gdb/
2009-06-27 Jan Kratochvil <jan.kratochvil@redhat.com>
* linux-nat.c (num_lwps): Do not count DEAD LWPs.
(delete_lwp): Only set LP as DEAD if it is INFERIOR_PTID.
(iterate_over_lwps): Skip DEAD LPs. Discard DEAD LPs not in
INFERIOR_PTID.
(linux_nat_resume): Do not resume DEAD LPs. Extend the debug message.
* linux-nat.h (struct lwp_info): New field `dead'.
gdb/testsuite/
2009-06-27 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.threads/current-lwp-dead.exp, gdb.threads/current-lwp-dead.c: New.
--- gdb-6.8.50.20090302/gdb/linux-nat.c.orig 2009-06-29 10:56:39.000000000 +0200
+++ gdb-6.8.50.20090302/gdb/linux-nat.c 2009-06-29 11:01:25.000000000 +0200
@@ -1192,7 +1192,15 @@ delete_lwp (ptid_t ptid)
if (!lp)
return;
- num_lwps--;
+ if (!lp->dead)
+ num_lwps--;
+
+ if (ptid_equal (ptid, inferior_ptid))
+ {
+ /* Delay the deletion the same way as in delete_thread_1. */
+ lp->dead = 1;
+ return;
+ }
if (lpprev)
lpprev->next = lp->next;
@@ -1236,6 +1244,16 @@ iterate_over_lwps (int (*callback) (stru
for (lp = lwp_list; lp; lp = lpnext)
{
lpnext = lp->next;
+
+ /* Ignored already dead LWPs. Moreover delete them if we no longer have
+ to keep them around. */
+ if (lp->dead)
+ {
+ if (!ptid_equal (lp->ptid, inferior_ptid))
+ delete_lwp (lp->ptid);
+ continue;
+ }
+
if ((*callback) (lp, data))
return lp;
}
@@ -1943,15 +1961,19 @@ linux_nat_resume (struct target_ops *ops
if (resume_all)
iterate_over_lwps (resume_callback, NULL);
- linux_ops->to_resume (linux_ops, ptid, step, signo);
- memset (&lp->siginfo, 0, sizeof (lp->siginfo));
+ if (!lp->dead)
+ {
+ linux_ops->to_resume (linux_ops, ptid, step, signo);
+ memset (&lp->siginfo, 0, sizeof (lp->siginfo));
+ }
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
- "LLR: %s %s, %s (resume event thread)\n",
+ "LLR: %s %s, %s, %s (resume event thread)\n",
step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
target_pid_to_str (ptid),
- signo ? strsignal (signo) : "0");
+ signo ? strsignal (signo) : "0",
+ lp->dead ? "dead" : "alive");
if (target_can_async_p ())
target_async (inferior_event_handler, 0);
--- a/gdb/linux-nat.h
+++ b/gdb/linux-nat.h
@@ -32,6 +32,12 @@ struct lwp_info
and overall process id. */
ptid_t ptid;
+ /* If this flag is set, the lwp is known to be dead already (exit
+ event already received in a my_waitpid()). Such LWP should not longer be
+ iterated and it is being kept only temporarily if it is still referenced
+ by INFERIOR_PTID. */
+ int dead;
+
/* Non-zero if this LWP is cloned. In this context "cloned" means
that the LWP is reporting to its parent using a signal other than
SIGCHLD. */
new file mode 100644
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/current-lwp-dead.c
@@ -0,0 +1,75 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2009 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+ Do not use threads as we need to exploit a bug in LWP code masked by the
+ threads code otherwise.
+
+ INFERIOR_PTID must point to exited LWP. Here we use the initial LWP as it
+ is automatically INFERIOR_PTID for GDB.
+
+ Finally we need to call target_resume (RESUME_ALL, ...) which we invoke by
+ NEW_THREAD_EVENT (called from the new LWP as initial LWP is exited now). */
+
+#define _GNU_SOURCE
+#include <sched.h>
+#include <assert.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#define STACK_SIZE 0x1000
+
+static int
+fn_abort (void *unused)
+{
+ return 0; /* at-fn_abort */
+}
+
+static int
+fn (void *unused)
+{
+ int i;
+ unsigned char *stack;
+ int new_pid;
+
+ i = sleep (1);
+ assert (i == 0);
+
+ stack = malloc (STACK_SIZE);
+ assert (stack != NULL);
+
+ new_pid = clone (fn_abort, stack + STACK_SIZE, CLONE_FILES | CLONE_VM, NULL,
+ NULL, NULL, NULL);
+ assert (new_pid > 0);
+
+ return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+ unsigned char *stack;
+ int new_pid;
+
+ stack = malloc (STACK_SIZE);
+ assert (stack != NULL);
+
+ new_pid = clone (fn, stack + STACK_SIZE, CLONE_FILES | CLONE_VM, NULL, NULL,
+ NULL, NULL);
+ assert (new_pid > 0);
+
+ return 0;
+}
new file mode 100644
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/current-lwp-dead.exp
@@ -0,0 +1,31 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2009 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Please email any bugs, comments, and/or additions to this file to:
+# bug-gdb@gnu.org
+
+if { [prepare_for_testing current-lwp-dead.exp current-lwp-dead] } {
+ return -1
+}
+
+if {[runto_main] <= 0} {
+ untested current-lwp-dead.exp
+ return -1
+}
+
+gdb_breakpoint "fn_abort"
+gdb_continue_to_breakpoint "fn_abort" ".*at-fn_abort.*"