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NAME : HCPIRCBK
DESCRIPTION: *IDENT Resource Communication block
DSECT : IRCBK
FUNCTION : This DSECT maps the data exchanged between the
*IDENT system service and an authorized
resource.
LOCATED BY : Registers
CREATED BY : HCPEXC when building a request for a server
HCPEXE when processing a deliver for a request
from a different system
HCPIDS when getting a reply buffer for a
server
DELETED BY : HCPEXC when completing the function
HCPEXD when handling a return from the server
for the target system
HCPEXE on an error in deliver processing
HCPIDS on an IUCV SEND error
HCPIDS when a message-complete interruption is
received.
SERIALIZED : Task ownership
RELOCATION CONSIDERATIONS : None
COMMENTS :
This control block is conceptually one piece of data
mapped by three structures. There is a fixed-length
portion and two variable-length portions, all described
in greater detail below. In storage, these must be
adjacent, and in the order:
1) Fixed-length area
2) Supplementary GID information
3) Object token information.
The fixed-length section is set up as containing a header
and function-specific sections. The header contains only
general control block information, and is frozen at the
defined length. CHANGING THE LENGTH OF THE HEADER SECTION
WILL RESULT IN MAKING THE CONTROL BLOCK INCOMPATIBLE WITH
PREVIOUS RELEASES OF THE BLOCK.
The function-specific sections are different, but the
length of that section is determined by the length of
the longest of the set of function-specific sections.
A field in the header contains this execution-time-
calculated length so that fields can be added to the
function-specific section in future releases while still
allowing the new blocks to coexist with the old ones.
A variable-length section may contain no data; in this
case, the length field contains the length of itself
alone (a 4-byte length field, for example, would contain
the value '4' if the length of the corresponding data
field is zero).
For future expansion, function-specific fields can be
added to the function-specific area, or other
function-specific sections can be added. Variable-length
sections can be added after the last variable length
section.
Function type EXEC
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The IRCBK can reside in free storage, or in a frame
delivered to exec processing by the CP Application
Mailbox. When the exec function originally acquires an
IRCBK, it does so from free storage. If the request
is transmitted to a remote system, the CP Application
Mailbox on that system delivers a page to the exec
function which contains a copy of that IRCBK. That
copy is used and the information returned to the
originating system.
In addition, a two-way IUCV SEND is done to the server.
The reply buffer specified on that SEND is another copy
of the IRCBK, gotten from free storage.
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