Grzegorz Kossakowski wrote:
Grzegorz Kossakowski pisze:
It's not thread-specific but request-specific but here request means
the one coming from browser and handled by servlet container and not
those internal requests that Cocoon is doing when cocoon: or servlet:
protocols are being used.
in the setup method of the generator class we replace the
objectmodel injected by spring with the one passed with that method
... after doing this the errors are not that frequent .. but they
are still there :( .. its still being modified by some other threads
...
Could you please let us know how do u intend to implement ur
proposed solution
The idea is to introduce a new implementation of a Spring scope that
will work in a following way:
1. if requested object (like OM) exists in current context then just
return it
2. if requested object does not yet exist in current context then
find out if this context is derived from root one:
a) if the context is derived then ask the root for the object,
clone it and store cloned version in current context
b) if the context is not derived one so itself is a root then just
ask Spring to create a new instance of requested object and again
store it in current context
The introduction of new contexts should happen only in two cases:
1. new thread is being invoked (for multi-thread scenarios)
2. new internal request is being invoked (in case of using
servlet/cocoon protocols)
Even if this may sound scary, the implementation of this idea should
be very simple. It's only a few lines of code are needed to handle
everything. Of course, the problem is where to inject this code.
Actually, today I was so busy with other work that I hadn't enough
time to look into Cocoon itself but tomorrow I'll do so and give you
more detailed instructions how to implement this.
Hopefully, proposed solution should fix this problem once and for
ever (at least I fail to imagine any situation when this wouldn't work)
Imran, after taking a closer look at our code I can see that there are
little bit more issues that need to be fixed before I can fix this one.
I guess it's going to be much easier if I take care of a whole work
because it's really non-trivial stuff and you really need to know all
the internals of Cocoon in order to properly fix the problem you have.
Therefore I suggest that you provide me a simple application that
exhibits this problem so I can test my fixes and track the whole bug.
I suggest creation of two different scenarios where one will use
cocoon: protocol and another will use servlet: protocol.
The most preferred way of providing me this test-cases would be to
prepare two ITs as it's done in
http://svn.eu.apache.org/viewvc/cocoon/trunk/blocks/cocoon-it/
http://svn.eu.apache.org/viewvc/cocoon/trunk/core/cocoon-webapp/src/test/java/org/apache/cocoon/it/
In the first location you add sitemap entries and other resources that
you usually at to your block, and in the webapp you create a test-case
that tests expected behavior.
As soon as you provide me such test-cases (as a patch in JIRA) I'll
start working on this problem.
Grzegorz, i have attached the testcase to the issue
https://issues.apache.org/jira/browse/COCOON-2216
i have attached three files .. test-block is the main block .. webapp is
for running that block .. before that u will have to apply the patch
cocoon-trunk.patch to cocoon other wise it wont work at all ...
for both the block perform mvn install .. and then from webapp block mvn
jetty:run
so the page
http://localhost:8888/test-block/index.html
is generated using the parallel generator .. if ur lucky and dont get
the error the first time then just refresh and am sure the error will be
there .. there are five components included in that page ... out of
which 4 are normal jx components and the fifth one is cforms component
... all the jx component have been assigned different instance of the
same object but still the properties displayed on the page shows the
same value(they should be different) .. if u execute query for these
components individually then they appear without any error .. links for
querying them individually
[jx components .. shows xml output .. forgot to add the pipeline to
serialize it to html.. u can add one]
http://localhost:8888/test-block/showjx
http://localhost:8888/test-block/showjx1
http://localhost:8888/test-block/showjx2
http://localhost:8888/test-block/showjx3
[cforms component]
http://localhost:8888/test-block/form2bean.flow
most of the time we get the error
Caused by: org.apache.commons.jxpath.JXPathException: No value for
xpath: $cocoon/continuation/id
its because the objectmodel is being changed by all the components
simultaneously ....the error is there on the logs not on the page .. on
the page it will just ignore that component
u can change the line 427 in the class TestContentAggregator in the main
block ... this.parameters.setParameter("parallel", "true"); change that
to false and it will execute them in sequential and then the errors are
gone ...
Would greatly appreciate it if you could have a look and try to resolve
it ..
Thanks and regards
Imran
