(PHP 4, PHP 5, PHP 7, PHP 8)
shm_attach — Creates or open a shared memory segment
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 size
and the optional perm-bits permissions
.
A second call to shm_attach() for the same key
will return a different SysvSharedMemory instance, but both instances access the same underlying shared memory. size
and permissions
will be ignored.
key
A numeric shared memory segment ID
size
The memory size. If not provided, default to the sysvshm.init_mem
in the php.ini, otherwise 10000 bytes.
permissions
The optional permission bits. Default to 0666.
Returns a SysvSharedMemory instance on success, or false
on failure.
Version | Description |
---|---|
8.0.0 | On success, this function returns an SysvSharedMemory instance now; previously, a resource was returned. |
8.0.0 | size is nullable now. |