Merge pull request #6190 from dgquintas/lb_pollset_propagation

Enable use of pollset_set for a channel call

BUILD

@@ -187,6 +187,7 @@ cc_library(
     "src/core/lib/iomgr/iomgr.h",
     "src/core/lib/iomgr/iomgr_internal.h",
     "src/core/lib/iomgr/iomgr_posix.h",
+    "src/core/lib/iomgr/polling_entity.h",
     "src/core/lib/iomgr/pollset.h",
     "src/core/lib/iomgr/pollset_set.h",
     "src/core/lib/iomgr/pollset_set_windows.h",
@@ -333,6 +334,7 @@ cc_library(
     "src/core/lib/iomgr/iomgr.c",
     "src/core/lib/iomgr/iomgr_posix.c",
     "src/core/lib/iomgr/iomgr_windows.c",
+    "src/core/lib/iomgr/polling_entity.c",
     "src/core/lib/iomgr/pollset_set_windows.c",
     "src/core/lib/iomgr/pollset_windows.c",
     "src/core/lib/iomgr/resolve_address_posix.c",
@@ -558,6 +560,7 @@ cc_library(
     "src/core/lib/iomgr/iomgr.h",
     "src/core/lib/iomgr/iomgr_internal.h",
     "src/core/lib/iomgr/iomgr_posix.h",
+    "src/core/lib/iomgr/polling_entity.h",
     "src/core/lib/iomgr/pollset.h",
     "src/core/lib/iomgr/pollset_set.h",
     "src/core/lib/iomgr/pollset_set_windows.h",
@@ -694,6 +697,7 @@ cc_library(
     "src/core/lib/iomgr/iomgr.c",
     "src/core/lib/iomgr/iomgr_posix.c",
     "src/core/lib/iomgr/iomgr_windows.c",
+    "src/core/lib/iomgr/polling_entity.c",
     "src/core/lib/iomgr/pollset_set_windows.c",
     "src/core/lib/iomgr/pollset_windows.c",
     "src/core/lib/iomgr/resolve_address_posix.c",
@@ -896,6 +900,7 @@ cc_library(
     "src/core/lib/iomgr/iomgr.h",
     "src/core/lib/iomgr/iomgr_internal.h",
     "src/core/lib/iomgr/iomgr_posix.h",
+    "src/core/lib/iomgr/polling_entity.h",
     "src/core/lib/iomgr/pollset.h",
     "src/core/lib/iomgr/pollset_set.h",
     "src/core/lib/iomgr/pollset_set_windows.h",
@@ -1020,6 +1025,7 @@ cc_library(
     "src/core/lib/iomgr/iomgr.c",
     "src/core/lib/iomgr/iomgr_posix.c",
     "src/core/lib/iomgr/iomgr_windows.c",
+    "src/core/lib/iomgr/polling_entity.c",
     "src/core/lib/iomgr/pollset_set_windows.c",
     "src/core/lib/iomgr/pollset_windows.c",
     "src/core/lib/iomgr/resolve_address_posix.c",
@@ -1705,6 +1711,7 @@ objc_library(
     "src/core/lib/iomgr/iomgr.c",
     "src/core/lib/iomgr/iomgr_posix.c",
     "src/core/lib/iomgr/iomgr_windows.c",
+    "src/core/lib/iomgr/polling_entity.c",
     "src/core/lib/iomgr/pollset_set_windows.c",
     "src/core/lib/iomgr/pollset_windows.c",
     "src/core/lib/iomgr/resolve_address_posix.c",
@@ -1909,6 +1916,7 @@ objc_library(
     "src/core/lib/iomgr/iomgr.h",
     "src/core/lib/iomgr/iomgr_internal.h",
     "src/core/lib/iomgr/iomgr_posix.h",
+    "src/core/lib/iomgr/polling_entity.h",
     "src/core/lib/iomgr/pollset.h",
     "src/core/lib/iomgr/pollset_set.h",
     "src/core/lib/iomgr/pollset_set_windows.h",

Makefile

@@ -2502,6 +2502,7 @@ LIBGRPC_SRC = \
     src/core/lib/iomgr/iomgr.c \
     src/core/lib/iomgr/iomgr_posix.c \
     src/core/lib/iomgr/iomgr_windows.c \
+    src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_windows.c \
     src/core/lib/iomgr/pollset_windows.c \
     src/core/lib/iomgr/resolve_address_posix.c \
@@ -2764,6 +2765,7 @@ LIBGRPC_CRONET_SRC = \
     src/core/lib/iomgr/iomgr.c \
     src/core/lib/iomgr/iomgr_posix.c \
     src/core/lib/iomgr/iomgr_windows.c \
+    src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_windows.c \
     src/core/lib/iomgr/pollset_windows.c \
     src/core/lib/iomgr/resolve_address_posix.c \
@@ -3097,6 +3099,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/lib/iomgr/iomgr.c \
     src/core/lib/iomgr/iomgr_posix.c \
     src/core/lib/iomgr/iomgr_windows.c \
+    src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_windows.c \
     src/core/lib/iomgr/pollset_windows.c \
     src/core/lib/iomgr/resolve_address_posix.c \

binding.gyp

@@ -590,6 +590,7 @@
         'src/core/lib/iomgr/iomgr.c',
         'src/core/lib/iomgr/iomgr_posix.c',
         'src/core/lib/iomgr/iomgr_windows.c',
+        'src/core/lib/iomgr/polling_entity.c',
         'src/core/lib/iomgr/pollset_set_windows.c',
         'src/core/lib/iomgr/pollset_windows.c',
         'src/core/lib/iomgr/resolve_address_posix.c',

build.yaml

@@ -182,6 +182,7 @@ filegroups:
   - src/core/lib/iomgr/iomgr.h
   - src/core/lib/iomgr/iomgr_internal.h
   - src/core/lib/iomgr/iomgr_posix.h
+  - src/core/lib/iomgr/polling_entity.h
   - src/core/lib/iomgr/pollset.h
   - src/core/lib/iomgr/pollset_set.h
   - src/core/lib/iomgr/pollset_set_windows.h
@@ -257,6 +258,7 @@ filegroups:
   - src/core/lib/iomgr/iomgr.c
   - src/core/lib/iomgr/iomgr_posix.c
   - src/core/lib/iomgr/iomgr_windows.c
+  - src/core/lib/iomgr/polling_entity.c
   - src/core/lib/iomgr/pollset_set_windows.c
   - src/core/lib/iomgr/pollset_windows.c
   - src/core/lib/iomgr/resolve_address_posix.c

config.m4

@@ -109,6 +109,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/iomgr/iomgr.c \
     src/core/lib/iomgr/iomgr_posix.c \
     src/core/lib/iomgr/iomgr_windows.c \
+    src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_windows.c \
     src/core/lib/iomgr/pollset_windows.c \
     src/core/lib/iomgr/resolve_address_posix.c \

gRPC.podspec

@@ -190,6 +190,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/iomgr.h',
                       'src/core/lib/iomgr/iomgr_internal.h',
                       'src/core/lib/iomgr/iomgr_posix.h',
+                      'src/core/lib/iomgr/polling_entity.h',
                       'src/core/lib/iomgr/pollset.h',
                       'src/core/lib/iomgr/pollset_set.h',
                       'src/core/lib/iomgr/pollset_set_windows.h',
@@ -369,6 +370,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/iomgr.c',
                       'src/core/lib/iomgr/iomgr_posix.c',
                       'src/core/lib/iomgr/iomgr_windows.c',
+                      'src/core/lib/iomgr/polling_entity.c',
                       'src/core/lib/iomgr/pollset_set_windows.c',
                       'src/core/lib/iomgr/pollset_windows.c',
                       'src/core/lib/iomgr/resolve_address_posix.c',
@@ -558,6 +560,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/iomgr.h',
                               'src/core/lib/iomgr/iomgr_internal.h',
                               'src/core/lib/iomgr/iomgr_posix.h',
+                              'src/core/lib/iomgr/polling_entity.h',
                               'src/core/lib/iomgr/pollset.h',
                               'src/core/lib/iomgr/pollset_set.h',
                               'src/core/lib/iomgr/pollset_set_windows.h',

grpc.gemspec

@@ -198,6 +198,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/iomgr.h )
   s.files += %w( src/core/lib/iomgr/iomgr_internal.h )
   s.files += %w( src/core/lib/iomgr/iomgr_posix.h )
+  s.files += %w( src/core/lib/iomgr/polling_entity.h )
   s.files += %w( src/core/lib/iomgr/pollset.h )
   s.files += %w( src/core/lib/iomgr/pollset_set.h )
   s.files += %w( src/core/lib/iomgr/pollset_set_windows.h )
@@ -348,6 +349,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/iomgr.c )
   s.files += %w( src/core/lib/iomgr/iomgr_posix.c )
   s.files += %w( src/core/lib/iomgr/iomgr_windows.c )
+  s.files += %w( src/core/lib/iomgr/polling_entity.c )
   s.files += %w( src/core/lib/iomgr/pollset_set_windows.c )
   s.files += %w( src/core/lib/iomgr/pollset_windows.c )
   s.files += %w( src/core/lib/iomgr/resolve_address_posix.c )

package.xml

@@ -205,6 +205,7 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_internal.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_posix.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/polling_entity.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset_set.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset_set_windows.h" role="src" />
@@ -355,6 +356,7 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_posix.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_windows.c" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/polling_entity.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset_set_windows.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset_windows.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/resolve_address_posix.c" role="src" />

src/core/ext/census/grpc_filter.c

@@ -180,7 +180,7 @@ const grpc_channel_filter grpc_client_census_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     client_init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     client_destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,
@@ -193,7 +193,7 @@ const grpc_channel_filter grpc_server_census_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     server_init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     server_destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/ext/client_config/client_channel.c

@@ -376,7 +376,7 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
     int r;
     GRPC_LB_POLICY_REF(lb_policy, "cc_pick_subchannel");
     gpr_mu_unlock(&chand->mu_config);
-    r = grpc_lb_policy_pick(exec_ctx, lb_policy, calld->pollset,
+    r = grpc_lb_policy_pick(exec_ctx, lb_policy, calld->pollent,
                             initial_metadata, initial_metadata_flags,
                             connected_subchannel, on_ready);
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "cc_pick_subchannel");
@@ -461,10 +461,11 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   gpr_mu_destroy(&chand->mu_config);
 }
 
-static void cc_set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                           grpc_pollset *pollset) {
+static void cc_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                          grpc_call_element *elem,
+                                          grpc_polling_entity *pollent) {
   call_data *calld = elem->call_data;
-  calld->pollset = pollset;
+  calld->pollent = pollent;
 }
 
 const grpc_channel_filter grpc_client_channel_filter = {
@@ -472,7 +473,7 @@ const grpc_channel_filter grpc_client_channel_filter = {
     cc_start_transport_op,
     sizeof(call_data),
     init_call_elem,
-    cc_set_pollset,
+    cc_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/ext/client_config/lb_policy.c

@@ -99,12 +99,12 @@ void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx,
 }
 
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                        grpc_pollset *pollset,
+                        grpc_polling_entity *pollent,
                         grpc_metadata_batch *initial_metadata,
                         uint32_t initial_metadata_flags,
                         grpc_connected_subchannel **target,
                         grpc_closure *on_complete) {
-  return policy->vtable->pick(exec_ctx, policy, pollset, initial_metadata,
+  return policy->vtable->pick(exec_ctx, policy, pollent, initial_metadata,
                               initial_metadata_flags, target, on_complete);
 }
 

src/core/ext/client_config/lb_policy.h

@@ -35,6 +35,7 @@
 #define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
 
 #include "src/core/ext/client_config/subchannel.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A load balancing policy: specified by a vtable and a struct (which
@@ -59,7 +60,8 @@ struct grpc_lb_policy_vtable {
 
   /** implement grpc_lb_policy_pick */
   int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-              grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+              grpc_polling_entity *pollent,
+              grpc_metadata_batch *initial_metadata,
               uint32_t initial_metadata_flags,
               grpc_connected_subchannel **target, grpc_closure *on_complete);
   void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
@@ -124,7 +126,7 @@ void grpc_lb_policy_init(grpc_lb_policy *policy,
     \a target.
     Picking can be asynchronous. Any IO should be done under \a pollset. */
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
-                        grpc_pollset *pollset,
+                        grpc_polling_entity *pollent,
                         grpc_metadata_batch *initial_metadata,
                         uint32_t initial_metadata_flags,
                         grpc_connected_subchannel **target,

src/core/ext/client_config/subchannel.c

@@ -683,7 +683,7 @@ grpc_connected_subchannel *grpc_subchannel_get_connected_subchannel(
 
 grpc_subchannel_call *grpc_connected_subchannel_create_call(
     grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *con,
-    grpc_pollset *pollset) {
+    grpc_polling_entity *pollent) {
   grpc_channel_stack *chanstk = CHANNEL_STACK_FROM_CONNECTION(con);
   grpc_subchannel_call *call =
       gpr_malloc(sizeof(grpc_subchannel_call) + chanstk->call_stack_size);
@@ -692,7 +692,7 @@ grpc_subchannel_call *grpc_connected_subchannel_create_call(
   GRPC_CONNECTED_SUBCHANNEL_REF(con, "subchannel_call");
   grpc_call_stack_init(exec_ctx, chanstk, 1, subchannel_call_destroy, call,
                        NULL, NULL, callstk);
-  grpc_call_stack_set_pollset(exec_ctx, callstk, pollset);
+  grpc_call_stack_set_pollset_or_pollset_set(exec_ctx, callstk, pollent);
   return call;
 }
 

src/core/ext/client_config/subchannel.h

@@ -36,6 +36,7 @@
 
 #include "src/core/ext/client_config/connector.h"
 #include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A (sub-)channel that knows how to connect to exactly one target
@@ -109,7 +110,7 @@ void grpc_subchannel_call_unref(grpc_exec_ctx *exec_ctx,
 /** construct a subchannel call */
 grpc_subchannel_call *grpc_connected_subchannel_create_call(
     grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *connected_subchannel,
-    grpc_pollset *pollset);
+    grpc_polling_entity *pollent);
 
 /** process a transport level op */
 void grpc_connected_subchannel_process_transport_op(

src/core/ext/client_config/subchannel_call_holder.c

@@ -68,6 +68,7 @@ void grpc_subchannel_call_holder_init(
   holder->waiting_ops_capacity = 0;
   holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
   holder->owning_call = owning_call;
+  holder->pollent = NULL;
 }
 
 void grpc_subchannel_call_holder_destroy(grpc_exec_ctx *exec_ctx,
@@ -157,7 +158,7 @@ retry:
     gpr_atm_rel_store(
         &holder->subchannel_call,
         (gpr_atm)(uintptr_t)grpc_connected_subchannel_create_call(
-            exec_ctx, holder->connected_subchannel, holder->pollset));
+            exec_ctx, holder->connected_subchannel, holder->pollent));
     retry_waiting_locked(exec_ctx, holder);
     goto retry;
   }
@@ -183,7 +184,7 @@ static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
     gpr_atm_rel_store(
         &holder->subchannel_call,
         (gpr_atm)(uintptr_t)grpc_connected_subchannel_create_call(
-            exec_ctx, holder->connected_subchannel, holder->pollset));
+            exec_ctx, holder->connected_subchannel, holder->pollent));
     retry_waiting_locked(exec_ctx, holder);
   }
   gpr_mu_unlock(&holder->mu);

src/core/ext/client_config/subchannel_call_holder.h

@@ -35,6 +35,7 @@
 #define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_CALL_HOLDER_H
 
 #include "src/core/ext/client_config/subchannel.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 
 /** Pick a subchannel for grpc_subchannel_call_holder;
     Return 1 if subchannel is available immediately (in which case on_ready
@@ -71,7 +72,7 @@ typedef struct grpc_subchannel_call_holder {
 
   grpc_subchannel_call_holder_creation_phase creation_phase;
   grpc_connected_subchannel *connected_subchannel;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
 
   grpc_transport_stream_op *waiting_ops;
   size_t waiting_ops_count;

src/core/ext/lb_policy/pick_first/pick_first.c

@@ -39,7 +39,7 @@
 
 typedef struct pending_pick {
   struct pending_pick *next;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
   uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
@@ -118,8 +118,8 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   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_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                             p->base.interested_parties);
     grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
     gpr_free(pp);
     pp = next;
@@ -136,8 +136,8 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   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);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       *target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -162,8 +162,8 @@ static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
     } else {
@@ -196,7 +196,8 @@ static void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                   grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+                   grpc_polling_entity *pollent,
+                   grpc_metadata_batch *initial_metadata,
                    uint32_t initial_metadata_flags,
                    grpc_connected_subchannel **target,
                    grpc_closure *on_complete) {
@@ -221,10 +222,11 @@ static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
+    grpc_polling_entity_add_to_pollset_set(exec_ctx, pollent,
+                                           p->base.interested_parties);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
-    pp->pollset = pollset;
+    pp->pollent = pollent;
     pp->target = target;
     pp->initial_metadata_flags = initial_metadata_flags;
     pp->on_complete = on_complete;
@@ -304,8 +306,8 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         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_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                                   p->base.interested_parties);
           grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
           gpr_free(pp);
         }

src/core/ext/lb_policy/round_robin/round_robin.c

@@ -48,7 +48,7 @@ int grpc_lb_round_robin_trace = 0;
  * 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_polling_entity *pollent;
   uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
@@ -262,8 +262,8 @@ static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   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);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       *target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -288,8 +288,8 @@ static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
-                                   pp->pollset);
+      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                               p->base.interested_parties);
       *pp->target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -331,7 +331,8 @@ static void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                   grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+                   grpc_polling_entity *pollent,
+                   grpc_metadata_batch *initial_metadata,
                    uint32_t initial_metadata_flags,
                    grpc_connected_subchannel **target,
                    grpc_closure *on_complete) {
@@ -354,10 +355,11 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
+    grpc_polling_entity_add_to_pollset_set(exec_ctx, pollent,
+                                           p->base.interested_parties);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
-    pp->pollset = pollset;
+    pp->pollent = pollent;
     pp->target = target;
     pp->on_complete = on_complete;
     pp->initial_metadata_flags = initial_metadata_flags;
@@ -406,8 +408,8 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                     "[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_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
+                                                   p->base.interested_parties);
           grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
           gpr_free(pp);
         }

src/core/ext/load_reporting/load_reporting_filter.c

@@ -142,7 +142,7 @@ const grpc_channel_filter grpc_load_reporting_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/ext/transport/chttp2/transport/chttp2_transport.c

@@ -1734,6 +1734,13 @@ static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                                    add_to_pollset_locked, pollset, 0);
 }
 
+static void set_pollset_set(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
+                            grpc_stream *gs, grpc_pollset_set *pollset_set) {
+  grpc_chttp2_run_with_global_lock(exec_ctx, (grpc_chttp2_transport *)gt,
+                                   (grpc_chttp2_stream *)gs,
+                                   add_to_pollset_set_locked, pollset_set, 0);
+}
+
 /*******************************************************************************
  * BYTE STREAM
  */
@@ -2055,6 +2062,7 @@ static const grpc_transport_vtable vtable = {sizeof(grpc_chttp2_stream),
                                              "chttp2",
                                              init_stream,
                                              set_pollset,
+                                             set_pollset_set,
                                              perform_stream_op,
                                              perform_transport_op,
                                              destroy_stream,

src/core/ext/transport/cronet/transport/cronet_transport.c

@@ -152,6 +152,10 @@ static void next_recv_step(stream_obj *s, enum e_caller caller);
 static void set_pollset_do_nothing(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                                    grpc_stream *gs, grpc_pollset *pollset) {}
 
+static void set_pollset_set_do_nothing(grpc_exec_ctx *exec_ctx,
+                                       grpc_transport *gt, grpc_stream *gs,
+                                       grpc_pollset_set *pollset_set) {}
+
 static void enqueue_callbacks(grpc_closure *callback_list[]) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   if (callback_list[0]) {
@@ -646,7 +650,13 @@ static void destroy_transport(grpc_exec_ctx *exec_ctx, grpc_transport *gt) {
   }
 }
 
-const grpc_transport_vtable grpc_cronet_vtable = {
-    sizeof(stream_obj),     "cronet_http",     init_stream,
-    set_pollset_do_nothing, perform_stream_op, NULL,
-    destroy_stream,         destroy_transport, NULL};
+const grpc_transport_vtable grpc_cronet_vtable = {sizeof(stream_obj),
+                                                  "cronet_http",
+                                                  init_stream,
+                                                  set_pollset_do_nothing,
+                                                  set_pollset_set_do_nothing,
+                                                  perform_stream_op,
+                                                  NULL,
+                                                  destroy_stream,
+                                                  destroy_transport,
+                                                  NULL};

src/core/lib/channel/channel_stack.c

@@ -189,9 +189,9 @@ void grpc_call_stack_init(grpc_exec_ctx *exec_ctx,
   }
 }
 
-void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
-                                 grpc_call_stack *call_stack,
-                                 grpc_pollset *pollset) {
+void grpc_call_stack_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                                grpc_call_stack *call_stack,
+                                                grpc_polling_entity *pollent) {
   size_t count = call_stack->count;
   grpc_call_element *call_elems;
   char *user_data;
@@ -203,15 +203,16 @@ void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
 
   /* init per-filter data */
   for (i = 0; i < count; i++) {
-    call_elems[i].filter->set_pollset(exec_ctx, &call_elems[i], pollset);
+    call_elems[i].filter->set_pollset_or_pollset_set(exec_ctx, &call_elems[i],
+                                                     pollent);
     user_data +=
         ROUND_UP_TO_ALIGNMENT_SIZE(call_elems[i].filter->sizeof_call_data);
   }
 }
 
-void grpc_call_stack_ignore_set_pollset(grpc_exec_ctx *exec_ctx,
-                                        grpc_call_element *elem,
-                                        grpc_pollset *pollset) {}
+void grpc_call_stack_ignore_set_pollset_or_pollset_set(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_polling_entity *pollent) {}
 
 void grpc_call_stack_destroy(grpc_exec_ctx *exec_ctx, grpc_call_stack *stack,
                              const grpc_call_stats *call_stats,

src/core/lib/channel/channel_stack.h

@@ -48,6 +48,7 @@
 #include <grpc/support/time.h>
 
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/transport.h"
 
 typedef struct grpc_channel_element grpc_channel_element;
@@ -109,8 +110,9 @@ typedef struct {
      argument. */
   void (*init_call_elem)(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                          grpc_call_element_args *args);
-  void (*set_pollset)(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                      grpc_pollset *pollset);
+  void (*set_pollset_or_pollset_set)(grpc_exec_ctx *exec_ctx,
+                                     grpc_call_element *elem,
+                                     grpc_polling_entity *pollent);
   /* Destroy per call data.
      The filter does not need to do any chaining.
      The bottom filter of a stack will be passed a non-NULL pointer to
@@ -210,10 +212,11 @@ void grpc_call_stack_init(grpc_exec_ctx *exec_ctx,
                           grpc_call_context_element *context,
                           const void *transport_server_data,
                           grpc_call_stack *call_stack);
-/* Set a pollset for a call stack: must occur before the first op is started */
-void grpc_call_stack_set_pollset(grpc_exec_ctx *exec_ctx,
-                                 grpc_call_stack *call_stack,
-                                 grpc_pollset *pollset);
+/* Set a pollset or a pollset_set for a call stack: must occur before the first
+ * op is started */
+void grpc_call_stack_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                                grpc_call_stack *call_stack,
+                                                grpc_polling_entity *pollent);
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
 #define GRPC_CALL_STACK_REF(call_stack, reason) \
@@ -240,11 +243,11 @@ void grpc_call_stack_destroy(grpc_exec_ctx *exec_ctx, grpc_call_stack *stack,
                              const grpc_call_stats *call_stats,
                              void *and_free_memory);
 
-/* Ignore set pollset - used by filters to implement the set_pollset method
-   if they don't care about pollsets at all. Does nothing. */
-void grpc_call_stack_ignore_set_pollset(grpc_exec_ctx *exec_ctx,
-                                        grpc_call_element *elem,
-                                        grpc_pollset *pollset);
+/* Ignore set pollset{_set} - used by filters if they don't care about pollsets
+ * at all. Does nothing. */
+void grpc_call_stack_ignore_set_pollset_or_pollset_set(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_polling_entity *pollent);
 /* Call the next operation in a call stack */
 void grpc_call_next_op(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                        grpc_transport_stream_op *op);

src/core/lib/channel/compress_filter.c

@@ -325,7 +325,7 @@ const grpc_channel_filter grpc_compress_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/lib/channel/connected_channel.c

@@ -93,12 +93,13 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   GPR_ASSERT(r == 0);
 }
 
-static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                        grpc_pollset *pollset) {
+static void set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                       grpc_call_element *elem,
+                                       grpc_polling_entity *pollent) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
-  grpc_transport_set_pollset(exec_ctx, chand->transport,
-                             TRANSPORT_STREAM_FROM_CALL_DATA(calld), pollset);
+  grpc_transport_set_pops(exec_ctx, chand->transport,
+                          TRANSPORT_STREAM_FROM_CALL_DATA(calld), pollent);
 }
 
 /* Destructor for call_data */
@@ -138,7 +139,7 @@ static const grpc_channel_filter connected_channel_filter = {
     con_start_transport_op,
     sizeof(call_data),
     init_call_elem,
-    set_pollset,
+    set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/lib/channel/http_client_filter.c

@@ -250,7 +250,7 @@ const grpc_channel_filter grpc_http_client_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/lib/channel/http_server_filter.c

@@ -244,7 +244,7 @@ const grpc_channel_filter grpc_http_server_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/lib/http/httpcli.c

@@ -62,7 +62,7 @@ typedef struct {
   grpc_httpcli_response_cb on_response;
   void *user_data;
   grpc_httpcli_context *context;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
   grpc_iomgr_object iomgr_obj;
   gpr_slice_buffer incoming;
   gpr_slice_buffer outgoing;
@@ -97,8 +97,8 @@ static void next_address(grpc_exec_ctx *exec_ctx, internal_request *req);
 
 static void finish(grpc_exec_ctx *exec_ctx, internal_request *req,
                    int success) {
-  grpc_pollset_set_del_pollset(exec_ctx, req->context->pollset_set,
-                               req->pollset);
+  grpc_polling_entity_del_from_pollset_set(exec_ctx, req->pollent,
+                                           req->context->pollset_set);
   req->on_response(exec_ctx, req->user_data,
                    success ? &req->parser.http.response : NULL);
   grpc_http_parser_destroy(&req->parser);
@@ -222,7 +222,7 @@ static void on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
 
 static void internal_request_begin(
     grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-    grpc_pollset *pollset, const grpc_httpcli_request *request,
+    grpc_polling_entity *pollent, const grpc_httpcli_request *request,
     gpr_timespec deadline, grpc_httpcli_response_cb on_response,
     void *user_data, const char *name, gpr_slice request_text) {
   internal_request *req = gpr_malloc(sizeof(internal_request));
@@ -235,7 +235,7 @@ static void internal_request_begin(
   req->handshaker =
       request->handshaker ? request->handshaker : &grpc_httpcli_plaintext;
   req->context = context;
-  req->pollset = pollset;
+  req->pollent = pollent;
   grpc_closure_init(&req->on_read, on_read, req);
   grpc_closure_init(&req->done_write, done_write, req);
   gpr_slice_buffer_init(&req->incoming);
@@ -244,14 +244,15 @@ static void internal_request_begin(
   req->host = gpr_strdup(request->host);
   req->ssl_host_override = gpr_strdup(request->ssl_host_override);
 
-  grpc_pollset_set_add_pollset(exec_ctx, req->context->pollset_set,
-                               req->pollset);
+  GPR_ASSERT(pollent);
+  grpc_polling_entity_add_to_pollset_set(exec_ctx, req->pollent,
+                                         req->context->pollset_set);
   grpc_resolve_address(exec_ctx, request->host, req->handshaker->default_port,
                        on_resolved, req);
 }
 
 void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                      grpc_pollset *pollset,
+                      grpc_polling_entity *pollent,
                       const grpc_httpcli_request *request,
                       gpr_timespec deadline,
                       grpc_httpcli_response_cb on_response, void *user_data) {
@@ -261,14 +262,14 @@ void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
     return;
   }
   gpr_asprintf(&name, "HTTP:GET:%s:%s", request->host, request->http.path);
-  internal_request_begin(exec_ctx, context, pollset, request, deadline,
+  internal_request_begin(exec_ctx, context, pollent, request, deadline,
                          on_response, user_data, name,
                          grpc_httpcli_format_get_request(request));
   gpr_free(name);
 }
 
 void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                       grpc_pollset *pollset,
+                       grpc_polling_entity *pollent,
                        const grpc_httpcli_request *request,
                        const char *body_bytes, size_t body_size,
                        gpr_timespec deadline,
@@ -281,7 +282,7 @@ void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
   }
   gpr_asprintf(&name, "HTTP:POST:%s:%s", request->host, request->http.path);
   internal_request_begin(
-      exec_ctx, context, pollset, request, deadline, on_response, user_data,
+      exec_ctx, context, pollent, request, deadline, on_response, user_data,
       name, grpc_httpcli_format_post_request(request, body_bytes, body_size));
   gpr_free(name);
 }

src/core/lib/http/httpcli.h

@@ -41,6 +41,7 @@
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
 /* User agent this library reports */
@@ -100,7 +101,7 @@ void grpc_httpcli_context_destroy(grpc_httpcli_context *context);
    'on_response' is a callback to report results to (and 'user_data' is a user
      supplied pointer to pass to said call) */
 void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                      grpc_pollset *pollset,
+                      grpc_polling_entity *pollent,
                       const grpc_httpcli_request *request,
                       gpr_timespec deadline,
                       grpc_httpcli_response_cb on_response, void *user_data);
@@ -121,7 +122,7 @@ void grpc_httpcli_get(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
      supplied pointer to pass to said call)
    Does not support ?var1=val1&var2=val2 in the path. */
 void grpc_httpcli_post(grpc_exec_ctx *exec_ctx, grpc_httpcli_context *context,
-                       grpc_pollset *pollset,
+                       grpc_polling_entity *pollent,
                        const grpc_httpcli_request *request,
                        const char *body_bytes, size_t body_size,
                        gpr_timespec deadline,

src/core/lib/iomgr/polling_entity.c

@@ -0,0 +1,104 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/iomgr/polling_entity.h"
+
+grpc_polling_entity grpc_polling_entity_create_from_pollset_set(
+    grpc_pollset_set *pollset_set) {
+  grpc_polling_entity pollent;
+  pollent.pollent.pollset_set = pollset_set;
+  pollent.tag = POPS_POLLSET_SET;
+  return pollent;
+}
+
+grpc_polling_entity grpc_polling_entity_create_from_pollset(
+    grpc_pollset *pollset) {
+  grpc_polling_entity pollent;
+  pollent.pollent.pollset = pollset;
+  pollent.tag = POPS_POLLSET;
+  return pollent;
+}
+
+grpc_pollset *grpc_polling_entity_pollset(grpc_polling_entity *pollent) {
+  if (pollent->tag == POPS_POLLSET) {
+    return pollent->pollent.pollset;
+  }
+  return NULL;
+}
+
+grpc_pollset_set *grpc_polling_entity_pollset_set(
+    grpc_polling_entity *pollent) {
+  if (pollent->tag == POPS_POLLSET_SET) {
+    return pollent->pollent.pollset_set;
+  }
+  return NULL;
+}
+
+bool grpc_polling_entity_is_empty(const grpc_polling_entity *pollent) {
+  return pollent->tag == POPS_NONE;
+}
+
+void grpc_polling_entity_add_to_pollset_set(grpc_exec_ctx *exec_ctx,
+                                            grpc_polling_entity *pollent,
+                                            grpc_pollset_set *pss_dst) {
+  if (pollent->tag == POPS_POLLSET) {
+    GPR_ASSERT(pollent->pollent.pollset != NULL);
+    grpc_pollset_set_add_pollset(exec_ctx, pss_dst, pollent->pollent.pollset);
+  } else if (pollent->tag == POPS_POLLSET_SET) {
+    GPR_ASSERT(pollent->pollent.pollset_set != NULL);
+    grpc_pollset_set_add_pollset_set(exec_ctx, pss_dst,
+                                     pollent->pollent.pollset_set);
+  } else {
+    gpr_log(GPR_ERROR, "Invalid grpc_polling_entity tag '%d'", pollent->tag);
+    abort();
+  }
+}
+
+void grpc_polling_entity_del_from_pollset_set(grpc_exec_ctx *exec_ctx,
+                                              grpc_polling_entity *pollent,
+                                              grpc_pollset_set *pss_dst) {
+  if (pollent->tag == POPS_POLLSET) {
+    GPR_ASSERT(pollent->pollent.pollset != NULL);
+    grpc_pollset_set_del_pollset(exec_ctx, pss_dst, pollent->pollent.pollset);
+  } else if (pollent->tag == POPS_POLLSET_SET) {
+    GPR_ASSERT(pollent->pollent.pollset_set != NULL);
+    grpc_pollset_set_del_pollset_set(exec_ctx, pss_dst,
+                                     pollent->pollent.pollset_set);
+  } else {
+    gpr_log(GPR_ERROR, "Invalid grpc_polling_entity tag '%d'", pollent->tag);
+    abort();
+  }
+}

src/core/lib/iomgr/polling_entity.h

@@ -0,0 +1,81 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H
+#define GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H
+
+#include "src/core/lib/iomgr/pollset.h"
+#include "src/core/lib/iomgr/pollset_set.h"
+
+/* A grpc_polling_entity is a pollset-or-pollset_set container. It allows
+ * functions that
+ * accept a pollset XOR a pollset_set to do so through an abstract interface.
+ * No ownership is taken. */
+
+typedef struct grpc_polling_entity {
+  union {
+    grpc_pollset *pollset;
+    grpc_pollset_set *pollset_set;
+  } pollent;
+  enum pops_tag { POPS_NONE, POPS_POLLSET, POPS_POLLSET_SET } tag;
+} grpc_polling_entity;
+
+grpc_polling_entity grpc_polling_entity_create_from_pollset_set(
+    grpc_pollset_set *pollset_set);
+grpc_polling_entity grpc_polling_entity_create_from_pollset(
+    grpc_pollset *pollset);
+
+/** If \a pollent contains a pollset, return it. Otherwise, return NULL */
+grpc_pollset *grpc_polling_entity_pollset(grpc_polling_entity *pollent);
+
+/** If \a pollent contains a pollset_set, return it. Otherwise, return NULL */
+grpc_pollset_set *grpc_polling_entity_pollset_set(grpc_polling_entity *pollent);
+
+bool grpc_polling_entity_is_empty(const grpc_polling_entity *pollent);
+
+/** Add the pollset or pollset_set in \a pollent to the destination pollset_set
+ * \a
+ * pss_dst */
+void grpc_polling_entity_add_to_pollset_set(grpc_exec_ctx *exec_ctx,
+                                            grpc_polling_entity *pollent,
+                                            grpc_pollset_set *pss_dst);
+
+/** Delete the pollset or pollset_set in \a pollent from the destination
+ * pollset_set \a
+ * pss_dst */
+void grpc_polling_entity_del_from_pollset_set(grpc_exec_ctx *exec_ctx,
+                                              grpc_polling_entity *pollent,
+                                              grpc_pollset_set *pss_dst);
+/* pollset_set specific */
+
+#endif /* GRPC_CORE_LIB_IOMGR_POLLING_ENTITY_H */

src/core/lib/iomgr/pollset_set_windows.c

@@ -32,12 +32,15 @@
  */
 
 #include <grpc/support/port_platform.h>
+#include <stdint.h>
 
 #ifdef GPR_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/pollset_set_windows.h"
 
-grpc_pollset_set* grpc_pollset_set_create(void) { return NULL; }
+grpc_pollset_set* grpc_pollset_set_create(void) {
+  return (grpc_pollset_set*)((intptr_t)0xdeafbeef);
+}
 
 void grpc_pollset_set_destroy(grpc_pollset_set* pollset_set) {}
 

src/core/lib/iomgr/timer.c

@@ -278,7 +278,8 @@ static int refill_queue(shard_type *shard, gpr_timespec now) {
   return !grpc_timer_heap_is_empty(&shard->heap);
 }
 
-/* This pops the next non-cancelled timer with deadline <= now from the queue,
+/* This pollent the next non-cancelled timer with deadline <= now from the
+   queue,
    or returns NULL if there isn't one.
    REQUIRES: shard->mu locked */
 static grpc_timer *pop_one(shard_type *shard, gpr_timespec now) {

src/core/lib/security/credentials/composite/composite_credentials.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
@@ -35,6 +35,7 @@
 
 #include <string.h>
 
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/surface/api_trace.h"
 
 #include <grpc/support/alloc.h>
@@ -49,7 +50,7 @@ typedef struct {
   grpc_credentials_md_store *md_elems;
   grpc_auth_metadata_context auth_md_context;
   void *user_data;
-  grpc_pollset *pollset;
+  grpc_polling_entity *pollent;
   grpc_credentials_metadata_cb cb;
 } grpc_composite_call_credentials_metadata_context;
 
@@ -93,7 +94,7 @@ static void composite_call_metadata_cb(grpc_exec_ctx *exec_ctx, void *user_data,
     grpc_call_credentials *inner_creds =
         ctx->composite_creds->inner.creds_array[ctx->creds_index++];
     grpc_call_credentials_get_request_metadata(
-        exec_ctx, inner_creds, ctx->pollset, ctx->auth_md_context,
+        exec_ctx, inner_creds, ctx->pollent, ctx->auth_md_context,
         composite_call_metadata_cb, ctx);
     return;
   }
@@ -106,7 +107,7 @@ static void composite_call_metadata_cb(grpc_exec_ctx *exec_ctx, void *user_data,
 
 static void composite_call_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context auth_md_context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context auth_md_context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_composite_call_credentials *c = (grpc_composite_call_credentials *)creds;
   grpc_composite_call_credentials_metadata_context *ctx;
@@ -117,10 +118,10 @@ static void composite_call_get_request_metadata(
   ctx->user_data = user_data;
   ctx->cb = cb;
   ctx->composite_creds = c;
-  ctx->pollset = pollset;
+  ctx->pollent = pollent;
   ctx->md_elems = grpc_credentials_md_store_create(c->inner.num_creds);
   grpc_call_credentials_get_request_metadata(
-      exec_ctx, c->inner.creds_array[ctx->creds_index++], pollset,
+      exec_ctx, c->inner.creds_array[ctx->creds_index++], ctx->pollent,
       auth_md_context, composite_call_metadata_cb, ctx);
 }
 

src/core/lib/security/credentials/credentials.c

@@ -111,7 +111,7 @@ void grpc_call_credentials_release(grpc_call_credentials *creds) {
 
 void grpc_call_credentials_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   if (creds == NULL || creds->vtable->get_request_metadata == NULL) {
     if (cb != NULL) {
@@ -119,7 +119,7 @@ void grpc_call_credentials_get_request_metadata(
     }
     return;
   }
-  creds->vtable->get_request_metadata(exec_ctx, creds, pollset, context, cb,
+  creds->vtable->get_request_metadata(exec_ctx, creds, pollent, context, cb,
                                       user_data);
 }
 

src/core/lib/security/credentials/credentials.h

@@ -41,6 +41,7 @@
 
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/http/parser.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/security/transport/security_connector.h"
 
 struct grpc_http_response;
@@ -164,7 +165,8 @@ typedef void (*grpc_credentials_metadata_cb)(grpc_exec_ctx *exec_ctx,
 typedef struct {
   void (*destruct)(grpc_call_credentials *c);
   void (*get_request_metadata)(grpc_exec_ctx *exec_ctx,
-                               grpc_call_credentials *c, grpc_pollset *pollset,
+                               grpc_call_credentials *c,
+                               grpc_polling_entity *pollent,
                                grpc_auth_metadata_context context,
                                grpc_credentials_metadata_cb cb,
                                void *user_data);
@@ -180,7 +182,7 @@ grpc_call_credentials *grpc_call_credentials_ref(grpc_call_credentials *creds);
 void grpc_call_credentials_unref(grpc_call_credentials *creds);
 void grpc_call_credentials_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data);
 
 /* Metadata-only credentials with the specified key and value where

src/core/lib/security/credentials/fake/fake_credentials.c

@@ -106,7 +106,7 @@ static void on_simulated_token_fetch_done(grpc_exec_ctx *exec_ctx,
 
 static void md_only_test_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_md_only_test_credentials *c = (grpc_md_only_test_credentials *)creds;
 

src/core/lib/security/credentials/google_default/google_default_credentials.c

@@ -41,6 +41,7 @@
 
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/http/parser.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/security/credentials/jwt/jwt_credentials.h"
 #include "src/core/lib/security/credentials/oauth2/oauth2_credentials.h"
 #include "src/core/lib/support/env.h"
@@ -62,7 +63,7 @@ static gpr_once g_once = GPR_ONCE_INIT;
 static void init_default_credentials(void) { gpr_mu_init(&g_state_mu); }
 
 typedef struct {
-  grpc_pollset *pollset;
+  grpc_polling_entity pollent;
   int is_done;
   int success;
 } compute_engine_detector;
@@ -86,7 +87,7 @@ static void on_compute_engine_detection_http_response(
   }
   gpr_mu_lock(g_polling_mu);
   detector->is_done = 1;
-  grpc_pollset_kick(detector->pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&detector->pollent), NULL);
   gpr_mu_unlock(g_polling_mu);
 }
 
@@ -105,8 +106,9 @@ static int is_stack_running_on_compute_engine(void) {
      on compute engine. */
   gpr_timespec max_detection_delay = gpr_time_from_seconds(1, GPR_TIMESPAN);
 
-  detector.pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(detector.pollset, &g_polling_mu);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &g_polling_mu);
+  detector.pollent = grpc_polling_entity_create_from_pollset(pollset);
   detector.is_done = 0;
   detector.success = 0;
 
@@ -117,7 +119,7 @@ static int is_stack_running_on_compute_engine(void) {
   grpc_httpcli_context_init(&context);
 
   grpc_httpcli_get(
-      &exec_ctx, &context, detector.pollset, &request,
+      &exec_ctx, &context, &detector.pollent, &request,
       gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), max_detection_delay),
       on_compute_engine_detection_http_response, &detector);
 
@@ -128,19 +130,22 @@ static int is_stack_running_on_compute_engine(void) {
   gpr_mu_lock(g_polling_mu);
   while (!detector.is_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, detector.pollset, &worker,
-                      gpr_now(GPR_CLOCK_MONOTONIC),
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&detector.pollent),
+                      &worker, gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   gpr_mu_unlock(g_polling_mu);
 
   grpc_httpcli_context_destroy(&context);
-  grpc_closure_init(&destroy_closure, destroy_pollset, detector.pollset);
-  grpc_pollset_shutdown(&exec_ctx, detector.pollset, &destroy_closure);
+  grpc_closure_init(&destroy_closure, destroy_pollset,
+                    grpc_polling_entity_pollset(&detector.pollent));
+  grpc_pollset_shutdown(&exec_ctx,
+                        grpc_polling_entity_pollset(&detector.pollent),
+                        &destroy_closure);
   grpc_exec_ctx_finish(&exec_ctx);
   g_polling_mu = NULL;
 
-  gpr_free(detector.pollset);
+  gpr_free(grpc_polling_entity_pollset(&detector.pollent));
 
   return detector.success;
 }

src/core/lib/security/credentials/iam/iam_credentials.c

@@ -49,7 +49,7 @@ static void iam_destruct(grpc_call_credentials *creds) {
 
 static void iam_get_request_metadata(grpc_exec_ctx *exec_ctx,
                                      grpc_call_credentials *creds,
-                                     grpc_pollset *pollset,
+                                     grpc_polling_entity *pollent,
                                      grpc_auth_metadata_context context,
                                      grpc_credentials_metadata_cb cb,
                                      void *user_data) {

src/core/lib/security/credentials/jwt/jwt_credentials.c

@@ -64,7 +64,7 @@ static void jwt_destruct(grpc_call_credentials *creds) {
 
 static void jwt_get_request_metadata(grpc_exec_ctx *exec_ctx,
                                      grpc_call_credentials *creds,
-                                     grpc_pollset *pollset,
+                                     grpc_polling_entity *pollent,
                                      grpc_auth_metadata_context context,
                                      grpc_credentials_metadata_cb cb,
                                      void *user_data) {

src/core/lib/security/credentials/jwt/jwt_verifier.c

@@ -37,6 +37,7 @@
 #include <string.h>
 
 #include "src/core/lib/http/httpcli.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/security/util/b64.h"
 #include "src/core/lib/tsi/ssl_types.h"
 
@@ -321,7 +322,7 @@ grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims *claims,
 
 typedef struct {
   grpc_jwt_verifier *verifier;
-  grpc_pollset *pollset;
+  grpc_polling_entity pollent;
   jose_header *header;
   grpc_jwt_claims *claims;
   char *audience;
@@ -337,10 +338,11 @@ static verifier_cb_ctx *verifier_cb_ctx_create(
     grpc_jwt_claims *claims, const char *audience, gpr_slice signature,
     const char *signed_jwt, size_t signed_jwt_len, void *user_data,
     grpc_jwt_verification_done_cb cb) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   verifier_cb_ctx *ctx = gpr_malloc(sizeof(verifier_cb_ctx));
   memset(ctx, 0, sizeof(verifier_cb_ctx));
   ctx->verifier = verifier;
-  ctx->pollset = pollset;
+  ctx->pollent = grpc_polling_entity_create_from_pollset(pollset);
   ctx->header = header;
   ctx->audience = gpr_strdup(audience);
   ctx->claims = claims;
@@ -348,6 +350,7 @@ static verifier_cb_ctx *verifier_cb_ctx_create(
   ctx->signed_data = gpr_slice_from_copied_buffer(signed_jwt, signed_jwt_len);
   ctx->user_data = user_data;
   ctx->user_cb = cb;
+  grpc_exec_ctx_finish(&exec_ctx);
   return ctx;
 }
 
@@ -642,7 +645,7 @@ static void on_openid_config_retrieved(grpc_exec_ctx *exec_ctx, void *user_data,
     *(req.host + (req.http.path - jwks_uri)) = '\0';
   }
   grpc_httpcli_get(
-      exec_ctx, &ctx->verifier->http_ctx, ctx->pollset, &req,
+      exec_ctx, &ctx->verifier->http_ctx, &ctx->pollent, &req,
       gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay),
       on_keys_retrieved, ctx);
   grpc_json_destroy(json);
@@ -745,7 +748,7 @@ static void retrieve_key_and_verify(grpc_exec_ctx *exec_ctx,
   }
 
   grpc_httpcli_get(
-      exec_ctx, &ctx->verifier->http_ctx, ctx->pollset, &req,
+      exec_ctx, &ctx->verifier->http_ctx, &ctx->pollent, &req,
       gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay),
       http_cb, ctx);
   gpr_free(req.host);

src/core/lib/security/credentials/oauth2/oauth2_credentials.c

@@ -244,7 +244,7 @@ static void on_oauth2_token_fetcher_http_response(
 
 static void oauth2_token_fetcher_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_oauth2_token_fetcher_credentials *c =
       (grpc_oauth2_token_fetcher_credentials *)creds;
@@ -270,7 +270,7 @@ static void oauth2_token_fetcher_get_request_metadata(
     c->fetch_func(
         exec_ctx,
         grpc_credentials_metadata_request_create(creds, cb, user_data),
-        &c->httpcli_context, pollset, on_oauth2_token_fetcher_http_response,
+        &c->httpcli_context, pollent, on_oauth2_token_fetcher_http_response,
         gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), refresh_threshold));
   }
 }
@@ -295,7 +295,7 @@ static grpc_call_credentials_vtable compute_engine_vtable = {
 
 static void compute_engine_fetch_oauth2(
     grpc_exec_ctx *exec_ctx, grpc_credentials_metadata_request *metadata_req,
-    grpc_httpcli_context *httpcli_context, grpc_pollset *pollset,
+    grpc_httpcli_context *httpcli_context, grpc_polling_entity *pollent,
     grpc_httpcli_response_cb response_cb, gpr_timespec deadline) {
   grpc_http_header header = {"Metadata-Flavor", "Google"};
   grpc_httpcli_request request;
@@ -304,7 +304,7 @@ static void compute_engine_fetch_oauth2(
   request.http.path = GRPC_COMPUTE_ENGINE_METADATA_TOKEN_PATH;
   request.http.hdr_count = 1;
   request.http.hdrs = &header;
-  grpc_httpcli_get(exec_ctx, httpcli_context, pollset, &request, deadline,
+  grpc_httpcli_get(exec_ctx, httpcli_context, pollent, &request, deadline,
                    response_cb, metadata_req);
 }
 
@@ -336,7 +336,7 @@ static grpc_call_credentials_vtable refresh_token_vtable = {
 
 static void refresh_token_fetch_oauth2(
     grpc_exec_ctx *exec_ctx, grpc_credentials_metadata_request *metadata_req,
-    grpc_httpcli_context *httpcli_context, grpc_pollset *pollset,
+    grpc_httpcli_context *httpcli_context, grpc_polling_entity *pollent,
     grpc_httpcli_response_cb response_cb, gpr_timespec deadline) {
   grpc_google_refresh_token_credentials *c =
       (grpc_google_refresh_token_credentials *)metadata_req->creds;
@@ -353,7 +353,7 @@ static void refresh_token_fetch_oauth2(
   request.http.hdr_count = 1;
   request.http.hdrs = &header;
   request.handshaker = &grpc_httpcli_ssl;
-  grpc_httpcli_post(exec_ctx, httpcli_context, pollset, &request, body,
+  grpc_httpcli_post(exec_ctx, httpcli_context, pollent, &request, body,
                     strlen(body), deadline, response_cb, metadata_req);
   gpr_free(body);
 }
@@ -396,7 +396,7 @@ static void access_token_destruct(grpc_call_credentials *creds) {
 
 static void access_token_get_request_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_credentials *creds,
-    grpc_pollset *pollset, grpc_auth_metadata_context context,
+    grpc_polling_entity *pollent, grpc_auth_metadata_context context,
     grpc_credentials_metadata_cb cb, void *user_data) {
   grpc_access_token_credentials *c = (grpc_access_token_credentials *)creds;
   cb(exec_ctx, user_data, c->access_token_md->entries, 1, GRPC_CREDENTIALS_OK);

src/core/lib/security/credentials/oauth2/oauth2_credentials.h

@@ -70,7 +70,7 @@ void grpc_auth_refresh_token_destruct(grpc_auth_refresh_token *refresh_token);
 typedef void (*grpc_fetch_oauth2_func)(grpc_exec_ctx *exec_ctx,
                                        grpc_credentials_metadata_request *req,
                                        grpc_httpcli_context *http_context,
-                                       grpc_pollset *pollset,
+                                       grpc_polling_entity *pollent,
                                        grpc_httpcli_response_cb response_cb,
                                        gpr_timespec deadline);
 typedef struct {

src/core/lib/security/credentials/plugin/plugin_credentials.c

@@ -94,7 +94,7 @@ static void plugin_md_request_metadata_ready(void *request,
 
 static void plugin_get_request_metadata(grpc_exec_ctx *exec_ctx,
                                         grpc_call_credentials *creds,
-                                        grpc_pollset *pollset,
+                                        grpc_polling_entity *pollent,
                                         grpc_auth_metadata_context context,
                                         grpc_credentials_metadata_cb cb,
                                         void *user_data) {

src/core/lib/security/transport/client_auth_filter.c

@@ -54,11 +54,11 @@ typedef struct {
   grpc_call_credentials *creds;
   grpc_mdstr *host;
   grpc_mdstr *method;
-  /* pollset bound to this call; if we need to make external
-     network requests, they should be done under this pollset
-     so that work can progress when this call wants work to
-     progress */
-  grpc_pollset *pollset;
+  /* pollset{_set} bound to this call; if we need to make external
+     network requests, they should be done under a pollset added to this
+     pollset_set so that work can progress when this call wants work to progress
+  */
+  grpc_polling_entity *pollent;
   grpc_transport_stream_op op;
   uint8_t security_context_set;
   grpc_linked_mdelem md_links[MAX_CREDENTIALS_METADATA_COUNT];
@@ -184,9 +184,9 @@ static void send_security_metadata(grpc_exec_ctx *exec_ctx,
   build_auth_metadata_context(&chand->security_connector->base,
                               chand->auth_context, calld);
   calld->op = *op; /* Copy op (originates from the caller's stack). */
-  GPR_ASSERT(calld->pollset);
+  GPR_ASSERT(calld->pollent != NULL);
   grpc_call_credentials_get_request_metadata(
-      exec_ctx, calld->creds, calld->pollset, calld->auth_md_context,
+      exec_ctx, calld->creds, calld->pollent, calld->auth_md_context,
       on_credentials_metadata, elem);
 }
 
@@ -270,10 +270,11 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   memset(calld, 0, sizeof(*calld));
 }
 
-static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                        grpc_pollset *pollset) {
+static void set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
+                                       grpc_call_element *elem,
+                                       grpc_polling_entity *pollent) {
   call_data *calld = elem->call_data;
-  calld->pollset = pollset;
+  calld->pollent = pollent;
 }
 
 /* Destructor for call_data */
@@ -329,8 +330,14 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   GRPC_AUTH_CONTEXT_UNREF(chand->auth_context, "client_auth_filter");
 }
 
-const grpc_channel_filter grpc_client_auth_filter = {
-    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
-    init_call_elem,          set_pollset,          destroy_call_elem,
-    sizeof(channel_data),    init_channel_elem,    destroy_channel_elem,
-    grpc_call_next_get_peer, "client-auth"};
+const grpc_channel_filter grpc_client_auth_filter = {auth_start_transport_op,
+                                                     grpc_channel_next_op,
+                                                     sizeof(call_data),
+                                                     init_call_elem,
+                                                     set_pollset_or_pollset_set,
+                                                     destroy_call_elem,
+                                                     sizeof(channel_data),
+                                                     init_channel_elem,
+                                                     destroy_channel_elem,
+                                                     grpc_call_next_get_peer,
+                                                     "client-auth"};

src/core/lib/security/transport/server_auth_filter.c

@@ -220,9 +220,6 @@ static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
       grpc_server_security_context_destroy;
 }
 
-static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-                        grpc_pollset *pollset) {}
-
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                               const grpc_call_stats *stats, void *ignored) {}
@@ -258,7 +255,14 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
 }
 
 const grpc_channel_filter grpc_server_auth_filter = {
-    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
-    init_call_elem,          set_pollset,          destroy_call_elem,
-    sizeof(channel_data),    init_channel_elem,    destroy_channel_elem,
-    grpc_call_next_get_peer, "server-auth"};
+    auth_start_transport_op,
+    grpc_channel_next_op,
+    sizeof(call_data),
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    "server-auth"};

src/core/lib/surface/call.c

@@ -110,6 +110,7 @@ typedef struct batch_control {
 
 struct grpc_call {
   grpc_completion_queue *cq;
+  grpc_polling_entity pollent;
   grpc_channel *channel;
   grpc_call *parent;
   grpc_call *first_child;
@@ -218,13 +219,11 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call_stack,
 static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
                                   bool success);
 
-grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
-                            uint32_t propagation_mask,
-                            grpc_completion_queue *cq,
-                            const void *server_transport_data,
-                            grpc_mdelem **add_initial_metadata,
-                            size_t add_initial_metadata_count,
-                            gpr_timespec send_deadline) {
+grpc_call *grpc_call_create(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_completion_queue *cq, grpc_pollset_set *pollset_set_alternative,
+    const void *server_transport_data, grpc_mdelem **add_initial_metadata,
+    size_t add_initial_metadata_count, gpr_timespec send_deadline) {
   size_t i, j;
   grpc_channel_stack *channel_stack = grpc_channel_get_channel_stack(channel);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
@@ -261,9 +260,20 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
                        call->context, server_transport_data,
                        CALL_STACK_FROM_CALL(call));
   if (cq != NULL) {
+    GPR_ASSERT(
+        pollset_set_alternative == NULL &&
+        "Only one of 'cq' and 'pollset_set_alternative' should be non-NULL.");
     GRPC_CQ_INTERNAL_REF(cq, "bind");
-    grpc_call_stack_set_pollset(&exec_ctx, CALL_STACK_FROM_CALL(call),
-                                grpc_cq_pollset(cq));
+    call->pollent =
+        grpc_polling_entity_create_from_pollset(grpc_cq_pollset(cq));
+  }
+  if (pollset_set_alternative != NULL) {
+    call->pollent =
+        grpc_polling_entity_create_from_pollset_set(pollset_set_alternative);
+  }
+  if (!grpc_polling_entity_is_empty(&call->pollent)) {
+    grpc_call_stack_set_pollset_or_pollset_set(
+        &exec_ctx, CALL_STACK_FROM_CALL(call), &call->pollent);
   }
   if (parent_call != NULL) {
     GRPC_CALL_INTERNAL_REF(parent_call, "child");
@@ -318,10 +328,16 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
 void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
                                     grpc_completion_queue *cq) {
   GPR_ASSERT(cq);
+
+  if (grpc_polling_entity_pollset_set(&call->pollent) != NULL) {
+    gpr_log(GPR_ERROR, "A pollset_set is already registered for this call.");
+    abort();
+  }
   call->cq = cq;
   GRPC_CQ_INTERNAL_REF(cq, "bind");
-  grpc_call_stack_set_pollset(exec_ctx, CALL_STACK_FROM_CALL(call),
-                              grpc_cq_pollset(cq));
+  call->pollent = grpc_polling_entity_create_from_pollset(grpc_cq_pollset(cq));
+  grpc_call_stack_set_pollset_or_pollset_set(
+      exec_ctx, CALL_STACK_FROM_CALL(call), &call->pollent);
 }
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG

src/core/lib/surface/call.h

@@ -53,6 +53,8 @@ typedef void (*grpc_ioreq_completion_func)(grpc_exec_ctx *exec_ctx,
 grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
                             uint32_t propagation_mask,
                             grpc_completion_queue *cq,
+                            /* if not NULL, it'll be used in lieu of \a cq */
+                            grpc_pollset_set *pollset_set_alternative,
                             const void *server_transport_data,
                             grpc_mdelem **add_initial_metadata,
                             size_t add_initial_metadata_count,

src/core/lib/surface/channel.c

@@ -166,12 +166,14 @@ char *grpc_channel_get_target(grpc_channel *channel) {
 
 static grpc_call *grpc_channel_create_call_internal(
     grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
-    grpc_completion_queue *cq, grpc_mdelem *path_mdelem,
-    grpc_mdelem *authority_mdelem, gpr_timespec deadline) {
+    grpc_completion_queue *cq, grpc_pollset_set *pollset_set_alternative,
+    grpc_mdelem *path_mdelem, grpc_mdelem *authority_mdelem,
+    gpr_timespec deadline) {
   grpc_mdelem *send_metadata[2];
   size_t num_metadata = 0;
 
   GPR_ASSERT(channel->is_client);
+  GPR_ASSERT(!(cq != NULL && pollset_set_alternative != NULL));
 
   send_metadata[num_metadata++] = path_mdelem;
   if (authority_mdelem != NULL) {
@@ -180,8 +182,9 @@ static grpc_call *grpc_channel_create_call_internal(
     send_metadata[num_metadata++] = GRPC_MDELEM_REF(channel->default_authority);
   }
 
-  return grpc_call_create(channel, parent_call, propagation_mask, cq, NULL,
-                          send_metadata, num_metadata, deadline);
+  return grpc_call_create(channel, parent_call, propagation_mask, cq,
+                          pollset_set_alternative, NULL, send_metadata,
+                          num_metadata, deadline);
 }
 
 grpc_call *grpc_channel_create_call(grpc_channel *channel,
@@ -201,7 +204,22 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
            (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
-      channel, parent_call, propagation_mask, cq,
+      channel, parent_call, propagation_mask, cq, NULL,
+      grpc_mdelem_from_metadata_strings(GRPC_MDSTR_PATH,
+                                        grpc_mdstr_from_string(method)),
+      host ? grpc_mdelem_from_metadata_strings(GRPC_MDSTR_AUTHORITY,
+                                               grpc_mdstr_from_string(host))
+           : NULL,
+      deadline);
+}
+
+grpc_call *grpc_channel_create_pollset_set_call(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_pollset_set *pollset_set, const char *method, const char *host,
+    gpr_timespec deadline, void *reserved) {
+  GPR_ASSERT(!reserved);
+  return grpc_channel_create_call_internal(
+      channel, parent_call, propagation_mask, NULL, pollset_set,
       grpc_mdelem_from_metadata_strings(GRPC_MDSTR_PATH,
                                         grpc_mdstr_from_string(method)),
       host ? grpc_mdelem_from_metadata_strings(GRPC_MDSTR_AUTHORITY,
@@ -245,7 +263,7 @@ grpc_call *grpc_channel_create_registered_call(
           (int)deadline.tv_nsec, (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
-      channel, parent_call, propagation_mask, completion_queue,
+      channel, parent_call, propagation_mask, completion_queue, NULL,
       GRPC_MDELEM_REF(rc->path),
       rc->authority ? GRPC_MDELEM_REF(rc->authority) : NULL, deadline);
 }

src/core/lib/surface/channel.h

@@ -42,6 +42,11 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
                                   grpc_channel_stack_type channel_stack_type,
                                   grpc_transport *optional_transport);
 
+grpc_call *grpc_channel_create_pollset_set_call(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_pollset_set *pollset_set, const char *method, const char *host,
+    gpr_timespec deadline, void *reserved);
+
 /** Get a (borrowed) pointer to this channels underlying channel stack */
 grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel);
 

src/core/lib/surface/lame_client.c

@@ -128,7 +128,7 @@ const grpc_channel_filter grpc_lame_filter = {
     lame_start_transport_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/lib/surface/server.c

@@ -793,9 +793,9 @@ static void accept_stream(grpc_exec_ctx *exec_ctx, void *cd,
                           const void *transport_server_data) {
   channel_data *chand = cd;
   /* create a call */
-  grpc_call *call =
-      grpc_call_create(chand->channel, NULL, 0, NULL, transport_server_data,
-                       NULL, 0, gpr_inf_future(GPR_CLOCK_MONOTONIC));
+  grpc_call *call = grpc_call_create(chand->channel, NULL, 0, NULL, NULL,
+                                     transport_server_data, NULL, 0,
+                                     gpr_inf_future(GPR_CLOCK_MONOTONIC));
   grpc_call_element *elem =
       grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
   call_data *calld = elem->call_data;
@@ -910,7 +910,7 @@ const grpc_channel_filter grpc_server_top_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

src/core/lib/transport/transport.c

@@ -125,10 +125,19 @@ void grpc_transport_perform_op(grpc_exec_ctx *exec_ctx,
   transport->vtable->perform_op(exec_ctx, transport, op);
 }
 
-void grpc_transport_set_pollset(grpc_exec_ctx *exec_ctx,
-                                grpc_transport *transport, grpc_stream *stream,
-                                grpc_pollset *pollset) {
-  transport->vtable->set_pollset(exec_ctx, transport, stream, pollset);
+void grpc_transport_set_pops(grpc_exec_ctx *exec_ctx, grpc_transport *transport,
+                             grpc_stream *stream,
+                             grpc_polling_entity *pollent) {
+  grpc_pollset *pollset;
+  grpc_pollset_set *pollset_set;
+  if ((pollset = grpc_polling_entity_pollset(pollent)) != NULL) {
+    transport->vtable->set_pollset(exec_ctx, transport, stream, pollset);
+  } else if ((pollset_set = grpc_polling_entity_pollset_set(pollent)) != NULL) {
+    transport->vtable->set_pollset_set(exec_ctx, transport, stream,
+                                       pollset_set);
+  } else {
+    abort();
+  }
 }
 
 void grpc_transport_destroy_stream(grpc_exec_ctx *exec_ctx,

src/core/lib/transport/transport.h

@@ -37,6 +37,7 @@
 #include <stddef.h>
 
 #include "src/core/lib/channel/context.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 #include "src/core/lib/transport/byte_stream.h"
@@ -197,9 +198,8 @@ int grpc_transport_init_stream(grpc_exec_ctx *exec_ctx,
                                grpc_stream_refcount *refcount,
                                const void *server_data);
 
-void grpc_transport_set_pollset(grpc_exec_ctx *exec_ctx,
-                                grpc_transport *transport, grpc_stream *stream,
-                                grpc_pollset *pollset);
+void grpc_transport_set_pops(grpc_exec_ctx *exec_ctx, grpc_transport *transport,
+                             grpc_stream *stream, grpc_polling_entity *pollent);
 
 /* Destroy transport data for a stream.
 

src/core/lib/transport/transport_impl.h

@@ -53,6 +53,10 @@ typedef struct grpc_transport_vtable {
   void (*set_pollset)(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                       grpc_stream *stream, grpc_pollset *pollset);
 
+  /* implementation of grpc_transport_set_pollset */
+  void (*set_pollset_set)(grpc_exec_ctx *exec_ctx, grpc_transport *self,
+                          grpc_stream *stream, grpc_pollset_set *pollset_set);
+
   /* implementation of grpc_transport_perform_stream_op */
   void (*perform_stream_op)(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                             grpc_stream *stream, grpc_transport_stream_op *op);

src/python/grpcio/grpc_core_dependencies.py

@@ -103,6 +103,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/iomgr/iomgr.c',
   'src/core/lib/iomgr/iomgr_posix.c',
   'src/core/lib/iomgr/iomgr_windows.c',
+  'src/core/lib/iomgr/polling_entity.c',
   'src/core/lib/iomgr/pollset_set_windows.c',
   'src/core/lib/iomgr/pollset_windows.c',
   'src/core/lib/iomgr/resolve_address_posix.c',

test/core/channel/channel_stack_test.c

@@ -92,17 +92,18 @@ static void free_call(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
 }
 
 static void test_create_channel_stack(void) {
-  const grpc_channel_filter filter = {call_func,
-                                      channel_func,
-                                      sizeof(int),
-                                      call_init_func,
-                                      grpc_call_stack_ignore_set_pollset,
-                                      call_destroy_func,
-                                      sizeof(int),
-                                      channel_init_func,
-                                      channel_destroy_func,
-                                      get_peer,
-                                      "some_test_filter"};
+  const grpc_channel_filter filter = {
+      call_func,
+      channel_func,
+      sizeof(int),
+      call_init_func,
+      grpc_call_stack_ignore_set_pollset_or_pollset_set,
+      call_destroy_func,
+      sizeof(int),
+      channel_init_func,
+      channel_destroy_func,
+      get_peer,
+      "some_test_filter"};
   const grpc_channel_filter *filters = &filter;
   grpc_channel_stack *channel_stack;
   grpc_call_stack *call_stack;

test/core/end2end/tests/filter_causes_close.c

@@ -248,7 +248,7 @@ static const grpc_channel_filter test_filter = {
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
-    grpc_call_stack_ignore_set_pollset,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
     destroy_call_elem,
     sizeof(channel_data),
     init_channel_elem,

test/core/http/httpcli_test.c

@@ -48,7 +48,7 @@
 static int g_done = 0;
 static grpc_httpcli_context g_context;
 static gpr_mu *g_mu;
-static grpc_pollset *g_pollset;
+static grpc_polling_entity g_pops;
 
 static gpr_timespec n_seconds_time(int seconds) {
   return GRPC_TIMEOUT_SECONDS_TO_DEADLINE(seconds);
@@ -66,7 +66,7 @@ static void on_finish(grpc_exec_ctx *exec_ctx, void *arg,
   GPR_ASSERT(0 == memcmp(expect, response->body, response->body_length));
   gpr_mu_lock(g_mu);
   g_done = 1;
-  grpc_pollset_kick(g_pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&g_pops), NULL);
   gpr_mu_unlock(g_mu);
 }
 
@@ -86,12 +86,12 @@ static void test_get(int port) {
   req.http.path = "/get";
   req.handshaker = &grpc_httpcli_plaintext;
 
-  grpc_httpcli_get(&exec_ctx, &g_context, g_pollset, &req, n_seconds_time(15),
+  grpc_httpcli_get(&exec_ctx, &g_context, &g_pops, &req, n_seconds_time(15),
                    on_finish, (void *)42);
   gpr_mu_lock(g_mu);
   while (!g_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops), &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
@@ -117,12 +117,12 @@ static void test_post(int port) {
   req.http.path = "/post";
   req.handshaker = &grpc_httpcli_plaintext;
 
-  grpc_httpcli_post(&exec_ctx, &g_context, g_pollset, &req, "hello", 5,
+  grpc_httpcli_post(&exec_ctx, &g_context, &g_pops, &req, "hello", 5,
                     n_seconds_time(15), on_finish, (void *)42);
   gpr_mu_lock(g_mu);
   while (!g_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops), &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
@@ -132,8 +132,8 @@ static void test_post(int port) {
   gpr_free(host);
 }
 
-static void destroy_pollset(grpc_exec_ctx *exec_ctx, void *p, bool success) {
-  grpc_pollset_destroy(p);
+static void destroy_pops(grpc_exec_ctx *exec_ctx, void *p, bool success) {
+  grpc_pollset_destroy(grpc_polling_entity_pollset(p));
 }
 
 int main(int argc, char **argv) {
@@ -180,19 +180,21 @@ int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_init();
   grpc_httpcli_context_init(&g_context);
-  g_pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(g_pollset, &g_mu);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &g_mu);
+  g_pops = grpc_polling_entity_create_from_pollset(pollset);
 
   test_get(port);
   test_post(port);
 
   grpc_httpcli_context_destroy(&g_context);
-  grpc_closure_init(&destroyed, destroy_pollset, g_pollset);
-  grpc_pollset_shutdown(&exec_ctx, g_pollset, &destroyed);
+  grpc_closure_init(&destroyed, destroy_pops, &g_pops);
+  grpc_pollset_shutdown(&exec_ctx, grpc_polling_entity_pollset(&g_pops),
+                        &destroyed);
   grpc_exec_ctx_finish(&exec_ctx);
   grpc_shutdown();
 
-  gpr_free(g_pollset);
+  gpr_free(grpc_polling_entity_pollset(&g_pops));
 
   gpr_subprocess_destroy(server);
 

test/core/http/httpscli_test.c

@@ -48,7 +48,7 @@
 static int g_done = 0;
 static grpc_httpcli_context g_context;
 static gpr_mu *g_mu;
-static grpc_pollset *g_pollset;
+static grpc_polling_entity g_pops;
 
 static gpr_timespec n_seconds_time(int seconds) {
   return GRPC_TIMEOUT_SECONDS_TO_DEADLINE(seconds);
@@ -66,7 +66,7 @@ static void on_finish(grpc_exec_ctx *exec_ctx, void *arg,
   GPR_ASSERT(0 == memcmp(expect, response->body, response->body_length));
   gpr_mu_lock(g_mu);
   g_done = 1;
-  grpc_pollset_kick(g_pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&g_pops), NULL);
   gpr_mu_unlock(g_mu);
 }
 
@@ -87,12 +87,12 @@ static void test_get(int port) {
   req.http.path = "/get";
   req.handshaker = &grpc_httpcli_ssl;
 
-  grpc_httpcli_get(&exec_ctx, &g_context, g_pollset, &req, n_seconds_time(15),
+  grpc_httpcli_get(&exec_ctx, &g_context, &g_pops, &req, n_seconds_time(15),
                    on_finish, (void *)42);
   gpr_mu_lock(g_mu);
   while (!g_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops), &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
@@ -119,12 +119,12 @@ static void test_post(int port) {
   req.http.path = "/post";
   req.handshaker = &grpc_httpcli_ssl;
 
-  grpc_httpcli_post(&exec_ctx, &g_context, g_pollset, &req, "hello", 5,
+  grpc_httpcli_post(&exec_ctx, &g_context, &g_pops, &req, "hello", 5,
                     n_seconds_time(15), on_finish, (void *)42);
   gpr_mu_lock(g_mu);
   while (!g_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, g_pollset, &worker,
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&g_pops), &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC), n_seconds_time(20));
     gpr_mu_unlock(g_mu);
     grpc_exec_ctx_finish(&exec_ctx);
@@ -134,8 +134,8 @@ static void test_post(int port) {
   gpr_free(host);
 }
 
-static void destroy_pollset(grpc_exec_ctx *exec_ctx, void *p, bool success) {
-  grpc_pollset_destroy(p);
+static void destroy_pops(grpc_exec_ctx *exec_ctx, void *p, bool success) {
+  grpc_pollset_destroy(grpc_polling_entity_pollset(p));
 }
 
 int main(int argc, char **argv) {
@@ -183,19 +183,21 @@ int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_init();
   grpc_httpcli_context_init(&g_context);
-  g_pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(g_pollset, &g_mu);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &g_mu);
+  g_pops = grpc_polling_entity_create_from_pollset(pollset);
 
   test_get(port);
   test_post(port);
 
   grpc_httpcli_context_destroy(&g_context);
-  grpc_closure_init(&destroyed, destroy_pollset, g_pollset);
-  grpc_pollset_shutdown(&exec_ctx, g_pollset, &destroyed);
+  grpc_closure_init(&destroyed, destroy_pops, &g_pops);
+  grpc_pollset_shutdown(&exec_ctx, grpc_polling_entity_pollset(&g_pops),
+                        &destroyed);
   grpc_exec_ctx_finish(&exec_ctx);
   grpc_shutdown();
 
-  gpr_free(g_pollset);
+  gpr_free(grpc_polling_entity_pollset(&g_pops));
 
   gpr_subprocess_destroy(server);
 

test/core/security/oauth2_utils.c

@@ -46,7 +46,7 @@
 
 typedef struct {
   gpr_mu *mu;
-  grpc_pollset *pollset;
+  grpc_polling_entity pops;
   int is_done;
   char *token;
 } oauth2_request;
@@ -70,7 +70,7 @@ static void on_oauth2_response(grpc_exec_ctx *exec_ctx, void *user_data,
   gpr_mu_lock(request->mu);
   request->is_done = 1;
   request->token = token;
-  grpc_pollset_kick(request->pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&request->pops), NULL);
   gpr_mu_unlock(request->mu);
 }
 
@@ -83,30 +83,30 @@ char *grpc_test_fetch_oauth2_token_with_credentials(
   grpc_closure do_nothing_closure;
   grpc_auth_metadata_context null_ctx = {"", "", NULL, NULL};
 
-  request.pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(request.pollset, &request.mu);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &request.mu);
+  request.pops = grpc_polling_entity_create_from_pollset(pollset);
   request.is_done = 0;
 
   grpc_closure_init(&do_nothing_closure, do_nothing, NULL);
 
-  grpc_call_credentials_get_request_metadata(&exec_ctx, creds, request.pollset,
-                                             null_ctx, on_oauth2_response,
-                                             &request);
+  grpc_call_credentials_get_request_metadata(
+      &exec_ctx, creds, &request.pops, null_ctx, on_oauth2_response, &request);
 
   grpc_exec_ctx_finish(&exec_ctx);
 
   gpr_mu_lock(request.mu);
   while (!request.is_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, request.pollset, &worker,
-                      gpr_now(GPR_CLOCK_MONOTONIC),
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&request.pops),
+                      &worker, gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
   }
   gpr_mu_unlock(request.mu);
 
-  grpc_pollset_shutdown(&exec_ctx, request.pollset, &do_nothing_closure);
+  grpc_pollset_shutdown(&exec_ctx, grpc_polling_entity_pollset(&request.pops),
+                        &do_nothing_closure);
   grpc_exec_ctx_finish(&exec_ctx);
-  grpc_pollset_destroy(request.pollset);
-  gpr_free(request.pollset);
+  gpr_free(grpc_polling_entity_pollset(&request.pops));
   return request.token;
 }

test/core/security/print_google_default_creds_token.c

@@ -48,7 +48,7 @@
 
 typedef struct {
   gpr_mu *mu;
-  grpc_pollset *pollset;
+  grpc_polling_entity pops;
   int is_done;
 } synchronizer;
 
@@ -67,7 +67,7 @@ static void on_metadata_response(grpc_exec_ctx *exec_ctx, void *user_data,
   }
   gpr_mu_lock(sync->mu);
   sync->is_done = 1;
-  grpc_pollset_kick(sync->pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&sync->pops), NULL);
   gpr_mu_unlock(sync->mu);
 }
 
@@ -94,19 +94,20 @@ int main(int argc, char **argv) {
     goto end;
   }
 
-  sync.pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(sync.pollset, &sync.mu);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &sync.mu);
+  sync.pops = grpc_polling_entity_create_from_pollset(pollset);
   sync.is_done = 0;
 
   grpc_call_credentials_get_request_metadata(
       &exec_ctx, ((grpc_composite_channel_credentials *)creds)->call_creds,
-      sync.pollset, context, on_metadata_response, &sync);
+      &sync.pops, context, on_metadata_response, &sync);
 
   gpr_mu_lock(sync.mu);
   while (!sync.is_done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, sync.pollset, &worker,
-                      gpr_now(GPR_CLOCK_MONOTONIC),
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&sync.pops),
+                      &worker, gpr_now(GPR_CLOCK_MONOTONIC),
                       gpr_inf_future(GPR_CLOCK_MONOTONIC));
     gpr_mu_unlock(sync.mu);
     grpc_exec_ctx_flush(&exec_ctx);
@@ -117,7 +118,7 @@ int main(int argc, char **argv) {
   grpc_exec_ctx_finish(&exec_ctx);
 
   grpc_channel_credentials_release(creds);
-  gpr_free(sync.pollset);
+  gpr_free(grpc_polling_entity_pollset(&sync.pops));
 
 end:
   gpr_cmdline_destroy(cl);

test/core/util/port_server_client.c

@@ -51,14 +51,15 @@
 
 typedef struct freereq {
   gpr_mu *mu;
-  grpc_pollset *pollset;
+  grpc_polling_entity pops;
   int done;
 } freereq;
 
-static void destroy_pollset_and_shutdown(grpc_exec_ctx *exec_ctx, void *p,
-                                         bool success) {
-  grpc_pollset_destroy(p);
-  gpr_free(p);
+static void destroy_pops_and_shutdown(grpc_exec_ctx *exec_ctx, void *p,
+                                      bool success) {
+  grpc_pollset *pollset = grpc_polling_entity_pollset(p);
+  grpc_pollset_destroy(pollset);
+  gpr_free(pollset);
   grpc_shutdown();
 }
 
@@ -67,7 +68,7 @@ static void freed_port_from_server(grpc_exec_ctx *exec_ctx, void *arg,
   freereq *pr = arg;
   gpr_mu_lock(pr->mu);
   pr->done = 1;
-  grpc_pollset_kick(pr->pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&pr->pops), NULL);
   gpr_mu_unlock(pr->mu);
 }
 
@@ -84,23 +85,23 @@ void grpc_free_port_using_server(char *server, int port) {
   memset(&pr, 0, sizeof(pr));
   memset(&req, 0, sizeof(req));
 
-  pr.pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(pr.pollset, &pr.mu);
-  shutdown_closure =
-      grpc_closure_create(destroy_pollset_and_shutdown, pr.pollset);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &pr.mu);
+  pr.pops = grpc_polling_entity_create_from_pollset(pollset);
+  shutdown_closure = grpc_closure_create(destroy_pops_and_shutdown, &pr.pops);
 
   req.host = server;
   gpr_asprintf(&path, "/drop/%d", port);
   req.http.path = path;
 
   grpc_httpcli_context_init(&context);
-  grpc_httpcli_get(&exec_ctx, &context, pr.pollset, &req,
+  grpc_httpcli_get(&exec_ctx, &context, &pr.pops, &req,
                    GRPC_TIMEOUT_SECONDS_TO_DEADLINE(10), freed_port_from_server,
                    &pr);
   gpr_mu_lock(pr.mu);
   while (!pr.done) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, pr.pollset, &worker,
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&pr.pops), &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1));
   }
@@ -108,14 +109,15 @@ void grpc_free_port_using_server(char *server, int port) {
 
   grpc_httpcli_context_destroy(&context);
   grpc_exec_ctx_finish(&exec_ctx);
-  grpc_pollset_shutdown(&exec_ctx, pr.pollset, shutdown_closure);
+  grpc_pollset_shutdown(&exec_ctx, grpc_polling_entity_pollset(&pr.pops),
+                        shutdown_closure);
   grpc_exec_ctx_finish(&exec_ctx);
   gpr_free(path);
 }
 
 typedef struct portreq {
   gpr_mu *mu;
-  grpc_pollset *pollset;
+  grpc_polling_entity pops;
   int port;
   int retries;
   char *server;
@@ -151,7 +153,7 @@ static void got_port_from_server(grpc_exec_ctx *exec_ctx, void *arg,
     pr->retries++;
     req.host = pr->server;
     req.http.path = "/get";
-    grpc_httpcli_get(exec_ctx, pr->ctx, pr->pollset, &req,
+    grpc_httpcli_get(exec_ctx, pr->ctx, &pr->pops, &req,
                      GRPC_TIMEOUT_SECONDS_TO_DEADLINE(10), got_port_from_server,
                      pr);
     return;
@@ -165,7 +167,7 @@ static void got_port_from_server(grpc_exec_ctx *exec_ctx, void *arg,
   GPR_ASSERT(port > 1024);
   gpr_mu_lock(pr->mu);
   pr->port = port;
-  grpc_pollset_kick(pr->pollset, NULL);
+  grpc_pollset_kick(grpc_polling_entity_pollset(&pr->pops), NULL);
   gpr_mu_unlock(pr->mu);
 }
 
@@ -180,10 +182,10 @@ int grpc_pick_port_using_server(char *server) {
 
   memset(&pr, 0, sizeof(pr));
   memset(&req, 0, sizeof(req));
-  pr.pollset = gpr_malloc(grpc_pollset_size());
-  grpc_pollset_init(pr.pollset, &pr.mu);
-  shutdown_closure =
-      grpc_closure_create(destroy_pollset_and_shutdown, pr.pollset);
+  grpc_pollset *pollset = gpr_malloc(grpc_pollset_size());
+  grpc_pollset_init(pollset, &pr.mu);
+  pr.pops = grpc_polling_entity_create_from_pollset(pollset);
+  shutdown_closure = grpc_closure_create(destroy_pops_and_shutdown, &pr.pops);
   pr.port = -1;
   pr.server = server;
   pr.ctx = &context;
@@ -192,21 +194,22 @@ int grpc_pick_port_using_server(char *server) {
   req.http.path = "/get";
 
   grpc_httpcli_context_init(&context);
-  grpc_httpcli_get(&exec_ctx, &context, pr.pollset, &req,
+  grpc_httpcli_get(&exec_ctx, &context, &pr.pops, &req,
                    GRPC_TIMEOUT_SECONDS_TO_DEADLINE(10), got_port_from_server,
                    &pr);
   grpc_exec_ctx_finish(&exec_ctx);
   gpr_mu_lock(pr.mu);
   while (pr.port == -1) {
     grpc_pollset_worker *worker = NULL;
-    grpc_pollset_work(&exec_ctx, pr.pollset, &worker,
+    grpc_pollset_work(&exec_ctx, grpc_polling_entity_pollset(&pr.pops), &worker,
                       gpr_now(GPR_CLOCK_MONOTONIC),
                       GRPC_TIMEOUT_SECONDS_TO_DEADLINE(1));
   }
   gpr_mu_unlock(pr.mu);
 
   grpc_httpcli_context_destroy(&context);
-  grpc_pollset_shutdown(&exec_ctx, pr.pollset, shutdown_closure);
+  grpc_pollset_shutdown(&exec_ctx, grpc_polling_entity_pollset(&pr.pops),
+                        shutdown_closure);
   grpc_exec_ctx_finish(&exec_ctx);
 
   return pr.port;

tools/doxygen/Doxyfile.core.internal

@@ -815,6 +815,7 @@ src/core/lib/iomgr/iocp_windows.h \
 src/core/lib/iomgr/iomgr.h \
 src/core/lib/iomgr/iomgr_internal.h \
 src/core/lib/iomgr/iomgr_posix.h \
+src/core/lib/iomgr/polling_entity.h \
 src/core/lib/iomgr/pollset.h \
 src/core/lib/iomgr/pollset_set.h \
 src/core/lib/iomgr/pollset_set_windows.h \
@@ -965,6 +966,7 @@ src/core/lib/iomgr/iocp_windows.c \
 src/core/lib/iomgr/iomgr.c \
 src/core/lib/iomgr/iomgr_posix.c \
 src/core/lib/iomgr/iomgr_windows.c \
+src/core/lib/iomgr/polling_entity.c \
 src/core/lib/iomgr/pollset_set_windows.c \
 src/core/lib/iomgr/pollset_windows.c \
 src/core/lib/iomgr/resolve_address_posix.c \

tools/run_tests/sources_and_headers.json

@@ -5624,6 +5624,7 @@
       "src/core/lib/iomgr/iomgr.h", 
       "src/core/lib/iomgr/iomgr_internal.h", 
       "src/core/lib/iomgr/iomgr_posix.h", 
+      "src/core/lib/iomgr/polling_entity.h", 
       "src/core/lib/iomgr/pollset.h", 
       "src/core/lib/iomgr/pollset_set.h", 
       "src/core/lib/iomgr/pollset_set_windows.h", 
@@ -5733,6 +5734,8 @@
       "src/core/lib/iomgr/iomgr_posix.c", 
       "src/core/lib/iomgr/iomgr_posix.h", 
       "src/core/lib/iomgr/iomgr_windows.c", 
+      "src/core/lib/iomgr/polling_entity.c", 
+      "src/core/lib/iomgr/polling_entity.h", 
       "src/core/lib/iomgr/pollset.h", 
       "src/core/lib/iomgr/pollset_set.h", 
       "src/core/lib/iomgr/pollset_set_windows.c", 

vsprojects/vcxproj/grpc/grpc.vcxproj

@@ -324,6 +324,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_internal.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set_windows.h" />
@@ -503,6 +504,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_windows.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set_windows.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_windows.c">

vsprojects/vcxproj/grpc/grpc.vcxproj.filters

@@ -82,6 +82,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_windows.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set_windows.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
@@ -701,6 +704,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>

vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj

@@ -313,6 +313,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_internal.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set_windows.h" />
@@ -471,6 +472,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_windows.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set_windows.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_windows.c">

vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters

@@ -85,6 +85,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_windows.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset_set_windows.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
@@ -611,6 +614,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>