diff options
| 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/gdbserver | |
| 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/gdbserver')
| -rw-r--r-- | gdb/gdbserver/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/gdbserver/linux-low.c | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 6efab5b..df8f9ab 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,8 @@ +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. + 2015-03-19 Pedro Alves <palves@redhat.com> * linux-low.c (select_event_lwp_callback): Update comments to diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 9558f46..e53e0fc 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -2238,6 +2238,7 @@ static int count_events_callback (struct inferior_list_entry *entry, void *data) { struct thread_info *thread = (struct thread_info *) entry; + struct lwp_info *lp = get_thread_lwp (thread); int *count = data; gdb_assert (count != NULL); @@ -2245,7 +2246,7 @@ count_events_callback (struct inferior_list_entry *entry, void *data) /* Count only resumed LWPs that have an event pending. */ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE && thread->last_resume_kind != resume_stop - && thread->status_pending_p) + && lp->status_pending_p) (*count)++; return 0; @@ -2273,6 +2274,7 @@ static int select_event_lwp_callback (struct inferior_list_entry *entry, void *data) { struct thread_info *thread = (struct thread_info *) entry; + struct lwp_info *lp = get_thread_lwp (thread); int *selector = data; gdb_assert (selector != NULL); @@ -2280,7 +2282,7 @@ select_event_lwp_callback (struct inferior_list_entry *entry, void *data) /* Select only resumed LWPs that have an event pending. */ if (thread->last_resume_kind != resume_stop && thread->last_status.kind == TARGET_WAITKIND_IGNORE - && thread->status_pending_p) + && lp->status_pending_p) if ((*selector)-- == 0) return 1; @@ -2324,6 +2326,7 @@ select_event_lwp (struct lwp_info **orig_lp) /* First see how many events we have. */ find_inferior (&all_threads, count_events_callback, &num_events); + gdb_assert (num_events > 0); /* Now randomly pick a LWP out of those that have had events. */ |