oneshot_monitor.c

fsmlabs的real time linux的内核

/*
 * (C) Finite State Machine Labs Inc. 1999 [e-mail]
 *
 * 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
 * [e-mail]
 */

#include <stdio.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <rtl_fifo.h>
#include <rtl_time.h>

struct samp {
	hrtime_t min, max, total;
	hrtime_t period;
	int cnt;
};

int main()
{
	int fd0;
	int n;
	struct samp sm;
	FILE *f;
	int i = 0;

	if ((fd0 = open("/dev/rtf0", O_RDONLY)) < 0) {
		fprintf(stderr, "Error opening /dev/rtf0\n");
		exit(1);
	}

	while (i < 50) {
		n = read(fd0, &sm, sizeof(sm));
#define NS_TO_US(x) ((x)/(NSECS_PER_SEC/1000000))
		if (
		    ((ulong) NS_TO_US((int) sm.min - (int) sm.period) <
		     -30)
		    || ((ulong) NS_TO_US((int) sm.max - (int) sm.period) >
			30)) exit - 1;
		i++;
#if 0
		printf
		    ("min: %5ldus \tavg: %5ldus \tmax: %5ldus \tperiod: %5ldus\n",
		     (ulong) NS_TO_US((int) sm.min - (int) sm.period),
		     (ulong) NS_TO_US(((int) sm.total / (int) sm.cnt) -
				      (int) sm.period),
		     (ulong) NS_TO_US((int) sm.max - (int) sm.period),
		     (ulong) NS_TO_US((int) sm.period));
		fflush(stdout);
		fprintf(f, "%d %ld %5ld %5ld %5ld\n",
			i, (ulong) NS_TO_US((int) sm.min /*-sm.period*/ ),
			(ulong) NS_TO_US(((int) sm.total / (int) sm.cnt) /*-sm.period*/ ),
			(ulong) NS_TO_US((int) sm.max /*-sm.period*/ ),
			(ulong) NS_TO_US((int) sm.period));
		fflush(f);
#endif
	}

	return 0;
}