/*********************************************************************************
 *      Copyright:  (C) 2025 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  deadlock.c
 *    Description:  This file is deadlock example program.
 *
 *        Version:  1.0.0(11/04/2025)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "11/04/2025 05:43:15 PM"
 *
 ********************************************************************************/

#include <stdio.h>
#include <unistd.h>
#include <pthread.h>

pthread_mutex_t lock1 = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t lock2 = PTHREAD_MUTEX_INITIALIZER;

void *thread1(void *arg)
{
    pthread_mutex_lock(&lock1);    // 获取锁1
    sleep(1);                      // 确保thread2能获取锁2
    pthread_mutex_lock(&lock2);    // 请求锁2 → 死锁！
    printf("Thread1 got both locks\n");
    pthread_mutex_unlock(&lock2);
    pthread_mutex_unlock(&lock1);
    return NULL;
}

void *thread2(void *arg)
{
    pthread_mutex_lock(&lock2);    // 获取锁2
    sleep(1);                      // 确保thread1能获取锁1
    pthread_mutex_lock(&lock1);    // 请求锁1 → 死锁！
    printf("Thread2 got both locks\n");
    pthread_mutex_unlock(&lock1);
    pthread_mutex_unlock(&lock2);
    return NULL;
}


int main (int argc, char **argv)
{
    pthread_t t1, t2;

    pthread_create(&t1, NULL, thread1, NULL);
    pthread_create(&t2, NULL, thread2, NULL);

    pthread_join(t1, NULL);
    pthread_join(t2, NULL);
    return 0;
}