xwayland: Cache client-id for the window-manager client

Instead of iterating over all clients which are listening for events on the
root window and checking if the client we are dealing with is the one
listening for SubstructureRedirectMask | ResizeRedirectMask events and thus
is the window-manager, cache the client-id of the window-manager in
xwl_screen and use that when checking if a client is the window-manager.

Note that we cache and compare the client-id rather then the ClienPtr,
this saves reading the ClientPtr from the global clients array when doing
the comparison.

Suggested-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Olivier Fourdan <ofourdan@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

hw/xwayland/xwayland-screen.c

@@ -638,6 +638,9 @@ xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
     xwl_screen->CloseScreen = pScreen->CloseScreen;
     pScreen->CloseScreen = xwl_close_screen;
 
+    xwl_screen->ChangeWindowAttributes = pScreen->ChangeWindowAttributes;
+    pScreen->ChangeWindowAttributes = xwl_change_window_attributes;
+
     xwl_screen->ResizeWindow = pScreen->ResizeWindow;
     pScreen->ResizeWindow = xwl_resize_window;
 

hw/xwayland/xwayland-screen.h

@@ -48,6 +48,7 @@ struct xwl_screen {
     int height;
     int depth;
     ScreenPtr screen;
+    int wm_client_id;
     int expecting_event;
     enum RootClipMode root_clip_mode;
 
@@ -62,6 +63,7 @@ struct xwl_screen {
     DestroyWindowProcPtr DestroyWindow;
     XYToWindowProcPtr XYToWindow;
     SetWindowPixmapProcPtr SetWindowPixmap;
+    ChangeWindowAttributesProcPtr ChangeWindowAttributes;
     ResizeWindowProcPtr ResizeWindow;
 
     struct xorg_list output_list;

hw/xwayland/xwayland-window.c

@@ -243,20 +243,11 @@ xwl_window_enable_viewport(struct xwl_window *xwl_window,
 }
 
 static Bool
-xwl_screen_client_is_window_manager(struct xwl_screen *xwl_screen,
+window_is_wm_window(WindowPtr window)
-                                    ClientPtr client)
 {
-    WindowPtr root = xwl_screen->screen->root;
+    struct xwl_screen *xwl_screen = xwl_screen_get(window->drawable.pScreen);
-    OtherClients *others;
 
-    for (others = wOtherClients(root); others; others = others->next) {
+    return CLIENT_ID(window->drawable.id) == xwl_screen->wm_client_id;
-        if (SameClient(others, client)) {
-            if (others->mask & (SubstructureRedirectMask | ResizeRedirectMask))
-                return TRUE;
-        }
-    }
-
-    return FALSE;
 }
 
 static ClientPtr
@@ -270,7 +261,7 @@ xwl_window_get_owner(struct xwl_window *xwl_window)
      * decoration window. In that case return the client of the
      * first *and only* child of the toplevel (decoration) window.
      */
-    if (xwl_screen_client_is_window_manager(xwl_window->xwl_screen, client)) {
+    if (window_is_wm_window(window)) {
         if (window->firstChild && window->firstChild == window->lastChild)
             return wClient(window->firstChild);
         else
@@ -356,9 +347,7 @@ xwl_window_check_resolution_change_emulation(struct xwl_window *xwl_window)
 Bool
 xwl_window_is_toplevel(WindowPtr window)
 {
-    struct xwl_screen *xwl_screen = xwl_screen_get(window->drawable.pScreen);
+    if (window_is_wm_window(window))
-
-    if (xwl_screen_client_is_window_manager(xwl_screen, wClient(window)))
         return FALSE;
 
     /* CSD and override-redirect toplevel windows */
@@ -660,6 +649,30 @@ xwl_window_set_window_pixmap(WindowPtr window,
             xwl_window_buffers_recycle(xwl_window);
 }
 
+Bool
+xwl_change_window_attributes(WindowPtr window, unsigned long mask)
+{
+    ScreenPtr screen = window->drawable.pScreen;
+    struct xwl_screen *xwl_screen = xwl_screen_get(screen);
+    OtherClients *others;
+    Bool ret;
+
+    screen->ChangeWindowAttributes = xwl_screen->ChangeWindowAttributes;
+    ret = (*screen->ChangeWindowAttributes) (window, mask);
+    xwl_screen->ChangeWindowAttributes = screen->ChangeWindowAttributes;
+    screen->ChangeWindowAttributes = xwl_change_window_attributes;
+
+    if (window != screen->root || !(mask & CWEventMask))
+        return ret;
+
+    for (others = wOtherClients(window); others; others = others->next) {
+        if (others->mask & (SubstructureRedirectMask | ResizeRedirectMask))
+            xwl_screen->wm_client_id = CLIENT_ID(others->resource);
+    }
+
+    return ret;
+}
+
 void
 xwl_resize_window(WindowPtr window,
                   int x, int y,

hw/xwayland/xwayland-window.h

@@ -69,6 +69,7 @@ void xwl_window_check_resolution_change_emulation(struct xwl_window *xwl_window)
 void xwl_window_set_window_pixmap(WindowPtr window, PixmapPtr pixmap);
 Bool xwl_realize_window(WindowPtr window);
 Bool xwl_unrealize_window(WindowPtr window);
+Bool xwl_change_window_attributes(WindowPtr window, unsigned long mask);
 void xwl_resize_window(WindowPtr window,
                        int x, int y,
                        unsigned int width, unsigned int height,