Viewing file:  threadable.py (3.3 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
# -*- test-case-name: twisted.python.threadable -*-
# Copyright (c) 2001-2004 Twisted Matrix Laboratories.
# See LICENSE for details.
"""
A module that will allow your program to be multi-threaded,
micro-threaded, and single-threaded. Currently microthreads are
unimplemented. The idea is to abstract away some commonly used
functionality so that I don't have to special-case it in all programs.
"""
import warnings
from twisted.python import hook
class DummyLock(object):
"""
Hack to allow locks to be unpickled on an unthreaded system.
"""
def __reduce__(self):
return (unpickle_lock, ())
def unpickle_lock():
if threadingmodule is not None:
return XLock()
else:
return DummyLock()
unpickle_lock.__safe_for_unpickling__ = True
def _synchPre(self, *a, **b):
if '_threadable_lock' not in self.__dict__:
_synchLockCreator.acquire()
if '_threadable_lock' not in self.__dict__:
self.__dict__['_threadable_lock'] = XLock()
_synchLockCreator.release()
self._threadable_lock.acquire()
def _synchPost(self, *a, **b):
self._threadable_lock.release()
def synchronize(*klasses):
"""Make all methods listed in each class' synchronized attribute synchronized.
The synchronized attribute should be a list of strings, consisting of the
names of methods that must be synchronized. If we are running in threaded
mode these methods will be wrapped with a lock.
"""
if threadmodule is not None:
for klass in klasses:
for methodName in klass.synchronized:
hook.addPre(klass, methodName, _synchPre)
hook.addPost(klass, methodName, _synchPost)
def init(with_threads=1):
"""Initialize threading.
Don't bother calling this. If it needs to happen, it will happen.
"""
global threaded, _synchLockCreator, XLock
if with_threads:
if not threaded:
if threadmodule is not None:
threaded = True
class XLock(threadingmodule._RLock, object):
def __reduce__(self):
return (unpickle_lock, ())
_synchLockCreator = XLock()
else:
raise RuntimeError("Cannot initialize threading, platform lacks thread support")
else:
if threaded:
raise RuntimeError("Cannot uninitialize threads")
else:
pass
_dummyID = object()
def getThreadID():
if threadmodule is None:
return _dummyID
return threadmodule.get_ident()
def isInIOThread():
"""Are we in the thread responsable for I/O requests (the event loop)?
"""
return ioThread == getThreadID()
def registerAsIOThread():
"""Mark the current thread as responsable for I/O requests.
"""
global ioThread
ioThread = getThreadID()
ioThread = None
threaded = False
def whenThreaded(cb):
warnings.warn("threadable.whenThreaded is deprecated. "
"Use application-level logic instead.",
DeprecationWarning, stacklevel=2)
cb()
try:
import thread as threadmodule
import threading as threadingmodule
except ImportError:
threadmodule = None
threadingmodule = None
else:
init(True)
__all__ = ['isInIOThread', 'registerAsIOThread', 'getThreadID', 'XLock',
'whenThreaded']
|