Module lockfile 

Session lockfile — explicit “this worktree is in use” marker.

Written when a user enters a worktree via gw shell or gw start. Removed on Drop. Readers verify PID liveness and delete stale files.

Structs

LockEntry

Serialized lockfile contents describing the session that owns a worktree.

SessionLock

RAII guard that removes the lockfile when dropped, provided the lockfile still belongs to this process. A Drop that blindly removed the file would delete another session’s lock if two processes raced the acquire.

Enums

AcquireError

Outcome of an acquire call. Callers may want to distinguish “an active session already owns this worktree” (should block entry) from “we could not write the lockfile at all” (degrade to a warning and proceed).

Constants

LOCK_VERSION

Current on-disk lockfile schema version. A mismatching version makes the lockfile “foreign” for the reader — read_and_clean_stale returns it as-is without removing the file. Writers still check PID ownership, so a foreign-version entry held by another PID is treated as a live foreign lock by acquire and refused.

Functions

acquire

Acquire an exclusive session lock for the given worktree. Cleans up stale locks; returns AcquireError::ForeignLock if a live foreign PID holds the lock, or AcquireError::Io/AcquireError::Serde for I/O / serialization failures.

pid_alive

Check whether a process with the given PID is currently alive.

read_and_clean_stale

Read the current lock entry, cleaning up if the owner is gone.