GDSX (Extended General Device Support) Manual

LINE^HANDLER Example, Running and Managing
Extended General Device Support (GDSX) Manual—529931-001
6-5
Running More Application Processes
The GDSX process, named $GDS, did its initialization processing and issued a
READUPDATE on $RECEIVE. Then the application program, named $A1, did its
initialization processing and issued a call to OPEN $GDS.#LX.T1. After TSCODE
received the OPEN, the SU T1 was opened, a DEVICE^HANDLER task was created
to manage communication to T1, and the LINE^HANDLER task was notified that the
SU was opened.
$GDS called REPLY with a completion code, indicating that the application’s OPEN for
$GDS.#LX.T1 was successful. After checking the condition code, the application
program issued a WRITEREAD to $GDS.#LX.T1, writing the prompt containing its own
CPU number and PIN. $GDS scanned the prompt text for characters to be converted
before issuing a WRITEREAD of the converted text to $TC1. (The datastream
conversion is discussed in Section 5, DEVICE^HANDLER Example, Design) Finally,
the IOP wrote the prompt to the screen and waited for input. Section 7,
LINE^HANDLER Example, Design discusses the functioning of the LINE^HANDLER
task in this message flow.
At the application terminal, enter a few text strings in response to the prompts, and
observe what happens. The strings should be uppercase text and in reverse order.
The input string read by the IOP was passed to $GDS, and then on to $A1, which
reversed the sequence of characters in the string. $A1 then issued a call to WRITE
the reversed string to $GDS.#LX.T1. After changing lowercase text to uppercase text,
$GDS issued a WRITE to terminal $TC1, and the IOP displayed the reversed string.
After checking the condition code for its WRITE, $GDS REPLYed to $A1, which then
sent another prompt to the terminal by way of GDSX. The processing is as depicted in
Figure 4-4 on page 4-10.
Running More Application Processes
At the TACL terminal, run two more requesters, again from program file APPL. These
processes will direct their output to logical subdevices T2 and T3, both under LINE
$LX, which is mapped by access name to application terminal $TC1:
> RUN APPL /NAME $A2, OUT $GDS.#LX.T2, NOWAIT/
> RUN APPL /NAME $A3, OUT $GDS.#LX.T3, NOWAIT/
Enter:
> STATUS *, TERM
Note the CPU and PIN values for the new requester processes $A2 and $A3.
At the SCF terminal, enter:
-> STATUS PROCESS $GDS
The STATUS command tells you that there are two TSCODE system tasks, and four
USCODE user tasks.
-> STATUS, SUB ALL