windows-nt-4.0/private/sdktools/vctools/crt/crtw32/time/clock.c

/***
*clock.c - Contains the clock runtime
*
*	Copyright (c) 1987-1995, Microsoft Corporation. All rights reserved.
*
*Purpose:
*	The clock runtime returns the processor time used by
*	the current process.
*
*Revision History:
*	01-17-87  JCR	Module created
*	06-01-87  SKS	"itime" must be declared static
*	07-20-87  JCR	Changes "inittime" to "_inittime"
*	12-11-87  JCR	Added "_LOAD_DS" to declaration
*	03-20-90  GJF	Made calling type _CALLTYPE1, added #include
*			<cruntime.h> and fixed the copyright. Also, cleaned
*			up the formatting a bit.
*	10-04-90  GJF	New-style function declarators.
*	01-22-91  GJF	ANSI naming.
*	07-25-91  GJF	Added _pinittime definition for new initialization
*			scheme [_WIN32_].
*	03-13-92  SKS	Changed itime from static local to external as
*			a part of return to initializer table scheme.
*			Changed _inittime to __inittime.
*	05-19-92  DJM	POSIX support.
*	04-06-93  SKS	Replace _CRTAPI* with __cdecl
*	10-29-93  GJF	Define entry for initialization section (used to be
*			in i386\cinitclk.asm). Also, deleted old Cruiser
*			support.
*	04-12-94  GJF	Made definition of __itimeb conditional on ndef
*			DLL_FOR_WIN32S.
*	02-10-95  GJF	Appended Mac version of source file (somewhat cleaned
*			up), with appropriate #ifdef-s.
*
*******************************************************************************/

#ifdef	_WIN32


#include <cruntime.h>
#include <stdio.h>
#include <time.h>

#ifdef	_POSIX_
#include <posix/sys/times.h>
#else	/* ndef _POSIX_ */
#include <internal.h>
#include <sys\timeb.h>
#include <sys\types.h>
#endif  /* _POSIX_ */


#ifndef _POSIX_

void __cdecl __inittime(void);

#ifdef	_MSC_VER

#pragma data_seg(".CRT$XIC")
static _PVFV pinit = __inittime;

#pragma data_seg()

#endif	/* _MSC_VER */

#ifndef DLL_FOR_WIN32S
struct _timeb __itimeb = { 0, 0, 0, 0 };
#endif	/* DLL_FOR_WIN32S */

/***
*clock_t clock() - Return the processor time used by this process.
*
*Purpose:
*	This routine calculates how much time the calling process
*	has used.  At startup time, startup calls __inittime which stores
*	the initial time.  The clock routine calculates the difference
*	between the current time and the initial time.
*
*	Clock must reference _cinitime so that _cinitim.asm gets linked in.
*	That routine, in turn, puts __inittime in the startup initialization
*	routine table.
*
*Entry:
*	No parameters.
*	itime is a static structure of type timeb.
*
*Exit:
*	If successful, clock returns the number of CLK_TCKs (milliseconds)
*	that have elapsed.  If unsuccessful, clock returns -1.
*
*Exceptions:
*	None.
*
*******************************************************************************/

clock_t __cdecl clock (
	void
	)
{
	struct _timeb now;
	clock_t elapsed;

	/* Calculate the difference between the initial time and now. */

	_ftime(&now);
	elapsed = (now.time - __itimeb.time) * CLOCKS_PER_SEC;
	elapsed += (int)now.millitm - (int)__itimeb.millitm;
	return(elapsed);

}

/***
*void __inittime() - Initialize the time location
*
*Purpose:
*	This routine stores the time of the process startup.
*	It is only linked in if the user issues a clock runtime call.
*
*Entry:
*	No arguments.
*
*Exit:
*	No return value.
*
*Exceptions:
*	None.
*
*******************************************************************************/

void __cdecl __inittime (
	void
	)
{
	_ftime(&__itimeb);
}

#else   /* _POSIX_ */

/***
*clock_t clock() - Return the processor time used by this process.
*
*Purpose:
*	This routine calculates how much time the calling process
*	has used. It uses the POSIX system call times().
*
*
*Entry:
*	No parameters.
*
*Exit:
*	If successful, clock returns the number of CLK_TCKs (milliseconds)
*	that have elapsed.  If unsuccessful, clock returns -1.
*
*Exceptions:
*	None.
*
*******************************************************************************/

clock_t __cdecl clock (
	void
	)
{
	struct tms now;
	clock_t elapsed;

	elapsed= times(&now);
	if (elapsed == (clock_t) -1)
	    return((clock_t) -1);
	else
	    return(now.tms_utime+now.tms_stime);
}

#endif	/* _POSIX_ */


#else	/* ndef _WIN32 */

#if	defined(_M_MPPC) || defined(_M_M68K)


#include <cruntime.h>
#include <stdio.h>
#include <time.h>
#include <sys\timeb.h>
#include <sys\types.h>
#include <internal.h>

static struct _timeb __itimeb;

/***
*clock_t clock() - Return the processor time used by this process.
*
*Purpose:
*	This routine calculates how much time the calling process
*	has used.  At startup time, startup calls _inittime which stores
*	the initial time.  The clock routine calculates the difference
*	between the current time and the initial time.
*
*	Clock must reference _cinitime so that _cinitim.asm gets linked in.
*	That routine, in turn, puts _inittime in the startup initialization
*	routine table.
*
*Entry:
*	No parameters.
*	itime is a static structure of type timeb.
*
*Exit:
*	If successful, clock returns the number of CLK_TCKs (milliseconds)
*	that have elapsed.  If unsuccessful, clock returns -1.
*
*Exceptions:
*	None.
*
*******************************************************************************/

clock_t __cdecl clock (
	void
	)
{
	struct _timeb now;
	clock_t elapsed;
	
	/* Calculate the difference between the initial time and now. */

	_ftime(&now);
	elapsed = (now.time - __itimeb.time) * CLOCKS_PER_SEC;
	elapsed += (int)now.millitm - (int)__itimeb.millitm;
	return(elapsed);

}



/***
*void _inittime() - Initialize the time location
*
*Purpose:
*	This routine stores the process's time of startup.
*	It is only linked in if the user issues a clock runtime
*	call.
*
*Entry:
*	No arguments.
*
*Exit:
*	No return value.
*
*Exceptions:
*	None.
*
*******************************************************************************/

void __cdecl _inittime (
	void
	)
{
	_ftime(&__itimeb);
}


/***
*time_t _GetApplicationStartTime() - Initialize the time location
*
*Purpose:
*	This routine stores the process's time of startup.
*	It is only linked in if the user issues a clock runtime
*	call.
*
*Entry:
*	No arguments.
*
*Exit:
*	initial application start time.
*
*Exceptions:
*	None.
*
*******************************************************************************/

time_t __cdecl _GetApplicationStartTime (
	void
	)
{
	
	/* The reference to _tzset causes _inittime to be executed at startup time.*/
	_tzset();
	return __itimeb.time ;
}


#endif	/* defined(_M_MPPC) || defined(_M_M68K) */

#endif	/* _WIN32 */