/* * (C) Finite State Machine Labs Inc. 2000 business@fsmlabs.com * * Released under the terms of GPL 2. * Open RTLinux makes use of a patented process described in * US Patent 5,995,745. Use of this process is governed * by the Open RTLinux Patent License which can be obtained from * www.fsmlabs.com/PATENT or by sending email to * licensequestions@fsmlabs.com */#include <stdio.h>#include <errno.h>#include <rtlinux_signal.h>/* number of tests to run */#define NUM_TESTS	32/* time between each test */#define HANGTIME	(NSECS_PER_SEC / 32)hrtime_t all_times[NUM_TESTS];volatile int testnum;void myhandler(int whatever){	if (testnum < NUM_TESTS) {		all_times[testnum] = gethrtime();		testnum++;	}}int main(void){	struct rtlinux_sigaction mysig, oldsig;	hrtime_t cur_drift, avg_drift, diff_time, worst_drift;	int i;	worst_drift = 0;	avg_drift = 0;	testnum = 0;	mysig.sa_handler = myhandler;	mysig.sa_flags = RTLINUX_SA_PERIODIC;	mysig.sa_period = HANGTIME;	if ((rtlinux_sigaction(RTLINUX_SIGTIMER0, &mysig, &oldsig))) {		perror("rtlinux_sigaction");		return (-1);	}	while (testnum < NUM_TESTS)		sleep(1);	mysig.sa_handler = RTLINUX_SIG_IGN;	if ((rtlinux_sigaction(RTLINUX_SIGTIMER0, &mysig, &oldsig))) {		perror("rtlinux_sigaction");		return (-1);	}	for (i = 1; i < NUM_TESTS; i++) {		diff_time = all_times[i] - all_times[i - 1];		cur_drift =		    (diff_time <		     HANGTIME) ? (HANGTIME -				  diff_time) : (diff_time - HANGTIME);		avg_drift += cur_drift;		worst_drift =		    (worst_drift < cur_drift) ? cur_drift : worst_drift;	}	avg_drift /= NUM_TESTS;	/* check to see if the worst case time was 50000 nanoseconds (50	 * microseconds) or more */	fprintf(stderr,		"avg_drift: %d.%02d us\tworst_drift: %d.%02d us\n",		(long) avg_drift / 1000, (long) (avg_drift % 1000) / 10,		(long) worst_drift / 1000,		(long) (worst_drift % 1000) / 10);	if (worst_drift >= 50000) {		return (-1);	}	return (0);}