periodic_handler.c

fsmlabs的real time linux的内核

/* vim: set ts=4: */
/*
 * Written by Der Herr Hofrat <[e-mail]>
 * Copyright Der Herr Hofrat 
 * Released under GPL V2
 */
/*
 * call a user-space allplication signal handler under control of an rt-clock 
 * source (periodic rt-thread actually). 
 */

#include <stdio.h>
#include <rtlinux_signal.h>

#define PERIOD 50000 /* period in nanoseconds */

void my_handler(int);
struct rtlinux_sigaction sig, oldsig;
long long rt_count=0;

int main(void) 
{
	int i=0;
	sig.sa_handler = my_handler;
	sig.sa_flags = RTLINUX_SA_PERIODIC;
	sig.sa_period = PERIOD;

	if(rtlinux_sigaction(RTLINUX_SIGTIMER0,&sig,&oldsig))
 	{
		fprintf(stderr,"errore creating signal handler\n");
		return -1;
	}
	/* keep the handler active for 10 seconds then reset it and exit 
	 * note that the loop takes longer than one second as the loop 
	 * time is sleep(1) + loop overhead - you actually can "measure" 
	 * the loop overhead by running the same handler for 10 seconds
	 * without the while loop and compare the number of timer-invocations
	 */
	while(i++<10){
		sleep(1);
		printf("periodic handler called %lld times\n",rt_count);
	}

//	sleep(10); /* instead of the while() loop above */
//	printf("periodic handler called %lld times\n",rt_count);

	/* reset the handler befor exiting */ 
	sig.sa_handler = RTLINUX_SIG_IGN;
	return 0;
}

void my_handler(int argument)
{
	rt_count++;
}