求助 linux下创建多线程 为何不能多次创建？
void* pthread_http(void *arg)//发送http请求并libxml解析函数
{
     ......  //略去定义
    while(1)
    {
        sleep(1);
        sem_wait(&empty_sem);
        pthread_mutex_lock(&mutex);
                                
        ParseRootFile(http,&param); //该函数中可以发送http请求
        in = in % num;   
        pthread_mutex_unlock(&mutex);
        sem_post(&full_sem);   
        pthread_exit(NULL);                              
    }
}
void* pthread_trans(void *arg) //转码函数
{
      .....//略去定义
        
    while(1)
    {
        sleep(2);
        sem_wait(&full_sem);
        pthread_mutex_lock(&mutex);              
        out = out % num;              
        if ((access(sstr, 0)) == -1)
        {                                                               strncat(cmd, xmlparam.srcpath[out], strlen(xmlparam.srcpath[out]));
            strncat(cmd, xmlparam.param[out],strlen(xmlparam.param[out]));       
            strncat(cmd, " &", 2);     
            system(cmd);       
        ++out;

        pthread_mutex_unlock(&mutex);
           sem_post(&empty_sem);
           pthread_exit(NULL);
      }        
}
int main()
{
    ....//略去定义
   
    ini = sem_init(&empty_sem, 0, MAX);
    ini2 = sem_init(&full_sem, 0, 0);
    if(ini && ini2 != 0)
    {
      &nb