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| author | Pedro Alves <palves@redhat.com> | 2015-03-15 19:35:26 +0000 |
|---|---|---|
| committer | Pedro Alves <palves@redhat.com> | 2015-03-19 12:38:05 +0000 |
| commit | 8bf3b159e55b42bb084f9da1af400a285025618f (patch) | |
| tree | 769fa2be997cc1a1ebff1ada69efe99cf1999c58 /gdb/linux-nat.c | |
| parent | eb54c8bf087f434b0cb91b35e7cde68a69ac9193 (diff) | |
| download | gdb-8bf3b159e55b42bb084f9da1af400a285025618f.zip gdb-8bf3b159e55b42bb084f9da1af400a285025618f.tar.gz gdb-8bf3b159e55b42bb084f9da1af400a285025618f.tar.bz2 | |
gdbserver/Linux: unbreak thread event randomization
Wanting to make sure the new continue-pending-status.exp test tests
both cases of threads 2 and 3 reporting an event, I added counters to
the test, to make it FAIL if events for both threads aren't seen.
Assuming a well behaved backend, and given a reasonable number of
iterations, it should PASS.
However, running that against GNU/Linux gdbserver, I found that
surprisingly, that FAILed. GDBserver always reported the breakpoint
hit for the same thread.
Turns out that I broke gdbserver's thread event randomization
recently, with git commit 582511be ([gdbserver] linux-low.c: better
starvation avoidance, handle non-stop mode too). In that commit I
missed that the thread structure also has a status_pending_p field...
The end result was that count_events_callback always returns 0, and
then if no thread is stepping, select_event_lwp always returns the
event thread. IOW, no randomization is happening at all. Quite
curious how all the other changes in that patch were sufficient to fix
non-stop-fair-events.exp anyway even with that broken.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/gdbserver/ChangeLog:
2015-03-19 Pedro Alves <palves@redhat.com>
* linux-low.c (count_events_callback, select_event_lwp_callback):
Use the lwp's status_pending_p field, not the thread's.
gdb/testsuite/ChangeLog:
2015-03-19 Pedro Alves <palves@redhat.com>
* gdb.threads/continue-pending-status.exp (saw_thread_2)
(saw_thread_3): New globals.
(top level): Increment them when an event for the corresponding
thread is seen.
(no thread starvation): New test.
Diffstat (limited to 'gdb/linux-nat.c')
| -rw-r--r-- | gdb/linux-nat.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index f5f92d9..40f1e1f 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -2841,6 +2841,7 @@ select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) /* First see how many events we have. */ iterate_over_lwps (filter, count_events_callback, &num_events); + gdb_assert (num_events > 0); /* Now randomly pick a LWP out of those that have had events. */ |