Re: [Boost-users] shared_ptr conundrum

10 Aug 2005


      "Timothy Ritchey" <tritchey@mac.com> wrote in message 
news:42F97B34.4010509@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