GDSX (Extended General Device Support) Manual

LINE^HANDLER Example, Design
Extended General Device Support (GDSX) Manual—529931-001
7-4
Intertask Communication—LINE^HANDLER
Perspective
Figure 7-2. Sending a WRITEREAD Through a LINE^HANDLER (page1of2)
Application
D^H Task
L^H Task IOP/Terminal
A WRITEREAD
is sent to GDSX.
TSCODE identifies which D^H task should handle the request..
TSCODE checks to see whether a ^READUPDATE has been
issued by the D^H task. ( The issuing of ^READUPDATE
makes it possible to receive incoming messages.)
TSCODE queues this request. (D^H task receives this
message when it issues a ^READUPDATE.)
NO
YES
Because a ^ READUPDATE has been issued, TSCODE notifies
the D^H task of the pending message by calling WAKE^TASK,
and forwards the message to the D^H task for processing.
The USCODE D^H task performs
datastream conversion.
The D^H task issues a ^WRITEREAD
and an ^AWAITIO to wait for
completion of the ^WRITEREAD.
TSCODE identifies which L^H task should handle the request.
TSCODE checks to see whether a ^READUPDATE has been
issued by the lL^H task.
NO
TSCODE queues this message. (The L^H task receives this
message when it issues a ^READUPDATE.)
YES
TSCODE notifies the L^H task of the pending message by calling
WAKE^TASK, and forwards the message to the L^H task of
processing.
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