Re: copy constructor for sockets

["Robert I. Eachus" <rieachus@comcast.net>]

Simon Wright wrote:

> Matthew Heaney <matthewjheaney@earthlink.net> writes:
> 
> 
>>>in which of these times you should decrement,
>>
>>Huh?  Every time, of course.  How could it be otherwise?  What would
>>a reference counting scheme even mean, if you didn't decrement the
>>refcount during finalization of the object?
> 
> I have it stuck in my head that Finalize can get called more than
> once. Which would make a mockery of (simple-minded) reference counting
> schemes, of course. Please tell me it ain't so! (or explain why it's
> not actually a problem ..)

Yes, Finalize can be called more than once, especially when exceptions 
occur.  The solution I usually use is to something else during the 
finalization, and only change the reference count if that succeeds.  In 
a reference counting scheme you need a "finalized" flag as well as an 
initialized flag, which can be different values in the same byte 
(uninitialized, valid, finalized).


-- 

                                           Robert I. Eachus

"The terrorists rejoice in the killing of the innocent, and have 
promised similar violence against Americans, against all free peoples, 
and against any Muslims who reject their ideology of murder. Their 
barbarism cannot be appeased, and their hatred cannot be satisfied. 
There's only one way to deal with terror: We must confront the enemy and 
stay on the offensive until these killers are defeated." -- George W. Bush