shm_attach

    (PHP 4, PHP 5, PHP 7, PHP 8)

    shm_attach — Creates or open a shared memory segment

    Descrição

    shm_attach(int$key, ?int$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.

    Parâmetros

    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.

    Valor Retornado

    Returns a SysvSharedMemory instance on success, ou false em caso de falha.

    Registro de Alterações

    VersãoDescrição
    8.0.0 On success, this function returns an SysvSharedMemory instance now; previously, a resource was returned.
    8.0.0size is nullable now.

    Veja Também

    • shm_detach() - Disconnects from shared memory segment
    • ftok() - Convert a pathname and a project identifier to a System V IPC key
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