#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <stdint.h>
#include <signal.h>
#include <errno.h>
#include <pthread.h>
#include <sys/wait.h>

static void *thread_func(void *arg __attribute__ ((unused)))
{
    while (1) {
	/* do nothing */
    }
    return NULL;
}

static void setup_main_signals(void)
{
    pthread_t tid;
    struct sigaction sa;
    sigset_t *s = malloc(sizeof(*s));
    if (!s) {
	perror("malloc");
	exit(1);
    }
    sigfillset(s);
    pthread_sigmask(SIG_SETMASK, s, NULL);

    memset(&sa, 0, sizeof(sa));
    sigfillset(&sa.sa_mask);
    sa.sa_handler = SIG_IGN;
    sigaction(SIGINT, &sa, NULL);
    sigaction(SIGTERM, &sa, NULL);
    sigaction(SIGHUP, &sa, NULL);
    sigaction(SIGQUIT, &sa, NULL);

    sigemptyset(s);
    sigaddset(s, SIGINT);
    sigaddset(s, SIGTERM);
    sigaddset(s, SIGHUP);
    sigaddset(s, SIGQUIT);
    pthread_sigmask(SIG_SETMASK, s, NULL);
    if (pthread_create(&tid, NULL, thread_func, s) < 0) {
	perror("pthread_create");
	exit(1);
    }
}

void cleanup_and_exit(void)
{
    const char *test1 = "./test1";
    fprintf(stderr, "cleanup and exit\n");
    if (execlp(test1, basename (test1), "-d", NULL) < 0) {
	perror(test1);
	_exit(1);
    }
    _exit(0);
}

int main(int argc __attribute__ ((unused)), char **argv)
{
    char *prog = argv[0];

    fprintf(stderr, "%s: uid = %d, euid = %d\n", prog, (int)getuid(),
	    (int)geteuid());

    setup_main_signals();

    cleanup_and_exit();
    return 0;
}