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 condition variable for thread synchronization. 19 */ 20 21#include "CondVar.h" 22#include "NfcJniUtil.h" 23 24#include <cutils/log.h> 25#include <errno.h> 26 27 28/******************************************************************************* 29** 30** Function: CondVar 31** 32** Description: Initialize member variables. 33** 34** Returns: None. 35** 36*******************************************************************************/ 37CondVar::CondVar () 38{ 39 memset (&mCondition, 0, sizeof(mCondition)); 40 int const res = pthread_cond_init (&mCondition, NULL); 41 if (res) 42 { 43 ALOGE ("CondVar::CondVar: fail init; error=0x%X", res); 44 } 45} 46 47 48/******************************************************************************* 49** 50** Function: ~CondVar 51** 52** Description: Cleanup all resources. 53** 54** Returns: None. 55** 56*******************************************************************************/ 57CondVar::~CondVar () 58{ 59 int const res = pthread_cond_destroy (&mCondition); 60 if (res) 61 { 62 ALOGE ("CondVar::~CondVar: fail destroy; error=0x%X", res); 63 } 64} 65 66 67/******************************************************************************* 68** 69** Function: wait 70** 71** Description: Block the caller and wait for a condition. 72** 73** Returns: None. 74** 75*******************************************************************************/ 76void CondVar::wait (Mutex& mutex) 77{ 78 int const res = pthread_cond_wait (&mCondition, mutex.nativeHandle()); 79 if (res) 80 { 81 ALOGE ("CondVar::wait: fail wait; error=0x%X", res); 82 } 83} 84 85 86/******************************************************************************* 87** 88** Function: wait 89** 90** Description: Block the caller and wait for a condition. 91** millisec: Timeout in milliseconds. 92** 93** Returns: True if wait is successful; false if timeout occurs. 94** 95*******************************************************************************/ 96bool CondVar::wait (Mutex& mutex, long millisec) 97{ 98 bool retVal = false; 99 struct timespec absoluteTime; 100 101 if (clock_gettime (CLOCK_MONOTONIC, &absoluteTime) == -1) 102 { 103 ALOGE ("CondVar::wait: fail get time; errno=0x%X", errno); 104 } 105 else 106 { 107 absoluteTime.tv_sec += millisec / 1000; 108 long ns = absoluteTime.tv_nsec + ((millisec % 1000) * 1000000); 109 if (ns > 1000000000) 110 { 111 absoluteTime.tv_sec++; 112 absoluteTime.tv_nsec = ns - 1000000000; 113 } 114 else 115 absoluteTime.tv_nsec = ns; 116 } 117 118 //pthread_cond_timedwait_monotonic_np() is an Android-specific function 119 //declared in /development/ndk/platforms/android-9/include/pthread.h; 120 //it uses monotonic clock. 121 //the standard pthread_cond_timedwait() uses realtime clock. 122 int waitResult = pthread_cond_timedwait_monotonic_np (&mCondition, mutex.nativeHandle(), &absoluteTime); 123 if ((waitResult != 0) && (waitResult != ETIMEDOUT)) 124 ALOGE ("CondVar::wait: fail timed wait; error=0x%X", waitResult); 125 retVal = (waitResult == 0); //waited successfully 126 return retVal; 127} 128 129 130/******************************************************************************* 131** 132** Function: notifyOne 133** 134** Description: Unblock the waiting thread. 135** 136** Returns: None. 137** 138*******************************************************************************/ 139void CondVar::notifyOne () 140{ 141 int const res = pthread_cond_signal (&mCondition); 142 if (res) 143 { 144 ALOGE ("CondVar::notifyOne: fail signal; error=0x%X", res); 145 } 146} 147 148