ted by using ASYNC_cleanup_thread(). No asynchronous jobs must be outstanding for the thread when ASYNC_cleanup_thread() is called. Failing to ensure this will result in memory leaks.</p>

<p>The <i>max_size</i> argument limits the number of <b>ASYNC_JOB</b>s that will be held in the pool. If <i>max_size</i> is set to 0 then no upper limit is set. When an <b>ASYNC_JOB</b> is needed but there are none available in the pool already then one will be automatically created, as long as the total of <b>ASYNC_JOB</