| /* |
| * |
| * 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 |
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| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #ifndef GRPCXX_COMPLETION_QUEUE_H |
| #define GRPCXX_COMPLETION_QUEUE_H |
| |
| #include <chrono> |
| #include <grpc++/impl/client_unary_call.h> |
| |
| struct grpc_completion_queue; |
| |
| namespace grpc { |
| |
| template <class R> |
| class ClientReader; |
| template <class W> |
| class ClientWriter; |
| template <class R, class W> |
| class ClientReaderWriter; |
| template <class R> |
| class ServerReader; |
| template <class W> |
| class ServerWriter; |
| template <class R, class W> |
| class ServerReaderWriter; |
| |
| class CompletionQueue; |
| class Server; |
| class ServerContext; |
| |
| class CompletionQueueTag { |
| public: |
| virtual ~CompletionQueueTag() {} |
| // Called prior to returning from Next(), return value |
| // is the status of the operation (return status is the default thing |
| // to do) |
| // If this function returns false, the tag is dropped and not returned |
| // from the completion queue |
| virtual bool FinalizeResult(void** tag, bool* status) = 0; |
| }; |
| |
| // grpc_completion_queue wrapper class |
| class CompletionQueue { |
| public: |
| CompletionQueue(); |
| explicit CompletionQueue(grpc_completion_queue* take); |
| ~CompletionQueue(); |
| |
| // Tri-state return for AsyncNext: SHUTDOWN, GOT_EVENT, TIMEOUT |
| enum NextStatus { SHUTDOWN, GOT_EVENT, TIMEOUT }; |
| |
| // Nonblocking (until deadline) read from queue. |
| // Cannot rely on result of tag or ok if return is TIMEOUT |
| NextStatus AsyncNext(void** tag, bool* ok, |
| std::chrono::system_clock::time_point deadline); |
| |
| // Blocking (until deadline) read from queue. |
| // Returns false if the queue is ready for destruction, true if event |
| |
| bool Next(void** tag, bool* ok) { |
| return ( |
| AsyncNext(tag, ok, (std::chrono::system_clock::time_point::max)()) != |
| SHUTDOWN); |
| } |
| |
| // Shutdown has to be called, and the CompletionQueue can only be |
| // destructed when false is returned from Next(). |
| void Shutdown(); |
| |
| grpc_completion_queue* cq() { return cq_; } |
| |
| private: |
| // Friend synchronous wrappers so that they can access Pluck(), which is |
| // a semi-private API geared towards the synchronous implementation. |
| template <class R> |
| friend class ::grpc::ClientReader; |
| template <class W> |
| friend class ::grpc::ClientWriter; |
| template <class R, class W> |
| friend class ::grpc::ClientReaderWriter; |
| template <class R> |
| friend class ::grpc::ServerReader; |
| template <class W> |
| friend class ::grpc::ServerWriter; |
| template <class R, class W> |
| friend class ::grpc::ServerReaderWriter; |
| friend class ::grpc::Server; |
| friend class ::grpc::ServerContext; |
| friend Status BlockingUnaryCall(ChannelInterface* channel, |
| const RpcMethod& method, |
| ClientContext* context, |
| const grpc::protobuf::Message& request, |
| grpc::protobuf::Message* result); |
| |
| // Wraps grpc_completion_queue_pluck. |
| // Cannot be mixed with calls to Next(). |
| bool Pluck(CompletionQueueTag* tag); |
| |
| // Does a single polling pluck on tag |
| void TryPluck(CompletionQueueTag* tag); |
| |
| grpc_completion_queue* cq_; // owned |
| }; |
| |
| } // namespace grpc |
| |
| #endif // GRPCXX_COMPLETION_QUEUE_H |