Clock.hpp

/*
	Copyright (c) 2009-2012 Christopher A. Taylor.  All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions are met:

	* Redistributions of source code must retain the above copyright 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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	  used to endorse or promote products derived from this software without
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	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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*/

#ifndef CAT_CLOCK_HPP
#define CAT_CLOCK_HPP

//#define CAT_CLOCK_EXTRA

#include "Platform.hpp"

#ifdef CAT_CLOCK_EXTRA
#include <string>
#endif

namespace cat {


class CAT_EXPORT Clock
{
#ifdef CAT_OS_WINDOWS
	// Windows version requires some initialization
	static const int LOWEST_ACCEPTABLE_PERIOD = 10;

    u32 _period;		// timegettime() and Windows scheduler period
	double _inv_freq;	// Performance counter frequency (does not change, so cache it)
#endif

public:
	bool OnInitialize();
	void OnFinalize();

	static u32 sec();						// Timestamp in seconds
    u32 msec_fast();						// Timestamp in milliseconds, less accurate than msec() but faster
    u32 msec();								// Timestamp in milliseconds
	double usec();							// Timestamp in microseconds
	static u32 cycles(bool sync = true);	// Timestamp in cycles (optionally sync)
    static void sleep(u32 milliseconds);

#ifdef CAT_CLOCK_EXTRA

    static std::string format(const char *format_string);

    static u32 MeasureClocks(int iterations, void (*FunctionPtr)());

#endif
};


} // namespace cat

#endif // CAT_CLOCK_HPP