PriorityCalls.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>


<overview>
<p>Specifying thread priorities using calls to <code>Thread.setPriority</code> 
and <code>Thread.getPriority</code> is not portable 
and may have adverse consequences such as starvation.
</p>

</overview>
<recommendation>

<p>Avoid setting thread priorities to control interactions between threads. 
Using the default thread priority should be sufficient for most applications.
</p>

<p>However, if you need to enforce a specific synchronization order, use one of the following 
alternatives:</p>

<ul>
    <li>Waiting for a notification using the <code>wait</code> and <code>notifyAll</code> methods</li>
    <li>Using the <code>java.util.concurrent</code> library</li>
</ul>

<p>In some cases, calls to <code>Thread.sleep</code> may be appropriate to temporarily stop 
execution (provided that there is no possibility for race conditions), but this is not generally 
recommended.</p>

</recommendation>
<references>


<li>
  J. Bloch, <em>Effective Java (second edition)</em>, Item 72. Addison-Wesley, 2008.
</li>
<li>
  Inform IT:
  <a href="http://www.informit.com/articles/article.aspx?p=26326&amp;seqNum=5">Adding Multithreading Capability to Your Java Applications</a>.
</li>


</references>
</qhelp>