This document describes the current stable version of Celery (4.4). For development docs, go here.

Source code for celery.concurrency.eventlet

# -*- coding: utf-8 -*-
"""Eventlet execution pool."""
from __future__ import absolute_import, unicode_literals

import sys

from kombu.asynchronous import timer as _timer  # noqa
from kombu.five import monotonic

from celery import signals  # noqa

from . import base  # noqa

__all__ = ('TaskPool',)

W_RACE = """\
Celery module with %s imported before eventlet patched\
RACE_MODS = ('billiard.', 'celery.', 'kombu.')

#: Warn if we couldn't patch early enough,
#: and thread/socket depending celery modules have already been loaded.
for mod in (mod for mod in sys.modules if mod.startswith(RACE_MODS)):
    for side in ('thread', 'threading', 'socket'):  # pragma: no cover
        if getattr(mod, side, None):
            import warnings
            warnings.warn(RuntimeWarning(W_RACE % side))

def apply_target(target, args=(), kwargs=None, callback=None,
                 accept_callback=None, getpid=None):
    kwargs = {} if not kwargs else kwargs
    return base.apply_target(target, args, kwargs, callback, accept_callback,

class Timer(_timer.Timer):
    """Eventlet Timer."""

    def __init__(self, *args, **kwargs):
        from eventlet.greenthread import spawn_after
        from greenlet import GreenletExit
        super(Timer, self).__init__(*args, **kwargs)

        self.GreenletExit = GreenletExit
        self._spawn_after = spawn_after
        self._queue = set()

    def _enter(self, eta, priority, entry, **kwargs):
        secs = max(eta - monotonic(), 0)
        g = self._spawn_after(secs, entry)
        self._queue.add(g), entry)
        g.entry = entry
        g.eta = eta
        g.priority = priority
        g.canceled = False
        return g

    def _entry_exit(self, g, entry):
            except self.GreenletExit:
                g.canceled = True

    def clear(self):
        queue = self._queue
        while queue:
            except (KeyError, self.GreenletExit):

    def cancel(self, tref):
        except self.GreenletExit:

    def queue(self):
        return self._queue

[docs]class TaskPool(base.BasePool): """Eventlet Task Pool.""" Timer = Timer signal_safe = False is_green = True task_join_will_block = False _pool = None _quick_put = None def __init__(self, *args, **kwargs): from eventlet import greenthread from eventlet.greenpool import GreenPool self.Pool = GreenPool self.getcurrent = greenthread.getcurrent self.getpid = lambda: id(greenthread.getcurrent()) self.spawn_n = greenthread.spawn_n super(TaskPool, self).__init__(*args, **kwargs)
[docs] def on_start(self): self._pool = self.Pool(self.limit) signals.eventlet_pool_started.send(sender=self) self._quick_put = self._pool.spawn_n self._quick_apply_sig = signals.eventlet_pool_apply.send
[docs] def on_stop(self): signals.eventlet_pool_preshutdown.send(sender=self) if self._pool is not None: self._pool.waitall() signals.eventlet_pool_postshutdown.send(sender=self)
[docs] def on_apply(self, target, args=None, kwargs=None, callback=None, accept_callback=None, **_): self._quick_apply_sig( sender=self, target=target, args=args, kwargs=kwargs, ) self._quick_put(apply_target, target, args, kwargs, callback, accept_callback, self.getpid)
[docs] def grow(self, n=1): limit = self.limit + n self._pool.resize(limit) self.limit = limit
[docs] def shrink(self, n=1): limit = self.limit - n self._pool.resize(limit) self.limit = limit
def _get_info(self): info = super(TaskPool, self)._get_info() info.update({ 'max-concurrency': self.limit, 'free-threads':, 'running-threads': self._pool.running(), }) return info