#include <stdio.h> #include <pthread.h> pthread_mutex_t Device_mutex ; int count=0; void thread_func1() {    while(1)    {        pthread_mutex_lock(&Device_mutex);        printf("thread1: %d\n",count);        pthread_mutex_unlock(&Device_mutex);        count++;        sleep(1);    } } void thread_func2() {    while(1)    {        pthread_mutex_lock(&Device_mutex);        printf("thread2: %d\n",count);        pthread_mutex_unlock(&Device_mutex);        count++;        sleep(1);    } } int main() {    pthread_t thread1, thread2;    pthread_mutex_init(&Device_mutex,NULL);    if(pthread_create(&thread1,NULL,(void*)thread_func1,NULL) == -1)  {   printf("create IP81 Thread error !\n");   exit(1);  }  sleep(1);  if(pthread_create(&thread2,NULL,(void *)thread_func2,NULL) == -1)  {   printf("create IP81_2 Thread error!\n");   exit(1);  }  sleep(1);  pthread_join(thread1,NULL);  pthread_join(thread2,NULL);  pthread_mutex_destroy(&Device_mutex);  return 0; }