/* * Periodic timing measurement for RTLinux. * * Copyright (C) 1999 FSM Labs (http://www.fsmlabs.com/) *  Written by Cort Dougan <cort@fsmlabs.com> */#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);	}	if ( (f = fopen("gnuplot.out", "w")) == NULL )	{		fprintf(stderr,"Cannot open gnuplot.out\n");		perror("open");		exit(-1);	}	while (i < 50)	{		n = read(fd0, &sm, sizeof(sm));#define NS_TO_US(x) ((x)/(NSECS_PER_SEC/1000000))		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);		i++;		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);	}	return 0;}