Hi! A PersistenceContext is not thread safe, therefore, Orchestra tries to avoid that by locking the request. It would be nice, if Orchestra does this just for requests requireing a PersistenceContext. But till today, we did not manage to spend some time to optimize that code.
You can set the webapp init parameter org.apache.myfaces.orchestra.CoreConfig:SERIALIZE_REQUESTS to false so that Orchestra does not check for thread safety. You then have to ensure threadsafety against the PersistenceContext yourself (which might not be easy … not to say, impossible :-( ) Ciao, Mario Von: vojtech.zav...@gmail.com [mailto:vojtech.zav...@gmail.com] Im Auftrag von Vojtech Zavrel Gesendet: Donnerstag, 20. August 2009 10:51 An: users@myfaces.apache.org Betreff: Concurrent requests and Orchestra Hi, we have a problem with concurrent request using combination Orchestra + Spring + Trinidad. The application uses more than one window per session, so we have migrated all our beans to orchestra's conversation scope using conversation.manual. We have a progress bar which is poling AJAX request during the main request is being done. Once user is waiting to the main request, there are partial requests each five seconds using Trinidad Javascript API. To be able handle more requests the partial request goes in another frame with same conversationContext. Both partial and full request are accessing to the same bean. And this is the problem because there is there is ReentrantLock used not to be able to access to FacesContex from different thread. So that means, that we are not able to access to the progressbar model and the partial request is locked till the full request is finished. But I haven't understood why there is this concurrent limitatins because they aren't in other scopes. This is the comment from the source code: // Fetch a context for this request if one already exists, and lock it 72 // so that concurrent requests that affect this context block until 73 // this request is complete. Not doing so can cause races for resources 74 // within the current context, such as beans or PersistenceContexts. But what kind of races and why there are not same problems using other scopes. Can anybody explain me the reasons please? Is there any possibility how to make a workaround? Thanks Daemon Thread [http-8080-1] (Suspended) Object.wait(long) line: not available [native method] [local variables unavailable] _ReentrantLock.lockInterruptibly() line: 80 ConversationContext.lockInterruptablyForCurrentThread() line: 475 ContextLockRequestHandler.init(FacesContext) line: 96 OrchestraFacesContextFactory$1.<init>(OrchestraFacesContextFactory, FacesContext, boolean, LinkedList, FacesContext) line: 119 OrchestraFacesContextFactory.getFacesContext(Object, Object, Object, Lifecycle) line: 100 RequestParameterFacesContextFactory.getFacesContext(Object, Object, Object, Lifecycle) line: 92 FacesContextFactoryImpl.getFacesContext(Object, Object, Object, Lifecycle) line: 64 FacesServlet.service(ServletRequest, ServletResponse) line: 260 ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 290 ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 206 TrinidadFilterImpl._invokeDoFilter(ServletRequest, ServletResponse, FilterChain) line: 238 TrinidadFilterImpl._doFilterImpl(ServletRequest, ServletResponse, FilterChain) line: 195 TrinidadFilterImpl.doFilter(ServletRequest, ServletResponse, FilterChain) line: 138 TrinidadFilter.doFilter(ServletRequest, ServletResponse, FilterChain) line: 92 ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 235 ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 206 LicenseFilter.doFilter(ServletRequest, ServletResponse, FilterChain) line: 123 ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 235 ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 206 ResponseHeaderFilter.doFilter(ServletRequest, ServletResponse, FilterChain) line: 54 ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 235 ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 206 SessionTimeoutFilter.doFilter(ServletRequest, ServletResponse, FilterChain) line: 116 ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 235 ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 206 StandardWrapperValve.invoke(Request, Response) line: 233 StandardContextValve.invoke(Request, Response) line: 175 StandardHostValve.invoke(Request, Response) line: 128 ErrorReportValve.invoke(Request, Response) line: 102 StandardEngineValve.invoke(Request, Response) line: 109 CoyoteAdapter.service(Request, Response) line: 263 Http11Processor.process(Socket) line: 844 Http11Protocol$Http11ConnectionHandler.process(Socket) line: 584 JIoEndpoint$Worker.run() line: 447 Thread.run() line: 619
