p8-7.c

SUN Solaris8平台下进程间通信

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
volatile sig_atomic_t usr_interrupt = 0;    /* 当到达SIGUSR1信号时设置此变量 */
void synch_signal (int sig)                      /* SIGUSR1信号句柄 */
{
   usr_interrupt = 1;
}
/* 子进程执行此函数 */
void child_function (void)
{
    printf ("I'm here!!!  My pid is %d.\n", (int) getpid ());
     /* 通知父进程 */
    kill (getppid(), SIGUSR1);
     /* 继续执行 */
    puts ("Bye, now....");
    exit (EXIT_SUCCESS);
}
int main(void)
{
    struct sigaction usr_action;
    sigset_t block_mask;
    pid_t child_id;     
    /* 建立信号句柄 */
    sigfillset (&block_mask);
    usr_action.sa_handler = synch_signal;
    usr_action.sa_mask = block_mask;
    usr_action.sa_flags = 0;
    sigaction (SIGUSR1, &usr_action, NULL);  
    /* 创建子进程 */
    child_id = fork ();
    if (child_id == 0)
        child_function();          /* 子进程不返回 */
    /* 等待子进程发送信号 */
    while (!usr_interrupt) ;     
    /* 收到信号后继续执行 */
    puts ("That's all!");     
    return 0;
}