代码如下：
#include

include

include

include

include

include

include

include

int main()
{

while(1)
{
    struct timeval stStart, stEnd;
    gettimeofday(&stStart, NULL);

    struct timeval tv={0, 33000};
    select(0,NULL,NULL,NULL,&tv);

    gettimeofday(&stEnd, NULL);
    unsigned int iDelayUseTime = ((stEnd.tv_sec-stStart.tv_sec)*1000*1000+(stEnd.tv_usec-stStart.tv_usec));

    printf("use time:%u\n", iDelayUseTime);
    if(iDelayUseTime < 30000 || 35000 < iDelayUseTime)
        exit(0);
}

return 0;

}

运行结果：