ack/lang/cem/libcc.ansi/time/clock.c

/*
 * clock - determine the processor time used
 */
/* $Id$ */

#include <time.h>

#if defined(__BSD4_2)

#define RUSAGE_SELF 0
#define RUSAGE_CHILDREN -1

struct rusage
{
	struct timeval ru_utime; /* user time used */
	struct timeval ru_stime; /* system time used */
	long ru_maxrss;
	long ru_ixrss; /* integral shared memory size */
	long ru_idrss; /* integral unshared data size */
	long ru_isrss; /* integral unshared stack size */
	long ru_minflt; /* page reclaims */
	long ru_majflt; /* page faults */
	long ru_nswap; /* swaps */
	long ru_inblock; /* block input operations */
	long ru_oublock; /* block output operations */
	long ru_msgsnd; /* messages sent */
	long ru_msgrcv; /* messages received */
	long ru_nsignals; /* signals received */
	long ru_nvcsw; /* voluntary context switches */
	long ru_nivcsw; /* involuntary context switches */
};

void _getrusage(int who, struct rusage* rusage);

#elif defined(_POSIX_SOURCE) || defined(__USG)

struct tms
{
	time_t tms_utime; /* user time */
	time_t tms_stime; /* system time */
	time_t tms_cutime; /* user time, children */
	time_t tms_cstime; /* system time, children */
};

long _times(struct tms* buffer);

#else /* Version 7 UNIX */

struct tbuffer
{
	long proc_user_time;
	long proc_system_time;
	long child_user_time;
	long child_system_time;
};

long _times(struct tbuffer* buffer);

#endif

clock_t
clock(void)
{
#if defined(__BSD4_2)
	struct rusage rusage;

	_getrusage(RUSAGE_SELF, &rusage);

	return (((unsigned long)rusage.ru_utime.tv_sec * CLOCKS_PER_SEC)
	    + rusage.ru_utime.tv_usec);
#elif defined(_POSIX_SOURCE) || defined(__USG)
	struct tms tms;

	_times(&tms);
	/* Assume that time_t can be converted to clock_t for Sys5 */
	return tms.tms_utime;
#else
	struct tbuffer tbuffer;

	_times(&tbuffer);
	return tbuffer.proc_user_time;
#endif
}