[PATCH 0/1] MR5860: win32u: Fix a deadlock when locking the same surface on different DCs.

[Rémi Bernon (＠rbernon)]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=56771

[PATCH 1/1] win32u: Fix a deadlock when locking the same surface on different DCs.

[Rémi Bernon]

From: Rémi Bernon

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=56771
---
 dlls/win32u/dibdrv/dc.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/dlls/win32u/dibdrv/dc.c b/dlls/win32u/dibdrv/dc.c
index 48320f5b676..ea7512b01ca 100644
--- a/dlls/win32u/dibdrv/dc.c
+++ b/dlls/win32u/dibdrv/dc.c
@@ -769,6 +769,20 @@ static inline void unlock_surface( struct windrv_physdev *dev )
     }
 }

+static inline void lock_surfaces( struct windrv_physdev *dst_dev, struct windrv_physdev *src_dev )
+{
+    lock_surface( dst_dev );
+    if (src_dev && !src_dev->lock_count++ && dst_dev->surface != src_dev->surface)
+        window_surface_lock( src_dev->surface );
+}
+
+static inline void unlock_surfaces( struct windrv_physdev *dst_dev, struct windrv_physdev *src_dev )
+{
+    if (src_dev && !--src_dev->lock_count && dst_dev->surface != src_dev->surface)
+        window_surface_unlock( src_dev->surface );
+    unlock_surface( dst_dev );
+}
+
 static void unlock_windrv_bits( struct gdi_image_bits *bits )
 {
     unlock_surface( bits->param );
@@ -820,13 +834,16 @@ void dibdrv_set_window_surface( DC *dc, struct window_surface *surface )
 static BOOL windrv_AlphaBlend( PHYSDEV dst_dev, struct bitblt_coords *dst,
                                PHYSDEV src_dev, struct bitblt_coords *src, BLENDFUNCTION func )
 {
-    struct windrv_physdev *physdev = get_windrv_physdev( dst_dev );
+    struct windrv_physdev *dst_physdev = get_windrv_physdev( dst_dev ), *src_physdev;
     BOOL ret;

-    lock_surface( physdev );
+    if (src_dev->funcs == &window_driver) src_physdev = get_windrv_physdev( src_dev );
+    else src_physdev = NULL;
+
+    lock_surfaces( dst_physdev, src_physdev );
     dst_dev = GET_NEXT_PHYSDEV( dst_dev, pAlphaBlend );
     ret = dst_dev->funcs->pAlphaBlend( dst_dev, dst, src_dev, src, func );
-    unlock_surface( physdev );
+    unlock_surfaces( dst_physdev, src_physdev );
     return ret;
 }

@@ -1166,13 +1183,16 @@ static COLORREF windrv_SetPixel( PHYSDEV dev, INT x, INT y, COLORREF color )
 static BOOL windrv_StretchBlt( PHYSDEV dst_dev, struct bitblt_coords *dst,
                                PHYSDEV src_dev, struct bitblt_coords *src, DWORD rop )
 {
-    struct windrv_physdev *physdev = get_windrv_physdev( dst_dev );
+    struct windrv_physdev *dst_physdev = get_windrv_physdev( dst_dev ), *src_physdev;
     BOOL ret;

-    lock_surface( physdev );
+    if (src_dev->funcs == &window_driver) src_physdev = get_windrv_physdev( src_dev );
+    else src_physdev = NULL;
+
+    lock_surfaces( dst_physdev, src_physdev );
     dst_dev = GET_NEXT_PHYSDEV( dst_dev, pStretchBlt );
     ret = dst_dev->funcs->pStretchBlt( dst_dev, dst, src_dev, src, rop );
-    unlock_surface( physdev );
+    unlock_surfaces( dst_physdev, src_physdev );
     return ret;
 }

[PATCH 1/1] win32u: Fix a deadlock when locking the same surface on different DCs.

[Marvin]

Hi,

It looks like your patch introduced the new failures shown below.
Please investigate and fix them before resubmitting your patch.
If they are not new, fixing them anyway would help a lot. Otherwise
please ask for the known failures list to be updated.

The tests also ran into some preexisting test failures. If you know how
to fix them that would be helpful. See the TestBot job for the details:

The full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=146338

Your paranoid android.

=== debian11b (64 bit WoW report) ===

user32:
input.c:4305: Test succeeded inside todo block: button_down_hwnd_todo 1: got MSG_TEST_WIN hwnd 00000000021B00E6, msg WM_LBUTTONDOWN, wparam 0x1, lparam 0x320032

[Rémi Bernon (＠rbernon)]

We could also restore the recursive mutex but I think having it not recursive will be interesting in the future, for instance to handle read/write locks differently.

[PATCH 0/1] MR5860: win32u: Fix a deadlock when locking the same surface on different DCs. - approved

[Huw Davies (＠huw)]

This merge request was approved by Huw Davies.