Re: [Boost-users] shared_ptr conundrum

From: Jeff Flinn (TriumphSprint2000_at_[hidden])
Date: 2005-08-10 08:35:59

"Timothy Ritchey" <tritchey_at_[hidden]> wrote in message 
news:42F97B34.4010509_at_mac.com...
> We have been using shared_ptrs pretty successfully throughout our
> application, but I have run across something that has just completely
> stumped me. BTW - this is a Windows .NET 2003 + Intel 8.1 compiler
> compiling in Debug mode on a multi-processor machine (dual Xeon Dell
> workstation).
>
> The code in question is:
>
> void Router::routeEnvelope(shared_ptr<Envelope> envelope) {
>
>     if(!running || !envelope)
>         return;
>
>     GUID target = envelope->getTo();
>     if(target == guid) {
> // PATH 1
>
>         // check to see if it is a failure envelope
> shared_ptr<EnvelopeFailure> envelopeFailure =
> shared_dynamic_cast<EnvelopeFailure>(envelope);
>         if(envelopeFailure) {
>             // there was a problem sending the original envelope
>             failedEnvelope(envelopeFailure->getFrom());
>         }

I'm not sure if this will help, but the following will limit the scope of 
'envelopeFailure'. This may be important if your code is reentrant through 
'envelopeController.injectEnvelope'. I'm not sure what 'shared_dynamic_cast' 
is above, but assume you meant 'dynamic_pointer_cast'?

    if( shared_ptr<EnvelopeFailure> envelopeFailure
        = dynamic_pointer_cast<EnvelopeFailure>(envelope) )
    {
        failedEnvelope( envelopeFailure->getFrom() );
    }

>         // pass it on up the stack
>         envelopeController.injectEnvelope(envelope);
>
>     } else {
>         // PATH 2
>         mutex::scoped_lock lock(envelopeQueueMonitor);
>         envelopeQueue.push(envelope);
>         envelopeReady.notify_all();
>     }
> }

Jeff Flinn