IPMASK (Input to SETMASK) IPSNDN IPSNDP IPRPYN IPRPYP IPCTRL This field specifies the mask byte to determine which, if any, of the IUCV interrupts a virtual machine is enabled for.
The SETMASK function cannot be invoked from CP system code.
The bits defined for IUCV are: X'80' X'40' X'20' X'10' X'08' Enable for nonpriority messages
Enable for priority messages
Enable for nonpriority replies
Enable for priority replies
Enable for IUCV control interrupts (CON­ NECT, SEVER, ACCEPT, QUIESCE,
RESUME) IPMSGID (Input to PURGE, RECEIVE, REJECT, REPLY, TESTCMPL) (Output from DESCRIBE, PURGE, RECEIVE, REJECT, SEND,
TESTCMPL)
(Reflected in these IUCV external interrupts: pending message, mes­
sage complete.)
As an input, this field specifies the message identifier of the message
to search for. The message identifier uniquely identifies a particular
message. It is generated by IUCV and returned by the SEND function
when the message is created.
This field is an optional input to the functions listed above. When this
field is specified, the path id and message class (IPSRCCLS for PURGE and TESTCMPL, IPTRGCLS for RECEIVE, REJECT and REPLY) must also be supplied.
When this field is used for the above functions, the bit IPFGMID field
of IPFLAGS 1 must be set to 1.
As an output or on an external interrupt, this field indicates the mes­
sage id of the message associated with this function or interrupt.
IPMSGLIM (Input to ACCEPT, CONNECT) (Output from ACCEPT, CONNECT) (Reflected in the pending-connection IUCV external interrupt.)
As an input, this field specifies the limit of outstanding messages to be
allowed on the path established by this CONNECT. A message limit
can also be specified on the IUCV directory control statement. If
message limit has been specified in the directory for this user, you may
not specify a value larger than the directory specification with this
parameter of the IUCV macro. Inter-User Communications Vehicle 167

The maximum value that can be specified is 255. For CP system code,
there is no overriding directory value. If this field contains a zero, IUCV assumes a default of 10. As an output or on an external interrupt, this field contains the mes­
sage limit for this path.
IPMSGTAG (Input to SEND) (Output from PURGE, TESTCMPL)
(Reflected in the message-complete IUCV external interrupt.)
This field specifies the tag data of the message created by invoking the
SEND function. IUCV returns the message tag when the message
completes. The source communicator can use this field to tie an
incoming message-complete interrupt or output of TESTCMPL to the
original SEND request.
As an output or on an external interrupt, this field indicates the mes­
sage tag of the message associated with this function or interrupt.
IPPATHID (Input to ACCEPT, PURGE, QUIESCE, RECEIVE, REJECT,
REPLY, RESUME, SEND, SEVER, TESTCMPL)
168 VM/SP System Programmer's Guide (Output from CONNECT, DESCRIBE, PURGE, RECEIVE,
REJECT, TESTCMPL)
(Reflected in these IUCV external interrupts: pending connection,
connection complete, pending message, message complete, sever, qui­
esce, resume.)
This field specifies the path identifiers associated with a message. IUCV assigns a path identification and returns the value in the CON­ NECT parameter list. All further communications on a path must
specify the P ATHID that was returned from CONNECT. P A THIDs
are sequential from X'OOOO' to the maximum connections allowed for
this virtual machine. As paths are severed, IU CV reuses the vacated
PATHIDs.
If you specify MSGID on the PURGE, RECEIVE, REJECT, or
TESTCMPL functions, IUCV requires that you specify PATHID and
message class (IPSRCCLS or IPTRGCLS, as appropriate).
This field is ignored if the IP ALL bit in IPFLAGS 1 is set to one.
When this field is used on the PURGE, RECEIVE, REJECT, and
TESTCMPL functions, the IPFGPID bit must be set to 1 in the
IPFLAGSI field. This bit is set by the IUCV macro when the
P ATHID= function is specified on the macro.
As an output or on an external interrupt, this field indicates the pathid
of the message associated with this function or interrupt.