1 /*
2 * Copyright 2008 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/timing.h"
12 #include "webrtc/base/timeutils.h"
13
14 #if defined(WEBRTC_POSIX)
15 #include <errno.h>
16 #include <math.h>
17 #include <sys/time.h>
18 #if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)
19 #include <mach/mach.h>
20 #include <mach/clock.h>
21 #endif
22 #elif defined(WEBRTC_WIN)
23 #include <sys/timeb.h>
24 #include "webrtc/base/win32.h"
25 #endif
26
27 namespace rtc {
28
Timing()29 Timing::Timing() {
30 #if defined(WEBRTC_WIN)
31 // This may fail, but we handle failure gracefully in the methods
32 // that use it (use alternative sleep method).
33 //
34 // TODO: Make it possible for user to tell if IdleWait will
35 // be done at lesser resolution because of this.
36 timer_handle_ = CreateWaitableTimer(NULL, // Security attributes.
37 FALSE, // Manual reset?
38 NULL); // Timer name.
39 #endif
40 }
41
~Timing()42 Timing::~Timing() {
43 #if defined(WEBRTC_WIN)
44 if (timer_handle_ != NULL)
45 CloseHandle(timer_handle_);
46 #endif
47 }
48
49 // static
WallTimeNow()50 double Timing::WallTimeNow() {
51 #if defined(WEBRTC_POSIX)
52 struct timeval time;
53 gettimeofday(&time, NULL);
54 // Convert from second (1.0) and microsecond (1e-6).
55 return (static_cast<double>(time.tv_sec) +
56 static_cast<double>(time.tv_usec) * 1.0e-6);
57
58 #elif defined(WEBRTC_WIN)
59 struct _timeb time;
60 _ftime(&time);
61 // Convert from second (1.0) and milliseconds (1e-3).
62 return (static_cast<double>(time.time) +
63 static_cast<double>(time.millitm) * 1.0e-3);
64 #endif
65 }
66
TimerNow()67 double Timing::TimerNow() {
68 return (static_cast<double>(TimeNanos()) / kNumNanosecsPerSec);
69 }
70
BusyWait(double period)71 double Timing::BusyWait(double period) {
72 double start_time = TimerNow();
73 while (TimerNow() - start_time < period) {
74 }
75 return TimerNow() - start_time;
76 }
77
IdleWait(double period)78 double Timing::IdleWait(double period) {
79 double start_time = TimerNow();
80
81 #if defined(WEBRTC_POSIX)
82 double sec_int, sec_frac = modf(period, &sec_int);
83 struct timespec ts;
84 ts.tv_sec = static_cast<time_t>(sec_int);
85 ts.tv_nsec = static_cast<long>(sec_frac * 1.0e9); // NOLINT
86
87 // NOTE(liulk): for the NOLINT above, long is the appropriate POSIX
88 // type.
89
90 // POSIX nanosleep may be interrupted by signals.
91 while (nanosleep(&ts, &ts) == -1 && errno == EINTR) {
92 }
93
94 #elif defined(WEBRTC_WIN)
95 if (timer_handle_ != NULL) {
96 LARGE_INTEGER due_time;
97
98 // Negative indicates relative time. The unit is 100 nanoseconds.
99 due_time.QuadPart = -LONGLONG(period * 1.0e7);
100
101 SetWaitableTimer(timer_handle_, &due_time, 0, NULL, NULL, TRUE);
102 WaitForSingleObject(timer_handle_, INFINITE);
103 } else {
104 // Still attempts to sleep with lesser resolution.
105 // The unit is in milliseconds.
106 Sleep(DWORD(period * 1.0e3));
107 }
108 #endif
109
110 return TimerNow() - start_time;
111 }
112
113 } // namespace rtc
114