--- /dev/null
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/grpc.h>
+#include <node.h>
+#include <uv.h>
+#include <v8.h>
+
+#include "call.h"
+#include "completion_queue.h"
+
+namespace grpc {
+namespace node {
+
+using v8::Local;
+using v8::Object;
+using v8::Value;
+
+grpc_completion_queue *queue;
+uv_prepare_t prepare;
+int pending_batches;
+
+static void drain_completion_queue(uv_prepare_t *handle) {
+ Nan::HandleScope scope;
+ grpc_event event;
+ (void)handle;
+ do {
+ event = grpc_completion_queue_next(queue, gpr_inf_past(GPR_CLOCK_MONOTONIC),
+ NULL);
+
+ if (event.type == GRPC_OP_COMPLETE) {
+ const char *error_message;
+ if (event.success) {
+ error_message = NULL;
+ } else {
+ error_message = "The async function encountered an error";
+ }
+ CompleteTag(event.tag, error_message);
+ grpc::node::DestroyTag(event.tag);
+ pending_batches--;
+ }
+ if (pending_batches == 0) {
+ uv_prepare_stop(&prepare);
+ }
+ } while (event.type != GRPC_QUEUE_TIMEOUT);
+}
+
+grpc_completion_queue *GetCompletionQueue() { return queue; }
+
+void CompletionQueueNext() {
+ if (pending_batches == 0) {
+ uv_prepare_start(&prepare, drain_completion_queue);
+ }
+ pending_batches++;
+}
+
+void CompletionQueueInit(Local<Object> exports) {
+ queue = grpc_completion_queue_create_for_next(NULL);
+ uv_prepare_init(uv_default_loop(), &prepare);
+ pending_batches = 0;
+}
+
+void CompletionQueueForcePoll() {
+ /* This sets the prepare object to poll on the completion queue the next time
+ * Node polls for IO. But it doesn't increment the number of pending batches,
+ * so it will immediately stop polling after that unless there is an
+ * intervening CompletionQueueNext call */
+ if (pending_batches == 0) {
+ uv_prepare_start(&prepare, drain_completion_queue);
+ }
+}
+
+} // namespace node
+} // namespace grpc