[jbossseam-issues] [JBoss JIRA] Resolved: (JBSEAM-3295) Major reentrancy problem with "Application Scope" components and injection/disinjection

Major reentrancy problem with "Application Scope" components and injection/disinjection --------------------------------------------------------------------------------------- Key: JBSEAM-3295 URL: https://jira.jboss.org/jira/browse/JBSEAM-3295 Project: Seam Issue Type: Bug Components: Core Affects Versions: 2.0.2.SP1 Environment: WebSphere v6.1.0.17 in POJO Mode Reporter: Denis Forveille Assignee: Pete Muir Priority: Blocker Fix For: 2.0.3.CR2, 2.1.0.BETA1 Attachments: BijectionInterceptor_Denis.java There is a major reentrancy problem with "Application Scope" components and injection/disinjection As in any component @In dependent object are injected/disinjected with the BijectionInterceptor interceptor As there is one instance of BijectionInterceptor per Component (It seems), there is only one instance of BijectionInterceptor in the JVM for an Application Scope Component, instance shared by all threads With that in mind, take: - 2 running thread (T1, T2) - One application scope component (C1) with many@In attributes (All referecing Application Scope components too..) T1 enters method M1 of C1. BijectionInterceptor inject @In depedencies of C1, and set the "reentrant" attribute of the instance of BijectionInterceptor attached to C1 to "true" T2 enters method M1of C1. BijectionInterceptor does nothing as "reentrant" is true T1 exits method M1 of C1. As this is thios thread (T1) that set "reentrant" initially, it performs the "disinjection" and set all the @In attribues of C1 to null T2 then fails with NPE as all the @In attributes of C1 are set to null !!!!! Core of the org.jboss.seam.core.BijectionInterceptor class: private boolean reentrant; //OK, since all Seam components are single-threaded @AroundInvoke public Object aroundInvoke(InvocationContext invocation) throws Exception{ if (reentrant) { return invocation.proceed(); } else { reentrant = true; try { Component component = getComponent(); boolean enforceRequired = !component.isLifecycleMethod( invocation.getMethod() ); component.inject( invocation.getTarget(), enforceRequired ); Object result = invocation.proceed(); component.outject( invocation.getTarget(), enforceRequired ); component.disinject( invocation.getTarget() ); return result; } finally { reentrant = false; } } }