[PATCH 1/5] win32u: Guard OpenGL function pointers initialization.

[Rémi Bernon]

From: Rémi Bernon

---
 dlls/win32u/opengl.c | 76 +++++++++++++++++++++++++-------------------
 1 file changed, 44 insertions(+), 32 deletions(-)

diff --git a/dlls/win32u/opengl.c b/dlls/win32u/opengl.c
index 1e9d60bbebd..3073f3ee4e7 100644
--- a/dlls/win32u/opengl.c
+++ b/dlls/win32u/opengl.c
@@ -73,20 +73,16 @@ static GLboolean (*pOSMesaMakeCurrent)( OSMesaContext ctx, void *buffer, GLenum
                                         GLsizei width, GLsizei height );
 static void (*pOSMesaPixelStore)( GLint pname, GLint value );

-static BOOL init_opengl(void)
+static struct opengl_funcs *osmesa_get_wgl_driver(void)
 {
-    static BOOL init_done = FALSE;
     static void *osmesa_handle;
     unsigned int i;

-    if (init_done) return (osmesa_handle != NULL);
-    init_done = TRUE;
-
     osmesa_handle = dlopen( SONAME_LIBOSMESA, RTLD_NOW );
     if (osmesa_handle == NULL)
     {
         ERR( "Failed to load OSMesa: %s\n", dlerror() );
-        return FALSE;
+        return NULL;
     }

#define LOAD_FUNCPTR(f) do if (!(p##f = dlsym( osmesa_handle, #f ))) \
@@ -111,12 +107,12 @@ static BOOL init_opengl(void)
         }
     }

-    return TRUE;
+    return &osmesa_opengl_funcs;

failed:
     dlclose( osmesa_handle );
     osmesa_handle = NULL;
-    return FALSE;
+    return NULL;
 }

static struct wgl_context *osmesa_create_context( HDC hdc, const PIXELFORMATDESCRIPTOR *descr )
@@ -353,35 +349,60 @@ static struct opengl_funcs osmesa_opengl_funcs =
     .wgl.p_get_pixel_formats = osmesa_get_pixel_formats,
 };

+#else  /* SONAME_LIBOSMESA */
+
 static struct opengl_funcs *osmesa_get_wgl_driver(void)
 {
-    if (!init_opengl())
-    {
-        static int warned;
-        if (!warned++) ERR( "OSMesa not available, no OpenGL bitmap support\n" );
-        return (void *)-1;
-    }
+    return NULL;
+}

-    return &osmesa_opengl_funcs;
+#endif  /* SONAME_LIBOSMESA */
+
+static struct opengl_funcs *display_funcs;
+static struct opengl_funcs *memory_funcs;
+
+static void memory_funcs_init(void)
+{
+    memory_funcs = osmesa_get_wgl_driver();
 }

-#else  /* SONAME_LIBOSMESA */
+static void display_funcs_init(void)
+{
+    display_funcs = user_driver->pwine_get_wgl_driver( WINE_WGL_DRIVER_VERSION );
+}

-static struct opengl_funcs *osmesa_get_wgl_driver(void)
+static struct opengl_funcs *get_dc_funcs( HDC hdc, void *null_funcs )
 {
+    DWORD is_disabled, is_display, is_memdc;
+    DC *dc;
+
+    if (!(dc = get_dc_ptr( hdc ))) return NULL;
+    is_memdc = get_gdi_object_type( hdc ) == NTGDI_OBJ_MEMDC;
+    is_display = dc->is_display;
+    is_disabled = dc->attr->disabled;
+    release_dc_ptr( dc );
+
+    if (is_disabled) return NULL;
+    if (is_display)
+    {
+        static pthread_once_t display_init_once = PTHREAD_ONCE_INIT;
+        pthread_once( &display_init_once, display_funcs_init );
+        return display_funcs ? display_funcs : null_funcs;
+    }
+    if (is_memdc)
+    {
+        static pthread_once_t memory_init_once = PTHREAD_ONCE_INIT;
+        pthread_once( &memory_init_once, memory_funcs_init );
+        return memory_funcs ? memory_funcs : null_funcs;
+    }
     return NULL;
 }

-#endif  /* SONAME_LIBOSMESA */
-
 /***********************************************************************
  *      __wine_get_wgl_driver  (win32u.@)
  */
 const struct opengl_funcs *__wine_get_wgl_driver( HDC hdc, UINT version )
 {
-    DWORD is_disabled, is_display, is_memdc;
-    DC *dc;
-
     if (version != WINE_WGL_DRIVER_VERSION)
     {
         ERR( "version mismatch, opengl32 wants %u but dibdrv has %u\n",
@@ -389,14 +410,5 @@ const struct opengl_funcs *__wine_get_wgl_driver( HDC hdc, UINT version )
         return NULL;
     }

-    if (!(dc = get_dc_ptr( hdc ))) return NULL;
-    is_memdc = get_gdi_object_type( hdc ) == NTGDI_OBJ_MEMDC;
-    is_display = dc->is_display;
-    is_disabled = dc->attr->disabled;
-    release_dc_ptr( dc );
-
-    if (is_disabled) return NULL;
-    if (is_display) return user_driver->pwine_get_wgl_driver( version );
-    if (is_memdc) return osmesa_get_wgl_driver();
-    return (void *)-1;
+    return get_dc_funcs( hdc, (void *)-1 );
 }