Skip to content

Keep thread pool executors around. #306

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
wants to merge 1 commit into
base: main
Choose a base branch
from
Draft

Keep thread pool executors around. #306

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 20 additions & 4 deletions asgiref/sync.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,9 @@
contextvars = None


SYNC_POOL_WORKER_COUNT = 10 # TODO: this is random for testing now


def _restore_context(context):
# Check for changes in contextvars, and set them to the current
# context for downstream consumers
Expand Down Expand Up @@ -84,9 +87,7 @@ async def __aexit__(self, exc, value, tb):
if not self.token:
return

executor = SyncToAsync.context_to_thread_executor.pop(self, None)
if executor:
executor.shutdown()
SyncToAsync.release_executor(self)
SyncToAsync.thread_sensitive_context.reset(self.token)

else:
Expand Down Expand Up @@ -343,6 +344,8 @@ class SyncToAsync:
# Single-thread executor for thread-sensitive code
single_thread_executor = ThreadPoolExecutor(max_workers=1)

executor_pool = []

# Maintain a contextvar for the current execution context. Optionally used
# for thread sensitive mode.
if sys.version_info >= (3, 7):
Expand Down Expand Up @@ -407,7 +410,10 @@ async def __call__(self, *args, **kwargs):
executor = self.context_to_thread_executor[thread_sensitive_context]
else:
# Create new thread executor in current context
executor = ThreadPoolExecutor(max_workers=1)
try:
executor = self.executor_pool.pop()
except IndexError:
executor = ThreadPoolExecutor(max_workers=1)
self.context_to_thread_executor[thread_sensitive_context] = executor
elif self.deadlock_context and self.deadlock_context.get(False):
raise RuntimeError(
Expand Down Expand Up @@ -506,6 +512,16 @@ def get_current_task():
except RuntimeError:
return None

@classmethod
def release_executor(cls, obj):
executor = cls.context_to_thread_executor.pop(obj, None)
if executor is None:
return
if len(cls.executor_pool) < SYNC_POOL_WORKER_COUNT:
cls.executor_pool.append(executor)
else:
executor.shutdown()


# Lowercase aliases (and decorator friendliness)
async_to_sync = AsyncToSync
Expand Down