Preventing tread collisions

Wed Dec 12 15:11:35 EST 2012

I have a program that has a main GUI and a camera. In the main GUI, you can manipulate the images taken by the camera. You can also use the menu to check the camera's settings. Images are taken by the camera in a separate thread, so the long exposures don't block the GUI. I block conflicts between the camera snapshot thread and the main thread by setting a flag called self.cameraActive. I check to see if the cameraActive flag is false and set the cameraActive to True just before starting the thread. I generate an event on exiting the thread which sets the cameraActive flag to False. I also check and set and reset the flag in all the menu commands that access the camera. Like this.
 def onProperties(self, event):
 """ Display a message window with the camera properties
 event -- The camera properties menu event
 """
 # Update the temperature
 if not self.cameraActive:
 self.cameraActive = True
 self.camera.getTemperature()
 camDict = self.camera.getPropertyDict()
 self.cameraActive = False
 else:
 camDict = {'Error': 'Camera Busy'}
 dictMessage(camDict, 'Camera Properties')
This works but my question is, is there a better way using semaphores, locks or something else to prevent collisions between threads?
Thanks