80 lines
1.8 KiB
C
80 lines
1.8 KiB
C
/*
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SST_Time_Win32.c
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Author: Patrick Baggett <ptbaggett@762studios.com>
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Created: 5/29/2013
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Purpose:
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libsst-os timing functions for Win32
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License:
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This program is free software. It comes without any warranty, to
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the extent permitted by applicable law. You can redistribute it
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and/or modify it under the terms of the Do What The Fuck You Want
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To Public License, Version 2, as published by Sam Hocevar. See
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http://sam.zoy.org/wtfpl/COPYING for more details.
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*/
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#include <SST/SST_Time.h>
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#include <windows.h>
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static LARGE_INTEGER freq; /* Frequency, as 64-bit integer */
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static double dfreq; /* Frequency, as a double value */
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/*
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Quick note about frequencies:
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x86 PCs typically have various sources of timers, but these 3 are the most common:
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* RDTSC -- x86 instruction to read a cycle counter, varies per CPU but can be in the low GHz range.
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* ACPI -- Advanced Configuration and Power Interface timer, about 3.57 MHz (so, about 280 nanosecond accuracy)
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* i8254 -- Intel chip on keyboard, about 1.193 MHz (so, about 838 nanosecond accuracy)
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*/
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int __libsst_init_time()
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{
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BOOL ok = QueryPerformanceFrequency(&freq);
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if(ok)
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dfreq = (double)freq.QuadPart;
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return (int)ok;
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}
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uint64_t SST_OS_GetRawTime()
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{
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LARGE_INTEGER v;
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QueryPerformanceCounter(&v);
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return (uint64_t)v.QuadPart;
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}
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uint64_t SST_OS_GetRawFrequency()
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{
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return (uint64_t)freq.QuadPart;
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}
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uint64_t SST_OS_GetMicroTime()
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{
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LARGE_INTEGER v;
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QueryPerformanceCounter(&v);
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return (uint64_t)((v.QuadPart * 1000LL * 1000LL) / freq.QuadPart);
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}
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uint64_t SST_OS_GetMilliTime() /* Not be confused with Miller Time (TM) :D */
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{
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LARGE_INTEGER v;
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QueryPerformanceCounter(&v);
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return (uint64_t)((v.QuadPart * 1000LL) / freq.QuadPart);
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}
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double SST_OS_GetFloatingTime()
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{
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LARGE_INTEGER v;
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QueryPerformanceCounter(&v);
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return (double)v.QuadPart / dfreq;
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} |