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<a href="http://community.jboss.org/index.jspa" style="text-decoration: none; color: #E1E1E1">JBoss Community</a></h1>
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Re: Deployer chain cleanup
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created by <a href="http://community.jboss.org/people/david.lloyd%40jboss.com">David Lloyd</a> in <i>JBoss AS7 Development</i> - <a href="http://community.jboss.org/message/570623#570623">View the full discussion</a>
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<div class="jive-rendered-content"><p>In an ideal world we'd be able to use an interceptor-chain kind of pattern where each processor calls invokeNext() or whatever, and any error cleanup could be done in a finally block.  However the grim reality is that we could face stack exhaustion if we had a truly large number of extensions involved.  I think the next-best option is what you suggest: a cleanup() method which is called if a later processor fails.</p><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>So to restate:</p><ol><li>Add a cleanup() method to DeploymentUnitProcessor</li><li>Each implementation of DUP should handle failure cleanly, so processDeployment is essentially atomic: either everything gets done or nothing (no partial state when an exception is thrown).</li><li>Then the implementation of cleanup() can perform a full cleanup safely, because it will only ever be called if processDeployment() had completed successfully <strong>and</strong> a later processDeployment() failed.</li><li>This implies that if a given processDeployment() fails, its cleanup() is <strong>not</strong> called, but the cleanup() methods on all the DUPs before the one that failed <strong>are</strong> called.</li></ol><p style="min-height: 8pt; height: 8pt; padding: 0px;"> </p><p>Make sense?</p></div>
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