1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* 18 * Encapsulate a mutex for thread synchronization. 19 */ 20 21 #pragma once 22 #include <pthread.h> 23 24 25 class Mutex 26 { 27 public: 28 /******************************************************************************* 29 ** 30 ** Function: Mutex 31 ** 32 ** Description: Initialize member variables. 33 ** 34 ** Returns: None. 35 ** 36 *******************************************************************************/ 37 Mutex (); 38 39 40 /******************************************************************************* 41 ** 42 ** Function: ~Mutex 43 ** 44 ** Description: Cleanup all resources. 45 ** 46 ** Returns: None. 47 ** 48 *******************************************************************************/ 49 ~Mutex (); 50 51 52 /******************************************************************************* 53 ** 54 ** Function: lock 55 ** 56 ** Description: Block the thread and try lock the mutex. 57 ** 58 ** Returns: None. 59 ** 60 *******************************************************************************/ 61 void lock (); 62 63 64 /******************************************************************************* 65 ** 66 ** Function: unlock 67 ** 68 ** Description: Unlock a mutex to unblock a thread. 69 ** 70 ** Returns: None. 71 ** 72 *******************************************************************************/ 73 void unlock (); 74 75 76 /******************************************************************************* 77 ** 78 ** Function: tryLock 79 ** 80 ** Description: Try to lock the mutex. 81 ** 82 ** Returns: True if the mutex is locked. 83 ** 84 *******************************************************************************/ 85 bool tryLock (); 86 87 88 /******************************************************************************* 89 ** 90 ** Function: nativeHandle 91 ** 92 ** Description: Get the handle of the mutex. 93 ** 94 ** Returns: Handle of the mutex. 95 ** 96 *******************************************************************************/ 97 pthread_mutex_t* nativeHandle (); 98 99 class Autolock { 100 public: 101 inline Autolock(Mutex& mutex) : mLock(mutex) { mLock.lock(); } 102 inline Autolock(Mutex* mutex) : mLock(*mutex) { mLock.lock(); } 103 inline ~Autolock() { mLock.unlock(); } 104 private: 105 Mutex& mLock; 106 }; 107 108 109 private: 110 pthread_mutex_t mMutex; 111 }; 112 113 typedef Mutex::Autolock AutoMutex; 114
