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This commit is contained in:
Erik Johnston 2016-04-07 14:24:12 +01:00
parent af03ecf352
commit 639cd07d6d

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@ -164,6 +164,14 @@ class Linearizer(object):
@defer.inlineCallbacks
def queue(self, key):
# If there is already a deferred in the queue, we pull it out so that
# we can wait on it later.
# Then we replace it with a deferred that we resolve *after* the
# context manager has exited.
# We only return the context manager after the previous deferred has
# resolved.
# This all has the net effect of creating a chain of deferreds that
# wait for the previous deferred before starting their work.
current_defer = self.key_to_defer.get(key)
new_defer = defer.Deferred()