Initial checkin of gRPC to third_party/

third_party/grpc/src/node/ext/completion_queue_async_worker.h

+/*
+ *
+ * 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 NET_GRPC_NODE_COMPLETION_QUEUE_ASYNC_WORKER_H_
+#define NET_GRPC_NODE_COMPLETION_QUEUE_ASYNC_WORKER_H_
+#include <nan.h>
+
+#include "grpc/grpc.h"
+
+namespace grpc {
+namespace node {
+
+/* A worker that asynchronously calls completion_queue_next, and queues onto the
+   node event loop a call to the function stored in the event's tag. */
+class CompletionQueueAsyncWorker : public Nan::AsyncWorker {
+ public:
+  CompletionQueueAsyncWorker();
+
+  ~CompletionQueueAsyncWorker();
+  /* Calls completion_queue_next with the provided deadline, and stores the
+     event if there was one or sets an error message if there was not */
+  void Execute();
+
+  /* Returns the completion queue attached to this class */
+  static grpc_completion_queue *GetQueue();
+
+  /* Convenience function to create a worker with the given arguments and queue
+     it to run asynchronously */
+  static void Next();
+
+  /* Initialize the CompletionQueueAsyncWorker class */
+  static void Init(v8::Local<v8::Object> exports);
+
+ protected:
+  /* Called when Execute has succeeded (completed without setting an error
+     message). Calls the saved callback with the event that came from
+     completion_queue_next */
+  void HandleOKCallback();
+
+  void HandleErrorCallback();
+
+ private:
+  grpc_event result;
+
+  static grpc_completion_queue *queue;
+
+  // Number of grpc_completion_queue_next calls in the thread pool
+  static int current_threads;
+  // Number of grpc_completion_queue_next calls waiting to enter the thread pool
+  static int waiting_next_calls;
+};
+
+}  // namespace node
+}  // namespace grpc
+
+#endif  // NET_GRPC_NODE_COMPLETION_QUEUE_ASYNC_WORKER_H_