~mshinke/nvdajp/betterJtalk

# _bgthread.py 

# -*- coding: utf-8 -*-

#A part of NonVisual Desktop Access (NVDA)

#Copyright (C) 2006-2010 NVDA Contributors <http://www.nvda-project.org/>

#Copyright (C) 2010-2012 Takuya Nishimoto (nishimotz.com)

#This file is covered by the GNU General Public License.

#See the file COPYING for more details.

#

# based on NVDA (synthDrivers/_espeak.py)

 

from logHandler import log

import threading

import Queue

 

bgThread = None

bgQueue = None

isSpeaking = False

 

class BgThread(threading.Thread):

        def __init__(self):

                threading.Thread.__init__(self)

                self.setDaemon(True)

 

        def run(self):

                global isSpeaking

                while True:

                        func, args, kwargs = bgQueue.get()

                        if not func:

                                break

                        try:

                                func(*args, **kwargs)

                        except:

                                log.error("Error running function from queue", exc_info=True)

                        bgQueue.task_done()

 

def execWhenDone(func, *args, **kwargs):

        global bgQueue

        # This can't be a kwarg in the function definition because it will consume the first non-keywor dargument which is meant for func.

        mustBeAsync = kwargs.pop("mustBeAsync", False)

        if mustBeAsync or bgQueue.unfinished_tasks != 0:

                # Either this operation must be asynchronous or There is still an operation in progress.

                # Therefore, run this asynchronously in the background thread.

                bgQueue.put((func, args, kwargs))

        else:

                func(*args, **kwargs)

 

def initialize():

        global bgThread, bgQueue

        bgQueue = Queue.Queue()

        bgThread = BgThread()

        bgThread.start()

 

def terminate():

        global bgThread, bgQueue

        bgQueue.put((None, None, None))

        bgThread.join()

        bgThread = None

        bgQueue = None