parallel/lib/Sync/Synchronizable.php

<?php
namespace Icicle\Concurrent\Sync;

/**
 * An object that can be synchronized for exclusive access across contexts.
 */
interface Synchronizable
{
    /**
     * @coroutine
     *
     * Asynchronously invokes a callback while maintaining an exclusive lock on the object.
     *
     * The arguments passed to the callback depend on the implementing object. If the callback throws an exception,
     * the lock on the object will be immediately released.
     *
     * @param callable<(mixed ...$args): \Generator|mixed> $callback The synchronized callback to invoke.
     *     The callback may be a regular function or a coroutine.
     *
     * @return \Generator
     *
     * @resolve mixed The return value of $callback.
     */
    public function synchronized(callable $callback): \Generator;
}