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    <p>Here's a relatively simple approach (ignores exceptions, attribute-access, special methods, etc):</p> <pre><code>import Queue import threading def serialize(q): """runs a serializer on queue q: put [-1]*4 on q to terminate.""" while True: # get output-queue for result, a callable, its args and kwds out_q, tocall, args, kwds = q.get() if out_q == -1: return result = tocall(*args, **kwds) out_q.put(result) class WrapCall(object): """Wraps a callable to serialize calls to it.""" def __init__(self, inq, ouq, tocall): self.inq = inq self.ouq = ouq self.tocall = tocall def __call__(self, *a, **k): self.inq.put((self.ouq, self.tocall, a, k)) if self.ouq is None: return None return self.ouq.get() class WrapObj(object): """Wraps any object to serialize all calls to its methods.""" def __init__(self, obj): self._o = obj self._q = Queue.Queue() t = threading.Thread(target=serialize, args=(self._q,)) t.setDaemon(True) t.start() self.t = t def __getattr__(self, n): """Wraps methods of self.w into an appropriate WrapCall instance.""" towrap = getattr(self._o, n) if not callable(towrap): raise TypeError('Cannot wrap noncallable attribute %r (type: %s)' % (n, type(towrap))) q = Queue.Queue() return WrapCall(self._q, q, towrap) def WrapperWait(self): """Return only when self.t has served all pending requests.""" q = Queue.Queue() w = WrapCall(self.__q, q, lambda: None) return w() </code></pre> <p>With this "serializer", you can do</p> <pre><code>myobj = WrapObj(Command()) </code></pre> <p>and now all calls to myobj's (non-special) methods are serialized in a thread-safe way.</p> <p>For your specific case, where there's only one method on the object, you could simplify this a bit further, but this is an already-simplified version of something I wrote and use often (supporting attribute getting and setting, special methods, etc, is a tad too complex to be worth it; the complete version does support catching and reraising exceptions raised in the wrapper object's methods, an optimization for calls whose results or exceptions you don't care about, and a few more tweaks, but not serialization of attributes and special methods).</p>
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    1. COVery cool. This is just about what i was hoping for.
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    2. COGetting an exception thrown: exceptions.AttributeError: 'WrapCall' object has no attribute 'delegate' Any ideas? Thanks, Ben
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    3. CO@Ben, sorry, I had renamed an attribute only partially -- it's now named `tocall`, **not** `delegate`, so I just edited it to fix.
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