User`s guide

44 DC 900-1516D
ICP2432 User’s Guide for OpenVMS Alpha (DLITE Interface)
buffer is indeed freed. Any further reference to the buffer results in unpredictable
results. Requests with a NULL buffer pointer and attempts to free a buffer not allocated
with
dlBufAlloc return with a buffer deallocation error message.
dlInit
The user application must call dlInit before any other DLITE service. If dlInit does not
find the DLI configuration file, it returns the
DLI_INIT_ERR_CFG_LOAD_FAILED
error. It does not try to find a DLI source configuration file and perform the configura-
tion processing in-line. The logging and tracing capabilities can fail initialization (e.g.
memory allocation or file I/O errors) without inhibiting DLITE from providing all its
other services. However, Protogate strongly discourages the operation of DLITE with-
out the log facility.
dlOpen
A session open (dlOpen) initiates communications with the VMS ICP2432 driver and
returns with the result of the operation: a session ID if successful, an error otherwise. A
successful open returns a
dlerrno of EWOULDBLOCK and generates a callback. This call-
back could be delivered before the API returns from the open request and would con-
tain the correct session ID. This callback can be ignored, since the application can use
the completion of the open request to control the open operation.
dlPoll
A new poll request of DLI_P0LL_GET_DRV_INFO returns VMS driver information.
The information shown in Figure3–3 is returned through the
pStat parameter provided
by the application (the application provides a pointer to an allocated area of type
DLI_ICP_DRV_INFO). The area used to return this information must have been allo-
cated by the requesting application.