twisted.python.lockfile.FilesystemLock

class documentation

class FilesystemLock: (source)

Known subclasses: twisted.internet.defer.DeferredFilesystemLock

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A mutex.

This relies on the filesystem property that creating a symlink is an atomic operation and that it will fail if the symlink already exists. Deleting the symlink will release the lock.

Method __init__ Undocumented
Method lock Acquire this lock.
Method unlock Release this lock.
Instance Variable clean Indicates whether this lock was released cleanly by its last owner. Only meaningful after lock has been called and returns True.
Instance Variable locked Indicates whether the lock is currently held by this object.
Instance Variable name The name of the file associated with this lock.
def __init__(self, name): (source)
overridden in twisted.internet.defer.DeferredFilesystemLock

Undocumented

def lock(self): (source)
Acquire this lock.
Returns
boolTrue if the lock is acquired, false otherwise.
Raises
OSErrorAny exception os.symlink() may raise, other than errno.EEXIST.
def unlock(self): (source)

Release this lock.

This deletes the directory with the given name.

Raises
OSErrorAny exception os.readlink() may raise.
ValueErrorIf the lock is not owned by this process.
clean = (source)
Indicates whether this lock was released cleanly by its last owner. Only meaningful after lock has been called and returns True.
locked: bool = (source)
Indicates whether the lock is currently held by this object.
name = (source)
The name of the file associated with this lock.