forked from 0ad/0ad
janwas
c45ef68a88
cpu: accessor functions ensure what they return is valid. no longer needs to call wtime_reset_impl (ugh). uses ModuleInitState. ia32: add APIC ID accessor and prevent redundant init This was SVN commit r5093.
58 lines
1.3 KiB
C++
58 lines
1.3 KiB
C++
/**
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* =========================================================================
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* File : tick_source.h
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* Project : 0 A.D.
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* Description : Interface for timer implementations
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* =========================================================================
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*/
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// license: GPL; see lib/license.txt
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#ifndef INCLUDED_TICK_SOURCE
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#define INCLUDED_TICK_SOURCE
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class TickSourceUnavailable : public std::runtime_error
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{
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public:
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TickSourceUnavailable(const std::string& msg)
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: std::runtime_error(msg)
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{
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}
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};
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class TickSource
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{
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public:
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TickSource() {}
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virtual ~TickSource() {}
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virtual bool IsSafe() const = 0;
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virtual const char* Name() const = 0;
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virtual u64 Ticks() const = 0;
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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 uint CounterBits() const = 0;
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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: cpu_ClockFrequency isn't exact).
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**/
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virtual double NominalFrequency() const = 0;
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/**
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* actual resolution [s]
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* (override if the timer adjustment is greater than 1 tick).
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**/
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virtual double Resolution() const
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{
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return 1.0 / NominalFrequency();
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}
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};
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#endif // #ifndef INCLUDED_TICK_SOURCE
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