1 /* 2 * Copyright 2004 The WebRTC Project Authors. All rights reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "webrtc/base/event.h" 12 13 #if defined(WEBRTC_WIN) 14 #include <windows.h> 15 #elif defined(WEBRTC_POSIX) 16 #include <pthread.h> 17 #include <sys/time.h> 18 #include <time.h> 19 #else 20 #error "Must define either WEBRTC_WIN or WEBRTC_POSIX." 21 #endif 22 23 #include "webrtc/base/checks.h" 24 25 namespace rtc { 26 27 #if defined(WEBRTC_WIN) 28 29 Event::Event(bool manual_reset, bool initially_signaled) { 30 event_handle_ = ::CreateEvent(NULL, // Security attributes. 31 manual_reset, 32 initially_signaled, 33 NULL); // Name. 34 RTC_CHECK(event_handle_); 35 } 36 37 Event::~Event() { 38 CloseHandle(event_handle_); 39 } 40 41 void Event::Set() { 42 SetEvent(event_handle_); 43 } 44 45 void Event::Reset() { 46 ResetEvent(event_handle_); 47 } 48 49 bool Event::Wait(int milliseconds) { 50 DWORD ms = (milliseconds == kForever) ? INFINITE : milliseconds; 51 return (WaitForSingleObject(event_handle_, ms) == WAIT_OBJECT_0); 52 } 53 54 #elif defined(WEBRTC_POSIX) 55 56 Event::Event(bool manual_reset, bool initially_signaled) 57 : is_manual_reset_(manual_reset), 58 event_status_(initially_signaled) { 59 RTC_CHECK(pthread_mutex_init(&event_mutex_, NULL) == 0); 60 RTC_CHECK(pthread_cond_init(&event_cond_, NULL) == 0); 61 } 62 63 Event::~Event() { 64 pthread_mutex_destroy(&event_mutex_); 65 pthread_cond_destroy(&event_cond_); 66 } 67 68 void Event::Set() { 69 pthread_mutex_lock(&event_mutex_); 70 event_status_ = true; 71 pthread_cond_broadcast(&event_cond_); 72 pthread_mutex_unlock(&event_mutex_); 73 } 74 75 void Event::Reset() { 76 pthread_mutex_lock(&event_mutex_); 77 event_status_ = false; 78 pthread_mutex_unlock(&event_mutex_); 79 } 80 81 bool Event::Wait(int milliseconds) { 82 pthread_mutex_lock(&event_mutex_); 83 int error = 0; 84 85 if (milliseconds != kForever) { 86 // Converting from seconds and microseconds (1e-6) plus 87 // milliseconds (1e-3) to seconds and nanoseconds (1e-9). 88 89 struct timespec ts; 90 #if HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE 91 // Use relative time version, which tends to be more efficient for 92 // pthread implementations where provided (like on Android). 93 ts.tv_sec = milliseconds / 1000; 94 ts.tv_nsec = (milliseconds % 1000) * 1000000; 95 #else 96 struct timeval tv; 97 gettimeofday(&tv, NULL); 98 99 ts.tv_sec = tv.tv_sec + (milliseconds / 1000); 100 ts.tv_nsec = tv.tv_usec * 1000 + (milliseconds % 1000) * 1000000; 101 102 // Handle overflow. 103 if (ts.tv_nsec >= 1000000000) { 104 ts.tv_sec++; 105 ts.tv_nsec -= 1000000000; 106 } 107 #endif 108 109 while (!event_status_ && error == 0) { 110 #if HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE 111 error = pthread_cond_timedwait_relative_np( 112 &event_cond_, &event_mutex_, &ts); 113 #else 114 error = pthread_cond_timedwait(&event_cond_, &event_mutex_, &ts); 115 #endif 116 } 117 } else { 118 while (!event_status_ && error == 0) 119 error = pthread_cond_wait(&event_cond_, &event_mutex_); 120 } 121 122 // NOTE(liulk): Exactly one thread will auto-reset this event. All 123 // the other threads will think it's unsignaled. This seems to be 124 // consistent with auto-reset events in WEBRTC_WIN 125 if (error == 0 && !is_manual_reset_) 126 event_status_ = false; 127 128 pthread_mutex_unlock(&event_mutex_); 129 130 return (error == 0); 131 } 132 133 #endif 134 135 } // namespace rtc 136
