title: what is the usage of PTHREAD_CREATE_JOINABLE in pthread?
body: <p>I read some codes as below:</p>
  
  <pre><code>void
  mcachefs_file_start_thread()
  {
    pthread_attr_t attrs;
    pthread_attr_init(&amp;attrs);
    pthread_attr_setdetachstate(&amp;attrs, PTHREAD_CREATE_JOINABLE);
    pthread_create(&amp;mcachefs_file_threadid, &amp;attrs, mcachefs_file_thread, NULL);
  }
  </code></pre>
  
  <p>Here, what is the usage of setting <code>attrs</code> as <code>PTHREAD_CREATE_JOINABLE</code>? Besides, isn't it the default attribute of a thread created by <code>pthead_create</code>?</p>