cpython-lru_cache-weakref: Lib/_threading

annotate Lib/_threading_local.py @ 70817:dd775b1561ba

Fix markup.

author	Georg Brandl <georg@python.org>
date	Tue, 14 Jun 2011 21:09:55 +0200
parents	3c9232a684ae
children

rev	line source
37879 f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	1 """Thread-local objects.
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	2
37879 f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	3 (Note that this module provides a Python version of the threading.local
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	4 class. Depending on the version of Python you're using, there may be a
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	5 faster one available. You should always import the `local` class from
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	6 `threading`.)
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	7
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	8 Thread-local objects support the management of thread-local data.
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	9 If you have data that you want to be local to a thread, simply create
32686 9a3b4219bcbe Typo fixes Andrew M. Kuchling <amk@amk.ca> parents: 32673 diff changeset	10 a thread-local object and use its attributes:
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	11
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	12 >>> mydata = local()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	13 >>> mydata.number = 42
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	14 >>> mydata.number
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	15 42
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	16
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	17 You can also access the local-object's dictionary:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	18
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	19 >>> mydata.__dict__
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	20 {'number': 42}
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	21 >>> mydata.__dict__.setdefault('widgets', [])
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	22 []
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	23 >>> mydata.widgets
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	24 []
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	25
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	26 What's important about thread-local objects is that their data are
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	27 local to a thread. If we access the data in a different thread:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	28
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	29 >>> log = []
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	30 >>> def f():
40809 f340cb045bf9 - PEP 3106: dict.iterkeys(), .iteritems(), .itervalues() are now gone; Guido van Rossum <guido@python.org> parents: 37879 diff changeset	31 ... items = sorted(mydata.__dict__.items())
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	32 ... log.append(items)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	33 ... mydata.number = 11
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	34 ... log.append(mydata.number)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	35
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	36 >>> import threading
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	37 >>> thread = threading.Thread(target=f)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	38 >>> thread.start()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	39 >>> thread.join()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	40 >>> log
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	41 [[], 11]
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	42
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	43 we get different data. Furthermore, changes made in the other thread
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	44 don't affect data seen in this thread:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	45
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	46 >>> mydata.number
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	47 42
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	48
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	49 Of course, values you get from a local object, including a __dict__
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	50 attribute, are for whatever thread was current at the time the
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	51 attribute was read. For that reason, you generally don't want to save
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	52 these values across threads, as they apply only to the thread they
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	53 came from.
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	54
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	55 You can create custom local objects by subclassing the local class:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	56
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	57 >>> class MyLocal(local):
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	58 ... number = 2
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	59 ... initialized = False
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	60 ... def __init__(self, **kw):
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	61 ... if self.initialized:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	62 ... raise SystemError('__init__ called too many times')
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	63 ... self.initialized = True
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	64 ... self.__dict__.update(kw)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	65 ... def squared(self):
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	66 ... return self.number ** 2
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	67
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	68 This can be useful to support default values, methods and
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	69 initialization. Note that if you define an __init__ method, it will be
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	70 called each time the local object is used in a separate thread. This
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	71 is necessary to initialize each thread's dictionary.
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	72
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	73 Now if we create a local object:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	74
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	75 >>> mydata = MyLocal(color='red')
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	76
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	77 Now we have a default number:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	78
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	79 >>> mydata.number
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	80 2
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	81
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	82 an initial color:
32736 c3a096bfbd6b Whitespace normalization, via reindent.py. Tim Peters <tim.peters@gmail.com> parents: 32686 diff changeset	83
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	84 >>> mydata.color
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	85 'red'
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	86 >>> del mydata.color
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	87
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	88 And a method that operates on the data:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	89
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	90 >>> mydata.squared()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	91 4
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	92
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	93 As before, we can access the data in a separate thread:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	94
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	95 >>> log = []
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	96 >>> thread = threading.Thread(target=f)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	97 >>> thread.start()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	98 >>> thread.join()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	99 >>> log
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	100 [[('color', 'red'), ('initialized', True)], 11]
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	101
32686 9a3b4219bcbe Typo fixes Andrew M. Kuchling <amk@amk.ca> parents: 32673 diff changeset	102 without affecting this thread's data:
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	103
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	104 >>> mydata.number
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	105 2
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	106 >>> mydata.color
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	107 Traceback (most recent call last):
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	108 ...
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	109 AttributeError: 'MyLocal' object has no attribute 'color'
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	110
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	111 Note that subclasses can define slots, but they are not thread
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	112 local. They are shared across threads:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	113
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	114 >>> class MyLocal(local):
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	115 ... __slots__ = 'number'
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	116
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	117 >>> mydata = MyLocal()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	118 >>> mydata.number = 42
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	119 >>> mydata.color = 'red'
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	120
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	121 So, the separate thread:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	122
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	123 >>> thread = threading.Thread(target=f)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	124 >>> thread.start()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	125 >>> thread.join()
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	126
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	127 affects what we see:
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	128
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	129 >>> mydata.number
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	130 11
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	131
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	132 >>> del mydata
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	133 """
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	134
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	135 from weakref import ref
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	136 from contextlib import contextmanager
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	137
37879 f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	138 __all__ = ["local"]
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	139
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	140 # We need to use objects from the threading module, but the threading
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	141 # module may also want to use our `local` class, if support for locals
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	142 # isn't compiled in to the `thread` module. This creates potential problems
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	143 # with circular imports. For that reason, we don't import `threading`
f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	144 # until the bottom of this file (a hack sufficient to worm around the
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	145 # potential problems). Note that all platforms on CPython do have support
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	146 # for locals in the `thread` module, and there is no circular import problem
37879 f731859e9b3b Merge p3yk branch with the trunk up to revision 45595. This breaks a fair Thomas Wouters <thomas@python.org> parents: 35941 diff changeset	147 # then, so problems introduced by fiddling the order of imports here won't
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	148 # manifest.
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	149
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	150 class _localimpl:
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	151 """A class managing thread-local dicts"""
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	152 __slots__ = 'key', 'dicts', 'localargs', 'locallock', '__weakref__'
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	153
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	154 def __init__(self):
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	155 # The key used in the Thread objects' attribute dicts.
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	156 # We keep it a string for speed but make it unlikely to clash with
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	157 # a "real" attribute.
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	158 self.key = '_threading_local._localimpl.' + str(id(self))
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	159 # { id(Thread) -> (ref(Thread), thread-local dict) }
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	160 self.dicts = {}
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	161
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	162 def get_dict(self):
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	163 """Return the dict for the current thread. Raises KeyError if none
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	164 defined."""
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	165 thread = current_thread()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	166 return self.dicts[id(thread)][1]
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	167
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	168 def create_dict(self):
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	169 """Create a new dict for the current thread, and return it."""
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	170 localdict = {}
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	171 key = self.key
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	172 thread = current_thread()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	173 idt = id(thread)
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	174 def local_deleted(_, key=key):
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	175 # When the localimpl is deleted, remove the thread attribute.
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	176 thread = wrthread()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	177 if thread is not None:
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	178 del thread.__dict__[key]
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	179 def thread_deleted(_, idt=idt):
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	180 # When the thread is deleted, remove the local dict.
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	181 # Note that this is suboptimal if the thread object gets
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	182 # caught in a reference loop. We would like to be called
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	183 # as soon as the OS-level thread ends instead.
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	184 local = wrlocal()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	185 if local is not None:
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	186 dct = local.dicts.pop(idt)
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	187 wrlocal = ref(self, local_deleted)
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	188 wrthread = ref(thread, thread_deleted)
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	189 thread.__dict__[key] = wrlocal
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	190 self.dicts[idt] = wrthread, localdict
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	191 return localdict
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	192
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	193
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	194 @contextmanager
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	195 def _patch(self):
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	196 impl = object.__getattribute__(self, '_local__impl')
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	197 try:
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	198 dct = impl.get_dict()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	199 except KeyError:
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	200 dct = impl.create_dict()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	201 args, kw = impl.localargs
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	202 self.__init__(args, *kw)
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	203 with impl.locallock:
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	204 object.__setattr__(self, '__dict__', dct)
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	205 yield
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	206
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	207
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	208 class local:
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	209 __slots__ = '_local__impl', '__dict__'
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	210
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	211 def __new__(cls, args, *kw):
59031 ef732c3db63d fixes issue #1522237, bad init check in _threading_local Jack Diederich <jackdied@gmail.com> parents: 57121 diff changeset	212 if (args or kw) and (cls.__init__ is object.__init__):
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	213 raise TypeError("Initialization arguments are not supported")
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	214 self = object.__new__(cls)
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	215 impl = _localimpl()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	216 impl.localargs = (args, kw)
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	217 impl.locallock = RLock()
c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	218 object.__setattr__(self, '_local__impl', impl)
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	219 # We need to create the thread dict in anticipation of
35941 033bb4db5ae8 Fix some comment typos Neal Norwitz <nnorwitz@gmail.com> parents: 32736 diff changeset	220 # __init__ being called, to make sure we don't call it
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	221 # again ourselves.
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	222 impl.create_dict()
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	223 return self
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	224
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	225 def __getattribute__(self, name):
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	226 with _patch(self):
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	227 return object.__getattribute__(self, name)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	228
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	229 def __setattr__(self, name, value):
64299 4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	230 if name == '__dict__':
4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	231 raise AttributeError(
4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	232 "%r object attribute '__dict__' is read-only"
4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	233 % self.__class__.__name__)
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	234 with _patch(self):
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	235 return object.__setattr__(self, name, value)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	236
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	237 def __delattr__(self, name):
64299 4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	238 if name == '__dict__':
4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	239 raise AttributeError(
4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	240 "%r object attribute '__dict__' is read-only"
4c978cd3640f Merged revisions 84344 via svnmerge from Antoine Pitrou <solipsis@pitrou.net> parents: 57121 diff changeset	241 % self.__class__.__name__)
64543 c2d6f0cf926a Issue #9707: Rewritten reference implementation of threading.local which Antoine Pitrou <solipsis@pitrou.net> parents: 64298 diff changeset	242 with _patch(self):
32673 97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	243 return object.__delattr__(self, name)
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	244
97768d87394a Implemented thread-local data as proposed on python-dev: Jim Fulton <jim@zope.com> parents: diff changeset	245
47615 045f83a1b864 Merged revisions 64125 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 40809 diff changeset	246 from threading import current_thread, RLock

Mercurial > cpython-lru_cache-weakref

annotate Lib/_threading_local.py @ 70817:dd775b1561ba