sigwaitとスレッドのサンプル

sample_thread_sigwait.c

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <pthread.h>

#include <sys/epoll.h>
#include <sys/signalfd.h>

#define EV_MAX 16

bool _epoll_add(int ep, int fd, uintptr_t ptr)
{
    int ret;
    struct epoll_event ev;
    memset(&ev, 0, sizeof(ev));
    ev.events = EPOLLIN;
    if (ptr == 0) {
        ev.data.fd = fd;
    } else {
        ev.data.u64 = ptr;
    }
    ret = epoll_ctl(ep, EPOLL_CTL_ADD, fd, &ev);
    if(ret == -1) {
        return false;
    }

    return true;
}

bool _epoll_del(int ep, int fd)
{
    int ret;
    ret = epoll_ctl(ep, EPOLL_CTL_DEL, fd, NULL);
    if(ret == -1) {
        return false;
    }

    return true;
}

void* th_func(void* param)
{
    int ret;
    int ep_fd = epoll_create(EV_MAX);

    sigset_t sigset;
    sigemptyset(&sigset);
    sigaddset(&sigset, SIGUSR1);
    int s_fd = signalfd(-1, &sigset, 0);
    ret = _epoll_add(ep_fd, s_fd, 0);
    if (ret == false) {
        printf("failed _epoll_add()\n");
        exit(EXIT_FAILURE);
    }

    struct epoll_event ev[EV_MAX];
    for (;;) {
        ret = epoll_wait(ep_fd, ev, EV_MAX, 1000);
        if (ret == -1) {
            // error
        } else if (ret == 0) {
            // timeout unit is [ms]
            printf("thread_timeout: %lu\n", pthread_self());
        } else {
            // ev check
            for (int i=0; i<ret; i++) {
                if (ev[i].data.fd == s_fd) {
                    struct signalfd_siginfo s_buf;
                    ret = read(s_fd, &s_buf, sizeof(s_buf));
                    printf("epoll signal\n");
                } else {
                    ;
                }
            }
        }
    }

    return NULL;
}

static bool _set_signal(sigset_t *sigset)
{
    int ret;
    sigemptyset(sigset);

    ret = sigaddset(sigset, SIGUSR1);
    if(ret == -1) {
        perror("sigaddset");
        return false;
    }

    ret = sigaddset(sigset, SIGHUP);
    if(ret == -1) {
        perror("sigaddset");
        return false;
    }

    ret = sigaddset(sigset, SIGINT);
    if(ret == -1) {
        perror("sigaddset");
        return false;
    }

    ret = sigaddset(sigset, SIGTERM);
    if(ret == -1) {
        perror("sigaddset");
        return false;
    }

    ret = pthread_sigmask(SIG_BLOCK, sigset, NULL);
    if(ret == -1) {
        perror("sigaddset");
        return false;
    }

    return 0;
}

int main()
{
    int ret;
    int retsig;
    sigset_t sigset;

    pthread_t tid;
    pthread_create(&tid, NULL, th_func, NULL);

    ret = _set_signal(&sigset);
    if (ret != 0) {
        printf("failed _set_signal()\n");
        exit(EXIT_FAILURE);
    }

    while (1) {
        ret = sigwait(&sigset, &retsig);
        if (ret == 0){
            printf("retsig:%d\n", retsig);
            break;
        }
    }

    printf("hogehoge\n");
    return 0;
}