GDSX (Extended General Device Support) Manual

DEVICE^HANDLER Example, Design
Extended General Device Support (GDSX) Manual—529931-001
5-4
Task I/O Calls
The following is a list of pseudo Guardian, TS/MP, and TMF procedures that must be
used instead of their counterparts. (Many TSCODE-supported procedures do not have
Figure 5-2. DEVICE^HANDLER Example: Sending a Request to a Terminal
Application IOP/TerminalGDS (TSCODE and USCODE)
A WRITEREAD with
data is sent to GSDX
TSCODE checks $RECEIVE for input and
identifies the USCODE D^H task that is to
handle the WRITEREAD
TSCODE checks to see whether a
^READUPDATE on the task's pseudo-
$RECEIVE has been issued by
the task. (Issuing ^READUPDATE makes it
possible to receive incoming messages.)
NO
TSCODE queues request. (D^H
task receives this message when it
issues a ^READUPDATE.)
YES
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 to
send the data to the terminal.
TSCODE receives the ^WRITEREAD and
sends a Guardian WRITEREAD to the
terminal
While the IOP handles the data, the D^H
task issues an ^AWAITIO, waiting for
completion of the ^WRITEREAD.
TSCODE receives the I/O completion
message and passes it to the D^H task for
processing.
The D^H task sends a response to the
application by calling ^REPLY.
Requester receives
response.
Data goes to the IOP and
is sent to the terminal.
The I/O completion
message is sent.
VST017.vsd