diff options
| -rw-r--r-- | Lib/tempfile.py | 77 | ||||
| -rw-r--r-- | Lib/test/test_tempfile.py | 61 |
2 files changed, 41 insertions, 97 deletions
diff --git a/Lib/tempfile.py b/Lib/tempfile.py index 900222f..692bea5 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -80,33 +80,6 @@ tempdir = None _once_lock = _allocate_lock() -def _once(var, initializer): - """Wrapper to execute an initialization operation just once, - even if multiple threads reach the same point at the same time. - - var is the name (as a string) of the variable to be entered into - the current global namespace. - - initializer is a callable which will return the appropriate initial - value for variable. It will be called only if variable is not - present in the global namespace, or its current value is None. - - Do not call _once from inside an initializer routine, it will deadlock. - """ - - vars = globals() - # Check first outside the lock. - if vars.get(var) is not None: - return - try: - _once_lock.acquire() - # Check again inside the lock. - if vars.get(var) is not None: - return - vars[var] = initializer() - finally: - _once_lock.release() - class _RandomNameSequence: """An instance of _RandomNameSequence generates an endless sequence of unpredictable strings which can safely be incorporated @@ -178,8 +151,7 @@ def _candidate_tempdir_list(): def _get_default_tempdir(): """Calculate the default directory to use for temporary files. - This routine should be called through '_once' (see above) as we - do not want multiple threads attempting this calculation simultaneously. + This routine should be called exactly once. We determine whether or not a candidate temp dir is usable by trying to create and write to a file in that directory. If this @@ -212,10 +184,19 @@ def _get_default_tempdir(): raise IOError, (_errno.ENOENT, ("No usable temporary directory found in %s" % dirlist)) +_name_sequence = None + def _get_candidate_names(): """Common setup sequence for all user-callable interfaces.""" - _once('_name_sequence', _RandomNameSequence) + global _name_sequence + if _name_sequence is None: + _once_lock.acquire() + try: + if _name_sequence is None: + _name_sequence = _RandomNameSequence() + finally: + _once_lock.release() return _name_sequence @@ -245,12 +226,21 @@ def gettempprefix(): """Accessor for tempdir.template.""" return template +tempdir = None + def gettempdir(): """Accessor for tempdir.tempdir.""" - _once('tempdir', _get_default_tempdir) + global tempdir + if tempdir is None: + _once_lock.acquire() + try: + if tempdir is None: + tempdir = _get_default_tempdir() + finally: + _once_lock.release() return tempdir -def mkstemp(suffix="", prefix=template, dir=gettempdir(), text=False): +def mkstemp(suffix="", prefix=template, dir=None, text=False): """mkstemp([suffix, [prefix, [dir, [text]]]]) User-callable function to create and return a unique temporary file. The return value is a pair (fd, name) where fd is the @@ -277,6 +267,9 @@ def mkstemp(suffix="", prefix=template, dir=gettempdir(), text=False): Caller is responsible for deleting the file when done with it. """ + if dir is None: + dir = gettempdir() + if text: flags = _text_openflags else: @@ -285,7 +278,7 @@ def mkstemp(suffix="", prefix=template, dir=gettempdir(), text=False): return _mkstemp_inner(dir, prefix, suffix, flags) -def mkdtemp(suffix="", prefix=template, dir=gettempdir()): +def mkdtemp(suffix="", prefix=template, dir=None): """mkdtemp([suffix, [prefix, [dir]]]) User-callable function to create and return a unique temporary directory. The return value is the pathname of the directory. @@ -299,6 +292,9 @@ def mkdtemp(suffix="", prefix=template, dir=gettempdir()): Caller is responsible for deleting the directory when done with it. """ + if dir is None: + dir = gettempdir() + names = _get_candidate_names() for seq in xrange(TMP_MAX): @@ -314,7 +310,7 @@ def mkdtemp(suffix="", prefix=template, dir=gettempdir()): raise IOError, (_errno.EEXIST, "No usable temporary directory name found") -def mktemp(suffix="", prefix=template, dir=gettempdir()): +def mktemp(suffix="", prefix=template, dir=None): """mktemp([suffix, [prefix, [dir]]]) User-callable function to return a unique temporary file name. The file is not created. @@ -332,6 +328,9 @@ def mktemp(suffix="", prefix=template, dir=gettempdir()): _warn("mktemp is a potential security risk to your program", RuntimeWarning, stacklevel=2) + if dir is None: + dir = gettempdir() + names = _get_candidate_names() for seq in xrange(TMP_MAX): name = names.next() @@ -383,7 +382,7 @@ class _TemporaryFileWrapper: self.close() def NamedTemporaryFile(mode='w+b', bufsize=-1, suffix="", - prefix=template, dir=gettempdir()): + prefix=template, dir=None): """Create and return a temporary file. Arguments: 'prefix', 'suffix', 'dir' -- as for mkstemp. @@ -396,6 +395,9 @@ def NamedTemporaryFile(mode='w+b', bufsize=-1, suffix="", closed. """ + if dir is None: + dir = gettempdir() + if 'b' in mode: flags = _bin_openflags else: @@ -417,7 +419,7 @@ if _os.name != 'posix' or _os.sys.platform == 'cygwin': else: def TemporaryFile(mode='w+b', bufsize=-1, suffix="", - prefix=template, dir=gettempdir()): + prefix=template, dir=None): """Create and return a temporary file. Arguments: 'prefix', 'suffix', 'directory' -- as for mkstemp. @@ -429,6 +431,9 @@ else: exist when it is closed. """ + if dir is None: + dir = gettempdir() + if 'b' in mode: flags = _bin_openflags else: diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py index 575986f..10426b3 100644 --- a/Lib/test/test_tempfile.py +++ b/Lib/test/test_tempfile.py @@ -84,67 +84,6 @@ class test_exports(TC): test_classes.append(test_exports) -class test__once(TC): - """Test the internal function _once.""" - - def setUp(self): - tempfile.once_var = None - self.already_called = 0 - - def tearDown(self): - del tempfile.once_var - - def callMeOnce(self): - self.failIf(self.already_called, "callMeOnce called twice") - self.already_called = 1 - return 24 - - def do_once(self): - tempfile._once('once_var', self.callMeOnce) - - def test_once_initializes(self): - """_once initializes its argument""" - - self.do_once() - - self.assertEqual(tempfile.once_var, 24, - "once_var=%d, not 24" % tempfile.once_var) - self.assertEqual(self.already_called, 1, - "already_called=%d, not 1" % self.already_called) - - def test_once_means_once(self): - """_once calls the callback just once""" - - self.do_once() - self.do_once() - self.do_once() - self.do_once() - - def test_once_namespace_safe(self): - """_once does not modify anything but its argument""" - - env_copy = tempfile.__dict__.copy() - - self.do_once() - - env = tempfile.__dict__ - - a = env.keys() - a.sort() - b = env_copy.keys() - b.sort() - - self.failIf(len(a) != len(b)) - for i in xrange(len(a)): - self.failIf(a[i] != b[i]) - - key = a[i] - if key != 'once_var': - self.failIf(env[key] != env_copy[key]) - -test_classes.append(test__once) - - class test__RandomNameSequence(TC): """Test the internal iterator object _RandomNameSequence.""" |