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

volatile sig_atomic_t got_sigalrm = 0;

void sigalrm_handler(int sig) {
    got_sigalrm = 1;
    printf("SIGALRM handler called\n");
}

int main() {
    printf("sigwaitinfo interruption test\n");
    
    sigset_t sigset;
    siginfo_t info;
    int target_signal = SIGUSR1;
    
    // Set SIGALRM handler
    struct sigaction sa = {0};
    sa.sa_handler = sigalrm_handler;
    sigaction(SIGALRM, &sa, NULL);
    
    // Block SIGUSR1 and save old mask
    sigemptyset(&sigset);
    sigaddset(&sigset, target_signal);
    pthread_sigmask(SIG_BLOCK, &sigset, NULL);
    printf("Blocked SIGUSR1, waiting with sigwaitinfo...\n");
    
    pid_t pid = fork();
    if (pid == 0) {
        sleep(1);
        printf("Child: sending SIGALRM to interrupt parent\n");
        kill(getppid(), SIGALRM);
        exit(0);
    }
    
    printf("Parent: calling sigwaitinfo([SIGUSR1])...\n");
    int result = sigwaitinfo(&sigset, &info);
    
    if (result == -1) {
        printf("sigwaitinfo failed: errno = %d (%s)\n", errno, strerror(errno));
    }
    
    printf("SIGALRM handler was called: %s\n", got_sigalrm ? "yes" : "no");
    
    int status;
    waitpid(pid, &status, 0);
    printf("Child exited with status: %d\n", WEXITSTATUS(status));
    
    return 0;
}