/* * Copyright (C) 2012 Apple 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: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 BlockingResponseMap_h #define BlockingResponseMap_h #include <condition_variable> #include <wtf/HashMap.h> #include <wtf/Noncopyable.h> template<typename T> class BlockingResponseMap { WTF_MAKE_NONCOPYABLE(BlockingResponseMap); public: BlockingResponseMap() : m_canceled(false) { } ~BlockingResponseMap() { ASSERT(m_responses.isEmpty()); } std::unique_ptr<T> waitForResponse(uint64_t requestID) { while (true) { std::unique_lock<std::mutex> lock(m_mutex); if (m_canceled) return nullptr; if (std::unique_ptr<T> response = m_responses.take(requestID)) return response; m_condition.wait(lock); } return nullptr; } void didReceiveResponse(uint64_t requestID, std::unique_ptr<T> response) { std::lock_guard<std::mutex> lock(m_mutex); ASSERT(!m_responses.contains(requestID)); m_responses.set(requestID, WTF::move(response)); // FIXME: Waking up all threads is quite inefficient. m_condition.notify_all(); } void cancel() { m_canceled = true; // FIXME: Waking up all threads is quite inefficient. m_condition.notify_all(); } private: std::mutex m_mutex; std::condition_variable m_condition; HashMap<uint64_t, std::unique_ptr<T>> m_responses; bool m_canceled; }; #endif // BlockingResponseMap_h