// https://syzkaller.appspot.com/bug?id=7579624a9731e0731cf1ae7736c43ba25c911e9a
#include <sys/inotify.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

int inotify_fd;
volatile int current_wd = -1;
volatile int stop = 0;

void *adder_thread(void *arg) {
    while (!stop) {
        int wd = inotify_add_watch(inotify_fd, "testfile", IN_CLOSE_WRITE | IN_CLOSE_NOWRITE);
        if (wd >= 0) {
            current_wd = wd;
        }
    }
    return NULL;
}

void *remover_thread(void *arg) {
    while (!stop) {
        int wd = current_wd;
        if (wd >= 0) {
            inotify_rm_watch(inotify_fd, wd);
        }
    }
    return NULL;
}

void *closer_thread(void *arg) {
    while (!stop) {
        int fd = open("testfile", O_RDONLY);
        if (fd >= 0) {
            close(fd);
        }
    }
    return NULL;
}

int main() {
    int res;
    
    inotify_fd = inotify_init();
    if (inotify_fd < 0) {
        printf("[-] Failed to inotify_init: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] inotify_init successful.\n");
    
    int fd = open("testfile", O_CREAT | O_RDWR, 0666);
    if (fd < 0) {
        printf("[-] Failed to open: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] open successful.\n");
    
    res = close(fd);
    if (res < 0) {
        printf("[-] Failed to close: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] close successful.\n");
    
    pthread_t t1, t2, t3;
    res = pthread_create(&t1, NULL, adder_thread, NULL);
    if (res != 0) {
        printf("[-] Failed to pthread_create t1: %s\n", strerror(res));
        exit(1);
    }
    printf("[+] pthread_create t1 successful.\n");

    res = pthread_create(&t2, NULL, remover_thread, NULL);
    if (res != 0) {
        printf("[-] Failed to pthread_create t2: %s\n", strerror(res));
        exit(1);
    }
    printf("[+] pthread_create t2 successful.\n");

    res = pthread_create(&t3, NULL, closer_thread, NULL);
    if (res != 0) {
        printf("[-] Failed to pthread_create t3: %s\n", strerror(res));
        exit(1);
    }
    printf("[+] pthread_create t3 successful.\n");

    sleep(5);
    stop = 1;
    
    res = pthread_join(t1, NULL);
    if (res != 0) {
        printf("[-] Failed to pthread_join t1: %s\n", strerror(res));
        exit(1);
    }
    printf("[+] pthread_join t1 successful.\n");

    res = pthread_join(t2, NULL);
    if (res != 0) {
        printf("[-] Failed to pthread_join t2: %s\n", strerror(res));
        exit(1);
    }
    printf("[+] pthread_join t2 successful.\n");

    res = pthread_join(t3, NULL);
    if (res != 0) {
        printf("[-] Failed to pthread_join t3: %s\n", strerror(res));
        exit(1);
    }
    printf("[+] pthread_join t3 successful.\n");
    
    res = close(inotify_fd);
    if (res < 0) {
        printf("[-] Failed to close inotify_fd: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] close inotify_fd successful.\n");
    
    res = unlink("testfile");
    if (res < 0) {
        printf("[-] Failed to unlink: %s\n", strerror(errno));
        exit(1);
    }
    printf("[+] unlink successful.\n");
    
    return 0;
}