How to execute a handler function before quit the program when receiving kill signal from“killall” or “kill -p pid”?

Question

I have the following code:

#include 
#include 
#include 

pthread_t test_thread;

void *thread_test_run (void *v)         


        

Answer 1

Because killall sends the signal SIGTERM by default, you can handle this type of signal.

#include <signal.h>

void handler(int sig)
{
     /* ... */
}

signal (SIGTERM, handler);

Answer 2

This is how I implement some sort of what you want in my utilite https://github.com/seriyps/wrk/commit/1d3c5dda0d46f0e567f3bae793bb3ae182de9438

static thread *threads;
int main(....){
    ...
    sigint_action.sa_handler = &sig_handler;
    sigemptyset (&sigint_action.sa_mask);
    /* reset handler in case when pthread_cancel didn't stop
       threads for some reason */
    sigint_action.sa_flags = SA_RESETHAND;
    sigaction(SIGTERM, &sigint_action, NULL);
    ...
}
static void sig_handler(int signum) {
    printf("interrupted\n");
    for (uint64_t i = 0; i < cfg.threads; i++) {
        if(pthread_cancel(threads[i].thread)) exit(1);
    }
}