timer.c

基于ARM9嵌入式开发板LINUX环境下的程序代码－linux-timer

/*
****************************************Copyright (c)**************************************************
**                               Guangzhou Zhiyuan Electronic Co.,LTD.
**                                     graduate school
**                                 http://www.zyinside.com
**
**------------------------------------- File Info ------------------------------------------------------
** File name:           timer.c
** Last modified Date:  2005-12-29
** Last Version:        1.0
** Descriptions:        Demo for Linux timer.
**------------------------------------------------------------------------------------------------------
** Created by:          Chenxibing
** Created date:        2005-12-29
** Version:             1.0
** Descriptions:        Preliminary version.
**
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Descriptions:
**
********************************************************************************************************
*/
#include <stdio.h>
#include <signal.h>
#include <sys/time.h>
//#include <fcntl.h>

/*
*******************************************************************************************************
** Function name: main()
** Descriptions	: Demo for timer.
** Input	: NONE
** Output	: NONE
** Created by	: Chenxibing
** Created Date	: 2005-12-29
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/
int limit = 10;
/* signal process */
void timeout_info(int signo)
{
    if(limit == 0)
    {
        printf("Sorry, time limit reached.\n");
	exit(0);
    }
    printf("only %d senconds left.\n", limit--);
}

/* init sigaction */
void init_sigaction(void)
{
    struct sigaction act;

    act.sa_handler = timeout_info;
    act.sa_flags   = 0;
    sigemptyset(&act.sa_mask);
    sigaction(SIGPROF, &act, NULL);
} 

/* init */
void init_time(void)
{
    struct itimerval val;

    val.it_value.tv_sec = 1;
    val.it_value.tv_usec = 0;
    val.it_interval = val.it_value;
    setitimer(ITIMER_PROF, &val, NULL);
}


int main(void)
{
    char *str;
    char c;

    init_sigaction();
    init_time();
    printf("You have only 10 seconds for thinking.\n");

    while(1);
    exit(0);
}