Tribblix: manual page: dat_psp

DAT_PSP_CREATE(3DAT) Direct Access Transport Library Functions

NAME

dat_psp_create - create a persistent Public Service Point

SYNOPSIS

cc [ flag... ] file... -ldat [ library... ]
#include <dat/udat.h>

DAT_RETURN
dat_psp_create(
IN DAT_IA_HANDLE ia_handle,
IN DAT_CONN_QUAL conn_qual,
IN DAT_EVD_HANDLE evd_handle,
IN DAT_PSP_FLAGS psp_flags,
OUT DAT_PSP_HANDLE *psp_handle
)

PARAMETERS

ia_handle
Handle for an instance of DAT IA.

conn_qual
Connection Qualifier of the IA on which the Public
Service Point is listening.

evd_handle
Event Dispatcher that provides the Connection Requested
Events to the Consumer. The size of the event queue
for the Event Dispatcher controls the size of the
backlog for the created Public Service Point.

psp_flags
Flag that indicates whether the Provider or Consumer
creates an Endpoint per arrived Connection Request. The
value of DAT_PSP_PROVIDER indicates that the Consumer
wants to get an Endpoint from the Provider; a value of
DAT_PSP_CONSUMER means the Consumer does not want the
Provider to provide an Endpoint for each arrived
Connection Request.

psp_handle
Handle to an opaque Public Service Point.

DESCRIPTION

The dat_psp_create() function creates a persistent Public Service
Point that can receive multiple requests for connection and generate
multiple Connection Request instances that are delivered through the
specified Event Dispatcher in Notification events.

The dat_psp_create() function is blocking. When the Public Service
Point is created, DAT_SUCCESS is returned and psp_handle contains a
handle to an opaque Public Service Point Object.

There is no explicit backlog for a Public Service Point. Instead,
Consumers can control the size of backlog through the queue size of
the associated Event Dispatcher.

The psp_flags parameter allows Consumers to request that the Provider
create an implicit Endpoint for each incoming Connection Request, or
request that the Provider should not create one per Connection
Request. If the Provider cannot satisfy the request, the operation
shall fail and DAT_MODEL_NOT_SUPPORTED is returned.

All Endpoints created by the Provider have DAT_HANDLE_NULL for the
Protection Zone and all Event Dispatchers. The Provider sets up
Endpoint attributes to match the Active side connection request. The
Consumer can change Endpoint parameters. Consumers should change
Endpoint parameters, especially PZ and EVD, and are advised to change
parameters for local accesses prior to the connection request
acceptance with the Endpoint.

RETURN VALUES

DAT_SUCCESS
The operation was successful.

DAT_INSUFFICIENT_RESOURCES
The operation failed due to resource
limitations.

DAT_INVALID_HANDLE
The ia_handle or evd_handle parameter
is invalid.

DAT_INVALID_PARAMETER
The conn_qual or psp_flags parameter is
invalid.

DAT_CONN_QUAL_IN_USE
The specified Connection Qualifier was
in use.

DAT_MODEL_NOT_SUPPORTED
The requested Model was not supported
by the Provider.

USAGE

Two uses of a Public Service Point are as follows:

Model 1
For this model, the Provider manipulates a pool of
Endpoints for a Public Service Point. The Provider can use
the same pool for more than one Public Service Point.

o The DAT Consumer creates a Public Service Point
with a flag set to DAT_PSP_PROVIDER.

o The Public Service Point does the following:

o Collects native transport information
reflecting a received Connection Reques

o Creates an instance of Connection Reques

o Creates a Connection Request Notice (event)
that includes the Connection Request
instance (thatwhich includes, among others,
Public Service Point, its Connection
Qualifier, Provider-generated Local
Endpoint, and information about remote
Endpoint)

o Delivers the Connection Request Notice to
the Consumer-specified target (CNO)
evd_handle

The Public Service Point is persistent and
continues to listen for incoming requests
for connection.

o Upon receiving a connection request, or at some
time subsequent to that, the DAT Consumer can
modify the provided local Endpoint to match the
Connection Request and must either accept() or
reject() the pending Connection Request.

o If accepted, the provided Local Endpoint is now
in a "connected" state and is fully usable for
this connection, pending only any native
transport mandated RTU (ready-to-use) messages.
This includes binding it to the IA port if that
was not done previously. The Consumer is
notified that the Endpoint is in Connected
state by a Connection Established Event on the
Endpoint connect_evd_handle.

o If rejected, control of the Local Endpoint
point is returned back to the Provider and its
ep_handle is no longer usable by the Consumer.

Model 2
For this model, the Consumer manipulates a pool of
Endpoints. Consumers can use the same pool for more than
one Service Point.

o DAT Consumer creates a Public Service Point
with a flag set to DAT_PSP_CONSUMER.

o Public Service Point:

o Collects native transport information
reflecting a received Connection Request

o Creates an instance of Connection Request

o Creates a Connection Request Notice (event)
that includes the Connection Request
instance (which includes, among others,
Public Service Point, its Connection
Qualifier, Provider-generated Local
Endpoint and information about remote
Endpoint)

o Delivers the Connection Request Notice to
the Consumer-specified target (CNO)
evd_handle

The Public Service Point is persistent and
continues to listen for incoming requests
for connection.

o The Consumer creates a pool of Endpoints that
it uses for accepting Connection Requests.
Endpoints can be created and modified at any
time prior to accepting a Connection Request
with that Endpoint.

o Upon receiving a connection request or at some
time subsequent to that, the DAT Consumer can
modify its local Endpoint to match the
Connection Request and must either accept() or
reject() the pending Connection Request.

o If accepted, the provided Local Endpoint is now
in a "connected" state and is fully usable for
this connection, pending only any native
transport mandated RTU messages. This includes
binding it to the IA port if that was not done
previously. The Consumer is notified that the
Endpoint is in Connected state by a Connection
Established Event on the Endpoint
connect_evd_handle.

o If rejected, the Consumer does not have to
provide any Endpoint for dat_cr_reject(3DAT).

ATTRIBUTES