(PECL apcu >= 5.0.0) Get total cache size

(PECL wincache >= 1.1.0) Acquires an exclusive lock on a given key

(PHP 4, PHP 5, PHP 7) Find out whether an extension is loaded

(PECL apd 0.2-0.4) Throw a warning and a callstack

(PHP 4, PHP 5) Alias of

(PECL wincache >= 1.1.0) Checks if a variable exists in the user cache

(PHP 5 >= 5.5.0, PHP 7, PECL ZendOpcache >= 7.0.0) Resets the contents of the opcode cache

(PECL weakref >= 0.2.0) Checks whether a certain object is in the map

(PHP 4, PHP 5, PHP 7) Gets the current configuration setting of magic_quotes_gpc

(PECL wincache >= 1.1.0) Increments the value associated with the key