Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
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CONTROLMESSAGESYSTEM Procedure
value input
INT:value
supplies a value to be used in taking an action. See the following list of action
codes and values.
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.
•
See the MESSAGESYSTEMINFO procedure for information on measuring process
message requirements.
•
Prior to D-series releases 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
action
code value action taken
01-
4095
This value (considered an unsigned number) sets the limit
on the number of outstanding incoming messages to the
process. The default limit is 255; opening $RECEIVE with
receive depth can increase this limit. Elapsed-time timeout
messages and system status messages are not affected
by this limit.
11-
4095
This value (considered an unsigned number) sets the limit
on the number of outstanding messages sent by the
process. The default limit is 1023. Elapsed-time timeout
messages and system status messages are not affected
by this limit.
2 N/A Beginning in the D-series RVU, this action code of the
operating system is obsolete.
3 N/A Beginning in the D-series RVU, this action code of the
operating system is obsolete.