1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 // 5 // This file contains helper classes for video accelerator unittests. 6 7 #ifndef CONTENT_COMMON_GPU_MEDIA_VIDEO_ACCELERATOR_UNITTEST_HELPERS_H_ 8 #define CONTENT_COMMON_GPU_MEDIA_VIDEO_ACCELERATOR_UNITTEST_HELPERS_H_ 9 10 #include <queue> 11 12 #include "base/synchronization/condition_variable.h" 13 #include "base/synchronization/lock.h" 14 15 namespace content { 16 17 // Helper class allowing one thread to wait on a notification from another. 18 // If notifications come in faster than they are Wait()'d for, they are 19 // accumulated (so exactly as many Wait() calls will unblock as Notify() calls 20 // were made, regardless of order). 21 template <typename StateEnum> 22 class ClientStateNotification { 23 public: 24 ClientStateNotification(); 25 ~ClientStateNotification(); 26 27 // Used to notify a single waiter of a ClientState. 28 void Notify(StateEnum state); 29 // Used by waiters to wait for the next ClientState Notification. 30 StateEnum Wait(); 31 32 private: 33 base::Lock lock_; 34 base::ConditionVariable cv_; 35 std::queue<StateEnum> pending_states_for_notification_; 36 }; 37 38 template <typename StateEnum> ClientStateNotification()39ClientStateNotification<StateEnum>::ClientStateNotification() : cv_(&lock_) {} 40 41 template <typename StateEnum> ~ClientStateNotification()42ClientStateNotification<StateEnum>::~ClientStateNotification() {} 43 44 template <typename StateEnum> Notify(StateEnum state)45void ClientStateNotification<StateEnum>::Notify(StateEnum state) { 46 base::AutoLock auto_lock(lock_); 47 pending_states_for_notification_.push(state); 48 cv_.Signal(); 49 } 50 51 template <typename StateEnum> Wait()52StateEnum ClientStateNotification<StateEnum>::Wait() { 53 base::AutoLock auto_lock(lock_); 54 while (pending_states_for_notification_.empty()) 55 cv_.Wait(); 56 StateEnum ret = pending_states_for_notification_.front(); 57 pending_states_for_notification_.pop(); 58 return ret; 59 } 60 61 } // namespace content 62 63 #endif // CONTENT_COMMON_GPU_MEDIA_VIDEO_ACCELERATOR_UNITTEST_HELPERS_H_ 64