New in Symfony 5.2: Shared locks

Contributed by Jérémy Derussé in #37752

In computer science, the readers–writers problems deal with situations in which many concurrent threads of execution try to access the same shared resource at one time.

A readers–writer lock is a synchronization primitive that solves one of those problems. It allows concurrent access for read-only operations, while write operations require exclusive access. This means that multiple threads can read the data in parallel but an exclusive lock is needed for writing or modifying data.

In Symfony 5.2 we've added support for them thanks to shared locks. When the lock store implements the new SharedLockStoreInterface, you can call the acquireRead() method to get a read-only lock, while the existing acquire() method gets a write lock:

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$lock = $factory->createLock('user'.$user->id);
if ($lock->acquireRead()) {
    // ...
}

Read the new docs about shared locks to learn all about them.