timer.c

该源码是创维特ARM7 JX44B0X板的例子程序

#include <stdio.h>
#include <sys/time.h>
#include <signal.h>

struct timeval tpstart,tpend;
float  timeuse;
static timer_count = 0;

void prompt_info(int signo)
{
    time_t t = time(NULL);
    /* [1] 2 seconds turned, print something */
    printf("[%d] prompt_info called\n", ++timer_count);
    /* [2] get current time and print it */
    ctime(&t);
    printf("    current time %s", ctime(&t));  
    /* [3] stop get time, and print it */
    gettimeofday(&tpend,NULL);
    timeuse=1000000*(tpend.tv_sec-tpstart.tv_sec)+tpend.tv_usec-tpstart.tv_usec;
    timeuse/=1000000;
    printf("    Used Time:%f\n",timeuse); 
} 

void init_sigaction(void)
{
    struct sigaction act;
    act.sa_handler=prompt_info;
    act.sa_flags=0;
    sigemptyset(&act.sa_mask);
    sigaction(SIGPROF,&act,NULL);

    /* begin get the time */
    gettimeofday(&tpstart,NULL);
}

void init_time()
{
    struct itimerval value;
    value.it_value.tv_sec=2;
    value.it_value.tv_usec=0;
    value.it_interval=value.it_value;
    setitimer(ITIMER_PROF,&value,NULL);
}

/*
 * timer application code
 * compile :
 *          $arm-elf-gcc -Wl,-elf2flt -o timer timer.c
 *          $cp timer /tftpboot/examples
 * run in target:
 *          #cd /var
 *          #ftp 192.168.1.180
 *          ftp>bin
 *          ftp>cd /tftpboot/examples
 *          ftp>get timer
 *          ftp>by 
 *          #./timer
 */
int main(int argc, char **argv)
{
    init_sigaction();
    init_time();
    while(1);
    exit(0);
}