source/queueHandler.py

   1 #queueHandler.py\r
   2 #A part of NonVisual Desktop Access (NVDA)\r
   3 #Copyright (C) 2006-2007 NVDA Contributors <http://www.nvda-project.org/>\r
   4 #This file is covered by the GNU General Public License.\r
   5 #See the file COPYING for more details.\r
   6 \r
   7 import types\r
   8 from Queue import Queue\r
   9 import globalVars\r
  10 from logHandler import log\r
  11 import watchdog\r
  12 \r
  13 eventQueue=Queue()\r
  14 eventQueue.__name__="eventQueue"\r
  15 generators={}\r
  16 lastGeneratorObjID=0\r
  17 \r
  18 def registerGeneratorObject(generatorObj):\r
  19         global generators,lastGeneratorObjID\r
  20         if not isinstance(generatorObj,types.GeneratorType):\r
  21                 raise TypeError('Arg 2 must be a generator object, not %s'%type(generatorObj))\r
  22         lastGeneratorObjID+=1\r
  23         log.debug("Adding generator %d"%lastGeneratorObjID)\r
  24         generators[lastGeneratorObjID]=generatorObj\r
  25         return lastGeneratorObjID\r
  26 \r
  27 def cancelGeneratorObject(generatorObjID):\r
  28         global generators\r
  29         try:\r
  30                 del generators[generatorObjID]\r
  31         except KeyError:\r
  32                 pass\r
  33 \r
  34 def queueFunction(queue,func,*args,**kwargs):\r
  35         queue.put_nowait((func,args,kwargs))\r
  36 \r
  37 def isRunningGenerators():\r
  38         res=len(generators)>0\r
  39         log.debug("generators running: %s"%res)\r
  40 \r
  41 def flushQueue(queue):\r
  42         for count in range(queue.qsize()+1):\r
  43                 if not queue.empty():\r
  44                         (func,args,kwargs)=queue.get_nowait()\r
  45                         watchdog.alive()\r
  46                         try:\r
  47                                 func(*args,**kwargs)\r
  48                         except:\r
  49                                 log.exception("Error in func %s from %s"%(func.__name__,queue.__name__))\r
  50 \r
  51 def isPendingItems(queue):\r
  52         if not queue.empty():\r
  53                 res=True\r
  54         else:\r
  55                 res=False\r
  56         return res\r
  57 \r
  58 def pumpAll():\r
  59         # This dict can mutate during iteration, so use keys().\r
  60         for ID in generators.keys():\r
  61                 # KeyError could occur within the generator itself, so retrieve the generator first.\r
  62                 try:\r
  63                         gen = generators[ID]\r
  64                 except KeyError:\r
  65                         # Generator was cancelled. This is fine.\r
  66                         continue\r
  67                 watchdog.alive()\r
  68                 try:\r
  69                         next(gen)\r
  70                 except StopIteration:\r
  71                         log.debug("generator %s finished"%ID)\r
  72                         del generators[ID]\r
  73                 except:\r
  74                         log.exception("error in generator %d"%ID)\r
  75                         del generators[ID]\r
  76         flushQueue(eventQueue)\r