(PHP 4, PHP 5, PHP 7, PHP 8)
shm_attach — Creates or open a shared memory segment
$key
, int|null $size = null
, int $permissions = 0666
) : SysvSharedMemory|false
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.
keyA 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.
permissionsThe optional permission bits. Default to 0666.
Returns a SysvSharedMemory instance on success, 或者在失败时返回 false.
| 版本 | 说明 |
|---|---|
| 8.0.0 | On success, this function returns an SysvSharedMemory instance now; previously, a resource was returned. |
| 8.0.0 |
size is nullable now.
|