634 lines
22 KiB
C
634 lines
22 KiB
C
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/* OS/2 Version
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* Timer.c - Source file for a statistical
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* dll package that exports four
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* entry points:
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* a) TimerOpen
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* b) TimerInit
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* c) TimerRead
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* d) TimerClose
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* e) TimerReport
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* f) TimerQueryPerformanceCounter
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* g) TimerConvertTicsToUSec
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*
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* Entry point a) opens a timer object
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* and returns a handle to the timer. This
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* handle is an index into an array of timer
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* objects (structs) that are allocated at
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* the time of the initialization of the dll.
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* This ensures that allocation is done once only.
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* Each application program will call this
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* this function so that it has its own set
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* of timers to use with TimerInit and TimerRead.
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* The units of the time returned by TimerRead
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* is also made available as a parameter to
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* this call.
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*
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* Entry point b) is called by the application
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* before commencing a timing operation. This
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* function is called with a handle to a timer
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* object that was opened. This function has to
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* to be called before a call to TimerRead. The
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* current time is stored in the timer object.
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*
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* Entry point c) is called each time the time
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* since the previous call to TimerInit is
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* desired. This call also uses the handle to
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* a timer that has been previosly opened. The
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* current time is obtained form the lowlevel
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* timer and this and the time at TimerInit time
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* are used, along with the clock frequency and
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* the return time units and the elapsed time
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* is obtained and returned as a ULONG.
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*
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* Entry point d) is called whenever an opened
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* timer is not needed any longer. This call
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* resets the timer and makes this timer as
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* available to future calls to TimerOpen.
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*
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* Entry point e) returns the time obtained during
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* the last call to TimerInit, TimerRead and the
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* last returned time.
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*
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* Entry point f) accepts pointers to 2 64 bit
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* vars. Upon return, the first will contain the
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* the current timer tic count and the second,
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* if not NULL, will point to the timer freq.
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*
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* Entry point g) accepts Elapsed Tics as ULONG,
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* Frequency as a ULONG and returns the time in
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* microsecs. as a ULONG.
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*
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* The dll initialization routine does the
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* following:
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* a) Obtains the timer overhead for calibration
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* purposes.
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* b) Allocates memory for a large number of
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* timer objects (this will be system dep).
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* c) Initializes each timer objects "Units'
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* element to a "TIMER_FREE" indicator.
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* d) Determines the lowlevel timer's frequency.
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*
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* TimerRead uses an external asm routine to perform
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* its computation for elapsed time.
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*
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* Created - Paramesh Vaidyanathan (vaidy)
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* Initial Version - October 18, '90
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*
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* Modified to include f). - Feb. 14, 1992. (vaidy).
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*/
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char *COPYRIGHT = "Copyright Microsoft Corporation, 1991-1998";
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#ifdef SLOOP
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#define INCL_DOSINFOSEG
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#define INCL_DOSDEVICES
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#define INCL_DOSPROCESS
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#endif
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#include <nt.h>
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#include <ntrtl.h>
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#include <nturtl.h>
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#include <windows.h>
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#include "timing.h"
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/*****************************END OF INCLUDES*************************/
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#define ITER_FOR_OVERHEAD 250
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#define SUCCESS_OK 0
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#define ONE_MILLION 1000000L
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#define MICROSEC_FACTOR 1000000
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#define TIMER_FREQ 1193167L /* clock frequency - Hz */
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/*********************************************************************/
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Timer pTimer [MAX_TIMERS]; /* array of timer struct */
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BOOL bTimerInit = FALSE; /* TRUE indicates low level timer exists */
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ULONG ulTimerOverhead = 50000L; /* timer overhead stored here */
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BOOL bCalibrated = FALSE; /* TRUE subtracts overhead also */
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ULONG ulFreq; /* timer frequency */
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LONG aScaleValues[] = {1000000000L, 1000000L, 1000L, 1L, 10L, 1000L};
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/* this is the table for scaling the units */
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ULONG ulElapsedTime = 0L;
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/********************* internal unexported routines ***************/
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ULONG CalibrateTimerForOverhead (VOID);
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/*****************DEFINE VARIBLES AND PROTOTYPE FNS. FOR PLATFORMS*****/
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NTSYSAPI
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NTSTATUS
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NTAPI
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NtQueryPerformanceCounter (
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OUT PLARGE_INTEGER PerformanceCount,
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OUT PLARGE_INTEGER PerformanceFrequency OPTIONAL
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);
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LARGE_INTEGER PerfFreq;
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LARGE_INTEGER CountCurrent;
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SHORT GetTimerFreq (VOID);
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/****************** internal unexported routines end***************/
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/*
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* Function - TimerOpen (EXPORTED)
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* Arguments -
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* (a) SHORT far * - address to which to return handle of
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* the timer object.
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* (b) TimerUnits - units in which to return time from
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* TimerRead. It is one of the enum
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* types defined in the header file.
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*
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* Returns - SHORT - 0 if handle was returned successfully
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* Else, an error code which may be one of:
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*
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* TIMERERR_NOT_AVAILABLE
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* TIMERERR_NO_MORE_HANDLES
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* TIMERERR_INVALID_UNITS
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*
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* Obtains the handle to a timer object after opening it.
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* Should precede any calls to timer manipulation. Checks
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* for validity of timer units.
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*/
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SHORT
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TimerOpen (
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SHORT * phTimerHandle,
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_TimerUnits TimerUnits
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)
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{
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SHORT csTemp;
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if ((TimerUnits < KILOSECONDS)
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|| (TimerUnits > NANOSECONDS)) /* out of the enum range */
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return (TIMERERR_INVALID_UNITS);
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if (!bTimerInit) /* set during dll initialization */
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return (TIMERERR_NOT_AVAILABLE);
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/* else check if any timers are not in use and return the first
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available timer handle....actually the index into the
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timer object array */
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for (csTemp = 0; csTemp < MAX_TIMERS; csTemp++) {
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if (pTimer [csTemp].TUnits == TIMER_FREE) {
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*phTimerHandle = csTemp; /* found a free timer. Return
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the handle */
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pTimer [csTemp].ulHi = pTimer[csTemp].ulLo = 0L;
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pTimer [csTemp].TUnits =
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TimerUnits; /* set the units for timer */
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return (SUCCESS_OK);
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}
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}
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/* if exec reached here, all timers are being used */
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return (TIMERERR_NO_MORE_HANDLES);
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}
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/*
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* Function - TimerInit (EXPORTED)
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* Arguments -
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* (a) SHORT - hTimerHandle
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*
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* Returns - SHORT - 0 if call successful
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* Else, an error code if handle invalid:
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*
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* TIMERERR_INVALID_HANDLE
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*
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* Calls the low-level timer and sets the ulHi and ulLo of the
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* chosen timer to the time returned by the timer. Should be
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* called after opening the timer with TimerOpen.
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*/
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SHORT
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TimerInit (
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SHORT hTimerHandle
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)
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{
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NTSTATUS NtStatus;
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if ((hTimerHandle > MAX_TIMERS - 1) ||
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(pTimer [hTimerHandle].TUnits == TIMER_FREE))
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/* this timer has not been opened or does not exist. Return error */
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return (TIMERERR_INVALID_HANDLE);
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/* otherwise get the time from the low-level timer into
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the structure */
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NtStatus = NtQueryPerformanceCounter (&CountCurrent, NULL);
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pTimer [hTimerHandle].ulLo = CountCurrent.LowPart;
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pTimer [hTimerHandle].ulHi = CountCurrent.HighPart;
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/* this timer structure has all the information needed to compute
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the elapsed time. So return success, if there was no problem */
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return (SUCCESS_OK);
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}
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/*
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* Function - TimerRead (EXPORTED)
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* Arguments -
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* (a) SHORT - hTimerHandle
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*
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* Returns - ULONG - elapsed time since last call to TimerInit
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* if call successful.
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*
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* Else, an error code if handle invalid or output
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* overflow. The error code will be the same:
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*
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* TIMERERR_OVERFLOW (max possible ULONG)
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*
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* Calls the low-level timer. Uses the ulLo and ulHi from the
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* timer's structure and subtracts the current time from the
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* saved time. Uses ReturnElapsedTime (an external ASM proc)
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* to return the elapsed time taking into account the clock
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* frequency and the units for this timer. Each call to this
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* returns the time from the previous TimerInit.
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*
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* The user should interpret the return value sensibly to check
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* if the result is an error or a real value.
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*/
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ULONG
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TimerRead (
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SHORT hTimerHandle
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)
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{
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NTSTATUS NtStatus;
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LARGE_INTEGER ElapsedTime, CountPrev, LargeOverhead;
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if ((hTimerHandle > MAX_TIMERS - 1)
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|| (pTimer [hTimerHandle].TUnits == TIMER_FREE))
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/* this timer has not been opened or does not exist.
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Return TIMERERR_OVERFLOW ie. 0xffffffff, the max. possible
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ULONG. The user should interpret such a result sensibly */
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return (TIMERERR_OVERFLOW);
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NtStatus = NtQueryPerformanceCounter (&CountCurrent, NULL);
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CountPrev.LowPart = pTimer [hTimerHandle].ulLo;
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CountPrev.HighPart = (LONG) pTimer [hTimerHandle].ulHi;
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ElapsedTime.LowPart = CountCurrent.LowPart;
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ElapsedTime.HighPart = (LONG) CountCurrent.HighPart;
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/* everything is just fine, convert to double, subtract the times,
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divide by the frequency, convert to MICROSECONDS and return
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the elapsed time as a ULONG */
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/* convert to us., divide the count by the clock frequency that
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has already been obtained */
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ElapsedTime = RtlLargeIntegerSubtract (ElapsedTime, CountPrev);
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ElapsedTime = RtlExtendedIntegerMultiply (ElapsedTime, MICROSEC_FACTOR);
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ElapsedTime = RtlExtendedLargeIntegerDivide (ElapsedTime,
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PerfFreq.LowPart,
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NULL);
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// if the timer is not calibrated, set ulElapsedTime to be the
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// low part of ElapsedTime. This is because, we do not have to
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// do to any arithmetic to this before returning the value.
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if (!bCalibrated)
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ulElapsedTime = ElapsedTime.LowPart;
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/* this code is common for all platforms but OS2386. For Win3.x
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if VTD.386 has been installed, the code below should not matter,
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since we should have returned the time by now.
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The elapsed time will be scaled, overhead subtracted
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and the time returned */
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/* we have ulElapsedTime. Scale it and do the needful */
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/* divide or multiply by the scale factor */
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if (bCalibrated) {
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// Applications like the PROBE call TimerRead repeatedly
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// without calling TimerInit, for more than 70 minutes. This
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// screws up things. So treat everything as 64 bit numbers
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// until the very end.
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if ((ElapsedTime.LowPart < ulTimerOverhead) &&
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(!ElapsedTime.HighPart)) { // low part is lower than overhead
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// and high part is zero..then make
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// elapsed time 0. We don't want
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// negative numbers.
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ElapsedTime.HighPart = 0L;
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ElapsedTime.LowPart = 0L;
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}
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else { // subtract the overhead in tics before converting
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// to time units
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LargeOverhead.HighPart = 0L;
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LargeOverhead.LowPart = ulTimerOverhead;
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ElapsedTime = RtlLargeIntegerSubtract (ElapsedTime,
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LargeOverhead);
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}
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if (pTimer [hTimerHandle].TUnits <= MICROSECONDS) {
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ElapsedTime = RtlExtendedLargeIntegerDivide (
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ElapsedTime,
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aScaleValues [pTimer [hTimerHandle].TUnits],
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NULL
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);
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} else {
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ElapsedTime = RtlExtendedIntegerMultiply (
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ElapsedTime,
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aScaleValues [pTimer [hTimerHandle].TUnits]
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);
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}
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// scaling is done. Now get the time back into 32 bits. This
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// should fit.
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ulElapsedTime = ElapsedTime.LowPart;
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}
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if ((LONG) ulElapsedTime < 0L) /* if this guy is -ve, return a 0 */
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return (0L);
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return (ulElapsedTime);
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}
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/*
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* Function - TimerClose (EXPORTED)
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* Arguments -
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* (a) SHORT - hTimerHandle
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*
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* Returns - SHORT - 0 if call successful
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* Else, an error code if handle invalid:
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*
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* TIMERERR_INVALID_HANDLE
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*
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* Releases the timer for use by future TimerOpen calls.
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* Resets the elements of the timer structure, setting the
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* Timer's Units element to TIMER_FREE.
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*/
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SHORT
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TimerClose (
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SHORT hTimerHandle
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)
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{
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if ((hTimerHandle > MAX_TIMERS - 1) ||
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(pTimer [hTimerHandle].TUnits == TIMER_FREE))
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/* error condition, wrong handle */
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return (TIMERERR_INVALID_HANDLE);
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/* otherwise, set the TimerUnits of this timer to TIMER_FREE,
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reset the other elements to zero and return */
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pTimer [hTimerHandle].TUnits = TIMER_FREE;
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pTimer [hTimerHandle].ulLo = 0L;
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pTimer [hTimerHandle].ulHi = 0L;
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return (SUCCESS_OK);
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}
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/*******************************************************************
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|
Added this routine TimerReport to report individual
|
||
|
|
times. Bob Day requested that such a routine be
|
||
|
|
created. It just maintains the time from the last
|
||
|
|
TimerInit and TimerRead and also the last time returned.
|
||
|
|
This routine copies this to a user specified buffer.
|
||
|
|
|
||
|
|
Accepts - PSZ - a pointer to a buffer to print the data out
|
||
|
|
SHORT - timer handle
|
||
|
|
|
||
|
|
Returns - TRUE if Timer exists and is open
|
||
|
|
- FALSE if Timer not opened
|
||
|
|
|
||
|
|
*******************************************************************/
|
||
|
|
|
||
|
|
BOOL
|
||
|
|
FAR
|
||
|
|
PASCAL
|
||
|
|
TimerReport (
|
||
|
|
PSZ pszReportString,
|
||
|
|
SHORT hTimerHandle
|
||
|
|
)
|
||
|
|
{
|
||
|
|
if (pTimer [hTimerHandle].TUnits == TIMER_FREE)
|
||
|
|
return (FALSE);
|
||
|
|
|
||
|
|
/* stored value is in pTimer[hTimerHandle].ulLo and .ulHi */
|
||
|
|
/*
|
||
|
|
wsprintf (pszReportString,
|
||
|
|
"Init Count (tics) %lu:%lu Current Count (tics) %lu:%lu Returned Time %lu ",
|
||
|
|
pTimer [hTimerHandle].ulHi,
|
||
|
|
pTimer [hTimerHandle].ulLo, CountCurrent.HighPart,
|
||
|
|
CountCurrent.LowPart,
|
||
|
|
ulElapsedTime);
|
||
|
|
*/
|
||
|
|
return (TRUE);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*******************************************************************
|
||
|
|
|
||
|
|
Added this routine TimerQueryPerformanceCounter to report
|
||
|
|
current tic count at behest of NT GDI folks.
|
||
|
|
|
||
|
|
|
||
|
|
Accepts - PQWORD - a pointer to a 64 bit struct. that will
|
||
|
|
contain tic count on return.
|
||
|
|
|
||
|
|
PQWORD [OPTIONAL) - a pointer to a 64 bit struct. that will
|
||
|
|
contain frequency on return.
|
||
|
|
|
||
|
|
Returns - None.
|
||
|
|
|
||
|
|
*******************************************************************/
|
||
|
|
|
||
|
|
VOID
|
||
|
|
FAR
|
||
|
|
PASCAL
|
||
|
|
TimerQueryPerformanceCounter (
|
||
|
|
PQWORD pqTic,
|
||
|
|
PQWORD pqFreq OPTIONAL
|
||
|
|
)
|
||
|
|
{
|
||
|
|
|
||
|
|
LARGE_INTEGER TempTic, TempFreq;
|
||
|
|
|
||
|
|
// call the NT API to do the needful and return.
|
||
|
|
NtQueryPerformanceCounter (&TempTic, &TempFreq);
|
||
|
|
pqTic->LowPart = TempTic.LowPart;
|
||
|
|
pqTic->HighPart = TempTic.HighPart;
|
||
|
|
pqFreq->LowPart = TempFreq.LowPart;
|
||
|
|
pqFreq->HighPart = TempFreq.HighPart;
|
||
|
|
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*******************************************************************
|
||
|
|
|
||
|
|
Added this routine TimerConvertTicsToUSec to return
|
||
|
|
time in usecs. for a given elapsed tic count and freq.
|
||
|
|
|
||
|
|
|
||
|
|
Accepts - ULONG - Elapsed Tic Count.
|
||
|
|
|
||
|
|
ULONG - Frequency.
|
||
|
|
|
||
|
|
Returns - Elapsed Time in usecs. as a ULONG.
|
||
|
|
- Zero if input freq. is zero.
|
||
|
|
|
||
|
|
*******************************************************************/
|
||
|
|
|
||
|
|
ULONG
|
||
|
|
TimerConvertTicsToUSec (
|
||
|
|
ULONG ulElapsedTics,
|
||
|
|
ULONG ulInputFreq
|
||
|
|
)
|
||
|
|
{
|
||
|
|
|
||
|
|
LARGE_INTEGER ElapsedTime;
|
||
|
|
ULONG ulRemainder = 0L;
|
||
|
|
|
||
|
|
// if the person gives me a zero freq, return him a zero.
|
||
|
|
// Let him tear his hair.
|
||
|
|
|
||
|
|
if (!ulInputFreq)
|
||
|
|
return 0L;
|
||
|
|
|
||
|
|
// multiply tics by a million and divide by the frequency.
|
||
|
|
|
||
|
|
ElapsedTime = RtlEnlargedIntegerMultiply (ulElapsedTics, MICROSEC_FACTOR);
|
||
|
|
|
||
|
|
ElapsedTime = RtlExtendedLargeIntegerDivide (ElapsedTime,
|
||
|
|
ulInputFreq,
|
||
|
|
&ulRemainder);
|
||
|
|
|
||
|
|
ElapsedTime.LowPart += (ulRemainder > (ulInputFreq / 2L));
|
||
|
|
|
||
|
|
return (ElapsedTime.LowPart) ; /* get the result into a ULONG */
|
||
|
|
}
|
||
|
|
|
||
|
|
/**************** ROUTINES NOT EXPORTED, FOLLOW ************************/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function - CalibrateTimerForOverhead (NOT EXPORTED)
|
||
|
|
* Arguments - None
|
||
|
|
* Returns - ULONG
|
||
|
|
*
|
||
|
|
* Calls TimerElapsedTime a few times to compute the expected
|
||
|
|
* mean. Calls TimerElapsedTime more number of times and
|
||
|
|
* averages the mean out of those calls that did not exceed
|
||
|
|
* the expected mean by 15%.
|
||
|
|
*/
|
||
|
|
|
||
|
|
ULONG
|
||
|
|
CalibrateTimerForOverhead (VOID)
|
||
|
|
{
|
||
|
|
ULONG ulOverhead [ITER_FOR_OVERHEAD];
|
||
|
|
ULONG ulTempTotal = 0L;
|
||
|
|
ULONG ulExpectedValue = 0L;
|
||
|
|
SHORT csIter;
|
||
|
|
SHORT csNoOfSamples = ITER_FOR_OVERHEAD;
|
||
|
|
SHORT hTimerHandle;
|
||
|
|
|
||
|
|
if (TimerOpen (&hTimerHandle, MICROSECONDS)) /* open failed. Return 0 */
|
||
|
|
return (0L);
|
||
|
|
|
||
|
|
for (csIter = 0; csIter < 5; csIter++) {
|
||
|
|
TimerInit (hTimerHandle);
|
||
|
|
ulOverhead [csIter] = TimerRead (hTimerHandle);
|
||
|
|
/* if negative, make zero */
|
||
|
|
if (((LONG) ulOverhead [csIter]) < 0)
|
||
|
|
ulOverhead [csIter] = 0L;
|
||
|
|
}
|
||
|
|
/* The get elapsed time function has been called 6 times.
|
||
|
|
The idea is to calculate the expected mean, then call
|
||
|
|
TimerElapsedTime a bunch of times and throw away all times
|
||
|
|
that are 15% larger than this mean. This would give a
|
||
|
|
really good overhead time */
|
||
|
|
|
||
|
|
for (csIter = 0; csIter < 5; csIter++ )
|
||
|
|
ulTempTotal += ulOverhead [csIter];
|
||
|
|
|
||
|
|
ulExpectedValue = ulTempTotal / 5;
|
||
|
|
|
||
|
|
for (csIter = 0; csIter < ITER_FOR_OVERHEAD; csIter++) {
|
||
|
|
TimerInit (hTimerHandle);
|
||
|
|
ulOverhead [csIter] = TimerRead (hTimerHandle);
|
||
|
|
/* if negative, make zero */
|
||
|
|
if (((LONG) ulOverhead [csIter]) < 0)
|
||
|
|
ulOverhead [csIter] = 0L;
|
||
|
|
}
|
||
|
|
|
||
|
|
ulTempTotal = 0L; /* reset this value */
|
||
|
|
for (csIter = 0; csIter < ITER_FOR_OVERHEAD; csIter++ ) {
|
||
|
|
if (ulOverhead [csIter] <= (ULONG) (115L * ulExpectedValue/100L))
|
||
|
|
/* include all samples that is < 115% of ulExpectedValue */
|
||
|
|
ulTempTotal += ulOverhead [csIter];
|
||
|
|
else
|
||
|
|
/* ignore this sample and dec. sample count */
|
||
|
|
csNoOfSamples--;
|
||
|
|
}
|
||
|
|
TimerClose (hTimerHandle);
|
||
|
|
|
||
|
|
if (csNoOfSamples == 0) /* no valid times. Return a 0 for overhead */
|
||
|
|
return (0L);
|
||
|
|
|
||
|
|
return (ulTempTotal/csNoOfSamples);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function - GetTimerFreq (NOT EXPORTED)
|
||
|
|
*
|
||
|
|
* Arguments - None
|
||
|
|
*
|
||
|
|
*
|
||
|
|
* Return - 0 if successful or an error code if timer not aailable
|
||
|
|
*
|
||
|
|
* Calls the function to return freq
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
SHORT
|
||
|
|
GetTimerFreq (VOID)
|
||
|
|
{
|
||
|
|
LARGE_INTEGER PerfCount, Freq;
|
||
|
|
NTSTATUS NtStatus;
|
||
|
|
|
||
|
|
NtStatus = NtQueryPerformanceCounter (&PerfCount, &Freq);
|
||
|
|
|
||
|
|
if ((Freq.LowPart == 0L) && (Freq.HighPart == 0L))
|
||
|
|
/* frequency of zero implies timer not available */
|
||
|
|
return (TIMERERR_NOT_AVAILABLE);
|
||
|
|
|
||
|
|
PerfFreq.LowPart = Freq.LowPart;
|
||
|
|
PerfFreq.HighPart = (LONG) Freq.HighPart;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/***************************************************
|
||
|
|
|
||
|
|
NT native dll init routine
|
||
|
|
|
||
|
|
****************************************************/
|
||
|
|
SHORT csTempCtr; /* a counter - had to make this global..compile fails */
|
||
|
|
ULONG culTemp; /* - do - */
|
||
|
|
|
||
|
|
NTSTATUS
|
||
|
|
TimerDllInitialize (
|
||
|
|
IN PVOID DllHandle,
|
||
|
|
ULONG Reason,
|
||
|
|
IN PCONTEXT Context OPTIONAL
|
||
|
|
)
|
||
|
|
{
|
||
|
|
DllHandle, Context; // avoid compiler warnings
|
||
|
|
|
||
|
|
if (Reason != DLL_PROCESS_ATTACH) { // if detaching return immediately
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (csTempCtr = 0; csTempCtr < MAX_TIMERS; csTempCtr++) {
|
||
|
|
pTimer [csTempCtr].ulLo = 0L;
|
||
|
|
pTimer [csTempCtr].ulHi = 0L;
|
||
|
|
pTimer [csTempCtr].TUnits = TIMER_FREE;
|
||
|
|
}
|
||
|
|
|
||
|
|
bTimerInit = TRUE;
|
||
|
|
GetTimerFreq ();
|
||
|
|
ulTimerOverhead = CalibrateTimerForOverhead ();
|
||
|
|
/* the timer overhead will be placed in a global variable */
|
||
|
|
bCalibrated = TRUE;
|
||
|
|
return TRUE;
|
||
|
|
|
||
|
|
}
|