Bug 56042

Summary: java.lang.IllegalStateException: Calling [asyncComplete()] is not valid for a request with Async state [MUST_DISPATCH]
Product: Tomcat 7 Reporter: Rossen Stoyanchev <rstoyanchev>
Component: CatalinaAssignee: Tomcat Developers Mailing List <dev>
Severity: normal    
Priority: P2    
Version: 7.0.50   
Target Milestone: ---   
Hardware: PC   
OS: Linux   

Description Rossen Stoyanchev 2014-01-21 02:26:34 UTC
The issue appears if the response has been set before startAsync:

AsyncContext asyncContext = request.startAsync(request, response);

You might wonder why would anyone do that? The actual scenario is a bit more complex. It involves a separate thread that completes very fast, even before startAsync is called. 
The resulting stack trace:
java.lang.IllegalStateException: Calling [asyncComplete()] is not valid for a request with Async state [MUST_DISPATCH]
	at org.apache.coyote.AsyncStateMachine.asyncComplete(AsyncStateMachine.java:227)
	at org.apache.coyote.http11.Http11Processor.actionInternal(Http11Processor.java:358)
	at org.apache.coyote.http11.AbstractHttp11Processor.action(AbstractHttp11Processor.java:871)
	at org.apache.coyote.Request.action(Request.java:344)
	at org.apache.catalina.core.AsyncContextImpl.complete(AsyncContextImpl.java:92)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:140)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:744)

The Servlet spec says: "It is illegal to call startAsync if ..., or if the response has been committed and closed, ...". 

If that is indeed the reason, a clear error should be raised, and startAsync not be allowed to proceed. Or perhaps it is an issue that can be fixed? For what it's worth it actually works in Jetty even though the spec says it is illegal.
Comment 1 Mark Thomas 2014-01-23 22:49:14 UTC
The problem was in the ErrorReportValve. It was taking over if the response had an error state and async had been started. As part of this it called complete().

The issue was that if dispatch had been called (e.g. to generate a custom error page in the app) the ErrorReportValve didn't let that happen. IN this case the ErrorReportValve no longer takes over so the dispatch() target can handle the error reporting. It will need to commit the response to stop the ErrorReportValve taking over after the dispatch.
Comment 2 Mark Thomas 2014-01-23 22:49:30 UTC
Fixed in 8.0.x for 8.0.0 and 7.0.x for 7.0.51.