我很困惑为什么在线程中调用的函数总是返回相同的值。我已经确认每次调用的参数都不同。如果我在获取锁后调用该函数,则该函数返回正确的值。这显然违背了使用线程的目的,因为这个函数只是按顺序调用,一个线程接一个。这就是我所拥有的。该函数称为“get_related_properties”,我在代码中记下了它:
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()
这是get_related_properties,虽然它会进行其他调用,所以我不确定问题出在此处:
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
另外需要注意的是,我还尝试使用 Python 的copy 模块来复制函数,包括深拷贝和浅拷贝并调用函数 copy,但这些都不起作用。