint *tcp),
   ac->aborted = 0;
 
   grpc_alarm_init(&ac->alarm, deadline, on_alarm, ac,
-                  gpr_now(GPR_CLOCK_REALTIME));
+                  gpr_now(GPR_CLOCK_MONOTONIC));
   socket->write_info.outstanding = 1;
   grpc_socket_notify_on_write(socket, on_connect, ac);
   return;

src/core/support/sync_posix.c

@@ -63,10 +63,11 @@ void gpr_cv_destroy(gpr_cv *cv) { GPR_ASSERT(pthread_cond_destroy(cv) == 0); }
 
 int gpr_cv_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline) {
   int err = 0;
-  if (gpr_time_cmp(abs_deadline, gpr_inf_future(GPR_CLOCK_REALTIME)) == 0) {
+  if (gpr_time_cmp(abs_deadline, gpr_inf_future(abs_deadline.clock_type)) == 0) {
     err = pthread_cond_wait(cv, mu);
   } else {
     struct timespec abs_deadline_ts;
+    abs_deadline = gpr_convert_clock_type(abs_deadline, GPR_CLOCK_REALTIME);
     abs_deadline_ts.tv_sec = abs_deadline.tv_sec;
     abs_deadline_ts.tv_nsec = abs_deadline.tv_nsec;
     err = pthread_cond_timedwait(cv, mu, &abs_deadline_ts);

src/core/support/sync_win32.c

@@ -83,10 +83,10 @@ int gpr_cv_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline) {
   int timeout = 0;
   DWORD timeout_max_ms;
   mu->locked = 0;
-  if (gpr_time_cmp(abs_deadline, gpr_inf_future(GPR_CLOCK_REALTIME)) == 0) {
+  if (gpr_time_cmp(abs_deadline, gpr_inf_future(abs_deadline.clock_type)) == 0) {
     SleepConditionVariableCS(cv, &mu->cs, INFINITE);
   } else {
-    gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
+    gpr_timespec now = gpr_now(abs_deadline.clock_type);
     gpr_int64 now_ms = now.tv_sec * 1000 + now.tv_nsec / 1000000;
     gpr_int64 deadline_ms =
         abs_deadline.tv_sec * 1000 + abs_deadline.tv_nsec / 1000000;

src/core/support/time.c

@@ -290,3 +290,30 @@ gpr_int32 gpr_time_to_millis(gpr_timespec t) {
 double gpr_timespec_to_micros(gpr_timespec t) {
   return (double)t.tv_sec * GPR_US_PER_SEC + t.tv_nsec * 1e-3;
 }
+
+gpr_timespec gpr_convert_clock_type(gpr_timespec t, gpr_clock_type clock_type) {
+  if (t.clock_type == clock_type) {
+    return t;
+  }
+
+  if (t.tv_nsec == 0) {
+    if (t.tv_sec == TYPE_MAX(time_t)) {
+      t.clock_type = clock_type;
+      return t;
+    }
+    if (t.tv_sec == TYPE_MIN(time_t)) {
+      t.clock_type = clock_type;
+      return t;
+    }
+  }
+
+  if (clock_type == GPR_TIMESPAN) {
+    return gpr_time_sub(t, gpr_now(t.clock_type));
+  }
+
+  if (t.clock_type == GPR_TIMESPAN) {
+    return gpr_time_add(gpr_now(clock_type), t);
+  }
+
+  return gpr_time_add(gpr_now(clock_type), gpr_time_sub(t, gpr_now(t.clock_type)));
+}

src/core/support/time_posix.c

@@ -120,7 +120,7 @@ void gpr_sleep_until(gpr_timespec until) {
   for (;;) {
     /* We could simplify by using clock_nanosleep instead, but it might be
      * slightly less portable. */
-    now = gpr_now(GPR_CLOCK_REALTIME);
+    now = gpr_now(until.clock_type);
     if (gpr_time_cmp(until, now) <= 0) {
       return;
     }

src/core/support/time_win32.c

@@ -80,7 +80,7 @@ void gpr_sleep_until(gpr_timespec until) {
   for (;;) {
     /* We could simplify by using clock_nanosleep instead, but it might be
      * slightly less portable. */
-    now = gpr_now(GPR_CLOCK_REALTIME);
+    now = gpr_now(until.clock_type);
     if (gpr_time_cmp(until, now) <= 0) {
       return;
     }

src/core/surface/call.c

@@ -348,7 +348,7 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_completion_queue *cq,
   }
   grpc_call_stack_init(channel_stack, server_transport_data, initial_op_ptr,
                        CALL_STACK_FROM_CALL(call));
-  if (gpr_time_cmp(send_deadline, gpr_inf_future(GPR_CLOCK_REALTIME)) != 0) {
+  if (gpr_time_cmp(send_deadline, gpr_inf_future(send_deadline.clock_type)) != 0) {
     set_deadline_alarm(call, send_deadline);
   }
   return call;
@@ -1278,8 +1278,8 @@ static void set_deadline_alarm(grpc_call *call, gpr_timespec deadline) {
   }
   GRPC_CALL_INTERNAL_REF(call, "alarm");
   call->have_alarm = 1;
-  grpc_alarm_init(&call->alarm, deadline, call_alarm, call,
+  grpc_alarm_init(&call->alarm, gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC), call_alarm, call,
-                  gpr_now(GPR_CLOCK_REALTIME));
+                  gpr_now(GPR_CLOCK_MONOTONIC));
 }
 
 /* we offset status by a small amount when storing it into transport metadata

src/core/surface/completion_queue.c

@@ -148,6 +148,8 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
                                       gpr_timespec deadline) {
   grpc_event ret;
 
+  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
+
   GRPC_CQ_INTERNAL_REF(cc, "next");
   gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset));
   for (;;) {
@@ -188,6 +190,8 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   grpc_cq_completion *c;
   grpc_cq_completion *prev;
 
+  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
+
   GRPC_CQ_INTERNAL_REF(cc, "pluck");
   gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset));
   for (;;) {

src/core/transport/chttp2/stream_encoder.c

@@ -438,7 +438,7 @@ static void deadline_enc(grpc_chttp2_hpack_compressor *c, gpr_timespec deadline,
   char timeout_str[GRPC_CHTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE];
   grpc_mdelem *mdelem;
   grpc_chttp2_encode_timeout(
-      gpr_time_sub(deadline, gpr_now(GPR_CLOCK_REALTIME)), timeout_str);
+      gpr_time_sub(deadline, gpr_now(deadline.clock_type)), timeout_str);
   mdelem = grpc_mdelem_from_metadata_strings(
       c->mdctx, GRPC_MDSTR_REF(c->timeout_key_str),
       grpc_mdstr_from_string(c->mdctx, timeout_str));
@@ -560,6 +560,7 @@ void grpc_chttp2_encode(grpc_stream_op *ops, size_t ops_count, int eof,
   grpc_mdctx *mdctx = compressor->mdctx;
   grpc_linked_mdelem *l;
   int need_unref = 0;
+  gpr_timespec deadline;
 
   GPR_ASSERT(stream_id != 0);
 
@@ -589,9 +590,9 @@ void grpc_chttp2_encode(grpc_stream_op *ops, size_t ops_count, int eof,
           l->md = hpack_enc(compressor, l->md, &st);
           need_unref |= l->md != NULL;
         }
-        if (gpr_time_cmp(op->data.metadata.deadline,
+        deadline = op->data.metadata.deadline;
-                         gpr_inf_future(GPR_CLOCK_REALTIME)) != 0) {
+        if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) != 0) {
-          deadline_enc(compressor, op->data.metadata.deadline, &st);
+          deadline_enc(compressor, deadline, &st);
         }
         curop++;
         break;

src/core/transport/transport_op_string.c

@@ -61,7 +61,7 @@ static void put_metadata_list(gpr_strvec *b, grpc_metadata_batch md) {
     if (m != md.list.head) gpr_strvec_add(b, gpr_strdup(", "));
     put_metadata(b, m->md);
   }
-  if (gpr_time_cmp(md.deadline, gpr_inf_future(GPR_CLOCK_REALTIME)) != 0) {
+  if (gpr_time_cmp(md.deadline, gpr_inf_future(md.deadline.clock_type)) != 0) {
     char *tmp;
     gpr_asprintf(&tmp, " deadline=%d.%09d", md.deadline.tv_sec,
                  md.deadline.tv_nsec);

test/core/iomgr/alarm_test.c

@@ -41,6 +41,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
@@ -100,7 +101,7 @@ static void test_grpc_alarm(void) {
   alarm_arg arg2;
   void *fdone;
 
-  grpc_iomgr_init();
+  grpc_init();
 
   arg.counter = 0;
   arg.success = SUCCESS_NOT_SET;
@@ -113,7 +114,7 @@ static void test_grpc_alarm(void) {
   gpr_event_init(&arg.fcb_arg);
 
   grpc_alarm_init(&alarm, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(100), alarm_cb, &arg,
-                  gpr_now(GPR_CLOCK_REALTIME));
+                  gpr_now(GPR_CLOCK_MONOTONIC));
 
   alarm_deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1);
   gpr_mu_lock(&arg.mu);
@@ -165,7 +166,7 @@ static void test_grpc_alarm(void) {
   gpr_event_init(&arg2.fcb_arg);
 
   grpc_alarm_init(&alarm_to_cancel, GRPC_TIMEOUT_MILLIS_TO_DEADLINE(100),
-                  alarm_cb, &arg2, gpr_now(GPR_CLOCK_REALTIME));
+                  alarm_cb, &arg2, gpr_now(GPR_CLOCK_MONOTONIC));
   grpc_alarm_cancel(&alarm_to_cancel);
 
   alarm_deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1);
@@ -214,7 +215,7 @@ static void test_grpc_alarm(void) {
   gpr_mu_destroy(&arg2.mu);
   gpr_free(arg2.followup_closure);
 
-  grpc_iomgr_shutdown();
+  grpc_shutdown();
 }
 
 int main(int argc, char **argv) {

test/core/iomgr/endpoint_tests.c

@@ -254,7 +254,7 @@ static void read_and_write_test(grpc_endpoint_test_config config,
 
   gpr_mu_lock(GRPC_POLLSET_MU(g_pollset));
   while (!state.read_done || !state.write_done) {
-    GPR_ASSERT(gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), deadline) < 0);
+    GPR_ASSERT(gpr_time_cmp(gpr_now(GPR_CLOCK_MONOTONIC), deadline) < 0);
     grpc_pollset_work(g_pollset, deadline);
   }
   gpr_mu_unlock(GRPC_POLLSET_MU(g_pollset));
@@ -350,14 +350,14 @@ static void shutdown_during_write_test(grpc_endpoint_test_config config,
         deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE(10);
         gpr_mu_lock(GRPC_POLLSET_MU(g_pollset));
         while (!write_st.done) {
-          GPR_ASSERT(gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), deadline) < 0);
+          GPR_ASSERT(gpr_time_cmp(gpr_now(deadline.clock_type), deadline) < 0);
           grpc_pollset_work(g_pollset, deadline);
         }
         gpr_mu_unlock(GRPC_POLLSET_MU(g_pollset));
         grpc_endpoint_destroy(write_st.ep);
         gpr_mu_lock(GRPC_POLLSET_MU(g_pollset));
         while (!read_st.done) {
-          GPR_ASSERT(gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), deadline) < 0);
+          GPR_ASSERT(gpr_time_cmp(gpr_now(deadline.clock_type), deadline) < 0);
           grpc_pollset_work(g_pollset, deadline);
         }
         gpr_mu_unlock(GRPC_POLLSET_MU(g_pollset));

test/core/iomgr/fd_posix_test.c

@@ -249,7 +249,7 @@ static int server_start(server *sv) {
 static void server_wait_and_shutdown(server *sv) {
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!sv->done) {
-    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_REALTIME));
+    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
 }
@@ -356,7 +356,7 @@ static void client_start(client *cl, int port) {
 static void client_wait_and_shutdown(client *cl) {
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!cl->done) {
-    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_REALTIME));
+    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
 }
@@ -445,7 +445,7 @@ static void test_grpc_fd_change(void) {
   /* And now wait for it to run. */
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (a.cb_that_ran == NULL) {
-    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_REALTIME));
+    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   GPR_ASSERT(a.cb_that_ran == first_read_callback);
   gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
@@ -463,7 +463,7 @@ static void test_grpc_fd_change(void) {
 
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (b.cb_that_ran == NULL) {
-    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_REALTIME));
+    grpc_pollset_work(&g_pollset, gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   /* Except now we verify that second_read_callback ran instead */
   GPR_ASSERT(b.cb_that_ran == second_read_callback);

test/core/iomgr/tcp_client_posix_test.c

@@ -196,13 +196,13 @@ void test_times_out(void) {
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (gpr_time_cmp(gpr_time_add(connect_deadline,
                                    gpr_time_from_seconds(2, GPR_TIMESPAN)),
-                      gpr_now(GPR_CLOCK_REALTIME)) > 0) {
+                      gpr_now(connect_deadline.clock_type)) > 0) {
     int is_after_deadline =
-        gpr_time_cmp(connect_deadline, gpr_now(GPR_CLOCK_REALTIME)) <= 0;
+        gpr_time_cmp(connect_deadline, gpr_now(GPR_CLOCK_MONOTONIC)) <= 0;
     if (is_after_deadline &&
         gpr_time_cmp(gpr_time_add(connect_deadline,
                                   gpr_time_from_seconds(1, GPR_TIMESPAN)),
-                     gpr_now(GPR_CLOCK_REALTIME)) > 0) {
+                     gpr_now(GPR_CLOCK_MONOTONIC)) > 0) {
       /* allow some slack before insisting that things be done */
     } else {
       GPR_ASSERT(g_connections_complete ==

test/core/iomgr/tcp_server_posix_test.c

@@ -135,7 +135,7 @@ static void test_connect(int n) {
 
     gpr_log(GPR_DEBUG, "wait");
     while (g_nconnects == nconnects_before &&
-           gpr_time_cmp(deadline, gpr_now(GPR_CLOCK_REALTIME)) > 0) {
+           gpr_time_cmp(deadline, gpr_now(deadline.clock_type)) > 0) {
       grpc_pollset_work(&g_pollset, deadline);
     }
     gpr_log(GPR_DEBUG, "wait done");

test/core/util/test_config.h

@@ -52,12 +52,12 @@ extern "C" {
   (GRPC_TEST_SLOWDOWN_BUILD_FACTOR * GRPC_TEST_SLOWDOWN_MACHINE_FACTOR)
 
 #define GRPC_TIMEOUT_SECONDS_TO_DEADLINE(x)                                \
-  gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),                                \
+  gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),                               \
                gpr_time_from_micros(GRPC_TEST_SLOWDOWN_FACTOR * 1e6 * (x), \
                                     GPR_TIMESPAN))
 
 #define GRPC_TIMEOUT_MILLIS_TO_DEADLINE(x)                                 \
-  gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),                                \
+  gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),                               \
                gpr_time_from_micros(GRPC_TEST_SLOWDOWN_FACTOR * 1e3 * (x), \
                                     GPR_TIMESPAN))