sigsetjmp函数

sigsetjmp.c文件

#include <unistd.h>
#include <setjmp.h>
#include <stdlib.h>
#include <stdlib.h>
#include <signal.h>

static jmp_buf env_alrm;

void alarm_fun()
{
    printf("time out/n");
    siglongjmp(env_alrm,1);
}

int test_alrm()
{
    int test_value = 0;
    signal(SIGALRM,alarm_fun);
    if ( sigsetjmp(env_alrm, 1) != 0 )
     {
            alarm( 0 );
            signal( SIGALRM, SIG_IGN );
            return -1; /* timeout */
     }
    alarm(5);//5 sec;
    sleep(10);//改变这里看效果
    alarm(0);
    signal( SIGALRM, SIG_IGN );//忽略信号
    return 1;
}

int main()
{
    printf("%d",test_alrm());
    return 0;
}

sigsetjmp2.c文件

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

sigjmp_buf jmp_env;

static void alarm_fun(int signo);

int main(int argc, char * * argv)
{
    /*当超时时间sec_timeout大于等于运行时间run_time时会跳过printf("running...\n"); */
    int sec_timeout = 3;
    int run_time = 5;
    int ret = -1;

    printf("timeout = %d, run time = %d\n", sec_timeout, run_time);

    /*超过用alarm函数设置的时间时产生此信号，调用connect_alarm函数 */
    signal(SIGALRM, alarm_fun);

    printf("设置超时\n");

    ret = sigsetjmp(jmp_env, 1);
    if(ret == 0)
    {
        printf("*******ret = [%d]**********\n", ret);
        printf("直接调用sigsetjmp()函数，已经做好标记！\n");
    }
    if(ret == 1)
    {
        printf("*******ret = [%d]**********\n", ret);
        printf("由siglongjmp()函数跳转回来！\n");
        goto out;
    }
    alarm(sec_timeout);

      printf("running1...\n");
    sleep(run_time);
    printf("running2...\n");
    return 0;

out:
    /*取消先前设置的闹钟*/
    alarm(0);
    printf("取消超时！\n");
    return 0;

}

static void alarm_fun(int signo)
{
    printf("收到超时信号！\n");
    siglongjmp(jmp_env, 1);
    return;
}