1 /****************************************************************************** 2 * 3 * Copyright (C) 2012 Broadcom Corporation 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 /****************************************************************************** 20 * 21 * Synchronize two or more threads using a condition variable and a mutex. 22 * 23 ******************************************************************************/ 24 #pragma once 25 #include "CondVar.h" 26 #include "Mutex.h" 27 28 29 class SyncEvent 30 { 31 public: 32 /******************************************************************************* 33 ** 34 ** Function: ~SyncEvent 35 ** 36 ** Description: Cleanup all resources. 37 ** 38 ** Returns: None. 39 ** 40 *******************************************************************************/ 41 ~SyncEvent () 42 { 43 } 44 45 46 /******************************************************************************* 47 ** 48 ** Function: start 49 ** 50 ** Description: Start a synchronization operation. 51 ** 52 ** Returns: None. 53 ** 54 *******************************************************************************/ 55 void start () 56 { 57 mMutex.lock (); 58 } 59 60 61 /******************************************************************************* 62 ** 63 ** Function: wait 64 ** 65 ** Description: Block the thread and wait for the event to occur. 66 ** 67 ** Returns: None. 68 ** 69 *******************************************************************************/ 70 void wait () 71 { 72 mCondVar.wait (mMutex); 73 } 74 75 76 /******************************************************************************* 77 ** 78 ** Function: wait 79 ** 80 ** Description: Block the thread and wait for the event to occur. 81 ** millisec: Timeout in milliseconds. 82 ** 83 ** Returns: True if wait is successful; false if timeout occurs. 84 ** 85 *******************************************************************************/ 86 bool wait (long millisec) 87 { 88 bool retVal = mCondVar.wait (mMutex, millisec); 89 return retVal; 90 } 91 92 93 /******************************************************************************* 94 ** 95 ** Function: notifyOne 96 ** 97 ** Description: Notify a blocked thread that the event has occured. Unblocks it. 98 ** 99 ** Returns: None. 100 ** 101 *******************************************************************************/ 102 void notifyOne () 103 { 104 mCondVar.notifyOne (); 105 } 106 107 108 /******************************************************************************* 109 ** 110 ** Function: end 111 ** 112 ** Description: End a synchronization operation. 113 ** 114 ** Returns: None. 115 ** 116 *******************************************************************************/ 117 void end () 118 { 119 mMutex.unlock (); 120 } 121 122 private: 123 CondVar mCondVar; 124 Mutex mMutex; 125 }; 126 127 128 /*****************************************************************************/ 129 /*****************************************************************************/ 130 131 132 /***************************************************************************** 133 ** 134 ** Name: SyncEventGuard 135 ** 136 ** Description: Automatically start and end a synchronization event. 137 ** 138 *****************************************************************************/ 139 class SyncEventGuard 140 { 141 public: 142 /******************************************************************************* 143 ** 144 ** Function: SyncEventGuard 145 ** 146 ** Description: Start a synchronization operation. 147 ** 148 ** Returns: None. 149 ** 150 *******************************************************************************/ 151 SyncEventGuard (SyncEvent& event) 152 : mEvent (event) 153 { 154 event.start (); //automatically start operation 155 }; 156 157 158 /******************************************************************************* 159 ** 160 ** Function: ~SyncEventGuard 161 ** 162 ** Description: End a synchronization operation. 163 ** 164 ** Returns: None. 165 ** 166 *******************************************************************************/ 167 ~SyncEventGuard () 168 { 169 mEvent.end (); //automatically end operation 170 }; 171 172 private: 173 SyncEvent& mEvent; 174 }; 175 176
