Struct tor_persist::state_dir::LockFileGuard

pub struct LockFileGuard { /* private fields */ }

Available on crate feature state-dir only.

Re-export of the lock guard type, as obtained via ContainsInstanceStateGuard A lock-file for which we hold the lock.

So long as this object exists, we hold the lock on this file. When it is dropped, we will release the lock.

Semantics

• Only one LockFileGuard can exist at one time for any particular path.
• This applies across all tasks and threads in all programs; other acquisitions of the lock in the same process are prevented.
• This applies across even separate machines, if path is on a shared filesystem.

Restrictions

• path must only be deleted (or renamed) via the APIs in this module
• This restriction applies to all programs on the computer, so for example automatic file cleaning with find and rm is forbidden.
• Cross-filesystem locking is broken on Linux before 2.6.12.

Implementations

impl LockFileGuard

pub fn lock<P>(path: P) -> Result<LockFileGuard, Error>

where P: AsRef<Path>,

Try to construct a new LockFileGuard representing a lock we hold on the file path.

Blocks until we can get the lock.

pub fn try_lock<P>(path: P) -> Result<Option<LockFileGuard>, Error>

where P: AsRef<Path>,

Try to construct a new LockFileGuard representing a lock we hold on the file path.

Does not block; returns Ok(None) if somebody else holds the lock.

pub fn delete_lock_file<P>(self, path: P) -> Result<(), Error>

where P: AsRef<Path>,

Try to delete the lock file that we hold.

The provided path must be the same as was passed to lock.

Trait Implementations

impl Debug for LockFileGuard

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.