183ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi/* 283ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * Copyright (C) 2011 The Android Open Source Project 383ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * 483ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * Licensed under the Apache License, Version 2.0 (the "License"); 583ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * you may not use this file except in compliance with the License. 683ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * You may obtain a copy of the License at 783ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * 883ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * http://www.apache.org/licenses/LICENSE-2.0 983ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * 1083ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * Unless required by applicable law or agreed to in writing, software 1183ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * distributed under the License is distributed on an "AS IS" BASIS, 1283ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1383ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * See the License for the specific language governing permissions and 1483ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * limitations under the License. 1583ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi */ 1683ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 1783ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi#include "utils/threads.h" 1883ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 1983ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi//-------------------------------------------------------------------------------------------------- 2083ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivinamespace android { 2183ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 226cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Triviclass CallbackProtector : public RefBase { 2383ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 2483ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivipublic: 256cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi CallbackProtector(); 266cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi virtual ~CallbackProtector(); 2783ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 2883ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi /** 29485a038f9f0f898227b8ab4218e94c5d56b6ed0bGlenn Kasten * Indicates whether the CallbackProtector is non-NULL and it's safe to enter the callback. 306cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi */ 316cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi static bool enterCbIfOk(const sp<CallbackProtector> &protector); 326cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi 336cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi /** 34485a038f9f0f898227b8ab4218e94c5d56b6ed0bGlenn Kasten * Indicates whether it's safe to enter the callback. It would typically return false 35485a038f9f0f898227b8ab4218e94c5d56b6ed0bGlenn Kasten * if the associated object (AudioTrack, AudioPlayer, MediaPlayer) is about to be destroyed. 3683ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi */ 3783ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi bool enterCb(); 3883ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 3983ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi /** 406cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi * This method must be paired to each call to enterCb() or enterCbIfOk(), 416cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi * only it returned that it is safe enter the callback; 4283ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi */ 4383ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi void exitCb(); 4483ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 4583ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi /** 46485a038f9f0f898227b8ab4218e94c5d56b6ed0bGlenn Kasten * Called to signal the associated object is about to be destroyed, so whenever a callback is 4783ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * entered (see enterCb) it will be notified it is pointless to process the callback. This will 4883ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi * return immediately if there are no callbacks, and will block until current callbacks exit. 4983ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi */ 5083ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi void requestCbExitAndWait(); 5183ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 52f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten /** 53f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten * Similar to requestCbExitAndWait, but does not wait for current callbacks to exit. 54f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten */ 55f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten void requestCbExit(); 56f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten 57485a038f9f0f898227b8ab4218e94c5d56b6ed0bGlenn Kastenprivate: 5883ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi Mutex mLock; 5983ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi Condition mCbExitedCondition; 6083ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 6183ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi bool mSafeToEnterCb; 6283ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 636cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi /** Counts the number of callbacks actively locking the associated AudioPlayer */ 6483ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi unsigned int mCbCount; 656cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi 66f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten#ifdef USE_DEBUG 67f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten pthread_t mCallbackThread; 68f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten pid_t mCallbackTid; 69f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten pthread_t mRequesterThread; 70f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten pid_t mRequesterTid; 71f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten#endif 72f4b45a37248899ae2d27bb172f8387fbf1edff8eGlenn Kasten 736cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi // disallow "evil" constructors 746cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi CallbackProtector(const CallbackProtector &); 756cce136651f6fd2c7aecd45bc553270152d75462Jean-Michel Trivi CallbackProtector &operator=(const CallbackProtector &); 7683ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi}; 7783ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi 7883ac345e264c1e22b7a2f1a110b2fe92473394ecJean-Michel Trivi} // namespace android 79