flock

func Acquire ¶

func Acquire(path string) (release func(), err error)

Acquire takes an exclusive advisory lock on path, creating the file if needed. The returned release closes the file, which drops the flock. Callers must invoke release exactly once. The lock file persists between runs - flock state is held by the file descriptor, not by the inode on disk - so the lockfile contents are immaterial.

Acquire blocks indefinitely until the lock is available. Use AcquireContext with a deadline to bound the wait.

func AcquireContext ¶ added in v0.10.0

func AcquireContext(ctx context.Context, path string) (release func(), err error)

AcquireContext behaves like Acquire but honors ctx. When ctx carries a deadline it polls a non-blocking lock until the lock is acquired or the deadline/cancellation fires, returning a wrapped ctx.Err() on timeout. When ctx has no deadline it takes the same blocking kernel path as Acquire, so existing callers keep their exact behavior. This lets latency-critical hooks (turn-start) bound their wait and degrade gracefully instead of stalling behind a long-running lock holder (e.g. checkpoint condensation).

func AcquireContextIn ¶ added in v0.10.4

func AcquireContextIn(ctx context.Context, root *os.Root, name string) (release func(), err error)

AcquireContextIn is AcquireContext for a lock file named inside root.

func AcquireIn ¶ added in v0.10.4

func AcquireIn(root *os.Root, name string) (release func(), err error)

AcquireIn is Acquire for a lock file named inside root. It is the form the .git-resident locks use: their names carry agent-supplied session IDs, so resolving them through the git common dir's root keeps a name that escaped validation from naming a file outside the clone.