diff options
| -rw-r--r-- | gdbserver/linux-low.cc | 101 |
1 files changed, 50 insertions, 51 deletions
diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc index f773186..442b7d9 100644 --- a/gdbserver/linux-low.cc +++ b/gdbserver/linux-low.cc @@ -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); + } }); } |