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
23namespace rtc {
24
25#if defined(WEBRTC_WIN)
26
27Event::Event(bool manual_reset, bool initially_signaled)
28    : is_manual_reset_(manual_reset),
29      is_initially_signaled_(initially_signaled) {
30  event_handle_ = ::CreateEvent(NULL,                 // Security attributes.
31                                is_manual_reset_,
32                                is_initially_signaled_,
33                                NULL);                // Name.
34  ASSERT(event_handle_ != NULL);
35}
36
37Event::~Event() {
38  CloseHandle(event_handle_);
39}
40
41void Event::Set() {
42  SetEvent(event_handle_);
43}
44
45void Event::Reset() {
46  ResetEvent(event_handle_);
47}
48
49bool Event::Wait(int cms) {
50  DWORD ms = (cms == kForever)? INFINITE : cms;
51  return (WaitForSingleObject(event_handle_, ms) == WAIT_OBJECT_0);
52}
53
54#elif defined(WEBRTC_POSIX)
55
56Event::Event(bool manual_reset, bool initially_signaled)
57    : is_manual_reset_(manual_reset),
58      event_status_(initially_signaled) {
59  VERIFY(pthread_mutex_init(&event_mutex_, NULL) == 0);
60  VERIFY(pthread_cond_init(&event_cond_, NULL) == 0);
61}
62
63Event::~Event() {
64  pthread_mutex_destroy(&event_mutex_);
65  pthread_cond_destroy(&event_cond_);
66}
67
68void 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
75void Event::Reset() {
76  pthread_mutex_lock(&event_mutex_);
77  event_status_ = false;
78  pthread_mutex_unlock(&event_mutex_);
79}
80
81bool Event::Wait(int cms) {
82  pthread_mutex_lock(&event_mutex_);
83  int error = 0;
84
85  if (cms != 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 = cms / 1000;
94    ts.tv_nsec = (cms % 1000) * 1000000;
95#else
96    struct timeval tv;
97    gettimeofday(&tv, NULL);
98
99    ts.tv_sec = tv.tv_sec + (cms / 1000);
100    ts.tv_nsec = tv.tv_usec * 1000 + (cms % 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