1 /* 2 * Copyright (C) 2006 Apple Computer, Inc. All rights reserved. 3 * Copyright (C) 2008 Google Inc. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef CurrentTime_h 33 #define CurrentTime_h 34 35 #include "wtf/WTFExport.h" 36 37 namespace WTF { 38 39 // Returns the current UTC time in seconds, counted from January 1, 1970. 40 // Precision varies depending on platform but is usually as good or better 41 // than a millisecond. 42 WTF_EXPORT double currentTime(); 43 44 // Same thing, in milliseconds. 45 inline double currentTimeMS() 46 { 47 return currentTime() * 1000.0; 48 } 49 50 // Provides a monotonically increasing time in seconds since an arbitrary point in the past. 51 // On unsupported platforms, this function only guarantees the result will be non-decreasing. 52 WTF_EXPORT double monotonicallyIncreasingTime(); 53 54 typedef double(*TimeFunction)(void); 55 void setCurrentTimeFunction(TimeFunction); 56 void setMonotonicallyIncreasingTimeFunction(TimeFunction); 57 58 59 } // namespace WTF 60 61 using WTF::currentTime; 62 using WTF::currentTimeMS; 63 using WTF::monotonicallyIncreasingTime; 64 65 #endif // CurrentTime_h 66