Semaphore
PHP Manual

shm_attach

(PHP 4, PHP 5)

shm_attach — Creates or open a shared memory segment

Description

int shm_attach ( int $key [, int $memsize [, int $perm ]] )

shm_attach() returns an id that can be used to access the System V shared memory with the given key , the first call creates the shared memory segment with memsize and the optional perm-bits perm .

A second call to shm_attach() for the same key will return a different shared memory identifier, but both identifiers access the same underlying shared memory. memsize and perm will be ignored.

Parameters

key

memsize

The memory size. If not provided, default to the sysvshm.init_mem in the php.ini, otherwise 10000 bytes.

perm

The optional permission bits. Default to 0666.

Return Values

Returns a shared memory segment identifier.

See Also


Semaphore
PHP Manual