shm_attach
(PHP 4, PHP 5)
shm_attach — Creates or open a shared memory segment
说明
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.
参数
- 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.
返回值
Returns a shared memory segment identifier.
