Re: [cdi-dev] Building EJB-like @Asynchronous via interceptor in CDI

EE concurrency spec needs an update anyway. It currently doesn't explicitly require @RequestScoped beans to be supported on a new Thread. That breaks tons of frameworks and makes it barely usable in EE7. LieGrue, strub On Saturday, 17 January 2015, 13:12, arjan tijms <arjan.tijms(a)gmail.com&gt; wrote: > > >Hi, > > > >On Sat, Jan 17, 2015 at 11:05 AM, Antonio Goncalves < antonio.goncalves(a)gmail.com&gt; wrote: > >@arjan Your example is base on ManagedExecutorService from the Java EE Concurrency spec. That's one topic we've been wondering about : should the @Asynchronous interceptor go to the Java EE Concurrency spec or not ? But it looks like the spec might not be updated. > > >The example I showed here would IMHO best be placed in the Java EE Concurrency spec. That would in my opinion be a perfect analogy to @Transactional and JTA. As given, the interceptor uses CDI/Interceptors and Concurrency, so theoretically it could also be put into a third spec. > > >Personally I would find it strange to put something in spec A, when it may better belong in spec B, just because spec B is not updated. What's holding the update of Java EE Concurrency back? If most of the EG members would be of the opinion that an @Asynchronous interceptor belongs best in Java EE Concurrency, then we can just update that spec, right? > > >I know that MR releases can be quite fast and agile process wise, while still packing some punch. JTA 1.2 itself was just such an MR, and JASPIC 1.1 was too. I was somewhat involved with JASPIC 1.1 (as community member) and I think the setup time was pretty fast. Mid feb 2013 we created the JIRA issues, the MR draft was published early march 2013 and the release was with EE 7 end may 2013. > > >If it would just be about putting a few interceptors formally in Java EE Concurrency, then why not do such small update for it? > > >Kind regards, >Arjan > > >> >>Antonio >> >> >>On Sat, Jan 17, 2015 at 12:32 AM, arjan tijms <arjan.tijms(a)gmail.com&gt; wrote: >> >>Hi, >>> >>> >>> >>>On Fri, Jan 16, 2015 at 10:41 PM, Jozef Hartinger <jharting(a)redhat.com&gt; wrote: >>> >>>Hi Arjan, >>>> >>>>I did some changes recently in Weld interceptors and this usecase now works smoothly. The code is not part of a release yet. See this test for a simple implementation of an @Async interceptor (basically the same as your initial attempt). Note that the chain is repeatable but at the same time it is not reset after dispatch to a different thread so you no longer need the ThreadLocal nor any other workaround. >>>> >>> >>> >>>That's quite a coincidence, it's indeed rather similar ;) >>> >>> >>>I wonder how it now works though, as the InvocationContext "ctx" does not seem to be made aware that it's been dispatched to a different thread from within the code. Does it use an internal thread local to keep state or so? >>> >>> >>>I'll also try to see what this does on OWB. Do you think this is something that should work, or just something that Weld happens to support regardless of the spec? >>> >>> >>>Kind regards, >>>Arjan >>> >>> >>> >>> >>> >>> >>>> https://github.com/weld/core/blob/master/tests-arquillian/src/test/java/o... >>>> >>>>Jozef >>>> >>>> >>>> >>>>On 01/16/2015 06:17 PM, arjan tijms wrote: >>>> >>>>Hi, >>>>> >>>>> I'm attempting to emulate EJB's @Asynchronous in CDI using interceptors. >>>>> >>>>>Originally I had defined my interceptor as follows; >>>>> >>>>>@Interceptor >>>>>@Asynchronous >>>>>@Priority(APPLICATION) >>>>>public class AsynchronousInterceptor implements Serializable { >>>>> >>>>> private static final long serialVersionUID = 1L; >>>>> >>>>> @Resource >>>>> private ManagedExecutorService managedExecutorService; >>>>> >>>>> @AroundInvoke >>>>> public Object submitAsync(InvocationContext ctx) throws Exception { >>>>> return new FutureDelegator(managedExecutorService.submit( ()-> { return ctx.proceed(); } )); >>>>> } >>>>> >>>>>} >>>>> >>>>> >>>>>With FutureDelegator as follows: >>>>> >>>>>public class FutureDelegator implements Future<Object> { >>>>> >>>>> private Future<?> future; >>>>> >>>>> public FutureDelegator(Future<?> future) { >>>>> this.future = future; >>>>> } >>>>> >>>>> @Override >>>>> public Object get() throws InterruptedException, ExecutionException { >>>>> AsyncResult<?> asyncResult = (AsyncResult<?>) future.get(); >>>>> if (asyncResult == null) { >>>>> return null; >>>>> } >>>>> >>>>> return asyncResult.get(); >>>>> } >>>>> >>>>> @Override >>>>> public Object get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException { >>>>> AsyncResult<?> asyncResult = (AsyncResult<?>) future.get(timeout, unit); >>>>> if (asyncResult == null) { >>>>> return null; >>>>> } >>>>> >>>>> return asyncResult.get(); >>>>> } >>>>> >>>>> @Override >>>>> public boolean cancel(boolean mayInterruptIfRunning) { >>>>> return future.cancel(mayInterruptIfRunning); >>>>> } >>>>> >>>>> @Override >>>>> public boolean isCancelled() { >>>>> return future.isCancelled(); >>>>> } >>>>> @Override >>>>> public boolean isDone() { >>>>> return future.isDone(); >>>>> } >>>>> >>>>>} >>>>> >>>>> >>>>>This of course didn't quite work, as the InvocationContext will be reset after the @AroundInvoke method returns, and an infinite intercept loop results (on Weld). >>>>> >>>>>I got it to work though on Weld by using a thread local check to break that loop: >>>>> >>>>>@Interceptor >>>>>@Asynchronous >>>>>@Priority(PLATFORM_BEFORE) >>>>>public class AsynchronousInterceptor implements Serializable { >>>>> >>>>> private static final long serialVersionUID = 1L; >>>>> >>>>> @Resource >>>>> private ManagedExecutorService managedExecutorService; >>>>> >>>>> private static final ThreadLocal<Boolean> asyncInvocation = new ThreadLocal<Boolean>(); >>>>> >>>>> @AroundInvoke >>>>> public synchronized Object submitAsync(InvocationContext ctx) throws Exception { >>>>> >>>>> if (TRUE.equals(asyncInvocation.get())) { >>>>> return ctx.proceed(); >>>>> } >>>>> >>>>> return new FutureDelegator(managedExecutorService.submit( ()-> { >>>>> try { >>>>> asyncInvocation.set(TRUE); >>>>> return ctx.proceed(); >>>>> } finally { >>>>> asyncInvocation.remove(); >>>>> } >>>>> })); >>>>> } >>>>> >>>>>} >>>>> >>>>> >>>>>But I've got a feeling this works just by chance and not because the workaround is so clever. >>>>> >>>>> >>>>>What do you guys think, what would be the best way to support this with the current CDI version? Or would CDI/Interceptors need something like Servlet's async support, where the InvocationContext is put into async mode whereafter it "simply" allows an other thread to continue processing on it? >>>>> >>>>> >>>>>Kind regards, >>>>>Arjan Tijms >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>>_______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 (http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information. >>>> >>> >>>_______________________________________________ >>>cdi-dev mailing list &gt;&gt;&gt;cdi-dev(a)lists.jboss.org >>>https://lists.jboss.org/mailman/listinfo/cdi-dev >>> >>>Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 ( http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information. >>> >> >> >> >>-- >> >>Antonio Goncalves >>Software architect, Java Champion and Pluralsight author >> >>Web site | Twitter | LinkedIn | Pluralsight | Paris JUG | Devoxx France > > > >_______________________________________________ >cdi-dev mailing list &gt;cdi-dev(a)lists.jboss.org >https://lists.jboss.org/mailman/listinfo/cdi-dev > >Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 ( http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information. > >