The buildbot shows that some machines FAIL this test frequently.
E.g.: https://sourceware.org/ml/gdb-testers/2015-q1/msg00997.html
If I stress my machine, I can sometimes see it fail too.
Bumping the 200 limit and tweaking the test to show the step count, I
get:
...
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 12 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 8 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 13 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 7 times
--> FAIL: gdb.base/gdb-sigterm.exp: SIGTERM stepped 228 times <--
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 11 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 13 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 12 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 8 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 9 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 7 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 11 times
PASS: gdb.base/gdb-sigterm.exp: SIGTERM stepped 8 times
...
Thinking that this might be a problem of SIGTERM reaching GDB, but
then the event loop taking too long to handle it, I hacked GDB to
print a debug log whenever the SIGTERM handler was called, and,
whenever the event loop finally calls the async SIGTERM handler.
Here's what I see:
infrun: 30011 [Thread 30011],
infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x4005de
--> infrun: got SIGTERM <--
infrun: stepping inside range [0x4005de-0x4005e0]
infrun: resume (step=1, signal=GDB_SIGNAL_0), ...
infrun: prepare_to_wait
--> infrun: handling async SIGTERM <--
Cannot execute this command while the target is running.
Use the "interrupt" command to stop the target
and then try again.
gdb.base/gdb-sigterm.exp: expect eof #27
FAIL: gdb.base/gdb-sigterm.exp: SIGTERM stepped 228 times
So, no delay on the GDB side. It just happens that occasionally it
takes more than 200 single-steps before SIGTERM even reaches GDB.
This just looks like a kernel/scheduling issue --- some extra usage
spike in the system (e.g., an I/O spike) might cause it for me. For
the build slaves, I'm guessing they're frequently busy enough to trip
on this often. Particularly more so now that we're having them run
tests in parallel mode.
The fix is to detect failure by timeout instead of counting single
steps. This should be more reliable. Indeed for me, after this
commit, I couldn't trigger a FAIL anymore, even after letting the test
run for an hour.
By timeout is also nicer in that a board file for a slow host/target
can increase it (like, e.g., an embedded GNU/Linux board).
Tested on x86_64 Fedora 20, native, gdbserver, and extended-remote
gdbserver.
gdb/testsuite/
2015-02-06 Pedro Alves <palves@redhat.com>
* gdb.base/gdb-sigterm.c (main): Use the TIMEOUT define to
determine how many seconds to pass to 'alarm'.
* gdb.base/gdb-sigterm.exp (top level): Build program with
-DTIMEOUT=$timeout.
(do_test): Return success/failure indication. Add more verbose
logging. Don't fail if 200 single steps are seen. Instead, fail
when the test times out.
(passes): New global.
(top level): Break the testing loop if testing fails on any
iteration. Use gdb_assert.
This finally makes background execution commands possible by default.
However, in order to do that, there's one last thing we need to do --
we need to separate the MI and target notions of "async". Unlike the
CLI, where the user explicitly requests foreground vs background
execution in the execution command itself (c vs c&), MI chose to treat
"set target-async" specially -- setting it changes the default
behavior of execution commands.
So, we can't simply "set target-async" default to on, as that would
affect MI frontends. Instead we have to make the setting MI-specific,
and teach MI about sync commands on top of an async target.
Because the "target" word in "set target-async" ends up as a potential
source of confusion, the patch adds a "set mi-async" option, and makes
"set target-async" a deprecated alias.
Rather than make the targets always async, this patch introduces a new
"maint set target-async" option so that the GDB developer can control
whether the target is async. This makes it simpler to debug issues
arising only in the synchronous mode; important because sync mode
seems unlikely to go away.
Unlike in previous revisions, "set target-async" does not affect this
new maint parameter. The rationale for this is that then one can
easily run the test suite in the "maint set target-async off" mode and
have tests that enable mi-async fail just like they fail on
non-async-capable targets. This emulation is exactly the point of the
maint option.
I had asked Tom in a previous iteration to split the actual change of
the target async default to a separate patch, but it turns out that
that is quite awkward in this version of the patch, because with MI
async and target async decoupled (unlike in previous versions), if we
don't flip the default at the same time, then just "set target-async
on" alone never actually manages to do anything. It's best to not
have that transitory state in the tree.
Given "set target-async on" now only has effect for MI, the patch goes
through the testsuite removing it from non-MI tests. MI tests are
adjusted to use the new and less confusing "mi-async" spelling.
2014-05-29 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* NEWS: Mention "maint set target-async", "set mi-async", and that
background execution commands are now always available.
* target.h (target_async_permitted): Update comment.
* target.c (target_async_permitted, target_async_permitted_1):
Default to 1.
(set_target_async_command): Rename to ...
(maint_set_target_async_command): ... this.
(show_target_async_command): Rename to ...
(maint_show_target_async_command): ... this.
(_initialize_target): Adjust.
* infcmd.c (prepare_execution_command): Make extern.
* inferior.h (prepare_execution_command): Declare.
* infrun.c (set_observer_mode): Leave target async alone.
* mi/mi-interp.c (mi_interpreter_init): Install
mi_on_sync_execution_done as sync_execution_done observer.
(mi_on_sync_execution_done): New function.
(mi_execute_command_input_handler): Don't print the prompt if we
just started a synchronous command with an async target.
(mi_on_resume): Check sync_execution before printing prompt.
* mi/mi-main.h (mi_async_p): Declare.
* mi/mi-main.c: Include gdbcmd.h.
(mi_async_p): New function.
(mi_async, mi_async_1): New globals.
(set_mi_async_command, show_mi_async_command, mi_async): New
functions.
(exec_continue): Call prepare_execution_command.
(run_one_inferior, mi_cmd_exec_run, mi_cmd_list_target_features)
(mi_execute_async_cli_command): Use mi_async_p.
(_initialize_mi_main): Install "set mi-async". Make
"target-async" a deprecated alias.
2014-05-29 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* gdb.texinfo (Non-Stop Mode): Remove "set target-async 1"
from example.
(Asynchronous and non-stop modes): Document '-gdb-set mi-async'.
Mention that target-async is now deprecated.
(Maintenance Commands): Document maint set/show target-async.
2014-05-29 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* gdb.base/async-shell.exp: Don't enable target-async.
* gdb.base/async.exp
* gdb.base/corefile.exp (corefile_test_attach): Remove 'async'
parameter. Adjust.
(top level): Don't test with "target-async".
* gdb.base/dprintf-non-stop.exp: Don't enable target-async.
* gdb.base/gdb-sigterm.exp: Don't test with "target-async".
* gdb.base/inferior-died.exp: Don't enable target-async.
* gdb.base/interrupt-noterm.exp: Likewise.
* gdb.mi/mi-async.exp: Use "mi-async" instead of "target-async".
* gdb.mi/mi-nonstop-exit.exp: Likewise.
* gdb.mi/mi-nonstop.exp: Likewise.
* gdb.mi/mi-ns-stale-regcache.exp: Likewise.
* gdb.mi/mi-nsintrall.exp: Likewise.
* gdb.mi/mi-nsmoribund.exp: Likewise.
* gdb.mi/mi-nsthrexec.exp: Likewise.
* gdb.mi/mi-watch-nonstop.exp: Likewise.
* gdb.multi/watchpoint-multi.exp: Adjust comment.
* gdb.python/py-evsignal.exp: Don't enable target-async.
* gdb.python/py-evthreads.exp: Likewise.
* gdb.python/py-prompt.exp: Likewise.
* gdb.reverse/break-precsave.exp: Don't test with "target-async".
* gdb.server/solib-list.exp: Don't enable target-async.
* gdb.threads/thread-specific-bp.exp: Likewise.
* lib/mi-support.exp: Adjust to use mi-async.
That "set debug lin-lwp 1" command even is not needed for the functionality of
this testcase.
This patch does fix a testcase error on aarch64-none-elf.
gdb/testsuite/
2014-03-24 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.base/gdb-sigterm.exp (do_test): Remove "set debug lin-lwp 1".
Message-ID: <20140323165745.GA23830@host2.jankratochvil.net>
gdb/
2014-03-18 Jan Kratochvil <jan.kratochvil@redhat.com>
PR gdb/15358
* defs.h (sync_quit_force_run): New declaration.
(QUIT): Check also SYNC_QUIT_FORCE_RUN.
* event-top.c (async_sigterm_handler): New declaration.
(async_sigterm_token): New variable.
(async_init_signals): Create also async_sigterm_token.
(async_sigterm_handler): New function.
(sync_quit_force_run): New variable.
(handle_sigterm): Replace quit_force call by other calls.
* utils.c (quit): Call quit_force if SYNC_QUIT_FORCE_RUN.
gdb/testsuite/
2014-03-18 Jan Kratochvil <jan.kratochvil@redhat.com>
PR gdb/15358
* gdb.base/gdb-sigterm.c: New file.
* gdb.base/gdb-sigterm.exp: New file.
Message-ID: <20140316135334.GA30698@host2.jankratochvil.net>
