Re: NSRunLoop behavior
Re: NSRunLoop behavior
- Subject: Re: NSRunLoop behavior
- From: Keary Suska <email@hidden>
- Date: Tue, 21 Sep 2010 07:54:31 -0600
On Sep 21, 2010, at 5:55 AM, Rafael Cerioli wrote:
> Hi,
>
> I'm trying to understand how run loops work. I've written this useless piece of code and I'm not sure why "success" does not show up...
> What happens is that waitUntilReady never terminates, because it seems that the runUntilDate in myButtonAction never ends as well.
Yes, as that is what your code is doing.
> My theory would be that calling a runUntilDate from myButtonAction (myButtonAction is started by a run loop observer) will just prevent other sources and observers in the *current* run loop's loop (or run loop's run ??) to be processed until myButtonAction terminates.
No--there is no "prevention" whatsoever. -runUntilDate: tells the current runloop *specifically* to process all input sources, and to not exit until all sources are processed *and* the specified expiration date has been reached.
> So, waitUntilReady's call to runUntilDate would prevent the end of myButtonAction's current run loop's loop.
>
> Does someone have more info about that ?
>
> - (void) myButtonAction {
> // A button event has been sent, waking up the run loop and calling that method
>
> // this will be called in 1 second
> [self performSelector:@selector(waitUntilReady) withObject:nil afterDelay:1];
This is an input source, so the runloop will not exit until the method exits.
> // process the current run loop during 10 seconds :
> [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:10]];
Which never happens, as you never get to this line, because the method cannot exit.
> [self setReady:YES];
> }
>
> - (void) waitUntilReady {
>
> while(![self isReady]) {
> // this should just process the run loop once :
> [[NSRunLoop currentRunLoop] runUntilDate:[NSDate date]];
> }
>
> NSLog(@"success!");
> }
HTH,
Keary Suska
Esoteritech, Inc.
"Demystifying technology for your home or business"
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden