[vlc-devel] [PATCH] win32/drawable: process the WM_SIZE asynchronously

[Steve Lhomme]

The vout_window_ReportSize call may make changes in underlying HWND's which in
turn might make reentrant calls to WinVoutEventProc, which might in turn call
WM_SIZE in the same stack (when resizing quickly).

vout_window_ReportSize() is not reentrant so we should avoid calling it in
calls that might be reentrant (WM_SIZE in this case).

We keep the latest WM_SIZE so when the asynchronous call is done, we already
have the most up to date value.
---
 modules/video_output/win32/drawable.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/modules/video_output/win32/drawable.c b/modules/video_output/win32/drawable.c
index 90106558848..c6f2f573a2f 100644
--- a/modules/video_output/win32/drawable.c
+++ b/modules/video_output/win32/drawable.c
@@ -77,6 +77,8 @@ struct drawable_sys
     HWND hWnd;
     HWND embed_hwnd;
     RECT rect_parent;
+
+    unsigned int width, height;
 };
 
 static LRESULT CALLBACK WinVoutEventProc(HWND hwnd, UINT message,
@@ -131,7 +133,13 @@ static LRESULT CALLBACK WinVoutEventProc(HWND hwnd, UINT message,
         return 0;
 
     case WM_SIZE:
-        vout_window_ReportSize(wnd, LOWORD(lParam), HIWORD(lParam));
+        sys->width  = LOWORD(lParam);
+        sys->height = HIWORD(lParam);
+        PostMessage(hwnd, WM_USER, 0, lParam);
+        return 0;
+
+    case WM_USER:
+        vout_window_ReportSize(wnd, sys->width, sys->height);
         return 0;
 
     default:
-- 
2.29.2