Convert ReadWriteLock to async/await. (#8202)

1 files changed, 8 insertions, 8 deletions

diff --git a/synapse/util/async_helpers.py b/synapse/util/async_helpers.py
index f562770922..dfefbd996d 100644
--- a/synapse/util/async_helpers.py
+++ b/synapse/util/async_helpers.py
@@ -20,6 +20,7 @@ from contextlib import contextmanager
 from typing import Dict, Sequence, Set, Union
 
 import attr
+from typing_extensions import ContextManager
 
 from twisted.internet import defer
 from twisted.internet.defer import CancelledError
@@ -338,11 +339,11 @@ class Linearizer(object):
 
 
 class ReadWriteLock(object):
-    """A deferred style read write lock.
+    """An async read write lock.
 
     Example:
 
-        with (yield read_write_lock.read("test_key")):
+        with await read_write_lock.read("test_key"):
             # do some work
     """
 
@@ -365,8 +366,7 @@ class ReadWriteLock(object):
         # Latest writer queued
         self.key_to_current_writer = {}  # type: Dict[str, defer.Deferred]
 
-    @defer.inlineCallbacks
-    def read(self, key):
+    async def read(self, key: str) -> ContextManager:
         new_defer = defer.Deferred()
 
         curr_readers = self.key_to_current_readers.setdefault(key, set())
@@ -376,7 +376,8 @@ class ReadWriteLock(object):
 
         # We wait for the latest writer to finish writing. We can safely ignore
         # any existing readers... as they're readers.
-        yield make_deferred_yieldable(curr_writer)
+        if curr_writer:
+            await make_deferred_yieldable(curr_writer)
 
         @contextmanager
         def _ctx_manager():
@@ -388,8 +389,7 @@ class ReadWriteLock(object):
 
         return _ctx_manager()
 
-    @defer.inlineCallbacks
-    def write(self, key):
+    async def write(self, key: str) -> ContextManager:
         new_defer = defer.Deferred()
 
         curr_readers = self.key_to_current_readers.get(key, set())
@@ -405,7 +405,7 @@ class ReadWriteLock(object):
         curr_readers.clear()
         self.key_to_current_writer[key] = new_defer
 
-        yield make_deferred_yieldable(defer.gatherResults(to_wait_on))
+        await make_deferred_yieldable(defer.gatherResults(to_wait_on))
 
         @contextmanager
         def _ctx_manager():