Guardian Procedure Calls Reference Manual

Action Takenvalueaction

code

Beginning in the D-series RVU, this action code of the operating

system is obsolete.

N/A2

Beginning in the D-series RVU, this action code of the operating

system is obsolete.

N/A3

For systems running G06.29 and later G-series RVUs.

For systems running H06.06 and later H-series RVUs or any J-series RVU.

Returned Value

INT:ref:1

Error code:

Success, no error.0

Bad actioncode.2

Bad value.21

Missing parameter.29

Considerations

• If a requester tries to send a message to a process that already has as many incoming messages

as allowed (as specified by action code 0), then the message is not sent, and the requester

receives an error 30. If a time limit set by a process expires (such as a time limit set with

SIGNALTIMEOUT), then a message notifying the process of the expiration is sent to the process

anyway, and is not counted as part of that limit.

• If a process that already has as many outstanding outgoing messages as allowed (as specified

by action code 1) tries to send a message, the process receives an error 30.

• CONTROLMESSAGESYSTEM is tied to the internal operation of the message system; current

functions might not be supported by future versions of the message system. So, if a nonzero

error is returned, the caller should log the error, but otherwise ignore it.

• For information on measuring process message requirements, see the MESSAGESYSTEMINFO

Procedure (page 830).

• Before D-series RVUs of the operating system, the RESERVELCBS procedure allowed you to

reserve message-system control blocks. It also performed certain secondary functions concerning

limits. Beginning in the D-series RVU of the operating system, reserving message-system control

blocks is no longer applicable, and the secondary functions of the procedure are accomplished

by calling CONTROLMESSAGESYSTEM. Although RESERVELCBS no longer performs any

function, it can still be called without error.

216 Guardian Procedure Calls (C)