MatthiasMullie\Scrapbook\Adapters\Apc::lock PHP Method

Apc Class Documentation Show file Open project: matthiasmullie/scrapbook

lock() protected method

APC provides nothing that would allow us to do CAS. To "emulate" CAS, we'll work with locks: all cache writes also briefly create a lock cache entry (yup: #writes * 3, for lock & unlock - luckily, they're not over the network) Writes are disallows when a lock can't be obtained (= locked by another write), which makes it possible for us to first retrieve, compare & then set in a nob-atomic way. However, there's a possibility for interference with direct APC access touching the same keys - e.g. other scripts, not using this class. If CAS is of importance, make sure the only things touching APC on your server is using these classes!

protected lock ( string \| string[] $keys ) : array
$keys	string \| string[]
return	array	Array of successfully locked keys

    protected function lock($keys)
    {
        // both string (single key) and array (multiple) are accepted
        $keys = (array) $keys;
        $locked = array();
        for ($i = 0; $i < 10; ++$i) {
            $locked += $this->acquire($keys);
            $keys = array_diff($keys, $locked);
            if (empty($keys)) {
                break;
            }
            usleep(1);
        }
        return $locked;
    }

Apc

APCuIterator

__construct

acquire

add

apcu_add

apcu_clear_cache

apcu_delete

apcu_fetch

apcu_store

cas

decrement

delete

deleteMulti

doIncrement

expire

flush

get

getMulti

increment

lock

replace

set

setMulti

touch

ttl

unlock