Avoid race condition when handling a SIGWINCH signal

The control variable win_resized must be cleared before responding to
it.

Otherwise there is a small window where another SIGWINCH might occur in
between the handling of an earlier SIGWINCH and the clearing of
win_resized, at which point win_resized would be set (again) by the
signal handler.  Shortly thereafter we would clear win_resized even
though we only handled the earlier SIGWINCH but not the latest one.
This chain of events is all avoided if we clear win_resized first.

gdb/ChangeLog:

	* tui/tui-win.c (tui_async_resize_screen): Clear win_resized
	first before resizing the window.
	* tui.c (tui_enable): Likewise.

diff --git a/gdb/tui/tui-win.c b/gdb/tui/tui-win.c
index 683c0eda33ec79d56edee34b160dfd04619aa3f3..8c0685bd41d4782a000081e44c3e7c6484ceb8c4 100644 (file)
--- a/gdb/tui/tui-win.c
+++ b/gdb/tui/tui-win.c
@@ -858,10 +858,10 @@ tui_async_resize_screen (gdb_client_data arg)
     }
   else
     {
+      tui_set_win_resized_to (FALSE);
       tui_resize_all ();
       tui_refresh_all_win ();
       tui_update_gdb_sizes ();
-      tui_set_win_resized_to (FALSE);
       tui_redisplay_readline ();
     }
 }

diff --git a/gdb/tui/tui.c b/gdb/tui/tui.c
index 9fac06e51cc3b1afdbfc1707cbd790a1c7e688b9..b04e106e5c474eeae101a4b9c44a5f6b8cc914db 100644 (file)
--- a/gdb/tui/tui.c
+++ b/gdb/tui/tui.c
@@ -492,8 +492,8 @@ tui_enable (void)
      window.  */
   if (tui_win_resized ())
     {
-      tui_resize_all ();
       tui_set_win_resized_to (FALSE);
+      tui_resize_all ();
     }
 
   if (deprecated_safe_get_selected_frame ())