forked from mirrors/0ad
janwas
a3696c0b91
lib/sysdep: clean up by moving OS and cpu-arch folders into "os" and "arch" folders This was SVN commit r6162.
55 lines
1.2 KiB
C++
55 lines
1.2 KiB
C++
/**
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* =========================================================================
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* File : qpc.h
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* Project : 0 A.D.
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* Description : Timer implementation using QueryPerformanceCounter
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* =========================================================================
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*/
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// license: GPL; see lib/license.txt
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#ifndef INCLUDED_QPC
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#define INCLUDED_QPC
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#include "counter.h"
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class CounterQPC : public ICounter
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{
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public:
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CounterQPC()
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: m_frequency(-1)
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{
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}
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virtual const char* Name() const
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{
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return "QPC";
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}
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virtual LibError Activate();
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virtual void Shutdown();
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virtual bool IsSafe() const;
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virtual u64 Counter() const;
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/**
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* WHRT uses this to ensure the counter (running at nominal frequency)
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* doesn't overflow more than once during CALIBRATION_INTERVAL_MS.
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**/
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virtual size_t CounterBits() const;
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/**
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* initial measurement of the tick rate. not necessarily correct
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* (e.g. when using TSC: os_cpu_ClockFrequency isn't exact).
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**/
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virtual double NominalFrequency() const;
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private:
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// used in several places and QPF is a bit slow+cumbersome.
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// (i64 allows easier conversion to double)
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i64 m_frequency;
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};
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#endif // #ifndef INCLUDED_QPC
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