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 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 42 Timing::~Timing() { 43 #if defined(WEBRTC_WIN) 44 if (timer_handle_ != NULL) 45 CloseHandle(timer_handle_); 46 #endif 47 } 48 49 // static 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 67 double Timing::TimerNow() { 68 return (static_cast<double>(TimeNanos()) / kNumNanosecsPerSec); 69 } 70 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 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