[
https://issues.apache.org/jira/browse/CXF-7575?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16343634#comment-16343634
]
Sergey Beryozkin commented on CXF-7575:
---------------------------------------
Sorry for a delay. I'm having problems reproducing it. I've updated existing
test
https://github.com/apache/cxf/blob/master/systests/jaxrs/src/test/java/org/apache/cxf/systest/jaxrs/BookContinuationStore.java#L73
as per you patch (removed sleep()) and the client to do it 5000 times, it is
just running, quite slow, not sure why, but no any failures.
It's quite hard to see where the problem might be, if the application code has
called 'resume()' before JAXRSInvoker tries to really suspend (and hence return
the current thread to the pool) then the async response (or rather its object)
is returned on the original thread immediately without even interacting with
the Continuation.
How do you set up the server, is it Jetty, Tomcat. etc ?
Sergey
> @Suspended race condition
> -------------------------
>
> Key: CXF-7575
> URL: https://issues.apache.org/jira/browse/CXF-7575
> Project: CXF
> Issue Type: Bug
> Components: JAX-RS
> Affects Versions: 3.1.14
> Reporter: John Bellassai
> Priority: Major
> Attachments: CXF-7575.patch
>
>
> There appears to be a race condition with the use of AsyncResponseImpl where
> my user thread can invoke resume() before initialSuspend is set to false by
> suspendContinuationIfNeeded() and therefore the resume() call does not
> actually resume the Continuation _and returns true_, indicating that the
> resume was successful even though it wasn't.
> I've spent all day trying to make sense of this problem and my understanding
> of how all of this works together is still a bit spotty, but it seems to me
> that AsyncResponseImpl.suspendContinuationIfNeeded() (or something similar)
> should be called _before_ invoking the JAXRS method. Right now, that method
> is only called after the JAXRS method is invoked by JAXRSInvoker so the
> instance of AsyncResponse passed into the JAXRS method appears to not
> actually get suspended (or perhaps _marked_ internally as suspended) until
> after the JAXRS method returns. If my async task happens to get finished
> very quickly and calls resume() before that happens, it fails silently.
> I seem to be able to circumvent this problem by running the following at the
> start of my JAXRS method (pseudo code):
> {code}
> @POST
> @Path(....)
> void myJaxrsMethod(@Suspended AsyncResponse asyncResponse, ...) {
> if(asyncResponse instanceof AsyncResponseImpl) {
> ((AsyncResponseImpl)asyncResponse).suspendContinuationIfNeeded()
> }
> Runnable asyncTask = createAsyncTask(asyncResponse)
> submitAsyncTask(asyncTask)
> }
> {code}
> which is why I suspect suspendContinuationIfNeeded() should be called before
> JAXRSInvoker invokes the JAXRS method.
> One of the things that made this really difficult to track down was that
> AsyncResponseImpl.resume() returns true even if the Continuation was not
> resumed! If you make it into doResumeFinal(), like was happening in my case,
> the return is always true even if cont.resume() is not called. So from user
> code, it looks like everything is ok, but the response never gets sent to the
> client.
> This seems somewhat related to the problems reported in CXF-7037
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
