henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * libjingle |
| 3 | * Copyright 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 | #ifndef TALK_BASE_TIMING_H_ |
| 29 | #define TALK_BASE_TIMING_H_ |
| 30 | |
| 31 | #if defined(WIN32) |
| 32 | #include "talk/base/win32.h" |
| 33 | #endif |
| 34 | |
| 35 | namespace talk_base { |
| 36 | |
| 37 | class Timing { |
| 38 | public: |
| 39 | Timing(); |
| 40 | virtual ~Timing(); |
| 41 | |
| 42 | // WallTimeNow() returns the current wall-clock time in seconds, |
| 43 | // within 10 milliseconds resolution. |
| 44 | virtual double WallTimeNow(); |
| 45 | |
| 46 | // TimerNow() is like WallTimeNow(), but is monotonically |
| 47 | // increasing. It returns seconds in resolution of 10 microseconds |
| 48 | // or better. Although timer and wall-clock time have the same |
| 49 | // timing unit, they do not necessarily correlate because wall-clock |
| 50 | // time may be adjusted backwards, hence not monotonic. |
| 51 | // Made virtual so we can make a fake one. |
| 52 | virtual double TimerNow(); |
| 53 | |
| 54 | // BusyWait() exhausts CPU as long as the time elapsed is less than |
| 55 | // the specified interval in seconds. Returns the actual waiting |
| 56 | // time based on TimerNow() measurement. |
| 57 | double BusyWait(double period); |
| 58 | |
| 59 | // IdleWait() relinquishes control of CPU for specified period in |
| 60 | // seconds. It uses highest resolution sleep mechanism as possible, |
| 61 | // but does not otherwise guarantee the accuracy. Returns the |
| 62 | // actual waiting time based on TimerNow() measurement. |
| 63 | // |
| 64 | // This function is not re-entrant for an object. Create a fresh |
| 65 | // Timing object for each thread. |
| 66 | double IdleWait(double period); |
| 67 | |
| 68 | private: |
| 69 | #if defined(WIN32) |
| 70 | HANDLE timer_handle_; |
| 71 | #endif |
| 72 | }; |
| 73 | |
| 74 | } // namespace talk_base |
| 75 | |
| 76 | #endif // TALK_BASE_TIMING_H_ |