typedef void (*sigaction_func)(int, siginfo_t*, void*);
static void signal_handler(int signo, siginfo_t* siginfo, void* context)
{
    ……
}

static sigaction_func signal_install_handler(void)
{
    struct sigaction act, oact;
    sigemptyset(&act.sa_mask);
    act.sa_sigaction = signal_handler;
    act.sa_flags = 0;
    act.sa_flags |= SA_SIGINFO;  // 使用3个参数的信号处理函数
    act.sa_flags |= SA_RESTART;  // 信号返回时，重新调研系统函数。

    if (sigaction(RES_SIGNAL, &act, &oact) < 0) {
        errmsg("not able to set up signal action handler");
    }

    /* Return previously installed handler */
    return oact.sa_sigaction;
}