[X4U] Re: YIPPEE! - Quad 2.5 GHz

[Philip J Robar]

> On Oct 22, 2005, at 10:07 AM, TjL wrote:
>
>> On Sat, 22 Oct 2005 02:55:26 -0700 "Philip J Robar"  
>> <pjrobar at areyoureallythatstupid.org> wrote:
>>
>>> All OSX-native apps are multi-threaded and thus benefit from any  
>>> multi-proc system.
>>
>> Umm, no they're not. Applications must be explicitly coded to use
>> multiple threads. This is a non-trivial task.
>
> Are Apple apps? That's what I first read this to imply (all native  
> Apple apps vs OSX apps).

Other than guessing by an app's behavior, there's no way to know for  
sure unless you have access to an app's author or source code.


> I have heard it said in the past that only some apps *should* be  
> coded to use multiple threads.

This is a decision the programmer has to make. Threading an app  
basically does two things for you. It lets you takes advantage of  
multiple processors for tasks that are easily divided up in to chunks  
and it lets a user continue to use an application while a time  
consuming task they've request the app to perform runs in the  
background.

The disadvantage of multiple threads in an app is that they  
reintroduce many of the issues that caused problems (resource  
contentions/race conditions, memory trashing, etc.) in the bad old  
days of Mac OS Classic, albeit they are now confined to the app in  
question as opposed to threatening the whole OS. The question the  
programmer has to answer is is the increased internal complication  
and vastly increased chance of bugs offset by the potential increase  
in performance or user inter-activeness?

Phil