PROSAGA码农传奇-C/C++-sys / time.h计时器只运行一次

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  <P>
     <code>
      setitimer(ITIMER_REAL,...)
    </code>
     原因
     <code>
      SIGALRM
    </code>
     在计时器到期时被发送到调用进程。
     <code>
      SIGALRM
    </code>
     是一个通常致命的信号，其默认配置是杀死进程。
  </p>
  <P>
    如果你想阻止你的进程被这个信号杀死，你需要以某种方式处理它。
  </p>
  <P>
    示例（根据您的代码每隔100ms从处理程序打印EXPIRED）：
  </p>
   <pre>
    <code>
      #include <sys/time.h>
#include <stdio.h>
#include <stdint.h>
#include <signal.h>
#include <unistd.h>
void handler(int Sig)
{
    (void)Sig;
    char msg[]="EXPIRED\n";
    ssize_t nwr = write(1,msg,sizeof(msg)-1); (void)nwr;
}
int main(void) {
    struct itimerval timer1;
    struct sigaction sa;
    sa.sa_handler = handler;
    sa.sa_flags = 0;
    sigemptyset(&sa.sa_mask);
    sigaction(SIGALRM,&sa,0);

timer1.it_interval.tv_sec = 0;
    timer1.it_interval.tv_usec = 100000;
    timer1.it_value.tv_sec = 0;
    timer1.it_value.tv_usec = 100000 ;
    setitimer(ITIMER_REAL, &timer1, NULL);
    printf( "init interval counter: %ld.%ld\n", timer1.it_interval.tv_sec, 
    timer1.it_interval.tv_usec);
    printf( "init value counter: %ld.%ld\n\n", timer1.it_value.tv_sec, 
    timer1.it_value.tv_usec );

while(1) pause();
    return 0;
}

</code>
  </pre>
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