Block signal

在下面文章中，对此进行了介绍:

1、"man signal(7) # Signal mask and pending signals"

2、csdn Linux网络编程--select()和pselect()函数

#include<unistd.h>
#include<sys/time.h>
#include<sys/types.h>
#include <signal.h>
int sigint_event = 0;
void sigint_sig_handler(int s)
{ //设置信号处理函数
    sigint_event++;
    signal(SIGINT, sigint_sig_handler);
}
int main()
{
    int r;
    fd_set rd;
    FD_ZERO(&rd); //清空读描述符集合
    FD_SET(0, &rd); //将标准输入放入读描述符集合
    sigset_t sigmask, orignal_sigmask; //设置新掩码和保存原始掩码
    sigemptyset(&sigmask); //清空信号
    sigaddset(&sigmask, SIGINT); //将SIGINT信号加入sigmask中
    //设置信号SIG_BLOCK的掩码sigmask，并将原始的掩码保存在orignal_sigmask中
    sigprocmask(SIG_BLOCK, &sigmask, &orignal_sigmask);
    signal(SIGINT, sigint_sig_handler);    //挂接信号处理函数
    for (;;)
    {
        for (; sigint_event > 0; sigint_event--)
        {
            printf("sigint_event[%d]\n", sigint_event);
        }
        r = pselect(1, &rd, NULL, NULL, NULL, &orignal_sigmask);    //pselect函数IO复用
        if (r == -1)
        {
            perror("pselect");
        }
        else if (r)
        {
            printf("Data is avaialble now\n");
        }
        else
        {
            printf("NO Data within five seconds\n");
        }
        sleep(1);
    }
    return 0;
}

3、cnblogs pselect 和 select

sigset_t new, old, zero;

sigemptyset (&zero);
sigemptyset(&new);
sigaddset(&new, SIGINT);
sigprocmask(SIG_BLOCK, &new, old); //block SIGINT
if (intr_flag)
handle_intr();//handle the signal
if ((nready = pselet(..., &zero)) < 0)
{
    if (errno = EINTR)
    {
        if (intr_flag)
        handle_intr();
    }
    ...
}

see also

stackoverflow How to block signals in C?