DLPI Programmer's Guide

52 Chapter 2
DLPI Primitives
Local Management Primitives
A DLS provider may handle PPA de-initialization using the following
methods:
• automatic de-initialization upon receipt of the final
DL_DETACH_REQ (for style 2 providers) or DL_UNBIND_REQ (for
style 1 providers), or upon closing of the last stream associated with
the PPA;
• automatic de-initialization after expiration of a timer following the
last DL_DETACH_REQ, DL_UNBIND_REQ, or close as appropriate;
or
• no automatic de-initialization; administrative intervention is
required to de-initialize the PPA at some point after it is no longer
being accessed.
A specific DLS provider may support any of these methods, or possibly
some combination of them, but the method implemented has no impact
on the DLS user. From the DLS user’s viewpoint, the PPA is guaranteed
to be initialized and available for transmission until it closes or unbinds
the stream associated with the PPA.
DLS provider-specific addendum documentation should describe the
method chosen for PPA initialization and de-initialization.
DL_HP_PPA_REQ
This primitive is used to obtain a list of all the valid PPAs currently
installed in the system.
This message consists of one M_PCPROTO message block which
contains the following structure.
Format
typedef struct {
u_long dl_primitive;
} dl_hp_ppa_req_t;
Parameters
dl_primitive
DL_HP_PPA_REQ
State