Convert run_as_background_process inner function to async. (#8032)

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Patrick Cloke 2020-08-06 08:20:42 -04:00 committed by GitHub
parent 66f24449dd
commit c36228c403
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4 changed files with 16 additions and 26 deletions

1
changelog.d/8032.misc Normal file
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@ -0,0 +1 @@
Convert various parts of the codebase to async/await.

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@ -101,7 +101,7 @@ class ApplicationServicesHandler(object):
async def start_scheduler():
try:
return self.scheduler.start()
return await self.scheduler.start()
except Exception:
logger.error("Application Services Failure")

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@ -146,10 +146,9 @@ class SynapseRequest(Request):
Returns a context manager; the correct way to use this is:
@defer.inlineCallbacks
def handle_request(request):
async def handle_request(request):
with request.processing("FooServlet"):
yield really_handle_the_request()
await really_handle_the_request()
Once the context manager is closed, the completion of the request will be logged,
and the various metrics will be updated.

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@ -13,16 +13,15 @@
# See the License for the specific language governing permissions and
# limitations under the License.
import inspect
import logging
import threading
from asyncio import iscoroutine
from functools import wraps
from typing import TYPE_CHECKING, Dict, Optional, Set
from prometheus_client.core import REGISTRY, Counter, Gauge
from twisted.internet import defer
from twisted.python.failure import Failure
from synapse.logging.context import LoggingContext, PreserveLoggingContext
@ -167,7 +166,7 @@ class _BackgroundProcess(object):
)
def run_as_background_process(desc, func, *args, **kwargs):
def run_as_background_process(desc: str, func, *args, **kwargs):
"""Run the given function in its own logcontext, with resource metrics
This should be used to wrap processes which are fired off to run in the
@ -179,7 +178,7 @@ def run_as_background_process(desc, func, *args, **kwargs):
normal synapse inlineCallbacks function).
Args:
desc (str): a description for this background process type
desc: a description for this background process type
func: a function, which may return a Deferred or a coroutine
args: positional args for func
kwargs: keyword args for func
@ -188,8 +187,7 @@ def run_as_background_process(desc, func, *args, **kwargs):
follow the synapse logcontext rules.
"""
@defer.inlineCallbacks
def run():
async def run():
with _bg_metrics_lock:
count = _background_process_counts.get(desc, 0)
_background_process_counts[desc] = count + 1
@ -203,29 +201,21 @@ def run_as_background_process(desc, func, *args, **kwargs):
try:
result = func(*args, **kwargs)
# We probably don't have an ensureDeferred in our call stack to handle
# coroutine results, so we need to ensureDeferred here.
#
# But we need this check because ensureDeferred doesn't like being
# called on immediate values (as opposed to Deferreds or coroutines).
if iscoroutine(result):
result = defer.ensureDeferred(result)
if inspect.isawaitable(result):
result = await result
return (yield result)
return result
except Exception:
# failure.Failure() fishes the original Failure out of our stack, and
# thus gives us a sensible stack trace.
f = Failure()
logger.error(
"Background process '%s' threw an exception",
desc,
exc_info=(f.type, f.value, f.getTracebackObject()),
logger.exception(
"Background process '%s' threw an exception", desc,
)
finally:
_background_process_in_flight_count.labels(desc).dec()
with PreserveLoggingContext():
return run()
# Note that we return a Deferred here so that it can be used in a
# looping_call and other places that expect a Deferred.
return defer.ensureDeferred(run())
def wrap_as_background_process(desc):