dat_psp_create - create a persistent Public Service Point
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
)
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.
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.
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.
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.
See attributes(7) for descriptions of the following
attributes:
ATTRIBUTE
TYPE |
ATTRIBUTE VALUE |
Interface Stability |
Standard: uDAPL, 1.1, 1.2 |
MT-Level |
Safe |