HP 3000 Manuals HP 3000 Manuals
DATA BREAK SET
Sets a breakpoint at the specified data item or data-item value.
Syntax
{DATA BREAK SET}item_name[[,length [,count [,{cmdlist}]]]]
{DBS } [,rel-op ,value [,{cmdlist}] ]
Parameters
item_name The name of a Transact/iX data item at which the data
breakpoint is set. Marker items are not valid item
names.
length The number of bytes of the item that will be checked if
a data breakpoint occurs. If any portion of the item
(up to the specified length) has changed, a data
breakpoint occurs. The default value for length is the
storage length multiplied by occurrence count. (See
DEFINE(ITEM) in Chapter 8, "Transact Verbs.")
count A number indicating how often you want to stop at the
data breakpoint, that is, every n times it is reached.
The default for this parameter is 1.
rel-op An operator that indicates the relationship between the
value that is supplied and the data item value that will
cause a breakpoint. Valid operators are LT, LE, EQ, GE,
GT, and NE.
value The value to compare against. If the data item is of
type X or U, the comparison between the data item and
the supplied value parameter is based on the shorter of
the two.
cmdlst A set of commands executed every n times the breakpoint
is reached. The cmdlist parameter must consist of valid
TRANDEBUG commands separated by semicolons. It cannot
consist of NMDEBUG commands or commands that contain
command lists. For example, {AUTORPT;STEP;;;;MODIFY
STATUS-15;CONTINUE}. (Each of the semicolons following
STEP acts like a carriage return if AUTORPT is set.)
The entire DATA BREAK SET command, including the cmdlst
parameter, can be up to 80 characters long.
Discussion
This command allows you to set a data-change breakpoint or a data-value
breakpoint at a specified item within the Transact/iX program. If a
data-change breakpoint is set, the breakpoint count value is decremented
each time the item value changes. When the count reaches zero, control
returns to TRANDEBUG, and the breakpoint information is displayed.
If a data-value breakpoint is set, anytime the item value changes and the
desired relation between the data item and the supplied value becomes
true, a data breakpoint occurs and control returns to TRANDEBUG.
For either breakpoint type, if the item is listed again or if the item is
removed from the list register, a data breakpoint occurs and control
returns to TRANDEBUG.
This command can be used to determine which instruction is modifying a
specific data item. The data breakpoint will always occur at the
instruction after the one that modified the data item. TRANDEBUG
displays a message if the data breakpoint is set successfully. You can
only set data breakpoints in the current system.
The range of valid breakpoints is 0 to 63. A combined total of up to 64
breakpoints can be set using the DATA BREAK SET and DATA BREAK REGISTER
commands. Another set of up to 64 breakpoints can be set using the BREAK
SET command.
Examples
The following examples show the setting of data breakpoints in TRANDEBUG.
TRANDEBUG> data break set item1
DATA BREAKPOINT SET:
SYSTEM ITEM NAME LENGTH COUNT TYPE
_____________________________________________________
0. MYPROG ITEM1 4 1 CHANGE
TRANDEBUG> data break set item2,,,{DISPLAY MATCH}
DATA BREAKPOINT SET:
SYSTEM ITEM NAME LENGTH COUNT TYPE
_____________________________________________________
1. MYPROG ITEM2 4 1 CHANGE
CMD LIST>>>>> DISPLAY MATCH
TRANDEBUG> continue
DATA BREAKPOINT ENCOUNTERED, EXECUTION STOPPED:
'ITEM2' VALUE HAS CHANGED:
OLD VALUE>>>>> 5
NEW VALUE>>>>> -1
MATCH REGISTER:
ITEM1 EQ : 123
TRANDEBUG> data break set item3, EQ,abcd
DATA BREAKPOINT SET:
SYSTEM ITEM NAME LENGTH COUNT TYPE
_____________________________________________________
2. MYPROG ITEM3 4 1 VALUE
EQ VALUE>>>>>> abcd
TRANDEBUG> dbs item4,LE,3,{DISPLAY MATCH}
DATA BREAKPOINT SET:
SYSTEM ITEM NAME LENGTH COUNT TYPE
_____________________________________________________
1. MYPROG ITEM4 4 1 VALUE
LE VALUE>>>>> 3
CMD LIST>>>>> DISPLAY MATCH
TRANDEBUG> continue
DATA BREAKPOINT ENCOUNTERED, EXECUTION STOPPED:
'ITEM4' DATA VALUE BREAKPOINT
LE VALUE>>>>> 3
MATCH REGISTER:
ITEM1 EQ : 123
The column TYPE shows the data breakpoint type VALUE or CHANGE. VALUE
means that a breakpoint is related to a specified value. The value that
causes the breakpoint is displayed after the string VALUE>>>>> and can
take multiple lines. The relation between the item name and the value
that causes the breakpoint is displayed in front of the string
VALUE>>>>>. CHANGE indicates a data breakpoint when the item_name value
changes. The command list associated with the breakpoint is listed after
the string CMD LIST>>>>> and can also take multiple lines.