Re: [jboss-as7-dev] IMPORTANT TCCL & JAXP Changes!

On Monday 29 August 2011 08:32 PM, Jason T. Greene wrote: > Hello Everyone, > > While we still want to avoid using TCCL for anything but interacting > with thirdparty components or the SDK [1], there are some changes that > have been made to the current master that make it easier to work with. > > To discourage use in AS, and prevent the wrong classloader from ever > being used, in many contexts (e.g. service lifeycle methods) we used to > null the TCCL. Unfortunately due to (yet another) bug in various JAXP > API implementations, a null TCCL, would trigger this problem: > https://issues.jboss.org/browse/AS7-1630 > > It also made using JAXP from a service or a management operation a > little unwieldy since you had to push/pop TCCL yourself, as decribed in [1]. > > To address these issues we now ALWAYS set TCCL to the defining > classloader of the component in the following cases: > > - MSC Service lifecycle (start, stop) > - Listener callbacks > - MSC Lifecycle Context Execution Tasks > - Operation Handler invocations (includes all subsystem logic) Does this also include DUPs which trigger the component class instantiation? Last time I checked [1], there was an issue where a DUP would trigger a class load of a user class, leading to the static block of that user class being run and if that static block used JAXP API, it would run into trouble due to null TCCL. [1] http://lists.jboss.org/pipermail/jboss-as7-dev/2011-July/003337.html -Jaikiran > > What does this mean to you? > > 1. If you are writing code that is executing in a service or as part of > your subsystem you no longer need to worry about setting the TCCL, it > will be set to your module classloader for you. You can therefore use > JAXP or any other service loader style framework without worrying about > this. > > 2. If you are writing code that is executed on behalf of an EE request, > then TCCL will STILL point to the spec required deployment classloader. > You MUST still push/pop the TCCL as described in [1] when using JAXP or > any other service loader framework. > > If you have any questions about this, feel free to ping me about it. > > [1] http://community.jboss.org/wiki/ModuleCompatibleClassloadingGuide _______________________________________________ jboss-as7-dev mailing list jboss-as7-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/jboss-as7-dev