Author: brosner
Date: Wed Dec 10 10:09:09 2008
New Revision: 118
Modified:
trunk/notification/lockfile.py
Log:
Updated the lockfile to 0.6. This fixes Python 2.4 compatibility.
Modified: trunk/notification/lockfile.py
==============================================================================
--- trunk/notification/lockfile.py (original)
+++ trunk/notification/lockfile.py Wed Dec 10 10:09:09 2008
@@ -7,13 +7,13 @@
Usage:
->>> lock = FileLock(_testfile())
+>>> lock = FileLock('somefile')
>>> try:
... lock.acquire()
... except AlreadyLocked:
-... print _testfile(), 'is locked already.'
+... print 'somefile', 'is locked already.'
... except LockFailed:
-... print _testfile(), 'can\\'t be locked.'
+... print 'somefile', 'can\\'t be locked.'
... else:
... print 'got lock'
got lock
@@ -21,7 +21,7 @@
True
>>> lock.release()
->>> lock = FileLock(_testfile())
+>>> lock = FileLock('somefile')
>>> print lock.is_locked()
False
>>> with lock:
@@ -46,21 +46,27 @@
UnlockError - base class for all unlocking exceptions
AlreadyUnlocked - File was not locked.
NotMyLock - File was locked but not by the current
thread/process
-
-To do:
- * Write more test cases
- - verify that all lines of code are executed
- * Describe on-disk file structures in the documentation.
"""
-from __future__ import division, with_statement
+from __future__ import division
+import sys
import socket
import os
import threading
import time
import errno
-import thread
+
+# Work with PEP8 and non-PEP8 versions of threading module.
+try:
+ threading.current_thread
+except AttributeError:
+ threading.current_thread = threading.currentThread
+ threading.Thread.get_name = threading.Thread.getName
+
+__all__ = ['Error', 'LockError', 'LockTimeout', 'AlreadyLocked',
+ 'LockFailed', 'UnlockError', 'NotLocked', 'NotMyLock',
+ 'LinkFileLock', 'MkdirFileLock', 'SQLiteFileLock']
class Error(Exception):
"""
@@ -149,14 +155,15 @@
"""Base class for platform-specific lock classes."""
def __init__(self, path, threaded=True):
"""
- >>> lock = LockBase(_testfile())
+ >>> lock = LockBase('somefile')
+ >>> lock = LockBase('somefile', threaded=False)
"""
self.path = path
self.lock_file = os.path.abspath(path) + ".lock"
self.hostname = socket.gethostname()
self.pid = os.getpid()
if threaded:
- tname = "%x-" % thread.get_ident()
+ tname = "%s-" % threading.current_thread().get_name()
else:
tname = ""
dirname = os.path.dirname(self.lock_file)
@@ -178,187 +185,45 @@
* If timeout <= 0, raise AlreadyLocked immediately if the file is
already locked.
-
- >>> # As simple as it gets.
- >>> lock = FileLock(_testfile())
- >>> lock.acquire()
- >>> lock.release()
-
- >>> # No timeout test
- >>> e1, e2 = threading.Event(), threading.Event()
- >>> t = _in_thread(_lock_wait_unlock, e1, e2)
- >>> e1.wait() # wait for thread t to acquire lock
- >>> lock2 = FileLock(_testfile())
- >>> lock2.is_locked()
- True
- >>> lock2.i_am_locking()
- False
- >>> try:
- ... lock2.acquire(timeout=-1)
- ... except AlreadyLocked:
- ... pass
- ... except Exception, e:
- ... print 'unexpected exception', repr(e)
- ... else:
- ... print 'thread', threading.currentThread().getName(),
- ... print 'erroneously locked an already locked file.'
- ... lock2.release()
- ...
- >>> e2.set() # tell thread t to release lock
- >>> t.join()
-
- >>> # Timeout test
- >>> e1, e2 = threading.Event(), threading.Event()
- >>> t = _in_thread(_lock_wait_unlock, e1, e2)
- >>> e1.wait() # wait for thread t to acquire filelock
- >>> lock2 = FileLock(_testfile())
- >>> lock2.is_locked()
- True
- >>> try:
- ... lock2.acquire(timeout=0.1)
- ... except LockTimeout:
- ... pass
- ... except Exception, e:
- ... print 'unexpected exception', repr(e)
- ... else:
- ... lock2.release()
- ... print 'thread', threading.currentThread().getName(),
- ... print 'erroneously locked an already locked file.'
- ...
- >>> e2.set()
- >>> t.join()
"""
- pass
+ raise NotImplemented("implement in subclass")
def release(self):
"""
Release the lock.
If the file is not locked, raise NotLocked.
- >>> lock = FileLock(_testfile())
- >>> lock.acquire()
- >>> lock.release()
- >>> lock.is_locked()
- False
- >>> lock.i_am_locking()
- False
- >>> try:
- ... lock.release()
- ... except NotLocked:
- ... pass
- ... except NotMyLock:
- ... print 'unexpected exception', NotMyLock
- ... except Exception, e:
- ... print 'unexpected exception', repr(e)
- ... else:
- ... print 'erroneously unlocked file'
-
- >>> e1, e2 = threading.Event(), threading.Event()
- >>> t = _in_thread(_lock_wait_unlock, e1, e2)
- >>> e1.wait()
- >>> lock2 = FileLock(_testfile())
- >>> lock2.is_locked()
- True
- >>> lock2.i_am_locking()
- False
- >>> try:
- ... lock2.release()
- ... except NotMyLock:
- ... pass
- ... except Exception, e:
- ... print 'unexpected exception', repr(e)
- ... else:
- ... print 'erroneously unlocked a file locked by another thread.'
- ...
- >>> e2.set()
- >>> t.join()
"""
- pass
+ raise NotImplemented("implement in subclass")
def is_locked(self):
"""
Tell whether or not the file is locked.
- >>> lock = FileLock(_testfile())
- >>> lock.acquire()
- >>> lock.is_locked()
- True
- >>> lock.release()
- >>> lock.is_locked()
- False
"""
- pass
+ raise NotImplemented("implement in subclass")
def i_am_locking(self):
- """Return True if this object is locking the file.
-
- >>> lock1 = FileLock(_testfile(), threaded=False)
- >>> lock1.acquire()
- >>> lock2 = FileLock(_testfile())
- >>> lock1.i_am_locking()
- True
- >>> lock2.i_am_locking()
- False
- >>> try:
- ... lock2.acquire(timeout=2)
- ... except LockTimeout:
- ... lock2.break_lock()
- ... lock2.is_locked()
- ... lock1.is_locked()
- ... lock2.acquire()
- ... else:
- ... print 'expected LockTimeout...'
- ...
- False
- False
- >>> lock1.i_am_locking()
- False
- >>> lock2.i_am_locking()
- True
- >>> lock2.release()
"""
- pass
+ Return True if this object is locking the file.
+ """
+ raise NotImplemented("implement in subclass")
def break_lock(self):
- """Remove a lock. Useful if a locking thread failed to unlock.
-
- >>> lock = FileLock(_testfile())
- >>> lock.acquire()
- >>> lock2 = FileLock(_testfile())
- >>> lock2.is_locked()
- True
- >>> lock2.break_lock()
- >>> lock2.is_locked()
- False
- >>> try:
- ... lock.release()
- ... except NotLocked:
- ... pass
- ... except Exception, e:
- ... print 'unexpected exception', repr(e)
- ... else:
- ... print 'break lock failed'
"""
- pass
+ Remove a lock. Useful if a locking thread failed to unlock.
+ """
+ raise NotImplemented("implement in subclass")
def __enter__(self):
- """Context manager support.
-
- >>> lock = FileLock(_testfile())
- >>> with lock:
- ... lock.is_locked()
- ...
- True
- >>> lock.is_locked()
- False
+ """
+ Context manager support.
"""
self.acquire()
return self
def __exit__(self, *_exc):
- """Context manager support.
-
- >>> 'tested in __enter__'
- 'tested in __enter__'
+ """
+ Context manager support.
"""
self.release()
@@ -366,23 +231,6 @@
"""Lock access to a file using atomic property of link(2)."""
def acquire(self, timeout=None):
- """
- >>> d = _testfile()
- >>> os.mkdir(d)
- >>> os.chmod(d, 0444)
- >>> try:
- ... lock = LinkFileLock(os.path.join(d, 'test'))
- ... try:
- ... lock.acquire()
- ... except LockFailed:
- ... pass
- ... else:
- ... lock.release()
- ... print 'erroneously locked', os.path.join(d, 'test')
- ... finally:
- ... os.chmod(d, 0664)
- ... os.rmdir(d)
- """
try:
open(self.unique_name, "wb").close()
except IOError:
@@ -440,9 +288,10 @@
"""Lock file by creating a directory."""
def __init__(self, path, threaded=True):
"""
- >>> lock = MkdirFileLock(_testfile())
+ >>> lock = MkdirFileLock('somefile')
+ >>> lock = MkdirFileLock('somefile', threaded=False)
"""
- LockBase.__init__(self, path)
+ LockBase.__init__(self, path, threaded)
if threaded:
tname = "%x-" % thread.get_ident()
else:
@@ -467,7 +316,8 @@
while True:
try:
os.mkdir(self.lock_file)
- except OSError, err:
+ except OSError:
+ err = sys.exc_info()[1]
if err.errno == errno.EEXIST:
# Already locked.
if os.path.exists(self.unique_name):
@@ -603,8 +453,7 @@
if not self.is_locked():
raise NotLocked
if not self.i_am_locking():
- raise NotMyLock, ("locker:", self._who_is_locking(),
- "me:", self.unique_name)
+ raise NotMyLock((self._who_is_locking(), self.unique_name))
cursor = self.connection.cursor()
cursor.execute("delete from locks"
" where unique_name = ?",
@@ -645,84 +494,3 @@
FileLock = LinkFileLock
else:
FileLock = MkdirFileLock
-
-def _in_thread(func, *args, **kwargs):
- """Execute func(*args, **kwargs) after dt seconds.
-
- Helper for docttests.
- """
- def _f():
- func(*args, **kwargs)
- t = threading.Thread(target=_f, name='/*/*')
- t.start()
- return t
-
-def _testfile():
- """Return platform-appropriate lock file name.
-
- Helper for doctests.
- """
- import tempfile
- return os.path.join(tempfile.gettempdir(), 'trash-%s' % os.getpid())
-
-def _lock_wait_unlock(event1, event2):
- """Lock from another thread.
-
- Helper for doctests.
- """
- lock = FileLock(_testfile())
- with lock:
- event1.set() # we're in,
- event2.wait() # wait for boss's permission to leave
-
-def _test():
- global FileLock
-
- import doctest
- import sys
-
- def test_object(c):
- nfailed = ntests = 0
- for (obj, recurse) in ((c, True),
- (LockBase, True),
- (sys.modules["__main__"], False)):
- tests = doctest.DocTestFinder(recurse=recurse).find(obj)
- runner = doctest.DocTestRunner(verbose="-v" in sys.argv)
- tests.sort(key = lambda test: test.name)
- for test in tests:
- f, t = runner.run(test)
- nfailed += f
- ntests += t
- print FileLock.__name__, "tests:", ntests, "failed:", nfailed
- return nfailed, ntests
-
- nfailed = ntests = 0
-
- if hasattr(os, "link"):
- FileLock = LinkFileLock
- f, t = test_object(FileLock)
- nfailed += f
- ntests += t
-
- if hasattr(os, "mkdir"):
- FileLock = MkdirFileLock
- f, t = test_object(FileLock)
- nfailed += f
- ntests += t
-
- try:
- import sqlite3
- except ImportError:
- print "SQLite3 is unavailable - not testing SQLiteFileLock."
- else:
- print "Testing SQLiteFileLock with sqlite", sqlite3.sqlite_version,
- print "& pysqlite", sqlite3.version
- FileLock = SQLiteFileLock
- f, t = test_object(FileLock)
- nfailed += f
- ntests += t
-
- print "total tests:", ntests, "total failed:", nfailed
-
-if __name__ == "__main__":
- _test()
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