| Index: third_party/cherrypy/_cpthreadinglocal.py
|
| ===================================================================
|
| --- third_party/cherrypy/_cpthreadinglocal.py (revision 0)
|
| +++ third_party/cherrypy/_cpthreadinglocal.py (revision 0)
|
| @@ -0,0 +1,239 @@
|
| +# This is a backport of Python-2.4's threading.local() implementation
|
| +
|
| +"""Thread-local objects
|
| +
|
| +(Note that this module provides a Python version of thread
|
| + threading.local class. Depending on the version of Python you're
|
| + using, there may be a faster one available. You should always import
|
| + the local class from threading.)
|
| +
|
| +Thread-local objects support the management of thread-local data.
|
| +If you have data that you want to be local to a thread, simply create
|
| +a thread-local object and use its attributes:
|
| +
|
| + >>> mydata = local()
|
| + >>> mydata.number = 42
|
| + >>> mydata.number
|
| + 42
|
| +
|
| +You can also access the local-object's dictionary:
|
| +
|
| + >>> mydata.__dict__
|
| + {'number': 42}
|
| + >>> mydata.__dict__.setdefault('widgets', [])
|
| + []
|
| + >>> mydata.widgets
|
| + []
|
| +
|
| +What's important about thread-local objects is that their data are
|
| +local to a thread. If we access the data in a different thread:
|
| +
|
| + >>> log = []
|
| + >>> def f():
|
| + ... items = mydata.__dict__.items()
|
| + ... items.sort()
|
| + ... log.append(items)
|
| + ... mydata.number = 11
|
| + ... log.append(mydata.number)
|
| +
|
| + >>> import threading
|
| + >>> thread = threading.Thread(target=f)
|
| + >>> thread.start()
|
| + >>> thread.join()
|
| + >>> log
|
| + [[], 11]
|
| +
|
| +we get different data. Furthermore, changes made in the other thread
|
| +don't affect data seen in this thread:
|
| +
|
| + >>> mydata.number
|
| + 42
|
| +
|
| +Of course, values you get from a local object, including a __dict__
|
| +attribute, are for whatever thread was current at the time the
|
| +attribute was read. For that reason, you generally don't want to save
|
| +these values across threads, as they apply only to the thread they
|
| +came from.
|
| +
|
| +You can create custom local objects by subclassing the local class:
|
| +
|
| + >>> class MyLocal(local):
|
| + ... number = 2
|
| + ... initialized = False
|
| + ... def __init__(self, **kw):
|
| + ... if self.initialized:
|
| + ... raise SystemError('__init__ called too many times')
|
| + ... self.initialized = True
|
| + ... self.__dict__.update(kw)
|
| + ... def squared(self):
|
| + ... return self.number ** 2
|
| +
|
| +This can be useful to support default values, methods and
|
| +initialization. Note that if you define an __init__ method, it will be
|
| +called each time the local object is used in a separate thread. This
|
| +is necessary to initialize each thread's dictionary.
|
| +
|
| +Now if we create a local object:
|
| +
|
| + >>> mydata = MyLocal(color='red')
|
| +
|
| +Now we have a default number:
|
| +
|
| + >>> mydata.number
|
| + 2
|
| +
|
| +an initial color:
|
| +
|
| + >>> mydata.color
|
| + 'red'
|
| + >>> del mydata.color
|
| +
|
| +And a method that operates on the data:
|
| +
|
| + >>> mydata.squared()
|
| + 4
|
| +
|
| +As before, we can access the data in a separate thread:
|
| +
|
| + >>> log = []
|
| + >>> thread = threading.Thread(target=f)
|
| + >>> thread.start()
|
| + >>> thread.join()
|
| + >>> log
|
| + [[('color', 'red'), ('initialized', True)], 11]
|
| +
|
| +without affecting this thread's data:
|
| +
|
| + >>> mydata.number
|
| + 2
|
| + >>> mydata.color
|
| + Traceback (most recent call last):
|
| + ...
|
| + AttributeError: 'MyLocal' object has no attribute 'color'
|
| +
|
| +Note that subclasses can define slots, but they are not thread
|
| +local. They are shared across threads:
|
| +
|
| + >>> class MyLocal(local):
|
| + ... __slots__ = 'number'
|
| +
|
| + >>> mydata = MyLocal()
|
| + >>> mydata.number = 42
|
| + >>> mydata.color = 'red'
|
| +
|
| +So, the separate thread:
|
| +
|
| + >>> thread = threading.Thread(target=f)
|
| + >>> thread.start()
|
| + >>> thread.join()
|
| +
|
| +affects what we see:
|
| +
|
| + >>> mydata.number
|
| + 11
|
| +
|
| +>>> del mydata
|
| +"""
|
| +
|
| +# Threading import is at end
|
| +
|
| +class _localbase(object):
|
| + __slots__ = '_local__key', '_local__args', '_local__lock'
|
| +
|
| + def __new__(cls, *args, **kw):
|
| + self = object.__new__(cls)
|
| + key = 'thread.local.' + str(id(self))
|
| + object.__setattr__(self, '_local__key', key)
|
| + object.__setattr__(self, '_local__args', (args, kw))
|
| + object.__setattr__(self, '_local__lock', RLock())
|
| +
|
| + if args or kw and (cls.__init__ is object.__init__):
|
| + raise TypeError("Initialization arguments are not supported")
|
| +
|
| + # We need to create the thread dict in anticipation of
|
| + # __init__ being called, to make sure we don't call it
|
| + # again ourselves.
|
| + dict = object.__getattribute__(self, '__dict__')
|
| + currentThread().__dict__[key] = dict
|
| +
|
| + return self
|
| +
|
| +def _patch(self):
|
| + key = object.__getattribute__(self, '_local__key')
|
| + d = currentThread().__dict__.get(key)
|
| + if d is None:
|
| + d = {}
|
| + currentThread().__dict__[key] = d
|
| + object.__setattr__(self, '__dict__', d)
|
| +
|
| + # we have a new instance dict, so call out __init__ if we have
|
| + # one
|
| + cls = type(self)
|
| + if cls.__init__ is not object.__init__:
|
| + args, kw = object.__getattribute__(self, '_local__args')
|
| + cls.__init__(self, *args, **kw)
|
| + else:
|
| + object.__setattr__(self, '__dict__', d)
|
| +
|
| +class local(_localbase):
|
| +
|
| + def __getattribute__(self, name):
|
| + lock = object.__getattribute__(self, '_local__lock')
|
| + lock.acquire()
|
| + try:
|
| + _patch(self)
|
| + return object.__getattribute__(self, name)
|
| + finally:
|
| + lock.release()
|
| +
|
| + def __setattr__(self, name, value):
|
| + lock = object.__getattribute__(self, '_local__lock')
|
| + lock.acquire()
|
| + try:
|
| + _patch(self)
|
| + return object.__setattr__(self, name, value)
|
| + finally:
|
| + lock.release()
|
| +
|
| + def __delattr__(self, name):
|
| + lock = object.__getattribute__(self, '_local__lock')
|
| + lock.acquire()
|
| + try:
|
| + _patch(self)
|
| + return object.__delattr__(self, name)
|
| + finally:
|
| + lock.release()
|
| +
|
| +
|
| + def __del__():
|
| + threading_enumerate = enumerate
|
| + __getattribute__ = object.__getattribute__
|
| +
|
| + def __del__(self):
|
| + key = __getattribute__(self, '_local__key')
|
| +
|
| + try:
|
| + threads = list(threading_enumerate())
|
| + except:
|
| + # if enumerate fails, as it seems to do during
|
| + # shutdown, we'll skip cleanup under the assumption
|
| + # that there is nothing to clean up
|
| + return
|
| +
|
| + for thread in threads:
|
| + try:
|
| + __dict__ = thread.__dict__
|
| + except AttributeError:
|
| + # Thread is dying, rest in peace
|
| + continue
|
| +
|
| + if key in __dict__:
|
| + try:
|
| + del __dict__[key]
|
| + except KeyError:
|
| + pass # didn't have anything in this thread
|
| +
|
| + return __del__
|
| + __del__ = __del__()
|
| +
|
| +from threading import currentThread, enumerate, RLock
|
|
|
| Property changes on: third_party/cherrypy/_cpthreadinglocal.py
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|