example 2

/*
Output:
###############################################################################
PID = [6606]
th1 = 140563186882304

The signal handler for thread: '140563186882304' receive: SIGUSR1
SIGUSR2 was received
th1 = exit
###############################################################################
*/

#include <iostream>
#include <pthread.h>
#include <signal.h>
#include <string.h>
#include <sstream>

void hdl(int sig)
{
    std::cout << std::endl;

    std::string signal;
    if(sig == SIGUSR1)
        signal = "SIGUSR1";
    else if(sig == SIGUSR2)
        signal = "SIGUSR2";
    else
        signal = "Something else";

    std::cout << "The signal handler for thread: '" << pthread_self() << "' receive: " << signal << std::endl;
}

void show_me(void* arg)
{
    std::stringstream str;
    str << (char*)arg << " = " << pthread_self() << std::endl;
    std::cout << str.str();
}

void show_exit(void* arg)
{
    std::stringstream str;
    str << (char*)arg << " = " << "exit" << std::endl;
    std::cout << str.str();
}

void show_signal(int sig)
{
    if(sig == SIGUSR1)
        std::cout << "SIGUSR1 was received\n";
    else if(sig == SIGUSR2)
        std::cout << "SIGUSR2 was received\n";
    else
        std::cout << "Received = " << sig << std::endl;
}

void* th_wait(void* arg)
{
    show_me(arg);

    sigset_t   set;
    sigemptyset(&set);
    sigaddset(&set, SIGUSR2);

    int sig;
    sigwait(&set, &sig);
    show_signal(sig);

    show_exit(arg);
    pthread_exit((void *)0);
}

int main()
{
    std::cout << "PID = [" << getpid() << "]" << std::endl;

    struct sigaction act;
    memset(&act, 0, sizeof(act));
    act.sa_handler = hdl;
    sigset_t   set;
    sigemptyset(&set);
    sigaddset(&set, SIGUSR1);
    sigaddset(&set, SIGUSR2);
    act.sa_mask = set;
    sigaction(SIGUSR1, &act, 0);
    sigaction(SIGUSR2, &act, 0);

    pthread_t th1;

    char s_th_1[] = "th1";

    pthread_create(&th1, NULL, th_wait, (void*)s_th_1);

    sleep(2);
    pthread_kill(th1, SIGUSR1);
    pthread_kill(th1, SIGUSR2);

    pthread_join(th1, NULL);
}