Struct WatcherLock 

pub struct WatcherLock { /* private fields */ }

Proof that this process is the one watcher for this user.

Two watchers are two pollers with two toast budgets, and every toast shown twice; they also count the same activity into one database. The PID file cannot prevent that: it is read and written by whoever starts a watcher, and two starts at the same moment (a scheduled task and a Run key both firing at login) both read “nobody” and both write. An exclusive lock on a file is taken atomically by the OS and let go by the OS when the process dies however it dies, so there is no stale state to clean up.

The lock sits in the data directory, not beside the binary: two copies of kasl installed in two places share one data directory and one lock.

Implementations

impl WatcherLock

pub fn acquire() -> Result<Option<Self>>

Takes the lock, or returns None when another watcher holds it.

Trait Implementations

impl Debug for WatcherLock

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

Formats the value using the given formatter.