/*********************************************************************************
 *      Copyright:  (C) 2025 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  thread.c
 *    Description:  This file is thread example program
 *
 *        Version:  1.0.0(11/04/2025)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "11/04/2025 02:26:44 PM"
 *
 ********************************************************************************/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>

typedef struct worker_ctx_s
{
    int              shared_var;
    pthread_mutex_t  lock1; /* lock for thread1 */
    pthread_mutex_t  lock2; /* lock for thread2 */
} worker_ctx_t;

void *thread_worker1(void *args);
void *thread_worker2(void *args);

int main(int argc, char **argv)
{
    pthread_t        tid;
    pthread_attr_t   thread_attr;
    worker_ctx_t     worker_ctx;

    /* initial worker_ctx and lock  */
    worker_ctx.shared_var = 1000;
    pthread_mutex_init(&worker_ctx.lock1, NULL);
    pthread_mutex_init(&worker_ctx.lock2, NULL);

    /* lock thread2, let threa1 run first */
    pthread_mutex_lock(&worker_ctx.lock2);

    if( pthread_attr_init(&thread_attr) )
    {
        printf("pthread_attr_init() failure: %s\n", strerror(errno));
        return -1;
    }

    if( pthread_attr_setstacksize(&thread_attr, 120*1024) )
    {
        printf("pthread_attr_setstacksize() failure: %s\n", strerror(errno));
        return -1;
    }

    if( pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED) )
    {
        printf("pthread_attr_setdetachstate() failure: %s\n", strerror(errno));
        return -1;
    }

    pthread_create(&tid, &thread_attr, thread_worker1, &worker_ctx);
    printf("Thread worker1 tid[%ld] created ok\n", tid);

    pthread_create(&tid, NULL, thread_worker2, &worker_ctx);
    printf("Thread worker2 tid[%ld] created ok\n", tid);

    pthread_attr_destroy(&thread_attr);

    printf("Main/Control thread shared_var: %d\n", worker_ctx.shared_var);

    /* Wait until thread worker2 exit() */
    pthread_join(tid, NULL);

    while(1)
    {
        sleep(10);
    }

    /* destroy mutex lock */
    pthread_mutex_destroy(&worker_ctx.lock1);
    pthread_mutex_destroy(&worker_ctx.lock2);
    return 0;
}

void *thread_worker1(void *args)
{
    worker_ctx_t   *ctx = (worker_ctx_t *)args;

    if( !args )
    {
        printf("%s() get invalid arguments\n", __FUNCTION__);
        pthread_exit(NULL);
    }

    printf("Thread1 [%ld] start running...\n", pthread_self());

    while(1)
    {
        /* wait for thread1 lock */
        pthread_mutex_lock(&ctx->lock1);

        printf("+++: Thread1 before seelp shared_var: %d\n", ctx->shared_var);
        ctx->shared_var ++;
        sleep(2);
        printf("+++: Thread1 after  seelp shared_var: %d\n", ctx->shared_var);

        /* release thread2 lock */
        pthread_mutex_unlock(&ctx->lock2);
    }

    printf("Thread1 exit...\n");
    return NULL;
}

void *thread_worker2(void *args)
{
    worker_ctx_t   *ctx = (worker_ctx_t *)args;

    if( !args )
    {
        printf("%s() get invalid arguments\n", __FUNCTION__);
        pthread_exit(NULL);
    }

    printf("Thread2 [%ld] start running...\n", pthread_self());

    while(1)
    {
        /* wait for thread2 lock */
        if(0 != pthread_mutex_trylock(&ctx->lock2) )
        {
            continue; /* lock is busy */
        }

        printf("---: Thread2 before seelp shared_var: %d\n", ctx->shared_var);
        ctx->shared_var ++;
        sleep(2);
        printf("---: Thread2 after  seelp shared_var: %d\n", ctx->shared_var);

        /* release thread1 lock */
        pthread_mutex_unlock(&ctx->lock1);
    }

    printf("Thread2 exit...\n");
    return NULL;
}