Merge branch 'master' into new_tsi

BUILD

@@ -54,33 +54,46 @@ grpc_cc_library(
     ],
 )
 
-grpc_cc_library(
-    name = "grpc",
+grpc_cc_libraries(
+    name_list = ["grpc", "grpc_unsecure",],
     srcs = [
         "src/core/lib/surface/init.c",
-        "src/core/plugin_registry/grpc_plugin_registry.c",
+    ],
+    additional_src_list = [
+        [
+            "src/core/plugin_registry/grpc_plugin_registry.c",
+        ],
+        [
+            "src/core/lib/surface/init_unsecure.c",
+            "src/core/plugin_registry/grpc_unsecure_plugin_registry.c",
+        ],
     ],
     language = "c",
     standalone = True,
     deps = [
         "census",
         "grpc_base",
-        "grpc_lb_policy_grpclb_secure",
         "grpc_lb_policy_pick_first",
         "grpc_lb_policy_round_robin",
         "grpc_load_reporting",
         "grpc_max_age_filter",
-        "grpc_resolver_dns_ares",
         "grpc_resolver_dns_native",
         "grpc_resolver_sockaddr",
-        "grpc_secure",
         "grpc_transport_chttp2_client_insecure",
-        "grpc_transport_chttp2_client_secure",
         "grpc_transport_chttp2_server_insecure",
-        "grpc_transport_chttp2_server_secure",
         "grpc_message_size_filter",
         "grpc_deadline_filter",
     ],
+    additional_dep_list = [
+        [
+            "grpc_secure",
+            "grpc_resolver_dns_ares",
+            "grpc_lb_policy_grpclb_secure",
+            "grpc_transport_chttp2_client_secure",
+            "grpc_transport_chttp2_server_secure",
+        ],
+        [],
+    ],
 )
 
 grpc_cc_library(
@@ -98,32 +111,6 @@ grpc_cc_library(
     ],
 )
 
-grpc_cc_library(
-    name = "grpc_unsecure",
-    srcs = [
-        "src/core/lib/surface/init.c",
-        "src/core/lib/surface/init_unsecure.c",
-        "src/core/plugin_registry/grpc_unsecure_plugin_registry.c",
-    ],
-    language = "c",
-    standalone = True,
-    deps = [
-        "census",
-        "grpc_base",
-        "grpc_lb_policy_grpclb",
-        "grpc_lb_policy_pick_first",
-        "grpc_lb_policy_round_robin",
-        "grpc_load_reporting",
-        "grpc_max_age_filter",
-        "grpc_resolver_dns_native",
-        "grpc_resolver_sockaddr",
-        "grpc_transport_chttp2_client_insecure",
-        "grpc_transport_chttp2_server_insecure",
-        "grpc_message_size_filter",
-        "grpc_deadline_filter",
-    ],
-)
-
 grpc_cc_library(
     name = "grpc++",
     srcs = [

bazel/grpc_build_system.bzl

@@ -49,14 +49,17 @@ def grpc_cc_library(name, srcs = [], public_hdrs = [], hdrs = [], external_deps
     ]
   )
 
-def grpc_cc_libraries(name_list, additional_dep_list, srcs = [], public_hdrs = [], hdrs = [], external_deps = [], deps = [], standalone = False, language="C++"):
-  for i in range(len(name_list)):
+def grpc_cc_libraries(name_list, additional_src_list = [], additional_dep_list = [], srcs = [], public_hdrs = [], hdrs = [], external_deps = [], deps = [], standalone = False, language="C++"):
+  names = len(name_list)
+  asl = additional_src_list + [[]]*(names - len(additional_src_list))
+  adl = additional_dep_list + [[]]*(names - len(additional_dep_list))
+  for i in range(names):
     grpc_cc_library(
       name = name_list[i],
-      srcs = srcs,
+      srcs = srcs + asl[i],
       hdrs = hdrs,
       public_hdrs = public_hdrs,
-      deps = deps + additional_dep_list[i],
+      deps = deps + adl[i],
       external_deps = external_deps,
       standalone = standalone,
       language = language

grpc.def

@@ -89,7 +89,6 @@ EXPORTS
     grpc_server_request_registered_call
     grpc_server_create
     grpc_server_register_completion_queue
-    grpc_server_register_non_listening_completion_queue
     grpc_server_add_insecure_http2_port
     grpc_server_start
     grpc_server_shutdown_and_notify

include/grpc++/impl/codegen/client_unary_call.h

@@ -52,7 +52,9 @@ template <class InputMessage, class OutputMessage>
 Status BlockingUnaryCall(ChannelInterface* channel, const RpcMethod& method,
                          ClientContext* context, const InputMessage& request,
                          OutputMessage* result) {
-  CompletionQueue cq(true);  // Pluckable completion queue
+  CompletionQueue cq(grpc_completion_queue_attributes{
+      GRPC_CQ_CURRENT_VERSION, GRPC_CQ_PLUCK,
+      GRPC_CQ_DEFAULT_POLLING});  // Pluckable completion queue
   Call call(channel->CreateCall(method, context, &cq));
   CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage,
             CallOpRecvInitialMetadata, CallOpRecvMessage<OutputMessage>,

include/grpc++/impl/codegen/completion_queue.h

@@ -102,7 +102,9 @@ class CompletionQueue : private GrpcLibraryCodegen {
  public:
   /// Default constructor. Implicitly creates a \a grpc_completion_queue
   /// instance.
-  CompletionQueue() : CompletionQueue(false) {}
+  CompletionQueue()
+      : CompletionQueue(grpc_completion_queue_attributes{
+            GRPC_CQ_CURRENT_VERSION, GRPC_CQ_NEXT, GRPC_CQ_DEFAULT_POLLING}) {}
 
   /// Wrap \a take, taking ownership of the instance.
   ///
@@ -182,6 +184,16 @@ class CompletionQueue : private GrpcLibraryCodegen {
   };
   void CompleteAvalanching();
 
+ protected:
+  /// Private constructor of CompletionQueue only visible to friend classes
+  CompletionQueue(const grpc_completion_queue_attributes& attributes) {
+    cq_ = g_core_codegen_interface->grpc_completion_queue_create(
+        g_core_codegen_interface->grpc_completion_queue_factory_lookup(
+            &attributes),
+        &attributes, NULL);
+    InitialAvalanching();  // reserve this for the future shutdown
+  }
+
  private:
   // Friend synchronous wrappers so that they can access Pluck(), which is
   // a semi-private API geared towards the synchronous implementation.
@@ -215,18 +227,6 @@ class CompletionQueue : private GrpcLibraryCodegen {
                                   const InputMessage& request,
                                   OutputMessage* result);
 
-  /// Private constructor of CompletionQueue only visible to friend classes
-  CompletionQueue(bool is_pluck) {
-    if (is_pluck) {
-      cq_ = g_core_codegen_interface->grpc_completion_queue_create_for_pluck(
-          nullptr);
-    } else {
-      cq_ = g_core_codegen_interface->grpc_completion_queue_create_for_next(
-          nullptr);
-    }
-    InitialAvalanching();  // reserve this for the future shutdown
-  }
-
   NextStatus AsyncNextInternal(void** tag, bool* ok, gpr_timespec deadline);
 
   /// Wraps \a grpc_completion_queue_pluck.
@@ -289,17 +289,19 @@ class CompletionQueue : private GrpcLibraryCodegen {
 /// by servers. Instantiated by \a ServerBuilder.
 class ServerCompletionQueue : public CompletionQueue {
  public:
-  bool IsFrequentlyPolled() { return is_frequently_polled_; }
+  bool IsFrequentlyPolled() { return polling_type_ != GRPC_CQ_NON_LISTENING; }
 
  private:
-  bool is_frequently_polled_;
+  grpc_cq_polling_type polling_type_;
   friend class ServerBuilder;
   /// \param is_frequently_polled Informs the GRPC library about whether the
   /// server completion queue would be actively polled (by calling Next() or
   /// AsyncNext()). By default all server completion queues are assumed to be
   /// frequently polled.
-  ServerCompletionQueue(bool is_frequently_polled = true)
-      : is_frequently_polled_(is_frequently_polled) {}
+  ServerCompletionQueue(grpc_cq_polling_type polling_type)
+      : CompletionQueue(grpc_completion_queue_attributes{
+            GRPC_CQ_CURRENT_VERSION, GRPC_CQ_NEXT, polling_type}),
+        polling_type_(polling_type) {}
 };
 
 }  // namespace grpc

include/grpc++/impl/codegen/core_codegen.h

@@ -44,8 +44,15 @@
 namespace grpc {
 
 /// Implementation of the core codegen interface.
-class CoreCodegen : public CoreCodegenInterface {
+class CoreCodegen final : public CoreCodegenInterface {
  private:
+  virtual const grpc_completion_queue_factory*
+  grpc_completion_queue_factory_lookup(
+      const grpc_completion_queue_attributes* attributes) override;
+  virtual grpc_completion_queue* grpc_completion_queue_create(
+      const grpc_completion_queue_factory* factory,
+      const grpc_completion_queue_attributes* attributes,
+      void* reserved) override;
   grpc_completion_queue* grpc_completion_queue_create_for_next(
       void* reserved) override;
   grpc_completion_queue* grpc_completion_queue_create_for_pluck(

include/grpc++/impl/codegen/core_codegen_interface.h

@@ -59,6 +59,12 @@ class CoreCodegenInterface {
   virtual void assert_fail(const char* failed_assertion, const char* file,
                            int line) = 0;
 
+  virtual const grpc_completion_queue_factory*
+  grpc_completion_queue_factory_lookup(
+      const grpc_completion_queue_attributes* attributes) = 0;
+  virtual grpc_completion_queue* grpc_completion_queue_create(
+      const grpc_completion_queue_factory* factory,
+      const grpc_completion_queue_attributes* attributes, void* reserved) = 0;
   virtual grpc_completion_queue* grpc_completion_queue_create_for_next(
       void* reserved) = 0;
   virtual grpc_completion_queue* grpc_completion_queue_create_for_pluck(

include/grpc++/impl/codegen/sync_stream.h

@@ -156,7 +156,9 @@ class ClientReader final : public ClientReaderInterface<R> {
   ClientReader(ChannelInterface* channel, const RpcMethod& method,
                ClientContext* context, const W& request)
       : context_(context),
-        cq_(true),  // Pluckable cq
+        cq_(grpc_completion_queue_attributes{
+            GRPC_CQ_CURRENT_VERSION, GRPC_CQ_PLUCK,
+            GRPC_CQ_DEFAULT_POLLING}),  // Pluckable cq
         call_(channel->CreateCall(method, context, &cq_)) {
     CallOpSet<CallOpSendInitialMetadata, CallOpSendMessage,
               CallOpClientSendClose>
@@ -230,7 +232,9 @@ class ClientWriter : public ClientWriterInterface<W> {
   ClientWriter(ChannelInterface* channel, const RpcMethod& method,
                ClientContext* context, R* response)
       : context_(context),
-        cq_(true),  // Pluckable cq
+        cq_(grpc_completion_queue_attributes{
+            GRPC_CQ_CURRENT_VERSION, GRPC_CQ_PLUCK,
+            GRPC_CQ_DEFAULT_POLLING}),  // Pluckable cq
         call_(channel->CreateCall(method, context, &cq_)) {
     finish_ops_.RecvMessage(response);
     finish_ops_.AllowNoMessage();
@@ -330,7 +334,9 @@ class ClientReaderWriter final : public ClientReaderWriterInterface<W, R> {
   ClientReaderWriter(ChannelInterface* channel, const RpcMethod& method,
                      ClientContext* context)
       : context_(context),
-        cq_(true),  // Pluckable cq
+        cq_(grpc_completion_queue_attributes{
+            GRPC_CQ_CURRENT_VERSION, GRPC_CQ_PLUCK,
+            GRPC_CQ_DEFAULT_POLLING}),  // Pluckable cq
         call_(channel->CreateCall(method, context, &cq_)) {
     if (!context_->initial_metadata_corked_) {
       CallOpSet<CallOpSendInitialMetadata> ops;

include/grpc/grpc.h

@@ -93,55 +93,6 @@ GRPCAPI const char *grpc_version_string(void);
 /** Return a string specifying what the 'g' in gRPC stands for */
 GRPCAPI const char *grpc_g_stands_for(void);
 
-/** Specifies the type of APIs to use to pop events from the completion queue */
-typedef enum {
-  /** Events are popped out by calling grpc_completion_queue_next() API ONLY */
-  GRPC_CQ_NEXT = 1,
-
-  /** Events are popped out by calling grpc_completion_queue_pluck() API ONLY*/
-  GRPC_CQ_PLUCK
-} grpc_cq_completion_type;
-
-/** Completion queues internally MAY maintain a set of file descriptors in a
-    structure called 'pollset'. This enum specifies if a completion queue has an
-    associated pollset and any restrictions on the type of file descriptors that
-    can be present in the pollset.
-
-    I/O progress can only be made when grpc_completion_queue_next() or
-    grpc_completion_queue_pluck() are called on the completion queue (unless the
-    grpc_cq_polling_type is GRPC_CQ_NON_POLLING) and hence it is very important
-    to actively call these APIs */
-typedef enum {
-  /** The completion queue will have an associated pollset and there is no
-      restriction on the type of file descriptors the pollset may contain */
-  GRPC_CQ_DEFAULT_POLLING,
-
-  /** Similar to GRPC_CQ_DEFAULT_POLLING except that the completion queues will
-      not contain any 'listening file descriptors' (i.e file descriptors used to
-      listen to incoming channels) */
-  GRPC_CQ_NON_LISTENING,
-
-  /** The completion queue will not have an associated pollset. Note that
-      grpc_completion_queue_next() or grpc_completion_queue_pluck() MUST still
-      be called to pop events from the completion queue; it is not required to
-      call them actively to make I/O progress */
-  GRPC_CQ_NON_POLLING
-} grpc_cq_polling_type;
-
-#define GRPC_CQ_CURRENT_VERSION 1
-typedef struct grpc_completion_queue_attributes {
-  /* The version number of this structure. More fields might be added to this
-     structure in future. */
-  int version; /* Set to GRPC_CQ_CURRENT_VERSION */
-
-  grpc_cq_completion_type cq_completion_type;
-
-  grpc_cq_polling_type cq_polling_type;
-} grpc_completion_queue_attributes;
-
-/** The completion queue factory structure is opaque to the callers of grpc */
-typedef struct grpc_completion_queue_factory grpc_completion_queue_factory;
-
 /** Returns the completion queue factory based on the attributes. MAY return a
     NULL if no factory can be found */
 GRPCAPI const grpc_completion_queue_factory *
@@ -427,15 +378,6 @@ GRPCAPI void grpc_server_register_completion_queue(grpc_server *server,
                                                    grpc_completion_queue *cq,
                                                    void *reserved);
 
-/** Register a non-listening completion queue with the server. This API is
-    similar to grpc_server_register_completion_queue except that the server will
-    not use this completion_queue to listen to any incoming channels.
-
-    Registering a non-listening completion queue will have negative performance
-    impact and hence this API is not recommended for production use cases. */
-GRPCAPI void grpc_server_register_non_listening_completion_queue(
-    grpc_server *server, grpc_completion_queue *q, void *reserved);
-
 /** Add a HTTP2 over plaintext over tcp listener.
     Returns bound port number on success, 0 on failure.
     REQUIRES: server not started */

include/grpc/impl/codegen/grpc_types.h

@@ -556,6 +556,55 @@ typedef struct {
 
 typedef struct grpc_resource_quota grpc_resource_quota;
 
+/** Completion queues internally MAY maintain a set of file descriptors in a
+    structure called 'pollset'. This enum specifies if a completion queue has an
+    associated pollset and any restrictions on the type of file descriptors that
+    can be present in the pollset.
+
+    I/O progress can only be made when grpc_completion_queue_next() or
+    grpc_completion_queue_pluck() are called on the completion queue (unless the
+    grpc_cq_polling_type is GRPC_CQ_NON_POLLING) and hence it is very important
+    to actively call these APIs */
+typedef enum {
+  /** The completion queue will have an associated pollset and there is no
+      restriction on the type of file descriptors the pollset may contain */
+  GRPC_CQ_DEFAULT_POLLING,
+
+  /** Similar to GRPC_CQ_DEFAULT_POLLING except that the completion queues will
+      not contain any 'listening file descriptors' (i.e file descriptors used to
+      listen to incoming channels) */
+  GRPC_CQ_NON_LISTENING,
+
+  /** The completion queue will not have an associated pollset. Note that
+      grpc_completion_queue_next() or grpc_completion_queue_pluck() MUST still
+      be called to pop events from the completion queue; it is not required to
+      call them actively to make I/O progress */
+  GRPC_CQ_NON_POLLING
+} grpc_cq_polling_type;
+
+/** Specifies the type of APIs to use to pop events from the completion queue */
+typedef enum {
+  /** Events are popped out by calling grpc_completion_queue_next() API ONLY */
+  GRPC_CQ_NEXT = 1,
+
+  /** Events are popped out by calling grpc_completion_queue_pluck() API ONLY*/
+  GRPC_CQ_PLUCK
+} grpc_cq_completion_type;
+
+#define GRPC_CQ_CURRENT_VERSION 1
+typedef struct grpc_completion_queue_attributes {
+  /* The version number of this structure. More fields might be added to this
+     structure in future. */
+  int version; /* Set to GRPC_CQ_CURRENT_VERSION */
+
+  grpc_cq_completion_type cq_completion_type;
+
+  grpc_cq_polling_type cq_polling_type;
+} grpc_completion_queue_attributes;
+
+/** The completion queue factory structure is opaque to the callers of grpc */
+typedef struct grpc_completion_queue_factory grpc_completion_queue_factory;
+
 #ifdef __cplusplus
 }
 #endif

src/core/lib/surface/completion_queue.c

@@ -60,13 +60,154 @@ typedef struct {
   void *tag;
 } plucker;
 
+typedef struct {
+  bool can_get_pollset;
+  bool can_listen;
+  size_t (*size)(void);
+  void (*init)(grpc_pollset *pollset, gpr_mu **mu);
+  grpc_error *(*kick)(grpc_pollset *pollset,
+                      grpc_pollset_worker *specific_worker);
+  grpc_error *(*work)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                      grpc_pollset_worker **worker, gpr_timespec now,
+                      gpr_timespec deadline);
+  void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                   grpc_closure *closure);
+  void (*destroy)(grpc_pollset *pollset);
+} cq_poller_vtable;
+
+typedef struct non_polling_worker {
+  gpr_cv cv;
+  bool kicked;
+  struct non_polling_worker *next;
+  struct non_polling_worker *prev;
+} non_polling_worker;
+
+typedef struct {
+  gpr_mu mu;
+  non_polling_worker *root;
+  grpc_closure *shutdown;
+} non_polling_poller;
+
+static size_t non_polling_poller_size(void) {
+  return sizeof(non_polling_poller);
+}
+
+static void non_polling_poller_init(grpc_pollset *pollset, gpr_mu **mu) {
+  non_polling_poller *npp = (non_polling_poller *)pollset;
+  gpr_mu_init(&npp->mu);
+  *mu = &npp->mu;
+}
+
+static void non_polling_poller_destroy(grpc_pollset *pollset) {
+  non_polling_poller *npp = (non_polling_poller *)pollset;
+  gpr_mu_destroy(&npp->mu);
+}
+
+static grpc_error *non_polling_poller_work(grpc_exec_ctx *exec_ctx,
+                                           grpc_pollset *pollset,
+                                           grpc_pollset_worker **worker,
+                                           gpr_timespec now,
+                                           gpr_timespec deadline) {
+  non_polling_poller *npp = (non_polling_poller *)pollset;
+  if (npp->shutdown) return GRPC_ERROR_NONE;
+  non_polling_worker w;
+  gpr_cv_init(&w.cv);
+  if (worker != NULL) *worker = (grpc_pollset_worker *)&w;
+  if (npp->root == NULL) {
+    npp->root = w.next = w.prev = &w;
+  } else {
+    w.next = npp->root;
+    w.prev = w.next->prev;
+    w.next->prev = w.prev->next = &w;
+  }
+  w.kicked = false;
+  while (!npp->shutdown && !w.kicked && !gpr_cv_wait(&w.cv, &npp->mu, deadline))
+    ;
+  if (&w == npp->root) {
+    npp->root = w.next;
+    if (&w == npp->root) {
+      if (npp->shutdown) {
+        grpc_closure_sched(exec_ctx, npp->shutdown, GRPC_ERROR_NONE);
+      }
+      npp->root = NULL;
+    }
+  }
+  w.next->prev = w.prev;
+  w.prev->next = w.next;
+  gpr_cv_destroy(&w.cv);
+  if (worker != NULL) *worker = NULL;
+  return GRPC_ERROR_NONE;
+}
+
+static grpc_error *non_polling_poller_kick(
+    grpc_pollset *pollset, grpc_pollset_worker *specific_worker) {
+  non_polling_poller *p = (non_polling_poller *)pollset;
+  if (specific_worker == NULL) specific_worker = (grpc_pollset_worker *)p->root;
+  if (specific_worker != NULL) {
+    non_polling_worker *w = (non_polling_worker *)specific_worker;
+    if (!w->kicked) {
+      w->kicked = true;
+      gpr_cv_signal(&w->cv);
+    }
+  }
+  return GRPC_ERROR_NONE;
+}
+
+static void non_polling_poller_shutdown(grpc_exec_ctx *exec_ctx,
+                                        grpc_pollset *pollset,
+                                        grpc_closure *closure) {
+  non_polling_poller *p = (non_polling_poller *)pollset;
+  GPR_ASSERT(closure != NULL);
+  p->shutdown = closure;
+  if (p->root == NULL) {
+    grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_NONE);
+  } else {
+    non_polling_worker *w = p->root;
+    do {
+      gpr_cv_signal(&w->cv);
+      w = w->next;
+    } while (w != p->root);
+  }
+}
+
+static const cq_poller_vtable g_poller_vtable_by_poller_type[] = {
+    /* GRPC_CQ_DEFAULT_POLLING */
+    {.can_get_pollset = true,
+     .can_listen = true,
+     .size = grpc_pollset_size,
+     .init = grpc_pollset_init,
+     .kick = grpc_pollset_kick,
+     .work = grpc_pollset_work,
+     .shutdown = grpc_pollset_shutdown,
+     .destroy = grpc_pollset_destroy},
+    /* GRPC_CQ_NON_LISTENING */
+    {.can_get_pollset = true,
+     .can_listen = false,
+     .size = grpc_pollset_size,
+     .init = grpc_pollset_init,
+     .kick = grpc_pollset_kick,
+     .work = grpc_pollset_work,
+     .shutdown = grpc_pollset_shutdown,
+     .destroy = grpc_pollset_destroy},
+    /* GRPC_CQ_NON_POLLING */
+    {.can_get_pollset = false,
+     .can_listen = false,
+     .size = non_polling_poller_size,
+     .init = non_polling_poller_init,
+     .kick = non_polling_poller_kick,
+     .work = non_polling_poller_work,
+     .shutdown = non_polling_poller_shutdown,
+     .destroy = non_polling_poller_destroy},
+};
+
 /* Completion queue structure */
 struct grpc_completion_queue {
   /** owned by pollset */
   gpr_mu *mu;
 
   grpc_cq_completion_type completion_type;
-  grpc_cq_polling_type polling_type;
+
+  const cq_poller_vtable *poller_vtable;
 
   /** completed events */
   grpc_cq_completion completed_head;
@@ -127,15 +268,18 @@ grpc_completion_queue *grpc_completion_queue_create_internal(
       "polling_type=%d)",
       2, (completion_type, polling_type));
 
-  cc = gpr_zalloc(sizeof(grpc_completion_queue) + grpc_pollset_size());
-  grpc_pollset_init(POLLSET_FROM_CQ(cc), &cc->mu);
+  const cq_poller_vtable *poller_vtable =
+      &g_poller_vtable_by_poller_type[polling_type];
+
+  cc = gpr_zalloc(sizeof(grpc_completion_queue) + poller_vtable->size());
+  poller_vtable->init(POLLSET_FROM_CQ(cc), &cc->mu);
 #ifndef NDEBUG
   cc->outstanding_tags = NULL;
   cc->outstanding_tag_capacity = 0;
 #endif
 
   cc->completion_type = completion_type;
-  cc->polling_type = polling_type;
+  cc->poller_vtable = poller_vtable;
 
   /* Initial ref is dropped by grpc_completion_queue_shutdown */
   gpr_ref_init(&cc->pending_events, 1);
@@ -164,10 +308,6 @@ grpc_cq_completion_type grpc_get_cq_completion_type(grpc_completion_queue *cc) {
   return cc->completion_type;
 }
 
-grpc_cq_polling_type grpc_get_cq_polling_type(grpc_completion_queue *cc) {
-  return cc->polling_type;
-}
-
 #ifdef GRPC_CQ_REF_COUNT_DEBUG
 void grpc_cq_internal_ref(grpc_completion_queue *cc, const char *reason,
                           const char *file, int line) {
@@ -195,7 +335,7 @@ void grpc_cq_internal_unref(grpc_completion_queue *cc) {
 #endif
   if (gpr_unref(&cc->owning_refs)) {
     GPR_ASSERT(cc->completed_head.next == (uintptr_t)&cc->completed_head);
-    grpc_pollset_destroy(POLLSET_FROM_CQ(cc));
+    cc->poller_vtable->destroy(POLLSET_FROM_CQ(cc));
 #ifndef NDEBUG
     gpr_free(cc->outstanding_tags);
 #endif
@@ -280,7 +420,7 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
       }
     }
     grpc_error *kick_error =
-        grpc_pollset_kick(POLLSET_FROM_CQ(cc), pluck_worker);
+        cc->poller_vtable->kick(POLLSET_FROM_CQ(cc), pluck_worker);
     gpr_mu_unlock(cc->mu);
     if (kick_error != GRPC_ERROR_NONE) {
       const char *msg = grpc_error_string(kick_error);
@@ -295,8 +435,8 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
     GPR_ASSERT(!cc->shutdown);
     GPR_ASSERT(cc->shutdown_called);
     cc->shutdown = 1;
-    grpc_pollset_shutdown(exec_ctx, POLLSET_FROM_CQ(cc),
-                          &cc->pollset_shutdown_done);
+    cc->poller_vtable->shutdown(exec_ctx, POLLSET_FROM_CQ(cc),
+                                &cc->pollset_shutdown_done);
     gpr_mu_unlock(cc->mu);
   }
 
@@ -452,8 +592,8 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
       gpr_mu_lock(cc->mu);
       continue;
     } else {
-      grpc_error *err = grpc_pollset_work(&exec_ctx, POLLSET_FROM_CQ(cc), NULL,
-                                          now, iteration_deadline);
+      grpc_error *err = cc->poller_vtable->work(&exec_ctx, POLLSET_FROM_CQ(cc),
+                                                NULL, now, iteration_deadline);
       if (err != GRPC_ERROR_NONE) {
         gpr_mu_unlock(cc->mu);
         const char *msg = grpc_error_string(err);
@@ -644,8 +784,8 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
       grpc_exec_ctx_flush(&exec_ctx);
       gpr_mu_lock(cc->mu);
     } else {
-      grpc_error *err = grpc_pollset_work(&exec_ctx, POLLSET_FROM_CQ(cc),
-                                          &worker, now, iteration_deadline);
+      grpc_error *err = cc->poller_vtable->work(
+          &exec_ctx, POLLSET_FROM_CQ(cc), &worker, now, iteration_deadline);
       if (err != GRPC_ERROR_NONE) {
         del_plucker(cc, tag, &worker);
         gpr_mu_unlock(cc->mu);
@@ -689,8 +829,8 @@ void grpc_completion_queue_shutdown(grpc_completion_queue *cc) {
   if (gpr_unref(&cc->pending_events)) {
     GPR_ASSERT(!cc->shutdown);
     cc->shutdown = 1;
-    grpc_pollset_shutdown(&exec_ctx, POLLSET_FROM_CQ(cc),
-                          &cc->pollset_shutdown_done);
+    cc->poller_vtable->shutdown(&exec_ctx, POLLSET_FROM_CQ(cc),
+                                &cc->pollset_shutdown_done);
   }
   gpr_mu_unlock(cc->mu);
   grpc_exec_ctx_finish(&exec_ctx);
@@ -706,7 +846,7 @@ void grpc_completion_queue_destroy(grpc_completion_queue *cc) {
 }
 
 grpc_pollset *grpc_cq_pollset(grpc_completion_queue *cc) {
-  return POLLSET_FROM_CQ(cc);
+  return cc->poller_vtable->can_get_pollset ? POLLSET_FROM_CQ(cc) : NULL;
 }
 
 grpc_completion_queue *grpc_cq_from_pollset(grpc_pollset *ps) {
@@ -727,4 +867,10 @@ bool grpc_cq_is_non_listening_server_cq(grpc_completion_queue *cc) {
 
 void grpc_cq_mark_server_cq(grpc_completion_queue *cc) { cc->is_server_cq = 1; }
 
-int grpc_cq_is_server_cq(grpc_completion_queue *cc) { return cc->is_server_cq; }
+bool grpc_cq_is_server_cq(grpc_completion_queue *cc) {
+  return cc->is_server_cq;
+}
+
+bool grpc_cq_can_listen(grpc_completion_queue *cc) {
+  return cc->poller_vtable->can_listen;
+}

src/core/lib/surface/completion_queue.h

@@ -94,13 +94,11 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
 grpc_pollset *grpc_cq_pollset(grpc_completion_queue *cc);
 grpc_completion_queue *grpc_cq_from_pollset(grpc_pollset *ps);
 
-void grpc_cq_mark_non_listening_server_cq(grpc_completion_queue *cc);
-bool grpc_cq_is_non_listening_server_cq(grpc_completion_queue *cc);
 void grpc_cq_mark_server_cq(grpc_completion_queue *cc);
-int grpc_cq_is_server_cq(grpc_completion_queue *cc);
+bool grpc_cq_is_server_cq(grpc_completion_queue *cc);
+bool grpc_cq_can_listen(grpc_completion_queue *cc);
 
 grpc_cq_completion_type grpc_get_cq_completion_type(grpc_completion_queue *cc);
-grpc_cq_polling_type grpc_get_cq_polling_type(grpc_completion_queue *cc);
 
 grpc_completion_queue *grpc_completion_queue_create_internal(
     grpc_cq_completion_type completion_type, grpc_cq_polling_type polling_type);

src/core/lib/surface/server.c

@@ -981,7 +981,7 @@ const grpc_channel_filter grpc_server_top_filter = {
 
 static void register_completion_queue(grpc_server *server,
                                       grpc_completion_queue *cq,
-                                      bool is_non_listening, void *reserved) {
+                                      void *reserved) {
   size_t i, n;
   GPR_ASSERT(!reserved);
   for (i = 0; i < server->cq_count; i++) {
@@ -990,10 +990,6 @@ static void register_completion_queue(grpc_server *server,
 
   grpc_cq_mark_server_cq(cq);
 
-  if (is_non_listening) {
-    grpc_cq_mark_non_listening_server_cq(cq);
-  }
-
   GRPC_CQ_INTERNAL_REF(cq, "server");
   n = server->cq_count++;
   server->cqs = gpr_realloc(server->cqs,
@@ -1016,16 +1012,7 @@ void grpc_server_register_completion_queue(grpc_server *server,
        calls grpc_completion_queue_pluck() on server completion queues */
   }
 
-  register_completion_queue(server, cq, false, reserved);
-}
-
-void grpc_server_register_non_listening_completion_queue(
-    grpc_server *server, grpc_completion_queue *cq, void *reserved) {
-  GRPC_API_TRACE(
-      "grpc_server_register_non_listening_completion_queue(server=%p, cq=%p, "
-      "reserved=%p)",
-      3, (server, cq, reserved));
-  register_completion_queue(server, cq, true, reserved);
+  register_completion_queue(server, cq, reserved);
 }
 
 grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
@@ -1121,7 +1108,7 @@ void grpc_server_start(grpc_server *server) {
   server->requested_calls_per_cq =
       gpr_malloc(sizeof(*server->requested_calls_per_cq) * server->cq_count);
   for (i = 0; i < server->cq_count; i++) {
-    if (!grpc_cq_is_non_listening_server_cq(server->cqs[i])) {
+    if (grpc_cq_can_listen(server->cqs[i])) {
       server->pollsets[server->pollset_count++] =
           grpc_cq_pollset(server->cqs[i]);
     }

src/cpp/common/core_codegen.cc

@@ -54,6 +54,18 @@ struct grpc_byte_buffer;
 
 namespace grpc {
 
+const grpc_completion_queue_factory*
+CoreCodegen::grpc_completion_queue_factory_lookup(
+    const grpc_completion_queue_attributes* attributes) {
+  return ::grpc_completion_queue_factory_lookup(attributes);
+}
+
+grpc_completion_queue* CoreCodegen::grpc_completion_queue_create(
+    const grpc_completion_queue_factory* factory,
+    const grpc_completion_queue_attributes* attributes, void* reserved) {
+  return ::grpc_completion_queue_create(factory, attributes, reserved);
+}
+
 grpc_completion_queue* CoreCodegen::grpc_completion_queue_create_for_next(
     void* reserved) {
   return ::grpc_completion_queue_create_for_next(reserved);

src/cpp/server/server_builder.cc

@@ -83,7 +83,8 @@ ServerBuilder::~ServerBuilder() {
 
 std::unique_ptr<ServerCompletionQueue> ServerBuilder::AddCompletionQueue(
     bool is_frequently_polled) {
-  ServerCompletionQueue* cq = new ServerCompletionQueue(is_frequently_polled);
+  ServerCompletionQueue* cq = new ServerCompletionQueue(
+      is_frequently_polled ? GRPC_CQ_DEFAULT_POLLING : GRPC_CQ_NON_LISTENING);
   cqs_.push_back(cq);
   return std::unique_ptr<ServerCompletionQueue>(cq);
 }
@@ -242,6 +243,16 @@ std::unique_ptr<Server> ServerBuilder::BuildAndStart() {
       sync_server_cqs(std::make_shared<
                       std::vector<std::unique_ptr<ServerCompletionQueue>>>());
 
+  int num_frequently_polled_cqs = 0;
+  for (auto it = cqs_.begin(); it != cqs_.end(); ++it) {
+    if ((*it)->IsFrequentlyPolled()) {
+      num_frequently_polled_cqs++;
+    }
+  }
+
+  const bool is_hybrid_server =
+      has_sync_methods && num_frequently_polled_cqs > 0;
+
   if (has_sync_methods) {
     // This is a Sync server
     gpr_log(GPR_INFO,
@@ -251,9 +262,12 @@ std::unique_ptr<Server> ServerBuilder::BuildAndStart() {
             sync_server_settings_.max_pollers,
             sync_server_settings_.cq_timeout_msec);
 
+    grpc_cq_polling_type polling_type =
+        is_hybrid_server ? GRPC_CQ_NON_POLLING : GRPC_CQ_DEFAULT_POLLING;
+
     // Create completion queues to listen to incoming rpc requests
     for (int i = 0; i < sync_server_settings_.num_cqs; i++) {
-      sync_server_cqs->emplace_back(new ServerCompletionQueue());
+      sync_server_cqs->emplace_back(new ServerCompletionQueue(polling_type));
     }
   }
 
@@ -269,12 +283,10 @@ std::unique_ptr<Server> ServerBuilder::BuildAndStart() {
   //     server
   //  2. cqs_: Completion queues added via AddCompletionQueue() call
 
-  // All sync cqs (if any) are frequently polled by ThreadManager
-  int num_frequently_polled_cqs = sync_server_cqs->size();
-
   for (auto it = sync_server_cqs->begin(); it != sync_server_cqs->end(); ++it) {
     grpc_server_register_completion_queue(server->server_, (*it)->cq(),
                                           nullptr);
+    num_frequently_polled_cqs++;
   }
 
   // cqs_ contains the completion queue added by calling the ServerBuilder's
@@ -283,14 +295,8 @@ std::unique_ptr<Server> ServerBuilder::BuildAndStart() {
   // listening to incoming channels. Such completion queues must be registered
   // as non-listening queues
   for (auto it = cqs_.begin(); it != cqs_.end(); ++it) {
-    if ((*it)->IsFrequentlyPolled()) {
-      grpc_server_register_completion_queue(server->server_, (*it)->cq(),
-                                            nullptr);
-      num_frequently_polled_cqs++;
-    } else {
-      grpc_server_register_non_listening_completion_queue(server->server_,
-                                                          (*it)->cq(), nullptr);
-    }
+    grpc_server_register_completion_queue(server->server_, (*it)->cq(),
+                                          nullptr);
   }
 
   if (num_frequently_polled_cqs == 0) {

src/node/ext/server_generic.cc

@@ -44,9 +44,11 @@ namespace grpc {
 namespace node {
 
 Server::Server(grpc_server *server) : wrapped_server(server) {
-  shutdown_queue = grpc_completion_queue_create_for_pluck(NULL);
-  grpc_server_register_non_listening_completion_queue(server, shutdown_queue,
-                                                      NULL);
+  grpc_completion_queue_attributes attrs = {
+      GRPC_CQ_CURRENT_VERSION, GRPC_CQ_PLUCK, GRPC_CQ_NON_LISTENING};
+  shutdown_queue = grpc_completion_queue_create(
+      grpc_completion_queue_factory_lookup(&attrs), &attrs, NULL);
+  grpc_server_register_completion_queue(server, shutdown_queue, NULL);
 }
 
 Server::~Server() {

src/proto/grpc/health/v1/BUILD

@@ -0,0 +1,39 @@
+# Copyright 2017, 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.
+
+licenses(["notice"])  # 3-clause BSD
+
+package(default_visibility = ["//visibility:public"])
+
+load("//bazel:grpc_build_system.bzl", "grpc_proto_library")
+
+grpc_proto_library(
+    name = "health_proto",
+    srcs = ["health.proto"],
+)

src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi

@@ -356,8 +356,6 @@ cdef extern from "grpc/grpc.h":
   void grpc_server_register_completion_queue(grpc_server *server,
                                              grpc_completion_queue *cq,
                                              void *reserved) nogil
-  void grpc_server_register_non_listening_completion_queue(
-      grpc_server *server, grpc_completion_queue *cq, void *reserved) nogil
   int grpc_server_add_insecure_http2_port(
       grpc_server *server, const char *addr) nogil
   void grpc_server_start(grpc_server *server) nogil
@@ -502,4 +500,3 @@ cdef extern from "grpc/compression.h":
   int grpc_compression_options_is_algorithm_enabled(
       const grpc_compression_options *opts,
       grpc_compression_algorithm algorithm) nogil
-

src/python/grpcio/grpc/_cython/_cygrpc/server.pyx.pxi

@@ -82,20 +82,11 @@ cdef class Server:
           self.c_server, queue.c_completion_queue, NULL)
     self.registered_completion_queues.append(queue)
 
-  def register_non_listening_completion_queue(
-      self, CompletionQueue queue not None):
-    if self.is_started:
-      raise ValueError("cannot register completion queues after start")
-    with nogil:
-      grpc_server_register_non_listening_completion_queue(
-          self.c_server, queue.c_completion_queue, NULL)
-    self.registered_completion_queues.append(queue)
-
   def start(self):
     if self.is_started:
       raise ValueError("the server has already started")
     self.backup_shutdown_queue = CompletionQueue()
-    self.register_non_listening_completion_queue(self.backup_shutdown_queue)
+    self.register_completion_queue(self.backup_shutdown_queue)
     self.is_started = True
     with nogil:
       grpc_server_start(self.c_server)

src/ruby/ext/grpc/rb_grpc_imports.generated.c

@@ -127,7 +127,6 @@ grpc_server_register_method_type grpc_server_register_method_import;
 grpc_server_request_registered_call_type grpc_server_request_registered_call_import;
 grpc_server_create_type grpc_server_create_import;
 grpc_server_register_completion_queue_type grpc_server_register_completion_queue_import;
-grpc_server_register_non_listening_completion_queue_type grpc_server_register_non_listening_completion_queue_import;
 grpc_server_add_insecure_http2_port_type grpc_server_add_insecure_http2_port_import;
 grpc_server_start_type grpc_server_start_import;
 grpc_server_shutdown_and_notify_type grpc_server_shutdown_and_notify_import;
@@ -425,7 +424,6 @@ void grpc_rb_load_imports(HMODULE library) {
   grpc_server_request_registered_call_import = (grpc_server_request_registered_call_type) GetProcAddress(library, "grpc_server_request_registered_call");
   grpc_server_create_import = (grpc_server_create_type) GetProcAddress(library, "grpc_server_create");
   grpc_server_register_completion_queue_import = (grpc_server_register_completion_queue_type) GetProcAddress(library, "grpc_server_register_completion_queue");
-  grpc_server_register_non_listening_completion_queue_import = (grpc_server_register_non_listening_completion_queue_type) GetProcAddress(library, "grpc_server_register_non_listening_completion_queue");
   grpc_server_add_insecure_http2_port_import = (grpc_server_add_insecure_http2_port_type) GetProcAddress(library, "grpc_server_add_insecure_http2_port");
   grpc_server_start_import = (grpc_server_start_type) GetProcAddress(library, "grpc_server_start");
   grpc_server_shutdown_and_notify_import = (grpc_server_shutdown_and_notify_type) GetProcAddress(library, "grpc_server_shutdown_and_notify");

src/ruby/ext/grpc/rb_grpc_imports.generated.h

@@ -332,9 +332,6 @@ extern grpc_server_create_type grpc_server_create_import;
 typedef void(*grpc_server_register_completion_queue_type)(grpc_server *server, grpc_completion_queue *cq, void *reserved);
 extern grpc_server_register_completion_queue_type grpc_server_register_completion_queue_import;
 #define grpc_server_register_completion_queue grpc_server_register_completion_queue_import
-typedef void(*grpc_server_register_non_listening_completion_queue_type)(grpc_server *server, grpc_completion_queue *q, void *reserved);
-extern grpc_server_register_non_listening_completion_queue_type grpc_server_register_non_listening_completion_queue_import;
-#define grpc_server_register_non_listening_completion_queue grpc_server_register_non_listening_completion_queue_import
 typedef int(*grpc_server_add_insecure_http2_port_type)(grpc_server *server, const char *addr);
 extern grpc_server_add_insecure_http2_port_type grpc_server_add_insecure_http2_port_import;
 #define grpc_server_add_insecure_http2_port grpc_server_add_insecure_http2_port_import

test/cpp/end2end/BUILD

@@ -51,6 +51,7 @@ cc_test(
         "//src/proto/grpc/testing:echo_messages_proto",
         "//src/proto/grpc/testing:echo_proto",
         "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
+        "//src/proto/grpc/health/v1:health_proto",
         "//test/core/util:gpr_test_util",
         "//test/core/util:grpc_test_util",
         "//test/cpp/util:test_util",

test/cpp/end2end/async_end2end_test.cc

@@ -38,6 +38,7 @@
 #include <grpc++/channel.h>
 #include <grpc++/client_context.h>
 #include <grpc++/create_channel.h>
+#include <grpc++/ext/health_check_service_server_builder_option.h>
 #include <grpc++/server.h>
 #include <grpc++/server_builder.h>
 #include <grpc++/server_context.h>
@@ -49,6 +50,7 @@
 #include <gtest/gtest.h>
 
 #include "src/core/lib/iomgr/port.h"
+#include "src/proto/grpc/health/v1/health.grpc.pb.h"
 #include "src/proto/grpc/testing/duplicate/echo_duplicate.grpc.pb.h"
 #include "src/proto/grpc/testing/echo.grpc.pb.h"
 #include "test/core/util/port.h"
@@ -224,13 +226,15 @@ class ServerBuilderSyncPluginDisabler : public ::grpc::ServerBuilderOption {
 
 class TestScenario {
  public:
-  TestScenario(bool non_block, const grpc::string& creds_type,
+  TestScenario(bool non_block, const grpc::string& creds_type, bool hcs,
                const grpc::string& content)
       : disable_blocking(non_block),
+        health_check_service(hcs),
         credentials_type(creds_type),
         message_content(content) {}
   void Log() const;
   bool disable_blocking;
+  bool health_check_service;
   // Although the below grpc::string's are logically const, we can't declare
   // them const because of a limitation in the way old compilers (e.g., gcc-4.4)
   // manage vector insertion using a copy constructor
@@ -243,6 +247,8 @@ static std::ostream& operator<<(std::ostream& out,
   return out << "TestScenario{disable_blocking="
              << (scenario.disable_blocking ? "true" : "false")
              << ", credentials='" << scenario.credentials_type
+             << ", health_check_service="
+             << (scenario.health_check_service ? "true" : "false")
              << "', message_size=" << scenario.message_content.size() << "}";
 }
 
@@ -252,6 +258,8 @@ void TestScenario::Log() const {
   gpr_log(GPR_DEBUG, "%s", out.str().c_str());
 }
 
+class HealthCheck : public health::v1::Health::Service {};
+
 class AsyncEnd2endTest : public ::testing::TestWithParam<TestScenario> {
  protected:
   AsyncEnd2endTest() { GetParam().Log(); }
@@ -268,6 +276,9 @@ class AsyncEnd2endTest : public ::testing::TestWithParam<TestScenario> {
         GetParam().credentials_type);
     builder.AddListeningPort(server_address_.str(), server_creds);
     builder.RegisterService(&service_);
+    if (GetParam().health_check_service) {
+      builder.RegisterService(&health_check_);
+    }
     cq_ = builder.AddCompletionQueue();
 
     // TODO(zyc): make a test option to choose wheather sync plugins should be
@@ -340,6 +351,7 @@ class AsyncEnd2endTest : public ::testing::TestWithParam<TestScenario> {
   std::unique_ptr<grpc::testing::EchoTestService::Stub> stub_;
   std::unique_ptr<Server> server_;
   grpc::testing::EchoTestService::AsyncService service_;
+  HealthCheck health_check_;
   std::ostringstream server_address_;
   int port_;
 
@@ -1754,12 +1766,14 @@ std::vector<TestScenario> CreateTestScenarios(bool test_disable_blocking,
     messages.push_back(big_msg);
   }
 
-  for (auto cred = credentials_types.begin(); cred != credentials_types.end();
-       ++cred) {
-    for (auto msg = messages.begin(); msg != messages.end(); msg++) {
-      scenarios.emplace_back(false, *cred, *msg);
-      if (test_disable_blocking) {
-        scenarios.emplace_back(true, *cred, *msg);
+  for (auto health_check_service : {false, true}) {
+    for (auto cred = credentials_types.begin(); cred != credentials_types.end();
+         ++cred) {
+      for (auto msg = messages.begin(); msg != messages.end(); msg++) {
+        scenarios.emplace_back(false, *cred, health_check_service, *msg);
+        if (test_disable_blocking) {
+          scenarios.emplace_back(true, *cred, health_check_service, *msg);
+        }
       }
     }
   }