linux下信号处理函数实现的一点理解

linux下信号处理函数实现的一点理解

代码操作步骤如下：

[tqg@localhost test]$ vi test.cpp

#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>

void signal_handler(int sig)
{
        printf("catch signal: %d,thread id = %u\n",sig,pthread_self());
        pthread_exit(0);
}

void* thread_handler(void*arg)
{
        signal(SIGQUIT,signal_handler);

        printf("thread arg = %s\n",(char*)arg);

        sleep(10);
        printf("in thread\n");

        return (void*)0;
}

int main()
{
        char* pArg = "hello";
        pthread_t tid;
        pthread_create(&tid,NULL,thread_handler,pArg);

        printf("main thread id = %u\n",pthread_self());
        sleep(2);

        printf("killing now\n");
        pthread_kill(tid,SIGQUIT);

        sleep(20);

        printf("exit main now\n");

        return 0;
}
~
~
~
~
"test.cpp" 42L, 648C written
[tqg@localhost test]$ g++ -o test test.cpp -lpthread
[tqg@localhost test]$ ./test
main thread id = 3086875296
thread arg = hello
killing now
catch signal: 3,thread id = 3086871472
exit main now
[tqg@localhost test]$

可以看出，信号处理函数的执行是在要捕获信号的子线程thread_handler的上下文中执行的。