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4 the acp process, 5 interprocess communication, 7 counters – Compaq AAR-88LB-TE User Manual

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Architectural Changes
3.3 The Shared Library (LIBRTR.EXE)

Table 3–1 (Cont.) RTR Executables

RTR Version 2

RTR Version 3

RTRRTL

No longer apply.

3.4 The ACP Process

The RTR Application Control Process (ACP) handles application control, and has
the process name RTRACP. This is unchanged from RTR Version 2.

3.5 Interprocess Communication

In RTR Version 2, global sections (cache) were used for interprocess
communication. In RTR Version 3, interprocess communication is handled
with mailboxes. Each RTR process, including any application process, has three
mailboxes to communicate with the RTRACP process:

Read

Write

Beacon/Control

3.6 Shared Memory Parameters

With RTR Version 2, the SHOW RTR/PARAMS command showed the following:

Maximum links

Maximum facilities

Maximum relations

Maximum processes

Cache pages

The /PARAMS qualifier is obsolete in RTR Version 3, and the parameters it
showed no longer apply. In RTR Version 3, these parameters are handled with
OpenVMS mailboxes, which you can check using OpenVMS procedures. See the
OpenVMS System Manager’s Manual: Essentials for more information.

3.7 Counters

In RTR Version 2, shared memory in global sections was directly accessible

using the RTR command server. In RTR Version 3, process counters are still
kept in shared memory, but they are accessed from the command server through
RTRACP. Thus, accessing these and other counters involves communicating with
RTRACP. Other counters are contained within the address space of the ACP.

3–2 Architectural Changes