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Editing: _threading_local.cpython-33.pyc
� �� f� c @ s� d Z d d l m Z d d l m Z d g Z Gd d � d � Z e d d � � Z Gd d � d � Z d d l m Z m Z d S( u� Thread-local objects. (Note that this module provides a Python version of the 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 = sorted(mydata.__dict__.items()) ... 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 i ( u ref( u contextmanageru localc B sD | Ee Z d Z d Z d Z d d � Z d d � Z d d � Z d S( u _localimplu# A class managing thread-local dictsu keyu dictsu localargsu locallocku __weakref__c C s& d t t | � � | _ i | _ d S( Nu _threading_local._localimpl.( u stru idu keyu dicts( u self( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu __init__� s u _localimpl.__init__c C s t � } | j t | � d S( uP Return the dict for the current thread. Raises KeyError if none defined.i ( u current_threadu dictsu id( u selfu thread( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu get_dict� s u _localimpl.get_dictc s� i } | j } t � } t | � } | � f d d � } | � f d d � } t | | � � t | | � � � | j | <� | f | j | <| S( u8 Create a new dict for the current thread, and return it.c s& � � } | d k r" | j | =n d S( N( u Noneu __dict__( u _u keyu thread( u wrthread( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu local_deleted� s u- _localimpl.create_dict.<locals>.local_deletedc s. � � } | d k r* | j j | � } n d S( N( u Noneu dictsu pop( u _u idtu localu dct( u wrlocal( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu thread_deleted� s u. _localimpl.create_dict.<locals>.thread_deleted( u keyu current_threadu idu refu __dict__u dicts( u selfu localdictu keyu threadu idtu local_deletedu thread_deleted( ( u wrlocalu wrthreadu5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu create_dict� s u _localimpl.create_dictN( u keyu dictsu localargsu locallocku __weakref__( u __name__u __module__u __qualname__u __doc__u __slots__u __init__u get_dictu create_dict( u __locals__( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu _localimpl� s u _localimplc c s� t j | d � } y | j � } Wn= t k ra | j � } | j \ } } | j | | � Yn X| j � t j | d | � d VWd QXd S( Nu _local__implu __dict__( u objectu __getattribute__u get_dictu KeyErroru create_dictu localargsu __init__u locallocku __setattr__( u selfu implu dctu argsu kw( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu _patch� s u _patchc B sJ | Ee Z d Z d Z d d � Z d d � Z d d � Z d d � Z d S( u localu _local__implu __dict__c O s� | s | r- | j t j k r- t d � � n t j | � } t � } | | f | _ t � | _ t j | d | � | j � | S( Nu* Initialization arguments are not supportedu _local__impl( u __init__u objectu TypeErroru __new__u _localimplu localargsu RLocku locallocku __setattr__u create_dict( u clsu argsu kwu selfu impl( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu __new__� s u local.__new__c C s' t | � � t j | | � SWd QXd S( N( u _patchu objectu __getattribute__( u selfu name( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu __getattribute__� s u local.__getattribute__c C sO | d k r% t d | j j � � n t | � � t j | | | � SWd QXd S( Nu __dict__u+ %r object attribute '__dict__' is read-only( u AttributeErroru __class__u __name__u _patchu objectu __setattr__( u selfu nameu value( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu __setattr__� s u local.__setattr__c C sL | d k r% t d | j j � � n t | � � t j | | � SWd QXd S( Nu __dict__u+ %r object attribute '__dict__' is read-only( u AttributeErroru __class__u __name__u _patchu objectu __delattr__( u selfu name( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu __delattr__� s u local.__delattr__N( u _local__implu __dict__( u __name__u __module__u __qualname__u __slots__u __new__u __getattribute__u __setattr__u __delattr__( u __locals__( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu local� s ( u current_threadu RLockN( u __doc__u weakrefu refu contextlibu contextmanageru __all__u _localimplu _patchu localu threadingu current_threadu RLock( ( ( u5 /opt/alt/python33/lib64/python3.3/_threading_local.pyu <module>� s ,&
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