The temporary-storage browse transaction (CEBR) allows the
user to browse, copy, or delete items in a queue. CEBR invokes
DFHEDFBR to execute the required action.
The EDF display program, DFHEDFD, provides the following functions:
- To display the user program status
- To allow the user to modify argument values and responses
- To allow the user to display and modify the EXEC interface
block (EIB) and program working storage
- To allow the user to display any hexadecimal location in
the partition user screen
- To allow the user to suppress EDF displays until specified
conditions are met.
Method
- Data describing user status is passed to DFHEDFD in the TWA.
- Initialize exception and abend handling.
- If TS queue for user terminal already exists, read control
information; otherwise create control information about TS queue.
- Check for security violation.
- If necessary, remember user screen.
- Build required display by calling DFHEDFS.
- Send display to EDF screen.
- Extract modified information by calling DFHEDFS.
- Analyze request.
- Set up build information for next display.
- Go and build required display.
- When no further displays are required:
- Save function display
- If necessary, restore user screen
- Update control information
- If transaction is defined as remote, purge TS queue and
any shared storage associated with the EDF task
- Return to DFHEDFP.
The EDF map set, DFHEDFM, consists of three maps:
- DFHEDFM
- To display status information at the
various EDF interception points
- DFHEDFN
- To display the EDF stop conditions
- DFHEDFP
- To display a dump of storage.
All maps are (24,80). The first two lines of each map contain
the transaction ID, program name, status, and so on. The format of
these two lines must be identical for all maps. A menu is
displayed with each map, and includes a message line and a
reply field. The format of the menu must be identical for all
maps. The cursor is positioned by symbolic cursor positioning.
The EDF control program, DFHEDFP, provides the CEDF transaction for
starting EDF, and is used in two different ways:
- To control the debugging task
- To set debug mode on or off.
Input
Input to the DFHEDFP program is provided as follows:
- To control the debugging task
- Information describing the user task status is written into the
debug linkage area (DLA)
of CEDF by DFHEDFX.
- To set debug mode on or off
- The user enters a CEDF request
at the debug display terminal using the following syntax:
CEDF termid,ON|OFF
Alternatively, a PF key may be used to switch single-terminal
debug mode on.
Note:
To use EDF for a remote transaction, only single-terminal mode
is available.
Output
Output from the DFHEDFP program is as follows:
- To control the debugging task
- DFHEDFD displays user program status.
- To set debug mode on or off
- Switches the debug mode bit either in the user terminal TCTTE or,
if an EXEC task is running, in the user task EIS.
For two-terminal debugging, creates temporary-storage queue
element to connect user terminal with display terminal.
Method
- To control the program for debugging a task
- If the task is attached by DFHEDFX
and if only one terminal is being used for debugging,
link to DFHEDFD to display program status.
If two terminals are being used for debugging,
start CEDF at the display terminal, restore that terminal to the user,
resume the user task, then return to CICS®.
- To set debug mode on or off
- If invoked by using a PF key,
set the debug mode on for single-terminal debugging in the user TCTTE.
If invoked by a CEDF request, extract the user terminal ID
(default is display terminal), and extract the debug mode (default is
on).
If the user terminal ID does not exist, output a diagnostic
message.
If the EXEC task is running and the task is in debug mode,
output a diagnostic message; otherwise switch the debug bit in EIS,
or switch the debug bit in TCTTE.
Create a temporary-storage queue element naming the debug terminal.
The EDF response table, DFHEDFR, is
a table used by DFHEDFD to interpret the responses obtained
by EXEC commands.
The EDF task switch program, DFHEDFX, is
used to attach the debugging task, provide it with
all necessary information about the status of the user task,
and suspend the user task until the debugging task allows it
to resume.
Method
- Extract information describing the user task status and copy it
into the DLA for the attached task
- Issue wait on user terminal
- Attach CEDF
- Suspend the user task
- When the user task is resumed by EDF, check if EDF has not abended
- If the user requests an abend, abend the user task;
otherwise, return to caller.
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