Merge pull request #5307 from ctiller/hide-the-worker

Change pollset_work signature to allow moving grpc_pollset_worker to implementation

20 files changed, 81 insertions, 73 deletions

diff --git a/src/core/iomgr/pollset.h b/src/core/iomgr/pollset.h
index c6b0214dea..6585326f81 100644
--- a/src/core/iomgr/pollset.h
+++ b/src/core/iomgr/pollset.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -83,7 +83,7 @@ void grpc_pollset_destroy(grpc_pollset *pollset);
    pollset
    lock */
 void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                       grpc_pollset_worker *worker, gpr_timespec now,
+                       grpc_pollset_worker **worker, gpr_timespec now,
                        gpr_timespec deadline);
 
 /* Break one polling thread out of polling work for this pollset.
diff --git a/src/core/iomgr/pollset_posix.c b/src/core/iomgr/pollset_posix.c
index 1063727248..ee7e9f48f4 100644
--- a/src/core/iomgr/pollset_posix.c
+++ b/src/core/iomgr/pollset_posix.c
@@ -246,8 +246,11 @@ static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
 }
 
 void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                       grpc_pollset_worker *worker, gpr_timespec now,
+                       grpc_pollset_worker **worker_hdl, gpr_timespec now,
                        gpr_timespec deadline) {
+  grpc_pollset_worker worker;
+  *worker_hdl = &worker;
+
   /* pollset->mu already held */
   int added_worker = 0;
   int locked = 1;
@@ -255,16 +258,16 @@ void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
   int keep_polling = 0;
   GPR_TIMER_BEGIN("grpc_pollset_work", 0);
   /* this must happen before we (potentially) drop pollset->mu */
-  worker->next = worker->prev = NULL;
-  worker->reevaluate_polling_on_wakeup = 0;
+  worker.next = worker.prev = NULL;
+  worker.reevaluate_polling_on_wakeup = 0;
   if (pollset->local_wakeup_cache != NULL) {
-    worker->wakeup_fd = pollset->local_wakeup_cache;
-    pollset->local_wakeup_cache = worker->wakeup_fd->next;
+    worker.wakeup_fd = pollset->local_wakeup_cache;
+    pollset->local_wakeup_cache = worker.wakeup_fd->next;
   } else {
-    worker->wakeup_fd = gpr_malloc(sizeof(*worker->wakeup_fd));
-    grpc_wakeup_fd_init(&worker->wakeup_fd->fd);
+    worker.wakeup_fd = gpr_malloc(sizeof(*worker.wakeup_fd));
+    grpc_wakeup_fd_init(&worker.wakeup_fd->fd);
   }
-  worker->kicked_specifically = 0;
+  worker.kicked_specifically = 0;
   /* If there's work waiting for the pollset to be idle, and the
      pollset is idle, then do that work */
   if (!grpc_pollset_has_workers(pollset) &&
@@ -293,13 +296,13 @@ void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
     keep_polling = 0;
     if (!pollset->kicked_without_pollers) {
       if (!added_worker) {
-        push_front_worker(pollset, worker);
+        push_front_worker(pollset, &worker);
         added_worker = 1;
-        gpr_tls_set(&g_current_thread_worker, (intptr_t)worker);
+        gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
       }
       gpr_tls_set(&g_current_thread_poller, (intptr_t)pollset);
       GPR_TIMER_BEGIN("maybe_work_and_unlock", 0);
-      pollset->vtable->maybe_work_and_unlock(exec_ctx, pollset, worker,
+      pollset->vtable->maybe_work_and_unlock(exec_ctx, pollset, &worker,
                                              deadline, now);
       GPR_TIMER_END("maybe_work_and_unlock", 0);
       locked = 0;
@@ -321,10 +324,10 @@ void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
     /* If we're forced to re-evaluate polling (via grpc_pollset_kick with
        GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) then we land here and force
        a loop */
-    if (worker->reevaluate_polling_on_wakeup) {
-      worker->reevaluate_polling_on_wakeup = 0;
+    if (worker.reevaluate_polling_on_wakeup) {
+      worker.reevaluate_polling_on_wakeup = 0;
       pollset->kicked_without_pollers = 0;
-      if (queued_work || worker->kicked_specifically) {
+      if (queued_work || worker.kicked_specifically) {
         /* If there's queued work on the list, then set the deadline to be
            immediate so we get back out of the polling loop quickly */
         deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC);
@@ -333,12 +336,12 @@ void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
     }
   }
   if (added_worker) {
-    remove_worker(pollset, worker);
+    remove_worker(pollset, &worker);
     gpr_tls_set(&g_current_thread_worker, 0);
   }
   /* release wakeup fd to the local pool */
-  worker->wakeup_fd->next = pollset->local_wakeup_cache;
-  pollset->local_wakeup_cache = worker->wakeup_fd;
+  worker.wakeup_fd->next = pollset->local_wakeup_cache;
+  pollset->local_wakeup_cache = worker.wakeup_fd;
   /* check shutdown conditions */
   if (pollset->shutting_down) {
     if (grpc_pollset_has_workers(pollset)) {
@@ -360,6 +363,7 @@ void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
       gpr_mu_lock(&pollset->mu);
     }
   }
+  *worker_hdl = NULL;
   GPR_TIMER_END("grpc_pollset_work", 0);
 }
 
diff --git a/src/core/iomgr/pollset_windows.c b/src/core/iomgr/pollset_windows.c
index 35a956b27f..bbce23b46a 100644
--- a/src/core/iomgr/pollset_windows.c
+++ b/src/core/iomgr/pollset_windows.c
@@ -125,22 +125,25 @@ void grpc_pollset_reset(grpc_pollset *pollset) {
 }
 
 void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                       grpc_pollset_worker *worker, gpr_timespec now,
+                       grpc_pollset_worker **worker_hdl, gpr_timespec now,
                        gpr_timespec deadline) {
+  grpc_pollset_worker worker;
+  *worker_hdl = &worker;
+
   int added_worker = 0;
-  worker->links[GRPC_POLLSET_WORKER_LINK_POLLSET].next =
-      worker->links[GRPC_POLLSET_WORKER_LINK_POLLSET].prev =
-          worker->links[GRPC_POLLSET_WORKER_LINK_GLOBAL].next =
-              worker->links[GRPC_POLLSET_WORKER_LINK_GLOBAL].prev = NULL;
-  worker->kicked = 0;
-  worker->pollset = pollset;
-  gpr_cv_init(&worker->cv);
+  worker.links[GRPC_POLLSET_WORKER_LINK_POLLSET].next =
+      worker.links[GRPC_POLLSET_WORKER_LINK_POLLSET].prev =
+          worker.links[GRPC_POLLSET_WORKER_LINK_GLOBAL].next =
+              worker.links[GRPC_POLLSET_WORKER_LINK_GLOBAL].prev = NULL;
+  worker.kicked = 0;
+  worker.pollset = pollset;
+  gpr_cv_init(&worker.cv);
   if (!pollset->kicked_without_pollers && !pollset->shutting_down) {
     if (g_active_poller == NULL) {
       grpc_pollset_worker *next_worker;
       /* become poller */
       pollset->is_iocp_worker = 1;
-      g_active_poller = worker;
+      g_active_poller = &worker;
       gpr_mu_unlock(&grpc_polling_mu);
       grpc_iocp_work(exec_ctx, deadline);
       grpc_exec_ctx_flush(exec_ctx);
@@ -167,12 +170,12 @@ void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
       goto done;
     }
     push_front_worker(&g_global_root_worker, GRPC_POLLSET_WORKER_LINK_GLOBAL,
-                      worker);
+                      &worker);
     push_front_worker(&pollset->root_worker, GRPC_POLLSET_WORKER_LINK_POLLSET,
-                      worker);
+                      &worker);
     added_worker = 1;
-    while (!worker->kicked) {
-      if (gpr_cv_wait(&worker->cv, &grpc_polling_mu, deadline)) {
+    while (!worker.kicked) {
+      if (gpr_cv_wait(&worker.cv, &grpc_polling_mu, deadline)) {
         break;
       }
     }
@@ -186,10 +189,11 @@ done:
     gpr_mu_lock(&grpc_polling_mu);
   }
   if (added_worker) {
-    remove_worker(worker, GRPC_POLLSET_WORKER_LINK_GLOBAL);
-    remove_worker(worker, GRPC_POLLSET_WORKER_LINK_POLLSET);
+    remove_worker(&worker, GRPC_POLLSET_WORKER_LINK_GLOBAL);
+    remove_worker(&worker, GRPC_POLLSET_WORKER_LINK_POLLSET);
   }
-  gpr_cv_destroy(&worker->cv);
+  gpr_cv_destroy(&worker.cv);
+  *worker_hdl = NULL;
 }
 
 void grpc_pollset_kick(grpc_pollset *p, grpc_pollset_worker *specific_worker) {
diff --git a/src/core/security/google_default_credentials.c b/src/core/security/google_default_credentials.c
index bd4b0e462a..458d0d3ac3 100644
--- a/src/core/security/google_default_credentials.c
+++ b/src/core/security/google_default_credentials.c
@@ -122,7 +122,7 @@ static int is_stack_running_on_compute_engine(void) {
      called once for the lifetime of the process by the default credentials. */
   gpr_mu_lock(GRPC_POLLSET_MU(&detector.pollset));
   while (!detector.is_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &detector.pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
diff --git a/src/core/surface/completion_queue.c b/src/core/surface/completion_queue.c
index 0a80680f02..f9cb852722 100644
--- a/src/core/surface/completion_queue.c
+++ b/src/core/surface/completion_queue.c
@@ -50,7 +50,7 @@
 #include <grpc/support/time.h>
 
 typedef struct {
-  grpc_pollset_worker *worker;
+  grpc_pollset_worker **worker;
   void *tag;
 } plucker;
 
@@ -252,7 +252,7 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
     pluck_worker = NULL;
     for (i = 0; i < cc->num_pluckers; i++) {
       if (cc->pluckers[i].tag == tag) {
-        pluck_worker = cc->pluckers[i].worker;
+        pluck_worker = *cc->pluckers[i].worker;
         break;
       }
     }
@@ -275,7 +275,7 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
 grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
                                       gpr_timespec deadline, void *reserved) {
   grpc_event ret;
-  grpc_pollset_worker worker;
+  grpc_pollset_worker *worker = NULL;
   int first_loop = 1;
   gpr_timespec now;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
@@ -348,7 +348,7 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
 }
 
 static int add_plucker(grpc_completion_queue *cc, void *tag,
-                       grpc_pollset_worker *worker) {
+                       grpc_pollset_worker **worker) {
   if (cc->num_pluckers == GRPC_MAX_COMPLETION_QUEUE_PLUCKERS) {
     return 0;
   }
@@ -359,7 +359,7 @@ static int add_plucker(grpc_completion_queue *cc, void *tag,
 }
 
 static void del_plucker(grpc_completion_queue *cc, void *tag,
-                        grpc_pollset_worker *worker) {
+                        grpc_pollset_worker **worker) {
   int i;
   for (i = 0; i < cc->num_pluckers; i++) {
     if (cc->pluckers[i].tag == tag && cc->pluckers[i].worker == worker) {
@@ -376,7 +376,7 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   grpc_event ret;
   grpc_cq_completion *c;
   grpc_cq_completion *prev;
-  grpc_pollset_worker worker;
+  grpc_pollset_worker *worker = NULL;
   gpr_timespec now;
   int first_loop = 1;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
diff --git a/test/core/end2end/fixtures/h2_uchannel.c b/test/core/end2end/fixtures/h2_uchannel.c
index dbdd3524ed..33055561cb 100644
--- a/test/core/end2end/fixtures/h2_uchannel.c
+++ b/test/core/end2end/fixtures/h2_uchannel.c
@@ -264,7 +264,7 @@ static grpc_connected_subchannel *connect_subchannel(grpc_subchannel *c) {
   grpc_exec_ctx_flush(&exec_ctx);
   gpr_mu_lock(GRPC_POLLSET_MU(&pollset));
   while (g_state != GRPC_CHANNEL_READY) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1));
diff --git a/test/core/httpcli/httpcli_test.c b/test/core/httpcli/httpcli_test.c
index 651ef1fa3b..e954a920b0 100644
--- a/test/core/httpcli/httpcli_test.c
+++ b/test/core/httpcli/httpcli_test.c
@@ -89,7 +89,7 @@ static void test_get(int port) {
                    on_finish, (void *)42);
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!g_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
@@ -120,7 +120,7 @@ static void test_post(int port) {
                     n_seconds_time(15), on_finish, (void *)42);
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!g_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
diff --git a/test/core/httpcli/httpscli_test.c b/test/core/httpcli/httpscli_test.c
index db41be17e7..9f31eae278 100644
--- a/test/core/httpcli/httpscli_test.c
+++ b/test/core/httpcli/httpscli_test.c
@@ -90,7 +90,7 @@ static void test_get(int port) {
                    on_finish, (void *)42);
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!g_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
@@ -122,7 +122,7 @@ static void test_post(int port) {
                     n_seconds_time(15), on_finish, (void *)42);
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!g_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
diff --git a/test/core/iomgr/endpoint_tests.c b/test/core/iomgr/endpoint_tests.c
index 1b6a78da9a..6ba67df3b1 100644
--- a/test/core/iomgr/endpoint_tests.c
+++ b/test/core/iomgr/endpoint_tests.c
@@ -234,7 +234,7 @@ 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) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     GPR_ASSERT(gpr_time_cmp(gpr_now(GPR_CLOCK_MONOTONIC), deadline) < 0);
     grpc_pollset_work(&exec_ctx, g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), deadline);
diff --git a/test/core/iomgr/fd_posix_test.c b/test/core/iomgr/fd_posix_test.c
index 347a86af10..07761b6576 100644
--- a/test/core/iomgr/fd_posix_test.c
+++ b/test/core/iomgr/fd_posix_test.c
@@ -252,7 +252,7 @@ static void server_wait_and_shutdown(server *sv) {
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!sv->done) {
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
@@ -366,7 +366,7 @@ static void client_start(grpc_exec_ctx *exec_ctx, 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_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
@@ -467,7 +467,7 @@ 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_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
@@ -491,7 +491,7 @@ static void test_grpc_fd_change(void) {
 
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (b.cb_that_ran == NULL) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
diff --git a/test/core/iomgr/tcp_client_posix_test.c b/test/core/iomgr/tcp_client_posix_test.c
index b57478059f..cdd5b096fb 100644
--- a/test/core/iomgr/tcp_client_posix_test.c
+++ b/test/core/iomgr/tcp_client_posix_test.c
@@ -121,7 +121,7 @@ void test_succeeds(void) {
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
 
   while (g_connections_complete == connections_complete_before) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5));
@@ -161,7 +161,7 @@ void test_fails(void) {
 
   /* wait for the connection callback to finish */
   while (g_connections_complete == connections_complete_before) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
     gpr_timespec polling_deadline = test_deadline();
     if (!grpc_timer_check(&exec_ctx, now, &polling_deadline)) {
@@ -228,7 +228,7 @@ void test_times_out(void) {
   /* Make sure the event doesn't trigger early */
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   for (;;) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     gpr_timespec now = gpr_now(connect_deadline.clock_type);
     gpr_timespec continue_verifying_time =
         gpr_time_from_seconds(5, GPR_TIMESPAN);
diff --git a/test/core/iomgr/tcp_posix_test.c b/test/core/iomgr/tcp_posix_test.c
index d290c6bc3a..20b0b9e13b 100644
--- a/test/core/iomgr/tcp_posix_test.c
+++ b/test/core/iomgr/tcp_posix_test.c
@@ -190,7 +190,7 @@ static void read_test(size_t num_bytes, size_t slice_size) {
 
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (state.read_bytes < state.target_read_bytes) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), deadline);
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
@@ -236,7 +236,7 @@ static void large_read_test(size_t slice_size) {
 
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (state.read_bytes < state.target_read_bytes) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), deadline);
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
@@ -303,7 +303,7 @@ void drain_socket_blocking(int fd, size_t num_bytes, size_t read_size) {
   GPR_ASSERT(fcntl(fd, F_SETFL, flags & ~O_NONBLOCK) == 0);
 
   for (;;) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
@@ -365,7 +365,7 @@ static void write_test(size_t num_bytes, size_t slice_size) {
   drain_socket_blocking(sv[0], num_bytes, num_bytes);
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   for (;;) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     if (state.write_done) {
       break;
     }
@@ -425,7 +425,7 @@ static void release_fd_test(size_t num_bytes, size_t slice_size) {
 
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (state.read_bytes < state.target_read_bytes) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), deadline);
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
@@ -439,7 +439,7 @@ static void release_fd_test(size_t num_bytes, size_t slice_size) {
   grpc_tcp_destroy_and_release_fd(&exec_ctx, ep, &fd, &fd_released_cb);
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
   while (!fd_released_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), deadline);
   }
diff --git a/test/core/iomgr/tcp_server_posix_test.c b/test/core/iomgr/tcp_server_posix_test.c
index 272d97bfcb..43180b1698 100644
--- a/test/core/iomgr/tcp_server_posix_test.c
+++ b/test/core/iomgr/tcp_server_posix_test.c
@@ -183,7 +183,7 @@ static void tcp_connect(grpc_exec_ctx *exec_ctx, const struct sockaddr *remote,
   gpr_log(GPR_DEBUG, "wait");
   while (g_nconnects == nconnects_before &&
          gpr_time_cmp(deadline, gpr_now(deadline.clock_type)) > 0) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(exec_ctx, &g_pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), deadline);
     gpr_mu_unlock(GRPC_POLLSET_MU(&g_pollset));
diff --git a/test/core/iomgr/workqueue_test.c b/test/core/iomgr/workqueue_test.c
index 500170b542..a024915256 100644
--- a/test/core/iomgr/workqueue_test.c
+++ b/test/core/iomgr/workqueue_test.c
@@ -63,7 +63,7 @@ static void test_add_closure(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_workqueue *wq = grpc_workqueue_create(&exec_ctx);
   gpr_timespec deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5);
-  grpc_pollset_worker worker;
+  grpc_pollset_worker *worker = NULL;
   grpc_closure_init(&c, must_succeed, &done);
 
   grpc_workqueue_push(wq, &c, 1);
@@ -87,7 +87,7 @@ static void test_flush(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_workqueue *wq = grpc_workqueue_create(&exec_ctx);
   gpr_timespec deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5);
-  grpc_pollset_worker worker;
+  grpc_pollset_worker *worker = NULL;
   grpc_closure_init(&c, must_succeed, &done);
 
   grpc_exec_ctx_enqueue(&exec_ctx, &c, true, NULL);
diff --git a/test/core/security/oauth2_utils.c b/test/core/security/oauth2_utils.c
index 55ac31e62c..4dd595df95 100644
--- a/test/core/security/oauth2_utils.c
+++ b/test/core/security/oauth2_utils.c
@@ -95,7 +95,7 @@ char *grpc_test_fetch_oauth2_token_with_credentials(
 
   gpr_mu_lock(GRPC_POLLSET_MU(&request.pollset));
   while (!request.is_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &request.pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
diff --git a/test/core/security/print_google_default_creds_token.c b/test/core/security/print_google_default_creds_token.c
index 50fe61c996..6043bf5420 100644
--- a/test/core/security/print_google_default_creds_token.c
+++ b/test/core/security/print_google_default_creds_token.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -100,7 +100,7 @@ int main(int argc, char **argv) {
 
   gpr_mu_lock(GRPC_POLLSET_MU(&sync.pollset));
   while (!sync.is_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &sync.pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
diff --git a/test/core/security/verify_jwt.c b/test/core/security/verify_jwt.c
index 378a37f26c..5070cf0492 100644
--- a/test/core/security/verify_jwt.c
+++ b/test/core/security/verify_jwt.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -111,7 +111,7 @@ int main(int argc, char **argv) {
 
   gpr_mu_lock(GRPC_POLLSET_MU(&sync.pollset));
   while (!sync.is_done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &sync.pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
diff --git a/test/core/util/port_posix.c b/test/core/util/port_posix.c
index 4b31f810e5..ad21fe0f53 100644
--- a/test/core/util/port_posix.c
+++ b/test/core/util/port_posix.c
@@ -114,7 +114,7 @@ static void free_port_using_server(char *server, int port) {
                    &pr);
   gpr_mu_lock(GRPC_POLLSET_MU(&pr.pollset));
   while (!pr.done) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &pr.pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1));
@@ -280,7 +280,7 @@ static int pick_port_using_server(char *server) {
   grpc_exec_ctx_finish(&exec_ctx);
   gpr_mu_lock(GRPC_POLLSET_MU(&pr.pollset));
   while (pr.port == -1) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &pr.pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1));
diff --git a/test/core/util/port_windows.c b/test/core/util/port_windows.c
index 85d7c0ce07..b5bd0168ad 100644
--- a/test/core/util/port_windows.c
+++ b/test/core/util/port_windows.c
@@ -180,7 +180,7 @@ static int pick_port_using_server(char *server) {
                    &pr);
   gpr_mu_lock(GRPC_POLLSET_MU(&pr.pollset));
   while (pr.port == -1) {
-    grpc_pollset_worker worker;
+    grpc_pollset_worker *worker = NULL;
     grpc_pollset_work(&exec_ctx, &pr.pollset, &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1));
diff --git a/test/core/util/test_tcp_server.c b/test/core/util/test_tcp_server.c
index 66470c0288..e99d5dcffd 100644
--- a/test/core/util/test_tcp_server.c
+++ b/test/core/util/test_tcp_server.c
@@ -85,7 +85,7 @@ void test_tcp_server_start(test_tcp_server *server, int port) {
 }
 
 void test_tcp_server_poll(test_tcp_server *server, int seconds) {
-  grpc_pollset_worker worker;
+  grpc_pollset_worker *worker = NULL;
   gpr_timespec deadline =
       gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
                    gpr_time_from_seconds(seconds, GPR_TIMESPAN));