Hi,

I'm working on a problem with thread safety and found a comment in
IBOs sample "Threads" :

//Don't call inherited Destroy to avoid calling RemoveThread. Don't
laugh, RemoveThread
//isn't thread save, for two reasons: 1. It does Dec(ThreadCount)
asynchronous to the
//main thread instead of InterlockedDecrement(ThreadCount) what
would be SMP-safe.
//2. If ThreadCount becomes zero RemoveThread does a
PostMessage(ThreadWindow, CM_DESTROYWINDOW)
//to synchronize with the main thread and instruct the ThreadWindow
to destroy itself.
//This is very dangerous because it's not unlikely that a new thread
is started in the
//meantime (before the appeneded CM_DESTROYWINDOW is picked out of
the main-thread message queue)
//that relies on an existing ThreadWindow. Since it's not very
useful to destroy the
//ThreadWindow every time the (unsafe) ThreadCount becomes zero and
also the inherited
//TThread.Destroy not TObject.Destroy does nothing else that I
really need, I workaround this
//problem by just not calling these methods.

I changed my application to not call the destructor and it starts
collecting handles. Did I something wrong or is there a better solution.

The problem itself is that the IB_Connection. Open method raises a
floating point exception (invalid floating point operation). Currently
I guess it has something to do with my implementation. I do not create
a session object for every thread (wich I will change now). Does
anybody have an idea if this can cause an exception like that ?

thx
maik