Re: [RFA/doco] Document task-specific breakpoints

Joel Brobecker
2009-03-31T16:55:28Z

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> 2009-03-25 Joel Brobecker <brobecker@adacore.com>
>
> * gdb.texinfo (Ada Tasks): Add documentation about task-specific
> breakpoints.

I checked this patch in, with "Running" changed to "Runnable".
For the record, here is the final patch.

--
Joel

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diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index a1c0b80..8b1467e 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -3051,6 +3051,11 @@ C@t{++}, a function name may refer to more than one possible place to break.
@xref{Ambiguous Expressions,,Ambiguous Expressions}, for a discussion of
that situation.

+It is also possible to insert a breakpoint that will stop the program
+only if a specific thread or a specific task hits that breakpoint.
+@xref{Thread-Specific Breakpoints} and @ref{Ada Tasks} for more
+information about this feature.
+
@item break
When called without any arguments, @code{break} sets a breakpoint at
the next instruction to be executed in the selected stack frame
@@ -11750,6 +11755,58 @@ from the current task to the given task.
#4 0x804aacc in un () at un.adb:5
@end smallexample

+@item break @var{linespec} task @var{taskno}
+@itemx break @var{linespec} task @var{taskno} if @dots{}
+@cindex breakpoints and tasks, in Ada
+@cindex task breakpoints, in Ada
+@kindex break @dots{} task @var{taskno}@r{ (Ada)}
+These commands are like the @code{break @dots{} thread @dots{}}
+command (@pxref{Thread Stops}).
+@var{linespec} specifies source lines, as described
+in @ref{Specify Location}.
+
+Use the qualifier @samp{task @var{taskno}} with a breakpoint command
+to specify that you only want @value{GDBN} to stop the program when a
+particular Ada task reaches this breakpoint. @var{taskno} is one of the
+numeric task identifiers assigned by @value{GDBN}, shown in the first
+column of the @samp{info tasks} display.
+
+If you do not specify @samp{task @var{taskno}} when you set a
+breakpoint, the breakpoint applies to @emph{all} tasks of your
+program.
+
+You can use the @code{task} qualifier on conditional breakpoints as
+well; in this case, place @samp{task @var{taskno}} before the
+breakpoint condition (before the @code{if}).
+
+For example,
+
+@smallexample
+@iftex
+@leftskip=0.5cm
+@end iftex
+(@value{GDBP}) info tasks
+ ID TID P-ID Pri State Name
+ 1 140022020 0 15 Child Activation Wait main_task
+ 2 140045060 1 15 Accept/Select Wait t2
+ 3 140044840 1 15 Runnable t1
+* 4 140056040 1 15 Runnable t3
+(@value{GDBP}) b 15 task 2
+Breakpoint 5 at 0x120044cb0: file test_task_debug.adb, line 15.
+(@value{GDBP}) cont
+Continuing.
+task # 1 running
+task # 2 running
+
+Breakpoint 5, test_task_debug () at test_task_debug.adb:15
+15 flush;
+(@value{GDBP}) info tasks
+ ID TID P-ID Pri State Name
+ 1 140022020 0 15 Child Activation Wait main_task
+* 2 140045060 1 15 Runnable t2
+ 3 140044840 1 15 Runnable t1
+ 4 140056040 1 15 Delay Sleep t3
+@end smallexample
@end table

@node Ada Tasks and Core Files