src/Ko/SharedMemory.php
protected function lockExecute(callable $task)
    {
        if($this->mutex->isAcquired()) {
            return $task();
        }

        return $this->mutex->lockExecute($task);
    }
protected function lockExecute(callable $task)
    {
        if($this->mutex->isAcquired()) {
            return $task();
        }

        return $this->mutex->lockExecute($task);
    }
Lock shared memory if lock not already acquired by this process

@param callable $task Function to execute

@return mixed    Whatever the $task function returns