Re: [PATCH] [RFC] Move SetConsoleCtrlHandler calls to async thread

[Tom Tromey <tromey@adacore.com>]

Tom> Me neither.  I'll see if I can try a different console tomorrow.

I used powershell today.  It seems to mostly work.  I do see the
ctrl-break exit when running with 'set new-console on'... but

One weird thing is if I add logging (see appended hack), the problem
goes away.  That seems extra mysterious to me.

Another problem I thought of is what should happen with these interrupt
sequences when the user puts the inferior in the background, like with
"continue &".  Having them stop the inferior seems wrong, the user might
be trying to interrupt some gdb command instead.

I don't know how this area is supposed to work.

Tom

diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 3d6a3528914..d8e627621e5 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -462,6 +462,17 @@ windows_nat_target::process_thread_starter (LPVOID self)
   return 0;
 }
 
+static BOOL
+wrap_wait_for_debug_event (DEBUG_EVENT *event, DWORD timeout)
+{
+  fprintf (stderr, "+++ installing ctrl_c_handler\n");
+  SetConsoleCtrlHandler (&ctrl_c_handler, TRUE);
+  BOOL r = wait_for_debug_event (event, INFINITE);
+  fprintf (stderr, "+++ removing ctrl_c_handler\n");
+  SetConsoleCtrlHandler (&ctrl_c_handler, FALSE);
+  return r;
+}
+
 void
 windows_nat_target::process_thread ()
 {
@@ -507,9 +518,7 @@ windows_nat_target::process_thread ()
 		     immediately when the user tries to resume the execution
 		     in the inferior.  This is a classic race that we should
 		     try to fix one day.  */
-	      SetConsoleCtrlHandler (&ctrl_c_handler, TRUE);
-	      wait_for_debug_event (&m_last_debug_event, INFINITE);
-	      SetConsoleCtrlHandler (&ctrl_c_handler, FALSE);
+	      wrap_wait_for_debug_event (&m_last_debug_event, INFINITE);
 	      m_debug_event_pending = true;
 	    }
 	  serial_event_set (m_wait_event);
@@ -537,11 +546,7 @@ windows_nat_target::wait_for_debug_event_main_thread (DEBUG_EVENT *event)
 	  serial_event_clear (m_wait_event);
 	}
       else
-	{
-	  SetConsoleCtrlHandler (&ctrl_c_handler, TRUE);
-	  wait_for_debug_event (event, INFINITE);
-	  SetConsoleCtrlHandler (&ctrl_c_handler, FALSE);
-	}
+	wrap_wait_for_debug_event (event, INFINITE);
       return false;
     });
 }
@@ -1558,9 +1563,14 @@ ctrl_c_handler (DWORD event_type)
 {
   const int attach_flag = current_inferior ()->attach_flag;
 
+  fprintf (stderr, "+++ ctrl_c_handler, attach = %d\n", attach_flag);
+
   /* Only handle Ctrl-C and Ctrl-Break events.  Ignore others.  */
   if (event_type != CTRL_C_EVENT && event_type != CTRL_BREAK_EVENT)
     return FALSE;
+  fprintf (stderr, "+++ ctrl_c_handler, event type ok, new_console = %d, type = %s\n",
+	   (int) new_console,
+	   event_type == CTRL_C_EVENT ? "control-c" : "BREAK");
 
   /* If the inferior and the debugger share the same console, do nothing as
      the inferior has also received the Ctrl-C event.  */