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_(NULL) { 48 } 49 50 bool Event::EnsureInitialized() { 51 if (event_handle_ == NULL) { 52 event_handle_ = ::CreateEvent(NULL, // Security attributes. 53 is_manual_reset_, 54 is_initially_signaled_, 55 NULL); // Name. 56 } 57 58 return (event_handle_ != NULL); 59 } 60 61 Event::~Event() { 62 if (event_handle_ != NULL) { 63 CloseHandle(event_handle_); 64 event_handle_ = NULL; 65 } 66 } 67 68 bool Event::Set() { 69 if (!EnsureInitialized()) 70 return false; 71 72 SetEvent(event_handle_); 73 return true; 74 } 75 76 bool Event::Reset() { 77 if (!EnsureInitialized()) 78 return false; 79 80 ResetEvent(event_handle_); 81 return true; 82 } 83 84 bool Event::Wait(int cms) { 85 DWORD ms = (cms == kForever)? INFINITE : cms; 86 87 if (!EnsureInitialized()) 88 return false; 89 else 90 return (WaitForSingleObject(event_handle_, ms) == WAIT_OBJECT_0); 91 } 92 93 #elif defined(POSIX) 94 95 Event::Event(bool manual_reset, bool initially_signaled) 96 : is_manual_reset_(manual_reset), 97 event_status_(initially_signaled), 98 event_mutex_initialized_(false), 99 event_cond_initialized_(false) { 100 } 101 102 bool Event::EnsureInitialized() { 103 if (!event_mutex_initialized_) { 104 if (pthread_mutex_init(&event_mutex_, NULL) == 0) 105 event_mutex_initialized_ = true; 106 } 107 108 if (!event_cond_initialized_) { 109 if (pthread_cond_init(&event_cond_, NULL) == 0) 110 event_cond_initialized_ = true; 111 } 112 113 return (event_mutex_initialized_ && event_cond_initialized_); 114 } 115 116 Event::~Event() { 117 if (event_mutex_initialized_) { 118 pthread_mutex_destroy(&event_mutex_); 119 event_mutex_initialized_ = false; 120 } 121 122 if (event_cond_initialized_) { 123 pthread_cond_destroy(&event_cond_); 124 event_cond_initialized_ = false; 125 } 126 } 127 128 bool Event::Set() { 129 if (!EnsureInitialized()) 130 return false; 131 132 pthread_mutex_lock(&event_mutex_); 133 event_status_ = true; 134 pthread_cond_broadcast(&event_cond_); 135 pthread_mutex_unlock(&event_mutex_); 136 return true; 137 } 138 139 bool Event::Reset() { 140 if (!EnsureInitialized()) 141 return false; 142 143 pthread_mutex_lock(&event_mutex_); 144 event_status_ = false; 145 pthread_mutex_unlock(&event_mutex_); 146 return true; 147 } 148 149 bool Event::Wait(int cms) { 150 if (!EnsureInitialized()) 151 return false; 152 153 pthread_mutex_lock(&event_mutex_); 154 int error = 0; 155 156 if (cms != kForever) { 157 // Converting from seconds and microseconds (1e-6) plus 158 // milliseconds (1e-3) to seconds and nanoseconds (1e-9). 159 160 struct timeval tv; 161 gettimeofday(&tv, NULL); 162 163 struct timespec ts; 164 ts.tv_sec = tv.tv_sec + (cms / 1000); 165 ts.tv_nsec = tv.tv_usec * 1000 + (cms % 1000) * 1000000; 166 167 // Handle overflow. 168 if (ts.tv_nsec >= 1000000000) { 169 ts.tv_sec++; 170 ts.tv_nsec -= 1000000000; 171 } 172 173 while (!event_status_ && error == 0) 174 error = pthread_cond_timedwait(&event_cond_, &event_mutex_, &ts); 175 } else { 176 while (!event_status_ && error == 0) 177 error = pthread_cond_wait(&event_cond_, &event_mutex_); 178 } 179 180 // NOTE(liulk): Exactly one thread will auto-reset this event. All 181 // the other threads will think it's unsignaled. This seems to be 182 // consistent with auto-reset events in WIN32. 183 if (error == 0 && !is_manual_reset_) 184 event_status_ = false; 185 186 pthread_mutex_unlock(&event_mutex_); 187 188 return (error == 0); 189 } 190 191 #endif 192 193 } // namespace talk_base 194
