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.
currentTimeMS()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