GDSX Manual

Glossary
Extended General Device Support (GDSX) Manual–134303
Glossary-2
ITC
ITC. Intertask communication. The intertask communication facility permits
DEVICE^HANDLER tasks to have a device-oriented interface to subdevices on a line
or to communicate with other DEVICE^HANDLER tasks without using the Guardian
file and message system.
ITC file. Intertask communication file. A file created by TSCODE to manage
communication from a DEVICE^HANDLER task to an associated LINE^HANDLER
task. When an SU object is configured under a LINE, TSCODE assigns an ITC file
number to term^file^num so that DEVICE^HANDLER task requests are routed to the
associated LINE^HANDLER task, rather than directly to a device.
kernel. The part of TSCODE that coordinates all components of GDSX. The kernel
includes the monitor and listener tasks, and the backup task if GDSX is running as a
process pair.
LCB. Line control block. The internal representation of a LINE object, used to manage a
LINE^HANDLER task’s communication with a file.
LDCB. Logical device control block. A control block used to manage break ownership of a
device by a task.
LINE. With regard to GDSX, this is an SCF object that is managed by a LINE^HANDLER
task and mapped to a file, usually a physical communications line. Represented
internally by an LCB.
L^H. See LINE^HANDLER.
LINE^HANDLER. A USCODE procedure typically used to implement data
communications protocols and to allow each requester thread to use a shared resource
(often a communications line) without allowing the threads to interfere with each other.
Running copies of LINE^HANDLER code are called LINE^HANDLER tasks.
LINE^HANDLER is abbreviated L^H in figures. LINE^HANDLER tasks are also
called LINE tasks.
listener task. A system task that processes system messages and messages not supported by
other tasks.
migration. In this manual, migration refers to taking an application that runs on a C-series
system and changing it so that it runs on a D-series system.
monitor task. A system task that handles EMS messages, management programming
interfaces, and network management activities.
preconfigured SU. An SU object configured with SCF before a requester sends GDSX an
OPEN for the file associated with the SU. Contrast with dynamic SU.
PROCESS. With regard to GDSX, this SCF object type refers to a GDSX process.