From: Kevin Buettner <kevinb@redhat.com>
To: rda@sources.redhat.com
Subject: [commit] Handle LWPs that have died without leaving a status
Date: Thu, 10 Nov 2005 21:40:00 -0000 [thread overview]
Message-ID: <20051110144027.4ba0c27d@ironwood.lan> (raw)
I've just committed the patch below. It's been sitting in one of my
trees for a while and I don't remember all that much about it. I do
know that without this code, RDA will error out when using certain
linux kernel versions with the message:
<<< ERROR -- tkill (680, Stopped (signal)) failed: No such process >>>
I believe that this would occur because RDA was attempting to stop a
process which had already exited. Apparently, there were certain (buggy)
kernels which would fail to leave an exit status.
* lwp-pool.c (mark_lwp_as_dead_but_interesting): New function.
(wait_and_handle): Replace lines of code implementing guts of
new function mark_lwp_as_dead_but_interesting() with call to
that function. Make a new call to this function after it
has been determined that an lwp has exited without leaving a
status.
Index: lwp-pool.c
===================================================================
RCS file: /cvs/src/src/rda/unix/lwp-pool.c,v
retrieving revision 1.4
diff -u -p -r1.4 lwp-pool.c
--- lwp-pool.c 9 Nov 2005 02:16:46 -0000 1.4
+++ lwp-pool.c 10 Nov 2005 21:26:30 -0000
@@ -796,6 +796,17 @@ debug_report_state_change (struct gdbser
}
}
+/* Remove (dead) LWP from the hash table and put it on the `interesting'
+ queue. */
+static void
+mark_lwp_as_dead_but_interesting (struct lwp *l)
+{
+ hash_delete (l);
+ l->state = lwp_state_dead_interesting;
+ if (l->next)
+ queue_delete (l);
+ queue_enqueue (&interesting_queue, l);
+}
/* Wait for a status from the LWP L (or any LWP, if L is NULL),
passing FLAGS to waitpid, and record the resulting wait status in
@@ -868,15 +879,7 @@ wait_and_handle (struct gdbserv *serv, s
l->status = status;
if (WIFEXITED (status) || WIFSIGNALED (status))
- {
- /* Remove dead LWP's from the hash table, and put them in the
- interesting queue. */
- hash_delete (l);
- l->state = lwp_state_dead_interesting;
- if (l->next)
- queue_delete (l);
- queue_enqueue (&interesting_queue, l);
- }
+ mark_lwp_as_dead_but_interesting (l);
else
{
int stopsig;
@@ -1143,9 +1146,24 @@ lwp_pool_stop_all (struct gdbserv *serv)
case lwp_state_running:
/* A 'no such process' error here indicates an NPTL thread
that has exited. */
- kill_lwp (l->pid, SIGSTOP);
- l->state = lwp_state_running_stop_pending;
- queue_enqueue (&stopping_queue, l);
+ if (kill_lwp (l->pid, SIGSTOP) < 0)
+ {
+ /* Thread has exited. See if a status is available. */
+ if (wait_and_handle (serv, l, WNOHANG) < 0)
+ {
+ /* Nope, it's truly gone without providing a status.
+ Put it on the interesting queue so that GDB is
+ notified that it's gone. */
+ l->status = 0;
+ mark_lwp_as_dead_but_interesting (l);
+ }
+ }
+ else
+ {
+ l->state = lwp_state_running_stop_pending;
+ queue_enqueue (&stopping_queue, l);
+ }
+
break;
case lwp_state_stopped:
reply other threads:[~2005-11-10 21:40 UTC|newest]
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