currently we lock the processing on the target.getLock()....why not lock the page instantiation on the same lock?

-Igor


On 1/5/06, Jonathan Locke <[EMAIL PROTECTED]> wrote:

also, because we have Session.get(), any non-locked object (image
object, for example)
that accesses the session this way could have threading problems.  but
that doesn't
seem very likely.

Jonathan Locke wrote:
>
> just realized that the target lock problem will get much worse if igor
> ever gets his way with delayed init.  then components could naively
> do something involving the parent that wound up accessing the session.
>
> Jonathan Locke wrote:
>>
>> i think you should be synchronizing on the target's lock, retrieved
>> by target.getLock()
>>
>> Martijn Dashorst wrote:
>>> Here's my patch for this code. I think this should work but I'd like
>>> others to take a look at it:
>>>
>>> I changed the page construction, such that it is done within a
>>> synchronized block which synchronizes on the session object.
>>>
>>> In class: wicket.request.compound.DefaultRequestTargetResolverStrategy
>>>
>>>     protected IRequestTarget resolveBookmarkablePage(RequestCycle
>>> requestCycle,
>>>             RequestParameters requestParameters)
>>>     {
>>>         String bookmarkablePageClass =
>>> requestParameters.getBookmarkablePageClass();
>>>         Session session = requestCycle.getSession();
>>>         Application application = session.getApplication();
>>>         Class pageClass;
>>>         try
>>>         {
>>>             pageClass =
>>> session.getClassResolver().resolveClass(bookmarkablePageClass);
>>>         }
>>>         catch (RuntimeException e)
>>>         {
>>>             return new
>>> WebErrorCodeResponseTarget(HttpServletResponse.SC_NOT_FOUND,
>>>                     "Unable to load Bookmarkable Page");
>>>         }
>>>
>>>         try
>>>         {
>>>             final IPageFactory pageFactory = session.getPageFactory();
>>>                        synchronized (session) {
>>>                 Page newPage = pageFactory.newPage(pageClass,
>>>                         new
>>> PageParameters(requestParameters.getParameters()));
>>>                    // the response might have been set in the
>>> constructor of
>>>                 // the bookmarkable page
>>>                 IRequestTarget requestTarget =
>>> requestCycle.getRequestTarget();
>>>                    // is it possible that there is already another
>>> request target at
>>>                 // this point then the 2 below?
>>>                 if (!(requestTarget instanceof IPageRequestTarget ||
>>> requestTarget instanceof IBookmarkablePageRequestTarget))
>>>                 {
>>>                     requestTarget = new PageRequestTarget(newPage);
>>>                 }
>>>                 return requestTarget;
>>>             }
>>>         }
>>>         catch (RuntimeException e)
>>>         {
>>>             throw new WicketRuntimeException("Unable to instantiate
>>> Page class: "
>>>                     + bookmarkablePageClass + ". See below for
>>> details.", e);
>>>         }
>>>     }
>>>
>>>
>>> On 1/5/06, *Martijn Dashorst* < [EMAIL PROTECTED]
>>> <mailto:[EMAIL PROTECTED]>> wrote:
>>>
>>>     Testcase:
>>>
>>>     Take wicket examples, linkomatic.
>>>
>>>     Put a breakpoint on the Page3 constructor. Click on the pagelink
>>>     to the Page3 page twice (on the same page) and see two threads
>>>     waiting.
>>>
>>>     The synchronized block seems to be too late.
>>>
>>>     Martijn
>>>
>>>
>>>
>>>     On 1/5/06, *Martijn Dashorst* < [EMAIL PROTECTED]
>>>     <mailto:[EMAIL PROTECTED]>> wrote:
>>>
>>>         According to our limited test, BookmarkablePageTargets are
>>>         executed outside the synchronized block. This means that any
>>>         session access in the constructor of the Page is not
>>>         synchronized, and will get you into trouble. This is what
>>>         happens in our application.
>>>
>>>         Questions:
>>>          - is this by design?
>>>          - has anyone changed this behavior since december 16?
>>>
>>>         Martijn
>>>
>>>         --         Living a wicket life...
>>>
>>>         Martijn Dashorst - http://www.jroller.com/page/dashorst
>>>         <http://www.jroller.com/page/dashorst>
>>>
>>>         Wicket 1.1 is out: http://wicket.sourceforge.net/wicket-1.1
>>>
>>>
>>>
>>>     --     Living a wicket life...
>>>
>>>     Martijn Dashorst - http://www.jroller.com/page/dashorst
>>>
>>>     Wicket 1.1 is out: http://wicket.sourceforge.net/wicket-1.1
>>>
>>>
>>>
>>>
>>> --
>>> Living a wicket life...
>>>
>>> Martijn Dashorst - http://www.jroller.com/page/dashorst
>>>
>>> Wicket 1.1 is out: http://wicket.sourceforge.net/wicket-1.1
>>
>>
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