[binutils-gdb] Windows gdb: Don't abort get_windows_debug_event with no threads

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6e3ecea0e3ca191e81e82ee0194c49eea1ffb101

commit 6e3ecea0e3ca191e81e82ee0194c49eea1ffb101
Author: Hannes Domani <[email protected]>
Date:   Wed Aug 26 19:35:52 2026 +0200

    Windows gdb: Don't abort get_windows_debug_event with no threads
    
    When a machine is under heavy load, windows sometimes provides the debug
    events in a weird order:
    
      [windows events] get_windows_debug_event: kernel event for pid=22208 tid=0x6df0 code=CREATE_PROCESS_DEBUG_EVENT
      [windows events] get_windows_debug_event: kernel event for pid=22208 tid=0xe74 code=CREATE_THREAD_DEBUG_EVENT
      [windows events] get_windows_debug_event: kernel event for pid=22208 tid=0xe74 code=EXIT_THREAD_DEBUG_EVENT
      [windows events] get_windows_debug_event: kernel event for pid=22208 tid=0x6df0 code=EXIT_THREAD_DEBUG_EVENT
    
    At this point the process has seemingly no threads, even though for the last
    thread there should be EXIT_PROCESS_DEBUG_EVENT instead of
    EXIT_THREAD_DEBUG_EVENT.  But the next event shows that a new thread was
    created, which then finally got EXIT_PROCESS_DEBUG_EVENT:
    
      [windows events] get_windows_debug_event: kernel event for pid=22208 tid=0x5a7c code=CREATE_THREAD_DEBUG_EVENT
      [windows events] get_windows_debug_event: kernel event for pid=22208 tid=0x5a7c code=EXIT_PROCESS_DEBUG_EVENT
    
    Since the introduction of non-stop support, gdb fails with this error at
    the point of no threads:
    
      No unwaited-for children left.
    
    It's because it added this check which prevents getting the next debug
    event:
    
      /* If there are no resumed threads left, bail.  */
      if (windows_process->windows_initialization_done
          && !any_resumed_thread ())
        {
          ourstatus->set_no_resumed ();
          return minus_one_ptid;
        }
    
    This fixes it by changing any_resumed_thread to return true if there is
    no thread at all.
    
    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=34195
    Approved-By: Tom Tromey <[email protected]>

Diff:
---
 gdb/windows-nat.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index def8fa606f4..94d932a9a1e 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -1366,15 +1366,20 @@ windows_nat_target::thread_events (bool enable)
   m_report_thread_events = enable;
 }
 
-/* True if there is any resumed thread.  */
+/* True if there is any resumed thread, or no thread at all.  */
 
 bool
 windows_nat_target::any_resumed_thread ()
 {
+  bool has_thread = false;
   for (thread_info &thread : all_non_exited_threads (this))
-    if (thread.internal_state () == THREAD_INT_RUNNING)
-      return true;
-  return false;
+    {
+      has_thread = true;
+      if (thread.internal_state () == THREAD_INT_RUNNING)
+	return true;
+    }
+  DEBUG_EVENTS ("any_resumed_thread: has_thread=%d", has_thread);
+  return !has_thread;
 }
 
 /* Called for both EXIT_THREAD_DEBUG_EVENT and