[weld-dev] Race condition in HttpContextLifecycle requestInitialized

[Benjamin Confino]

Hello. 

We have a problem from a race condition in 
HttpContextLifecycle.requestInitialized()

The condition is as follows: 

Thread one calls nestedInvocationGuard.set(new Counter());
Thread two calls Counter counter = nestedInvocationGuard.get();  Object 
marker = request.getAttribute(GUARD_PARAMETER_NAME);
Thread one has not yet called request.setAttribute(GUARD_PARAMETER_NAME, 
GUARD_PARAMETER_VALUE);

This will result in thread two having a counter but no marker, leading to 
ServletLogger.LOG.guardLeak(counter.value);

I believe this issue is known because of the following comment. 

* This request has not been processed yet but the guard is set already. 
That indicates, that the guard leaked from a previous request
* processing - most likely the Servlet container did not invoke listener 
methods symmetrically. Log a warning and recover by
* re-initializing the guard

I am assuming that "symmetrically" is supposed to say "synchronised". 

I have checked with the relevant team and there is no way we can call that 
method from inside a synchronised block. So I was hoping that you might 
have some alternatives? 

I noticed that the file at 
https://github.com/doctau/weld-core/blob/master/impl/src/main/java/org/jboss/weld/servlet/HttpContextLifecycle.java 
has been updated and no longer has that race condition? Do you think 
including that update resolve this issue? And if so which release will 
include that update. 

Regards
Benjamin
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