PyObjC - Utility methods for threading

Safe replacements for stock NSObject methods

These safe replacements have the same signature as the stock NSObject methods, but will log exceptions instead of letting them escape into the rest of your program.

• pyobjc_performSelector_onThread_withObject_waitUntilDone_

  This is the safe alternative for performSelector_onThread_withObject_waitUntilDone_.

  (Introduced in Mac OS X 10.5)

• pyobjc_performSelector_onThread_withObject_waitUntilDone_modes_

  This is the safe alternative for performSelector_onThread_withObject_waitUntilDone_modes_.

  (Introduced in Mac OS X 10.5)

• pyobjc_performSelector_withObject_afterDelay_

  This is the safe alternative for performSelector_withObject_afterDelay_.

• pyobjc_performSelector_withObject_afterDelay_inModes_

  This is the safe alternative for performSelector_withObject_afterDelay_inModes_.

• pyobjc_performSelectorInBackground_withObject_

  This is the safe alternative for performSelectorInBackground_withObject_.

  (Introduced in Mac OS X 10.5)

• pyobjc_performSelectorOnMainThread_withObject_waitUntilDone_

  This is the safe alternative for performSelectorOnMainThread_withObject_waitUntilDone_.

• pyobjc_performSelectorOnMainThread_withObject_waitUntilDone_modes_

  This is the safe alternative for performSelectorOnMainThread_withObject_waitUntilDone_modes_.

Enhanced methods

The stock methods are quite useful, but at times it is usefull to get the result back from the other thread. The methods below will call the selector on another thread and will return the result from that call in the current thread. If the call on the "other" thread raises an exception this exception will be reraised in the current thread.

Note: these methods are synchronous, that is, they block the current thread until the call on the "other" thread is done.

As an example:

 1   class MyClass (NSObject):
 2
 3      def divideByZero_(self, arg):
 4           return arg/0
 5
 6      def doit(self):
 7          try:
 8              result = self.performSelectorOnMainThread_withObject_(
 9                   'divideByZero:', 55)
10              print result
11
12          except:
13              print "Division failed"

The available methods are:

• pyobjc_performSelector_onThread_withObject_(selector, thread, arg)

  (Introduced in Mac OS X 10.5)

• pyobjc_performSelector_onThread_withObject_modes_(selector, thread, arg, modes)

  (Introduced in Mac OS X 10.5)

• pyobjc_performSelectorOnMainThread_withObject_(selector, arg)

• pyobjc_performSelectorOnMainThread_withObject_modes_(selector, arg, modes)