Lock

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

Get a shared or exclusive lock on the file

public function lock(
  HH\Lib\File\LockType $type,
): HH\Lib\File\Lock;

This will block until it acquires the lock, which may be forever.

This involves a blocking syscall; async code will not execute while waiting for a lock.

Parameters

• HH\Lib\File\LockType $type

Returns

• HH\Lib\File\Lock