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gdbserver: Reindent check_zombie_leaders
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This fixes the indentation of
linux_process_target::check_zombie_leaders, which will help with
keeping its comments in sync with the gdb/linux-nat.c counterpart.

Change-Id: I37332343bd80423d934249e3de2d04feefad1891
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palves committed Mar 10, 2022
1 parent 5406bc3 commit aa40a98
Showing 1 changed file with 50 additions and 51 deletions.
101 changes: 50 additions & 51 deletions gdbserver/linux-low.cc
Original file line number Diff line number Diff line change
Expand Up @@ -1721,57 +1721,56 @@ iterate_over_lwps (ptid_t filter,
void
linux_process_target::check_zombie_leaders ()
{
for_each_process ([this] (process_info *proc) {
pid_t leader_pid = pid_of (proc);
struct lwp_info *leader_lp;

leader_lp = find_lwp_pid (ptid_t (leader_pid));

threads_debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
"num_lwps=%d, zombie=%d",
leader_pid, leader_lp!= NULL, num_lwps (leader_pid),
linux_proc_pid_is_zombie (leader_pid));

if (leader_lp != NULL && !leader_lp->stopped
/* Check if there are other threads in the group, as we may
have raced with the inferior simply exiting. */
&& !last_thread_of_process_p (leader_pid)
&& linux_proc_pid_is_zombie (leader_pid))
{
/* A leader zombie can mean one of two things:
- It exited, and there's an exit status pending
available, or only the leader exited (not the whole
program). In the latter case, we can't waitpid the
leader's exit status until all other threads are gone.
- There are 3 or more threads in the group, and a thread
other than the leader exec'd. On an exec, the Linux
kernel destroys all other threads (except the execing
one) in the thread group, and resets the execing thread's
tid to the tgid. No exit notification is sent for the
execing thread -- from the ptracer's perspective, it
appears as though the execing thread just vanishes.
Until we reap all other threads except the leader and the
execing thread, the leader will be zombie, and the
execing thread will be in `D (disc sleep)'. As soon as
all other threads are reaped, the execing thread changes
it's tid to the tgid, and the previous (zombie) leader
vanishes, giving place to the "new" leader. We could try
distinguishing the exit and exec cases, by waiting once
more, and seeing if something comes out, but it doesn't
sound useful. The previous leader _does_ go away, and
we'll re-add the new one once we see the exec event
(which is just the same as what would happen if the
previous leader did exit voluntarily before some other
thread execs). */

threads_debug_printf ("Thread group leader %d zombie "
"(it exited, or another thread execd).",
leader_pid);

delete_lwp (leader_lp);
}
for_each_process ([this] (process_info *proc)
{
pid_t leader_pid = pid_of (proc);
lwp_info *leader_lp = find_lwp_pid (ptid_t (leader_pid));

threads_debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
"num_lwps=%d, zombie=%d",
leader_pid, leader_lp!= NULL, num_lwps (leader_pid),
linux_proc_pid_is_zombie (leader_pid));

if (leader_lp != NULL && !leader_lp->stopped
/* Check if there are other threads in the group, as we may
have raced with the inferior simply exiting. */
&& !last_thread_of_process_p (leader_pid)
&& linux_proc_pid_is_zombie (leader_pid))
{
/* A leader zombie can mean one of two things:
- It exited, and there's an exit status pending
available, or only the leader exited (not the whole
program). In the latter case, we can't waitpid the
leader's exit status until all other threads are gone.
- There are 3 or more threads in the group, and a thread
other than the leader exec'd. On an exec, the Linux
kernel destroys all other threads (except the execing
one) in the thread group, and resets the execing thread's
tid to the tgid. No exit notification is sent for the
execing thread -- from the ptracer's perspective, it
appears as though the execing thread just vanishes.
Until we reap all other threads except the leader and the
execing thread, the leader will be zombie, and the
execing thread will be in `D (disc sleep)'. As soon as
all other threads are reaped, the execing thread changes
it's tid to the tgid, and the previous (zombie) leader
vanishes, giving place to the "new" leader. We could try
distinguishing the exit and exec cases, by waiting once
more, and seeing if something comes out, but it doesn't
sound useful. The previous leader _does_ go away, and
we'll re-add the new one once we see the exec event
(which is just the same as what would happen if the
previous leader did exit voluntarily before some other
thread execs). */

threads_debug_printf ("Thread group leader %d zombie "
"(it exited, or another thread execd).",
leader_pid);

delete_lwp (leader_lp);
}
});
}

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