RemoteLock

MMO\admin\helpers · 1 symbol · generated 5 Oct 2026

class

RemoteLock

A mutual-exclusion lock held ON the target, so two people (or a person and a cron) cannot deploy to the same machine at the same time.

class MMO\admin\helpers\RemoteLock

Namespace: MMO\admin\helpers

The lock is a DIRECTORY, not a file: `mkdir` is atomic and fails when the directory already exists, on every POSIX filesystem and over NFS -- which `test -e && touch` is not. That matters here because each command is a separate ssh round-trip, so anything relying on a shell-level `flock` holding across commands would not work. Breaking a lock is atomic for the same reason. An earlier version, on finding a stale lock, simply warned and carried on -- which let two runners that both observed the same stale lock both decide they now held it, the exact situation the lock exists to prevent. Here the breaker `mv`s the directory aside and `mkdir`s a fresh one: exactly one runner can win that sequence, and the loser is told so.

$lock = new RemoteLock($runner, $target->getLockFolder()); $lock->acquire('marc@laptop deploy v4.0.21'); try {...} finally {$lock->release();}

Index

	folder
	owned
	shell
	ttl
	acquire($owner, $force)	Take the lock, or fail loudly.
	breakLock($held)	Take an existing lock away from whoever holds it, atomically.
	claim($owner)	Record who holds the lock, for whoever hits it next.
	debugName()
	getFolder()
	getOwner()
	isOwned()
	isStale()
	release()	Release the lock, but only if this instance actually took it -- releasing someone else's lock would be worse than never locking at all.
	__construct($shell, $folder, $ttl)

Properties4

folder

protected string $folder

Type: string

owned

protected bool $owned = false

Type: bool

shell

protected MMO\core\server\ShellRunner $shell

Type: ShellRunner

ttl

protected int $ttl

Type: int

Methods10

acquire($owner, $force)

RemoteLock.php:61

Take the lock, or fail loudly.

function acquire(string $owner, bool $force = false): void

$owner	string	a description of who is taking it, stored inside the lock for the next person.
$force = false	bool	take the lock even if someone else holds it (only ever from an explicit user request).
returns	void
throws		if the lock is held and is neither stale nor forced, or if breaking it was lost to a race.

breakLock($held)

RemoteLock.php:91

Take an existing lock away from whoever holds it, atomically.

protected function breakLock(string $held): void

`mv` of a directory onto a new name is a single rename: exactly one of two concurrent breakers can succeed, and the `mkdir` that follows decides the winner a second time. A runner that loses either step stops rather than assuming it won.