signal

Code

#include <signal.h>
#include <errno.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/types.h>
void sig_handler(int signum)
{
    static int j = 0;
    static int k = 0;
    static int m = 0;
    pthread_t  sig_ppid = pthread_self(); 
    // used to show which thread the signal is handled in.
    if (signum == SIGUSR1) {
        printf("thread %ld, receive SIGUSR1 No. %d\n", sig_ppid, j);
        j++;
    //SIGRTMIN should not be considered constants from userland, 
    //there is compile error when use switch case
    } else if (signum == SIGRTMIN) {
        printf("thread %ld, receive SIGRTMIN No. %d\n", sig_ppid, k);
        k++;
    } else if(signum == 60)
    {
        //printf("thread %ld, receive SIG119 No. %d\n", sig_ppid, m);
        m++;
    }
}
/*
void* worker_thread()
{
    pthread_t  ppid = pthread_self();
    pthread_detach(ppid);
    while (1) {
        printf("I'm thread %d, I'm alive\n", ppid);
        sleep(10);
    }
}*/
void* sigmgr_thread(void *pwaitset)
{
    sigset_t   waitset, oset;
    sigset_t   *pwaitsetEx = (sigset_t *)pwaitset;
    siginfo_t  info;
    int        rc, i;
    pthread_t  ppid = pthread_self();
    pthread_detach(ppid);
    printf("I'm thread %d, I'm alive\n", ppid);
    sigemptyset(&waitset);
    sigaddset(&waitset, SIGRTMIN);
    sigaddset(&waitset, SIGUSR1);
    sigaddset(&waitset, 60);
    if (pthread_sigmask(SIG_BLOCK, &waitset, &oset) != 0)  //信号屏蔽
        printf("!! Set pthread mask failed\n");
    while (1)  {
        rc = sigwaitinfo(&waitset, &info);
        if (rc != -1) {
            printf("sigwaitinfo() fetch the signal - %d\n", rc);
            sig_handler(info.si_signo);
        } else {
            printf("sigwaitinfo() returned err: %d; %s\n", errno, strerror(errno));
        }
    }
}
int main()
{
    sigset_t bset, oset;
    int             i, rc;
    pid_t           pid = getpid();
    pthread_t       ppid;
    siginfo_t  info;
    // Block SIGRTMIN and SIGUSR1 which will be handled in 
    //dedicated thread sigmgr_thread()
    // Newly created threads will inherit the pthread mask from its creator 
    sigemptyset(&bset);
    sigaddset(&bset, SIGRTMIN);
    sigaddset(&bset, SIGUSR1);
    sigaddset(&bset, 60);  //自定义信号量     
    if (pthread_sigmask(SIG_BLOCK, &bset, &oset) != 0)  //信号屏蔽
        printf("!! Set pthread mask failed\n");
    // Create the dedicated thread sigmgr_thread() which will handle 
    // SIGUSR1 and SIGRTMIN synchronously
    pthread_create(&ppid, NULL, sigmgr_thread, (void *)&bset);
    // Create 5 worker threads, which will inherit the thread mask of
    // the creator main thread
    /*
    for (i = 0; i < 5; i++) {
        pthread_create(&ppid, NULL, worker_thread, NULL);
    }*/
    while (1)  {
        rc = sigwaitinfo(&bset, &info);
        if (rc != -1) {
            printf("sigwaitinfo() fetch the signal - %d\n", rc);
            sig_handler(info.si_signo);
        } else {
            printf("sigwaitinfo() returned err: %d; %s\n", errno, strerror(errno));
        }
    }
    // send out 50 SIGUSR1 and SIGRTMIN signals
    for (i = 0; i < 500; i++) {
           //kill(pid, SIGUSR1);
        sleep(10);
    }
    exit (0);
}

http://blog.csdn.net/i_am_jojo/article/details/7592219