1 /* 2 * libjingle 3 * Copyright 2004--2008, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "talk/base/event.h" 29 30 #if defined(WIN32) 31 #include <windows.h> 32 #elif defined(POSIX) 33 #include <pthread.h> 34 #include <sys/time.h> 35 #include <time.h> 36 #else 37 #error "Must define either WIN32 or POSIX." 38 #endif 39 40 namespace talk_base { 41 42 #if defined(WIN32) 43 44 Event::Event(bool manual_reset, bool initially_signaled) 45 : is_manual_reset_(manual_reset), 46 is_initially_signaled_(initially_signaled) { 47 event_handle_ = ::CreateEvent(NULL, // Security attributes. 48 is_manual_reset_, 49 is_initially_signaled_, 50 NULL); // Name. 51 ASSERT(event_handle_ != NULL); 52 } 53 54 Event::~Event() { 55 CloseHandle(event_handle_); 56 } 57 58 void Event::Set() { 59 SetEvent(event_handle_); 60 } 61 62 void Event::Reset() { 63 ResetEvent(event_handle_); 64 } 65 66 bool Event::Wait(int cms) { 67 DWORD ms = (cms == kForever)? INFINITE : cms; 68 return (WaitForSingleObject(event_handle_, ms) == WAIT_OBJECT_0); 69 } 70 71 #elif defined(POSIX) 72 73 Event::Event(bool manual_reset, bool initially_signaled) 74 : is_manual_reset_(manual_reset), 75 event_status_(initially_signaled) { 76 VERIFY(pthread_mutex_init(&event_mutex_, NULL) == 0); 77 VERIFY(pthread_cond_init(&event_cond_, NULL) == 0); 78 } 79 80 Event::~Event() { 81 pthread_mutex_destroy(&event_mutex_); 82 pthread_cond_destroy(&event_cond_); 83 } 84 85 void Event::Set() { 86 pthread_mutex_lock(&event_mutex_); 87 event_status_ = true; 88 pthread_cond_broadcast(&event_cond_); 89 pthread_mutex_unlock(&event_mutex_); 90 } 91 92 void Event::Reset() { 93 pthread_mutex_lock(&event_mutex_); 94 event_status_ = false; 95 pthread_mutex_unlock(&event_mutex_); 96 } 97 98 bool Event::Wait(int cms) { 99 pthread_mutex_lock(&event_mutex_); 100 int error = 0; 101 102 if (cms != kForever) { 103 // Converting from seconds and microseconds (1e-6) plus 104 // milliseconds (1e-3) to seconds and nanoseconds (1e-9). 105 106 struct timespec ts; 107 #if HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE 108 // Use relative time version, which tends to be more efficient for 109 // pthread implementations where provided (like on Android). 110 ts.tv_sec = cms / 1000; 111 ts.tv_nsec = (cms % 1000) * 1000000; 112 #else 113 struct timeval tv; 114 gettimeofday(&tv, NULL); 115 116 ts.tv_sec = tv.tv_sec + (cms / 1000); 117 ts.tv_nsec = tv.tv_usec * 1000 + (cms % 1000) * 1000000; 118 119 // Handle overflow. 120 if (ts.tv_nsec >= 1000000000) { 121 ts.tv_sec++; 122 ts.tv_nsec -= 1000000000; 123 } 124 #endif 125 126 while (!event_status_ && error == 0) { 127 #if HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE 128 error = pthread_cond_timedwait_relative_np( 129 &event_cond_, &event_mutex_, &ts); 130 #else 131 error = pthread_cond_timedwait(&event_cond_, &event_mutex_, &ts); 132 #endif 133 } 134 } else { 135 while (!event_status_ && error == 0) 136 error = pthread_cond_wait(&event_cond_, &event_mutex_); 137 } 138 139 // NOTE(liulk): Exactly one thread will auto-reset this event. All 140 // the other threads will think it's unsignaled. This seems to be 141 // consistent with auto-reset events in WIN32. 142 if (error == 0 && !is_manual_reset_) 143 event_status_ = false; 144 145 pthread_mutex_unlock(&event_mutex_); 146 147 return (error == 0); 148 } 149 150 #endif 151 152 } // namespace talk_base 153