error in SocketService::run()

[klaus triendl \(daten unlimited\)]

hi,

i tested the SampleSocketPort example with WinXP. i changed the example a
little - the server disconnects in the SampleSocketPort::expired() method
with disconnect(). This means that CloseSocket() is called with
m_bDoDisconnect=true and the SocketPort is deleted.
SampleSocketPort::expired() is called in SocketService::run(); after it
returns the whole starts from the beginning referring to the already deleted
object causing a segfault:


SocketService::run():

retry:
                        expires = port->getTimer(); // still returns 0 if port 
object has been
deleted
                        if(expires > 0)
                                if(expires < timer)
                                        timer = expires;

                        // if we expire, get new scheduling now

                        if(!expires)
                        {
                                port->endTimer(); // sets active=false
                                port->expired(); // segfault when it comes here 
the 2nd time
                        //      ^^^^^^^^^^^^^^^^ port object is deleted the 1st 
time
                                goto retry;
                        }

                        port = port->next; // points to some address after the 
port object is
deleted




the funny thing is that port->getTimer() (baseclass-method of
SampleSocketPort) doesn't cause a segfault after SampleSocketPort is
deleted, but i guess this is due to how objects are stored in memory. but
this doesn't help us because after the SampleSocketPort object is deleted
port->getTimer() still returns 0 and active has probably some value
(something other than 0 or 1 - i tested it), therefore we cannot rely on
active=false. we also cannot be sure that port->next=NULL or
port->next="address of next open port".

a possibility to handle this problem would be to let expired() return false
or true according to whether the object was deleted and to have a second
port pointer pointing to port->prev which comes into play if expired()
returns false (while deleting the port it detaches itself from the service,
thus 2ndportpointer->next would point to port->next).



any comments or suggestions?




--
klaus triendl