debian-celery/celery/_state.py

160 lines
3.8 KiB
Python

# -*- coding: utf-8 -*-
"""
celery._state
~~~~~~~~~~~~~~~
This is an internal module containing thread state
like the ``current_app``, and ``current_task``.
This module shouldn't be used directly.
"""
from __future__ import absolute_import, print_function
import os
import sys
import threading
import weakref
from celery.local import Proxy
from celery.utils.threads import LocalStack
try:
from weakref import WeakSet as AppSet
except ImportError: # XXX Py2.6
class AppSet(object): # noqa
def __init__(self):
self._refs = set()
def add(self, app):
self._refs.add(weakref.ref(app))
def __iter__(self):
dirty = []
try:
for appref in self._refs:
app = appref()
if app is None:
dirty.append(appref)
else:
yield app
finally:
while dirty:
self._refs.discard(dirty.pop())
__all__ = ['set_default_app', 'get_current_app', 'get_current_task',
'get_current_worker_task', 'current_app', 'current_task',
'connect_on_app_finalize']
#: Global default app used when no current app.
default_app = None
#: List of all app instances (weakrefs), must not be used directly.
_apps = AppSet()
#: global set of functions to call whenever a new app is finalized
#: E.g. Shared tasks, and builtin tasks are created
#: by adding callbacks here.
_on_app_finalizers = set()
_task_join_will_block = False
def connect_on_app_finalize(callback):
_on_app_finalizers.add(callback)
return callback
def _announce_app_finalized(app):
callbacks = set(_on_app_finalizers)
for callback in callbacks:
callback(app)
def _set_task_join_will_block(blocks):
global _task_join_will_block
_task_join_will_block = blocks
def task_join_will_block():
return _task_join_will_block
class _TLS(threading.local):
#: Apps with the :attr:`~celery.app.base.BaseApp.set_as_current` attribute
#: sets this, so it will always contain the last instantiated app,
#: and is the default app returned by :func:`app_or_default`.
current_app = None
_tls = _TLS()
_task_stack = LocalStack()
def set_default_app(app):
global default_app
default_app = app
def _get_current_app():
if default_app is None:
#: creates the global fallback app instance.
from celery.app import Celery
set_default_app(Celery(
'default',
loader=os.environ.get('CELERY_LOADER') or 'default',
fixups=[],
set_as_current=False, accept_magic_kwargs=True,
))
return _tls.current_app or default_app
def _set_current_app(app):
_tls.current_app = app
C_STRICT_APP = os.environ.get('C_STRICT_APP')
if os.environ.get('C_STRICT_APP'): # pragma: no cover
def get_current_app():
raise Exception('USES CURRENT APP')
import traceback
print('-- USES CURRENT_APP', file=sys.stderr) # noqa+
traceback.print_stack(file=sys.stderr)
return _get_current_app()
else:
get_current_app = _get_current_app
def get_current_task():
"""Currently executing task."""
return _task_stack.top
def get_current_worker_task():
"""Currently executing task, that was applied by the worker.
This is used to differentiate between the actual task
executed by the worker and any task that was called within
a task (using ``task.__call__`` or ``task.apply``)
"""
for task in reversed(_task_stack.stack):
if not task.request.called_directly:
return task
#: Proxy to current app.
current_app = Proxy(get_current_app)
#: Proxy to current task.
current_task = Proxy(get_current_task)
def _register_app(app):
_apps.add(app)
def _get_active_apps():
return _apps