'''Thread-safe version of Tkinter. Copyright (c) 2009, Allen B. Taylor This module is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser Public License for more details. You should have received a copy of the GNU Lesser Public License along with this program. If not, see . Usage: import mtTkinter as Tkinter # Use "Tkinter." as usual. or from mtTkinter import * # Use Tkinter module definitions as usual. This module modifies the original Tkinter module in memory, making all functionality thread-safe. It does this by wrapping the Tk class' tk instance with an object that diverts calls through an event queue when the call is issued from a thread other than the thread in which the Tk instance was created. The events are processed in the creation thread via an 'after' event. The modified Tk class accepts two additional keyword parameters on its __init__ method: mtDebug: 0 = No debug output (default) 1 = Minimal debug output ... 9 = Full debug output mtCheckPeriod: Amount of time in milliseconds (default 100) between checks for out-of-thread events when things are otherwise idle. Decreasing this value can improve GUI responsiveness, but at the expense of consuming more CPU cycles. Note that, because it modifies the original Tkinter module (in memory), other modules that use Tkinter (e.g., Pmw) reap the benefits automagically as long as mtTkinter is imported at some point before extra threads are created. Author: Allen B. Taylor, a.b.taylor@gmail.com ''' from Tkinter import * import threading import Queue class _Tk(object): """ Wrapper for underlying attribute tk of class Tk. """ def __init__(self, tk, mtDebug = 0, mtCheckPeriod = 10): self._tk = tk # Create the incoming event queue. self._eventQueue = Queue.Queue(1) # Identify the thread from which this object is being created so we can # tell later whether an event is coming from another thread. self._creationThread = threading.currentThread() # Store remaining values. self._debug = mtDebug self._checkPeriod = mtCheckPeriod def __getattr__(self, name): # Divert attribute accesses to a wrapper around the underlying tk # object. return _TkAttr(self, getattr(self._tk, name)) class _TkAttr(object): """ Thread-safe callable attribute wrapper. """ def __init__(self, tk, attr): self._tk = tk self._attr = attr def __call__(self, *args, **kwargs): """ Thread-safe method invocation. Diverts out-of-thread calls through the event queue. Forwards all other method calls to the underlying tk object directly. """ # Check if we're in the creation thread. if threading.currentThread() == self._tk._creationThread: # We're in the creation thread; just call the event directly. if self._tk._debug >= 8 or \ self._tk._debug >= 3 and self._attr.__name__ == 'call' and \ len(args) >= 1 and args[0] == 'after': #print 'Calling event directly:', \ # Python 2 #self._attr.__name__, args, kwargs # Python 2 print('Calling event directly: '+self._attr.__name__+' '+args+' '+kwargs) return self._attr(*args, **kwargs) else: # We're in a different thread than the creation thread; enqueue # the event, and then wait for the response. responseQueue = Queue.Queue(1) if self._tk._debug >= 1: #print 'Marshalling event:', self._attr.__name__, args, kwargs # Python 2 print('Marshalling event: '+self._attr.__name__+' '+args+' '+kwargs) self._tk._eventQueue.put((self._attr, args, kwargs, responseQueue)) isException, response = responseQueue.get() # Handle the response, whether it's a normal return value or # an exception. if isException: exType, exValue, exTb = response raise exType, exValue, exTb else: return response # Define a hook for class Tk's __init__ method. def _Tk__init__(self, *args, **kwargs): # We support some new keyword arguments that the original __init__ method # doesn't expect, so separate those out before doing anything else. new_kwnames = ('mtCheckPeriod', 'mtDebug') new_kwargs = {} for name, value in kwargs.items(): if name in new_kwnames: new_kwargs[name] = value del kwargs[name] # Call the original __init__ method, creating the internal tk member. self.__original__init__mtTkinter(*args, **kwargs) # Replace the internal tk member with a wrapper that handles calls from # other threads. self.tk = _Tk(self.tk, **new_kwargs) # Set up the first event to check for out-of-thread events. self.after_idle(_CheckEvents, self) # Replace Tk's original __init__ with the hook. Tk.__original__init__mtTkinter = Tk.__init__ Tk.__init__ = _Tk__init__ def _CheckEvents(tk): "Event checker event." used = False try: # Process all enqueued events, then exit. while True: try: # Get an event request from the queue. method, args, kwargs, responseQueue = \ tk.tk._eventQueue.get_nowait() except: # No more events to process. break else: # Call the event with the given arguments, and then return # the result back to the caller via the response queue. used = True if tk.tk._debug >= 2: #print 'Calling event from main thread:', \ # Python 2 #method.__name__, args, kwargs # Python 2 print('Calling event from main thread: '+method.__name__+' '+args+' '+kwargs) try: responseQueue.put((False, method(*args, **kwargs))) except SystemExit, ex: raise SystemExit, ex except Exception, ex: # Calling the event caused an exception; return the # exception back to the caller so that it can be raised # in the caller's thread. from sys import exc_info exType, exValue, exTb = exc_info() responseQueue.put((True, (exType, exValue, exTb))) finally: # Schedule to check again. If we just processed an event, check # immediately; if we didn't, check later. if used: tk.after_idle(_CheckEvents, tk) else: tk.after(tk.tk._checkPeriod, _CheckEvents, tk) # Test thread entry point. def _testThread(root): text = "This is Tcl/Tk version %s" % TclVersion if TclVersion >= 8.1: try: text = text + unicode("\nThis should be a cedilla: \347", "iso-8859-1") except NameError: pass # no unicode support try: if root.globalgetvar('tcl_platform(threaded)'): text = text + "\nTcl is built with thread support" else: raise RuntimeError except: text = text + "\nTcl is NOT built with thread support" text = text + "\nmtTkinter works with or without Tcl thread support" label = Label(root, text=text) label.pack() button = Button(root, text="Click me!", command=lambda root=root: root.button.configure( text="[%s]" % root.button['text'])) button.pack() root.button = button quit = Button(root, text="QUIT", command=root.destroy) quit.pack() # The following three commands are needed so the window pops # up on top on Windows... root.iconify() root.update() root.deiconify() # Simulate button presses... button.invoke() root.after(1000, _pressOk, root, button) # Test button continuous press event. def _pressOk(root, button): button.invoke() try: root.after(1000, _pressOk, root, button) except: pass # Likely we're exiting # Test. Mostly borrowed from the Tkinter module, but the important bits moved # into a separate thread. if __name__ == '__main__': import threading root = Tk(mtDebug = 1) thread = threading.Thread(target = _testThread, args=(root,)) thread.start() root.mainloop() thread.join()