Am Donnerstag, 12. Mai 2005 02:33 schrieb Craig Southeren: > > I'll see what I can do in the short time before I leave for vacation. A > simple program that demonstrates the problem would be very helpful. > > Also realise that I do not have ALSA on my Linux box :( > > Craig Hi Craig, to see the double registration, even the small hello.cxx from the pwlib docu is enough. Just set a breakpoint on "PFactory<PSoundChannel, PString>::Register_Internal(...)" and you will see it is hit 2 times per audio plugin. I have created a patch which fixes the issue for me and I think is correct. It is a little bit ugly because I have to find the key the worker is registered for, it would be nicer if the Worker class would save the keyname. The destructor is just the counterpart of the constructor and will fix the dangling pointer problem. The second part of the patch makes sure that there is only a single concrete class per factory. The singleton flag IMHO is wrong, as it is for instances, not for unique keys. There can only be one concrete class per key, but there may be multiple instances (in real life, almost every VoIP application will have at least two PSoundChannel(ALSA|OSS) instances ...). Maybe there should even be a warning message in PFactory<>::Register if it is called for an already existing key. Greetings, Stefan -- Stefan Brüns / Kastanienweg 6 - Zimmer 1206 / 52074 Aachen mailto:lurch gmx li http://www.kawo1.rwth-aachen.de/~lurchi/ phone: +49 241 169-4206 mobile: +49 160 3797725
--- include/ptlib/plugin.h.orig 2004-08-16 13:57:47.000000000 +0200
+++ include/ptlib/plugin.h 2005-05-13 18:54:35.000000000 +0200
@@ -64,6 +64,25 @@
: PFactory<_Abstract_T, _Key_T>::WorkerBase(singleton)
{
PFactory<_Abstract_T, _Key_T>::Register(key, this);
+ }
+
+ ~Worker()
+ {
+ typedef typename PFactory<_Abstract_T, _Key_T>::WorkerBase WorkerBase_T;
+ typedef std::map<_Key_T, WorkerBase_T *> KeyMap_T;
+ _Key_T key;
+
+ KeyMap_T km = PFactory<_Abstract_T, _Key_T>::GetKeyMap();
+
+ typename KeyMap_T::const_iterator entry;
+ for (entry = km.begin(); entry != km.end(); ++entry) {
+ if ( entry->second == this ) {
+ key = entry->first;
+ break;
+ }
+ }
+
+ PFactory<_Abstract_T, _Key_T>::Unregister(key);
}
protected:
@@ -88,7 +110,10 @@
typedef PDevicePluginFactory<DeviceBase> Factory_T;
typedef typename Factory_T::Worker Worker_T;
void CreateFactory(const PString & device)
- { new Worker_T(device, TRUE); }
+ {
+ if( !(Factory_T::IsRegistered(device)) )
+ new Worker_T(device, FALSE);
+ }
};
#define PWLIB_PLUGIN_API_VERSION 0
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