Ensure timely response to marks

test/cpp/qps/client_async.cc

@@ -206,21 +206,28 @@ class AsyncClient : public ClientImpl<StubType, RequestType> {
     void* got_tag;
     bool ok;
 
-    if (cli_cqs_[thread_idx]->Next(&got_tag, &ok)) {
-      // Got a regular event, so process it
-      ClientRpcContext* ctx = ClientRpcContext::detag(got_tag);
-      if (!ctx->RunNextState(ok, histogram)) {
-        // The RPC and callback are done, so clone the ctx
-        // and kickstart the new one
-        auto clone = ctx->StartNewClone();
-        clone->Start(cli_cqs_[thread_idx].get());
-        // delete the old version
-        delete ctx;
+    switch (cli_cqs_[thread_idx]->AsyncNext(
+        &got_tag, &ok,
+        std::chrono::system_clock::now() + std::chrono::milliseconds(10))) {
+      case CompletionQueue::SHUTDOWN:
+        return false;
+      case CompletionQueue::GOT_EVENT: {
+        // Got a regular event, so process it
+        ClientRpcContext* ctx = ClientRpcContext::detag(got_tag);
+        if (!ctx->RunNextState(ok, histogram)) {
+          // The RPC and callback are done, so clone the ctx
+          // and kickstart the new one
+          auto clone = ctx->StartNewClone();
+          clone->Start(cli_cqs_[thread_idx].get());
+          // delete the old version
+          delete ctx;
+        }
+        return true;
       }
-      return true;
-    } else {  // queue is shutting down
-      return false;
+      case CompletionQueue::TIMEOUT:
+        return true;
     }
+    GPR_UNREACHABLE_CODE(return false);
   }
 
  protected: