Re: patch for NSApplication.m

[Andreas Heppel]

Hello David,

On Wed, 24 Jul 2002 16:04:49 -0400
"DavidRelson" <relson@osagesoftware.com> wrote:

[text omitted...]

> 
> That makes sense, though I think having two assignments to NSApp is 
> wrong.  If the assignment is to be in -init, then +sharedApplication only 
> needs call [[self alloc] init] and doesn't need to assign the value to NSApp.
> 

I think the intention was to asign a value to NSApp as soon as possible. 
Imagine a situation where two threads call sharedInstance. The way it works now 
the dirst thread will set NSApp to a valid value calling [self alloc] and it 
will do no harm if the second thread _now_ calls sharedInstance. It will see 
the newly created application istead of creating anotrher new one. By using one 
statement like [[self alloc init] NSApp will be initialized only after the call 
to init (ok, a bit earlier considering the init method).
The whole construction does not really avoid race conditions, though, but 
rather requires the application to be 'well behaved'. If I remenber right the 
GoF didn't care about this point either (please, coreect me if I'm wrong).

Andreas