RSC/MP Programming Manual

Unsolicited Message Service

Aliases and UMS

Aliases identify recipients of unsolicited messages. Alias types are defined in the

RSC.H header file on the workstation and in the RSCH file on the host system. There

are two types of aliases:

SESSION_ALIAS sends messages to specific sessions.

GROUP_ALIAS sends messages to many sessions across applications and

terminals.

The workstation uses the RscSetOption function to register terminal and alias names

with the TDP. Because the SESSION_ALIAS must be unique for each workstation, if

your system uses a centrally-distributed RSC.INI file, the SESSION_ALIAS must be

supplied from the RscSetOptions call to establish the identity of a workstation session

to the UMS. Set the terminal name, represented by the TERM_NAME option, before

executing the RscConnect function. The alias name must be set before the execution

of the RscBeginSession function. See Figure 3-1 on page 3-10 for an illustration of the

functions that must be executed before sending or receiving a UMS message.

Alias names consist of up to 30 characters and are not case-sensitive. Terminal names

consist of up to 8 characters and are no t case-sensitive. A SESSION_ALIAS must be

unique for a TERM_NAME option. A GROUP_ALIAS does not need to be unique, even

among all TERM_NAME options. You register aliases by calling the RscSetOption

function before calling the RscBeginSession function.

A UMS message meant as a broadcast can specify that the message is to go to all

TERMs or groups/sessions by supplying an asterisk (*) for the TERM name or alias. A

UMS message intended for all members of one group should be submitted with an

alias type of GROUP_ALIAS; a message sent to a GROUP_ALIAS is always treated

as a broadcast. A workstation receiving a broadcast UMS message will always receive

an indication that it was initiated by a Guardian WRITE procedure

(RSC_UMS_WRITE) even if the initiating application used a WRITEREAD. If a UMS

message is intended for a specific workstation, all of these conditions must be met:

The server application issues a Guardian WRITEREAD.

A specific TERM name is supplied.

The UMS header specifies alias type as SESSION_ALIAS.

A specific session alias name is supplied (no t the wildcard *).

If any condition is not met, the workstation will receive the indication that the UMS was

initiated via a Guardian WRITE (RSC_UMS_WRITE). If all of the conditions are met,

the workstation will receive the indication that the UMS was initiated via a Guardian

WRITEREAD procedure (RSC_UMS_WRITEREAD).

HP NonStop Remote Server Call (RSC/MP) Programming Manual — 522360-006

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