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POPython function call in thread always returns same value
 

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  1. POPython function call in thread always returns same value
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    <p>I'm boggled over why a function called in a thread always returns the same value. I've confirmed that the parameters are different for each call. If I call the function after acquiring a lock then the function returns the correct value. This obviously defeats the purpose of using threads, because then this function is just called sequentially, one thread after another. Here is what I have. The function is called "get_related_properties" and I've made a note of it in the code:</p> <pre><code>class ThreadedGetMultipleRelatedProperties(): def __init__(self, property_values, **kwargs): self.property_values = property_values self.kwargs = kwargs self.timeout = kwargs.get('timeout', 20) self.lock = threading.RLock() def get_result_dict(self): queue = QueueWithTimeout() result_dictionary = {} num_threads = len(self.property_values) threads = [] for i in range(num_threads): t = GetMultipleRelatedPropertiesThread(queue, result_dictionary, self.lock) t.setDaemon(True) try: threads.append(t) t.start() except: return {"Error": "Unable to process results at this time." } for property_value in self.property_values: kwargs_copy = dict.copy(kwargs) kwargs_copy['property_value'] = property_value queue.put(self.kwargs_copy) queue.join_with_timeout(self.timeout) # cleanup threads for i in range(num_threads): queue.put(None) for t in threads: t.join() return result_dictionary class GetMultipleRelatedPropertiesThread(threading.Thread): def __init__(self, queue, result_dictionary, lock): threading.Thread.__init__(self) self.queue = queue self.result_dictionary = result_dictionary self.lock = lock def run(self): from mixpanel_helpers import get_related_properties while True: kwargs = self.queue.get() if kwargs == None: break current_property_value = kwargs.get('property_value') self.lock.acquire() # The function call below always returns the same value if called before acquire result = get_related_properties(**kwargs) try: self.result_dictionary[current_property_value] = result finally: self.lock.release() #signals to queue job is done self.queue.task_done() </code></pre> <p>Here is get_related_properties, although it makes other calls, so I'm not sure the problem lives in here:</p> <pre><code>def get_related_properties(property_name, property_value, related_properties, properties={}, **kwargs): kwargs['exclude_detailed_data'] = True properties[property_name] = property_value result = get_multiple_mixpanel_results(properties=properties, filter_on_values=related_properties, **kwargs) result_dictionary = {} for related_property in related_properties: try: # grab the last result here, because it'll more likely have the most up to date properties current_result = result[related_property][0]['__results'][0]['label'] except Exception as e: current_result = None try: related_property = int(related_property) except: pass result_dictionary[related_property] = current_result return result_dictionary </code></pre> <p>An additional note, I've also tried to copy the function using Python's <a href="http://docs.python.org/2/library/copy.html" rel="nofollow">copy module</a>, both a deep and shallow copy and call the function copy, but neither of those worked.</p>
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    1. PTQuestion
    1. USuser509721
    1. USuser509721
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      1. VTUpMod
    1. COCan you show the code for `get_related_properties`?
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      1. USBrenBarn
    2. COit looks like you're putting the same value in the queue over and over with `queue.put(self.kwargs)`. Wouldn't this give get_related_properties the same arguments for every call? How do you transmit 'property_value' to the thread, you pull it out of kwargs, but I don't see where you're putting it in.
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      1. POPython function call in thread always returns same value
      1. USbj0
    3. COIsn't it being added from the get_result_dict?
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      1. USdiedthreetimes
 

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