EMS Manual

EMS Definitions
EMS Manual—426909-005
14-3
Event-Message Restrictions

In an event message, the reporting subsystem can include error lists with errors it
encountered itself and error lists with errors encountered by a lower-level
subsystem that has a different subsystem ID.

Error lists do not have subjects. Therefore, all event-message subjects are visible
to EMSGET or EMSGETTKN without entering a list.

Each event message has one or more subjects.

Each event message is self-contained and does not depend on another event
message. That is, each event message describes exactly one event.
Event-Message Restrictions
The Event Message Subsystem restricts event messages to ZEMS-VAL-EVT-BUFLEN
bytes (currently 4024 bytes: 2012 words). Other subsystems that process event
messages, such as ViewPoint, can impose more restrictive length limits.
Definitions of Event-Message Tokens
All event-message header tokens and common event-message data-portion tokens
are described in this subsection.
In these definitions, the types of the token values are shown as int, enum,
timestamp, and so forth; these types correspond to ZSPI-TYP-INT, ZSPI-TYP-
ENUM, and ZSPI-TYP-TIMESTAMP, defined in the standard-definition file for SPI.
Definitions of SPI Tokens in the Event-Message Header
Besides EMS tokens, the event-message header contains SPI tokens (found in all
command messages):
ZSPI-TKN-MAX-FIELD-VERSION
(type int) is the highest field version among the
non-null fields of structures added to the buffer with
EMSADDTOKENMAPS.
ZSPI-TKN-SSID
(type ssid) is the subsystem ID used when the
buffer was initialized with EMSINIT; that is, the
subsystem ID of the subsystem that reported the
event.
ZSPI-TKN-USEDLEN
(type int) is the number of bytes actually used in
the buffer. A subsystem that reports events can
use this to determine how many bytes to send to
$0 through the WRITEREAD procedure.