diff --git a/synapse/rest/media/v1/_base.py b/synapse/rest/media/v1/_base.py
index d9c4af9389..c0d2f06855 100644
--- a/synapse/rest/media/v1/_base.py
+++ b/synapse/rest/media/v1/_base.py
@@ -143,6 +143,7 @@ def respond_with_responder(request, responder, media_type, file_size, upload_nam
respond_404(request)
return
+ logger.debug("Responding to media request with responder %s")
add_file_headers(request, media_type, file_size, upload_name)
with responder:
yield responder.write_to_consumer(request)
diff --git a/synapse/rest/media/v1/media_storage.py b/synapse/rest/media/v1/media_storage.py
index 7f263db239..d23fe10b07 100644
--- a/synapse/rest/media/v1/media_storage.py
+++ b/synapse/rest/media/v1/media_storage.py
@@ -255,7 +255,9 @@ class FileResponder(Responder):
self.open_file = open_file
def write_to_consumer(self, consumer):
- return FileSender().beginFileTransfer(self.open_file, consumer)
+ return make_deferred_yieldable(
+ FileSender().beginFileTransfer(self.open_file, consumer)
+ )
def __exit__(self, exc_type, exc_val, exc_tb):
self.open_file.close()
diff --git a/synapse/util/logcontext.py b/synapse/util/logcontext.py
index 01ac71e53e..e086e12213 100644
--- a/synapse/util/logcontext.py
+++ b/synapse/util/logcontext.py
@@ -302,7 +302,7 @@ def preserve_fn(f):
def run_in_background(f, *args, **kwargs):
"""Calls a function, ensuring that the current context is restored after
return from the function, and that the sentinel context is set once the
- deferred returned by the funtion completes.
+ deferred returned by the function completes.
Useful for wrapping functions that return a deferred which you don't yield
on (for instance because you want to pass it to deferred.gatherResults()).
@@ -320,24 +320,31 @@ def run_in_background(f, *args, **kwargs):
# by synchronous exceptions, so let's turn them into Failures.
return defer.fail()
- if isinstance(res, defer.Deferred) and not res.called:
- # The function will have reset the context before returning, so
- # we need to restore it now.
- LoggingContext.set_current_context(current)
-
- # The original context will be restored when the deferred
- # completes, but there is nothing waiting for it, so it will
- # get leaked into the reactor or some other function which
- # wasn't expecting it. We therefore need to reset the context
- # here.
- #
- # (If this feels asymmetric, consider it this way: we are
- # effectively forking a new thread of execution. We are
- # probably currently within a ``with LoggingContext()`` block,
- # which is supposed to have a single entry and exit point. But
- # by spawning off another deferred, we are effectively
- # adding a new exit point.)
- res.addBoth(_set_context_cb, LoggingContext.sentinel)
+ if not isinstance(res, defer.Deferred):
+ return res
+
+ if res.called and not res.paused:
+ # The function should have maintained the logcontext, so we can
+ # optimise out the messing about
+ return res
+
+ # The function may have reset the context before returning, so
+ # we need to restore it now.
+ ctx = LoggingContext.set_current_context(current)
+
+ # The original context will be restored when the deferred
+ # completes, but there is nothing waiting for it, so it will
+ # get leaked into the reactor or some other function which
+ # wasn't expecting it. We therefore need to reset the context
+ # here.
+ #
+ # (If this feels asymmetric, consider it this way: we are
+ # effectively forking a new thread of execution. We are
+ # probably currently within a ``with LoggingContext()`` block,
+ # which is supposed to have a single entry and exit point. But
+ # by spawning off another deferred, we are effectively
+ # adding a new exit point.)
+ res.addBoth(_set_context_cb, ctx)
return res
@@ -354,9 +361,18 @@ def make_deferred_yieldable(deferred):
(This is more-or-less the opposite operation to run_in_background.)
"""
- if isinstance(deferred, defer.Deferred) and not deferred.called:
- prev_context = LoggingContext.set_current_context(LoggingContext.sentinel)
- deferred.addBoth(_set_context_cb, prev_context)
+ if not isinstance(deferred, defer.Deferred):
+ return deferred
+
+ if deferred.called and not deferred.paused:
+ # it looks like this deferred is ready to run any callbacks we give it
+ # immediately. We may as well optimise out the logcontext faffery.
+ return deferred
+
+ # ok, we can't be sure that a yield won't block, so let's reset the
+ # logcontext, and add a callback to the deferred to restore it.
+ prev_context = LoggingContext.set_current_context(LoggingContext.sentinel)
+ deferred.addBoth(_set_context_cb, prev_context)
return deferred
|
