Re: [PATCH] Fix AIX thread exit events not being reported and UI to show kernel thread ID.

[John Baldwin <jhb@FreeBSD.org>]

On 4/18/24 6:26 AM, Aditya Kamath1 wrote:
> Respected community members,
> 
> Hi,
> 
> Thank you for the comments in the [RFC] thread<https://sourceware.org/pipermail/gdb-patches/2024-April/208104.html>.
> 
> Please find attached the patch. (See: 0001-Fix-AIX-thread-exit-events-not-being-reported-and-UI.patch)

Next time can you please send the patch inline as a separate e-mail?  You can use a cover
letter for the contents of this mail.  It is just easier to review in that case.

One thing I think I'm not fully understanding: does a thread never get removed from the
pth list once it has exited?  That is, is it on that list forever?  If so, I think
you could simplify this quite a bit to remove the qsort and the gcount and associated
list, etc.  Instead, I would keep track of exited threads whose exit has been reported
via a new std::unordered_set<> class member in the target to avoid reporting duplicate
events and then do something like:

    for (cmd = PTHDB_LIST_FIRST;; cmd = PTHDB_LIST_NEXT)
      {
        status = pthdb_pthread (data->pd_session, &pdtid, cmd);
        if (status != PTHDB_SUCCESS || pthid == PTHDB_INVALID_PTID)
  	continue;

        status = pthdb_pthread_tid (data->pd_session, pdtid, &tid);
        if (status != PTHDB_SUCCESS)
  	tid = PTHDB_INVALID_TID;

        ptid_t ptid (pid, 0, pthid);
        status = pthdb_pthread_state (data->pd_session, pdtid, &state);
        if (state == PST_TERM)
          {
             /* If this thread's exit was previously reported, ignore. */
             if (exited_threads.count (pdtid) != 0)
                 continue;
          }

        /* If this thread has never been reported to GDB, add it.  */
        if (!in_thread_list (proc_target, ptid))
          {
            aix_thread_info *priv = new aix_thread_info;
            /* init priv */
            add_thread_with_info (proc_target, ptid,
                                  private_thread_info_up (priv));
          }

        if (state == PST_TERM)
          {
            thread_info *thr = proc_target->find_thread (ptid);
            gdb_assert (thr != nullptr);
            delete_thread (thr);
            exited_threads.insert (pdtid);
          }
       }

-- 
John Baldwin