1 files changed, 28 insertions, 5 deletions
diff --git a/src/cpp/server/server_builder.cc b/src/cpp/server/server_builder.cc
index 61f0f6ae2a..a5bcd3db31 100644
--- a/src/cpp/server/server_builder.cc
+++ b/src/cpp/server/server_builder.cc
@@ -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
@@ -60,8 +60,9 @@ ServerBuilder::ServerBuilder()
   }
 }
 
-std::unique_ptr<ServerCompletionQueue> ServerBuilder::AddCompletionQueue() {
-  ServerCompletionQueue* cq = new ServerCompletionQueue();
+std::unique_ptr<ServerCompletionQueue> ServerBuilder::AddCompletionQueue(
+    bool is_frequently_polled) {
+  ServerCompletionQueue* cq = new ServerCompletionQueue(is_frequently_polled);
   cqs_.push_back(cq);
   return std::unique_ptr<ServerCompletionQueue>(cq);
 }
@@ -127,11 +128,33 @@ std::unique_ptr<Server> ServerBuilder::BuildAndStart() {
               compression_options_.enabled_algorithms_bitset);
   std::unique_ptr<Server> server(
       new Server(thread_pool.release(), true, max_message_size_, &args));
+
   ServerInitializer* initializer = server->initializer();
+
+  int num_non_listening_cqs = 0;
   for (auto cq = cqs_.begin(); cq != cqs_.end(); ++cq) {
-    grpc_server_register_completion_queue(server->server_, (*cq)->cq(),
-                                          nullptr);
+    // A completion queue that is not polled frequently (by calling Next() or
+    // AsyncNext()) is not safe to use for listening to incoming channels.
+    // Register all such completion queues as non-listening completion queues
+    // with the GRPC core library.
+    if ((*cq)->IsFrequentlyPolled()) {
+      grpc_server_register_completion_queue(server->server_, (*cq)->cq(),
+                                            nullptr);
+    } else {
+      grpc_server_register_non_listening_completion_queue(server->server_,
+                                                          (*cq)->cq(), nullptr);
+      num_non_listening_cqs++;
+    }
   }
+
+  // TODO: (sreek) - Find a good way to determine whether the server is a Sync
+  // server or an Async server. In case of Async server, return an error if all
+  // the completion queues are non-listening
+  if (num_non_listening_cqs > 0) {
+    gpr_log(GPR_INFO, "Number of non listening completion queues: %d out of %d",
+            num_non_listening_cqs, cqs_.size());
+  }
+
   for (auto service = services_.begin(); service != services_.end();
        service++) {
     if (!server->RegisterService((*service)->host.get(), (*service)->service)) {