(PHP 4 >= 4.0.4, PHP 5, PHP 7) Get size of shared memory block

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Write data into shared memory block

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Read data from shared memory block

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Create or open shared memory block

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Delete shared memory block

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Close shared memory block