Mini Shell
"""Internal state.
This is an internal module containing thread state
like the ``current_app``, and ``current_task``.
This module shouldn't be used directly.
"""
import os
import sys
import threading
import weakref
from celery.local import Proxy
from celery.utils.threads import LocalStack
__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
#: Function returning the app provided or the default app if none.
#:
#: The environment variable :envvar:`CELERY_TRACE_APP` is used to
#: trace app leaks. When enabled an exception is raised if there
#: is no active app.
app_or_default = None
#: List of all app instances (weakrefs), mustn't be used directly.
_apps = weakref.WeakSet()
#: Global set of functions to call whenever a new app is finalized.
#: Shared tasks, and built-in tasks are created by adding callbacks here.
_on_app_finalizers = set()
_task_join_will_block = False
def connect_on_app_finalize(callback):
"""Connect callback to be called when any app is finalized."""
_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()
#: Function used to push a task to the thread local stack
#: keeping track of the currently executing task.
#: You must remember to pop the task after.
push_current_task = _task_stack.push
#: Function used to pop a task from the thread local stack
#: keeping track of the currently executing task.
pop_current_task = _task_stack.pop
def set_default_app(app):
"""Set default 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.base import Celery
set_default_app(Celery(
'default', fixups=[], set_as_current=False,
loader=os.environ.get('CELERY_LOADER') or 'default',
))
return _tls.current_app or default_app
def _set_current_app(app):
_tls.current_app = app
if os.environ.get('C_STRICT_APP'): # pragma: no cover
def get_current_app():
"""Return the current app."""
raise RuntimeError('USES CURRENT APP')
elif os.environ.get('C_WARN_APP'): # pragma: no cover
def get_current_app():
import traceback
print('-- USES CURRENT_APP', file=sys.stderr) # +
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 _deregister_app(app):
_apps.discard(app)
def _get_active_apps():
return _apps
def _app_or_default(app=None):
if app is None:
return get_current_app()
return app
def _app_or_default_trace(app=None): # pragma: no cover
from traceback import print_stack
try:
from billiard.process import current_process
except ImportError:
current_process = None
if app is None:
if getattr(_tls, 'current_app', None):
print('-- RETURNING TO CURRENT APP --') # +
print_stack()
return _tls.current_app
if not current_process or current_process()._name == 'MainProcess':
raise Exception('DEFAULT APP')
print('-- RETURNING TO DEFAULT APP --') # +
print_stack()
return default_app
return app
def enable_trace():
"""Enable tracing of app instances."""
global app_or_default
app_or_default = _app_or_default_trace
def disable_trace():
"""Disable tracing of app instances."""
global app_or_default
app_or_default = _app_or_default
if os.environ.get('CELERY_TRACE_APP'): # pragma: no cover
enable_trace()
else:
disable_trace()
Zerion Mini Shell 1.0