[Pythonmac-SIG] newbie: threads in PyObjC

[Ian Baird]

Tom,

One problem you have here is that you need to create an instance of
the Threaded class to point to as your selector's target object. This
error is causing the message:

2007-06-04 20:53:11.415 PyThread[555] *** +[Threaded newThread:]:
selector not recognized

Plus, you have an unneeded NSAutoreleasePool instance, so I'd rewrite
the code as follows:

---

def go_(self, sender):
        print 'go_'
        self.myNewThreadedInst = Threaded.alloc().init()
        NSThread.detachNewThreadSelector_toTarget_withObject_(
            'newThread:', myNewThreadedInst, None)

---

Try that out, it should work.

Ian

On 6/4/07, Tom Elliott <telliott99 at mac.com> wrote:
> I'm using the PyObjC bridge.  I have a computation that will be triggered by
> a user.  It takes about 2 minutes depending on the database we're using.
> I'd like the user to be able to kill it if he decides it's taking too long.
>
> It seems like threading should be  the solution.  My simple demo based on
> what I read in NSThread related docs is as follows.  (I've put the
> NSAutoreleasePool call in twice here, but tried it in either place,
> separately).
>
> from Foundation import *
> from AppKit import *
> import objc, time
>
> from PyObjCTools import NibClassBuilder
>
> class PyThreadAppDelegate(NibClassBuilder.AutoBaseClass):
>     def init(self):
>         self = super(PyThreadAppDelegate, self).init()
>         return self
>
>
>     def go_(self, sender):
>         print 'go_'
>         pool = NSAutoreleasePool.alloc().init()
>
> NSThread.detachNewThreadSelector_toTarget_withObject_(
>             'newThread:', Threaded, None)
>         del pool
>
>
>     def kill_(self, sender):
>         pass
>
>
> class Threaded(NSObject):
>
>     @objc.signature('v:@')
>     def newThread_(obj):
>         print 'Threaded'
>         pool = NSAutoreleasePool.alloc().init()
>         for i in range(5):
>             time.sleep(1)
>             print i
>         del pool
>
> This dies with:
>
> ===== Monday, June 4, 2007 8:53:09 PM US/Eastern =====
> go_
> 2007-06-04 20:53:11.414 PyThread[555] *** _NSAutoreleaseNoPool(): Object
> 0x1419cc0 of class NSCFString autoreleased with no pool in place - just
> leaking
> 2007-06-04 20:53:11.415 PyThread[555] *** +[Threaded newThread:]: selector
> not recognized
> 2007-06-04 20:53:11.415 PyThread[555] *** _NSAutoreleaseNoPool(): Object
> 0x146cb10 of class NSCFString autoreleased with no pool in place - just
> leaking
> 2007-06-04 20:53:11.415 PyThread[555] *** _NSAutoreleaseNoPool(): Object
> 0x146c9a0 of class NSCFString autoreleased with no pool in place - just
> leaking
> 2007-06-04 20:53:11.415 PyThread[555] *** _NSAutoreleaseNoPool(): Object
> 0x146c980 of class NSException autoreleased with no pool in place - just
> leaking
> 2007-06-04 20:53:11.415 PyThread[555] An uncaught exception was raised
> 2007-06-04 20:53:11.415 PyThread[555] *** +[Threaded newThread:]: selector
> not recognized
> 2007-06-04 20:53:11.415 PyThread[555] *** Uncaught exception:
> <NSInvalidArgumentException> *** +[Threaded newThread:]: selector not
> recognized
> Jun  4 20:53:12 joan-olsons-computer-2 crashdump[556]: PyThread crashed
> Jun  4 20:53:12 joan-olsons-computer-2 crashdump[556]: crash report written
> to:
> /Users/jolson/Library/Logs/CrashReporter/PyThread.crash.log
>
> In addition, I don't know how to talk to the thread to kill it.
>
> Thanks for any help,
>
> Tom Elliott
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