twisted.python.lockfile.FilesystemLock

class documentation

class FilesystemLock: (source)

Known subclasses: twisted.internet.defer.DeferredFilesystemLock

Constructor: FilesystemLock(name)

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
`bool`	True if the lock is acquired, false otherwise.
Raises
`OSError`	Any 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
`OSError`	Any exception `os.readlink()` may raise.
`ValueError`	If 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.