SchedulerLock

Best-effort overlap-prevention lock for ScheduledTaskDefinition::withoutOverlapping(), built on the app’s existing PSR-16 CacheInterface rather than a new lock subsystem.

PSR-16 has no atomic add-if-absent, so there is a narrow TOCTOU race between concurrent schedule:run invocations’ has() check and set() call — acceptable for the common “still running past the next * minute” case this guards against, not a hardened distributed lock.

Synopsis

final readonly class SchedulerLock

Source	SchedulerLock.php

Constructor

__construct()

public function __construct(CacheInterface $cache): mixed

Parameter	Type	Description
$cache	CacheInterface

Returns mixed

Methods

Method	Description
acquire(string $key, int $ttlSeconds): bool	Attempts to take the lock, returning false when it is already held.
release(string $key): void	Releases the lock by deleting its cache key.

acquire()

public function acquire(string $key, int $ttlSeconds): bool

Attempts to take the lock, returning false when it is already held.

On success the key is written to the cache with the given lifetime, so the lock expires by itself if a crashed run never releases it. The check and the write are two separate PSR-16 calls, so two invocations racing on the same key can both succeed.

Parameter	Type	Description
$key	string
$ttlSeconds	int

Returns bool

release()

public function release(string $key): void

Releases the lock by deleting its cache key.

Deleting a key that is not present is not an error, so releasing a lock that already expired is harmless.

Parameter	Type	Description
$key	string