[Ace-users] Re: Singlethread servant upcall (using CSD)

[johnc at ociweb]

Hi Jochen,

My response below:

On Oct 1, 1:58 am, Jochen Rothenbacher <jochen.rothenbac... at nsn.com>
wrote:
>     ACE VERSION: 5.5.6
>
>     HOST MACHINE and OPERATING SYSTEM:
>       sun solaris 10
>
>     TARGET MACHINE and OPERATING SYSTEM, if different from HOST:
>     COMPILER NAME AND VERSION (AND PATCHLEVEL):
>
>       CC: Sun C++ 5.7 Patch 117830-08 2006/07/12
>
>     THE $ACE_ROOT/ace/config.h FILE [if you use a link to a platform-
>     specific file, simply state which one]:
>
>       #include "ace/config-sunos5.10.h"
>
>     THE $ACE_ROOT/include/makeinclude/platform_macros.GNU FILE [if you
>     use a link to a platform-specific file, simply state which one
>     (unless this isn't used in this case, e.g., with Microsoft Visual
>     C++)]:
>
>       include $(ACE_ROOT)/include/makeinclude/platform_sunos5_sunc++.GNU
>
>     CONTENTS OF $ACE_ROOT/bin/MakeProjectCreator/config/default.features
>     (used by MPC when you generate your own makefiles):
>       ssl=0
>       qos=0
>
>     DOES THE PROBLEM AFFECT:
>         EXECUTION:
>         Singlethread servant upcall not working?
>
>     SYNOPSIS:
>        Although policy set to SINGLE_THREAD_MODEL calls are dispated in
>        two threads.
>
>     DESCRIPTION:
>
>        We have a multithreaded process framework using the CSD.
>
>        The process consists of a main thread with the mainloop which
>        triggers several event input queues to dispatch events. The input
>        queues have seperate (worker-)threads for feeding the queues with
>        events.
>
>        One of these input queues is feeded with CORBA calls using the
>        CSD. In this thread we run the CORBA::ORB::run() to handle events.
>
>        Each server is using a child POA which is configured with these
>        policies
>
>          // Create the child POA.
>          CORBA::PolicyList policies;
>          policies.length(2);
>            policies[0] =
>          mRootPoa->create_implicit_activation_policy
>                        (PortableServer::IMPLICIT_ACTIVATION);
>          policies[1] = mRootPoa->create_thread_policy
>                        (PortableServer::SINGLE_THREAD_MODEL);
>
>       The CSD is used as follows. We've overloaded
>       dispatch_remote_request_i()
>
>          TAO::CSD::Strategy_Base::DispatchResult
>                                SYS::Strategy::dispatch_remote_request_i
>                               (TAO_ServerRequest&   server_request,
>                                const PortableServer::ObjectId& object_id,
>                                PortableServer::POA_ptr         poa,
>                                const char*                     operation,
>                                PortableServer::Servant         servant)
>           {
>
>              // create the CorbaRequest object, and then add it to
>              // our "request queue".
>
>              if (mInputManager) {
>                 CorbaRequest* request = new CorbaRequest(server_request,
>                                                     object_id, poa,
>                                                     operation, servant);
>              (void)mInputManager->enqueue(request);
>              }
>            }
>
>        Further we configured "direct collocation" with the IDL Compiler
>        flags "Sp -Gd".
>
>        What we observed was that there were incoming calls using our
>        Strategy appearing in the thread where we call CORBA::ORB::run()
>        to handle events, but also a few in the main thread where
>        we call our mainloop.
>
>        Shouldn't the policy PortableServer::SINGLE_THREAD_MODEL guarantee
>        that there are no concurrent servant upcalls?

SINGLE_THREAD_MODEL policy is a POA policy. Using direct collocation
you are bypassing the POA and therefore the single threaded strategy
doesn't come into play. I recommend using the 'thru_poa' collocation
strategy. Let us know if you run into any further issues.

Please contact sales at ociweb.com for support.

regards,
Ciju


>
>        Gruss Jochen
>
> --
> ----------------------------------------------------------
> Jochen Rothenbacher