sky/engine/wtf/CurrentTime.h

/*
 * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
 * Copyright (C) 2008 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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#ifndef SKY_ENGINE_WTF_CURRENTTIME_H_
#define SKY_ENGINE_WTF_CURRENTTIME_H_

#include "sky/engine/wtf/WTFExport.h"

namespace WTF {

// Returns the current UTC time in seconds, counted from January 1, 1970.
// Precision varies depending on platform but is usually as good or better
// than a millisecond.
WTF_EXPORT double currentTime();

// Same thing, in milliseconds.
inline double currentTimeMS()
{
    return currentTime() * 1000.0;
}

// Provides a monotonically increasing time in seconds since an arbitrary point in the past.
// On unsupported platforms, this function only guarantees the result will be non-decreasing.
WTF_EXPORT double monotonicallyIncreasingTime();

typedef double(*TimeFunction)(void);

} // namespace WTF

using WTF::currentTime;
using WTF::currentTimeMS;
using WTF::monotonicallyIncreasingTime;

#endif  // SKY_ENGINE_WTF_CURRENTTIME_H_