Re: NSThread limits?

[Richard Frith-Macdonald]

On 7 Apr 2008, at 03:30, Marc Wan wrote:

> hello!
>
>  I am looking to create a server that maintains a pool of a few
> hundred threads at a time, and being a fan of objective-c, i had hoped
> to be able to use GNUStep to do this on non-mac platforms.
>
>  unfortunately, I don't seem to be able to fork more than about
> 150-160 threads using
> NSThread::detachNewThreadSelector:toTarget:withObject.  on my macs
> here, i can easily do 1000 (i didn't test higher).
>
>  after this on Linux, I get:
>
> : Uncaught exception NSInternalInconsistencyException, reason: Unable
> to detach thread (unknown error)
>
>
>  i had worried that this was a linux (ubuntu 6.10 LTS Server) issue,
> but /proc/sys/kernel/thread-max says that it'll handle over 143000
> threads ... some casual browsing of NSThread.m didn't immediately show
> any limitations.
>
>  any idea why this might be happening?

Probably you are using a buggy version of the gnu objc runtime, and  
are not using a new enough vewrsion of GNUstep to have the workaround  
for the bug.

There is a known bug where the runtime incorrectly creates threads as  
joinable, which means they consume resources we don't want them to,  
and thus limit the number of threads available to GNUstep.

You can get a version of the compiler/runtime without the bug, or you  
can use the workaround we have in GNUstep svn, which is to add a call  
to 'pthread_detach(pthread_self())' immediately after the call to  
'objc_thread_set_data(self)'  when a new thread is starting (that's in  
the private mathod _sendThreadMethod in older versions of NSThread.m).