Merge pull request #3590 from cherez/weakrefable_textures

Add weak reference support to Texture

Author: Starbuck5

src_c/include/_pygame.h

@@ -556,6 +556,7 @@ struct pgTextureObject {
     pgRendererObject *renderer;
     int width;
     int height;
+    PyObject *weakreflist;
 };
 
 typedef struct {

src_c/render.c

@@ -682,6 +682,7 @@ texture_from_surface(PyObject *self, PyObject *args, PyObject *kwargs)
     Py_XINCREF(new_texture->renderer);
     new_texture->width = surf->w;
     new_texture->height = surf->h;
+    new_texture->weakreflist = NULL;
     return (PyObject *)new_texture;
 }
 
@@ -1169,6 +1170,9 @@ texture_dealloc(pgTextureObject *self, PyObject *_null)
     if (self->texture) {
         SDL_DestroyTexture(self->texture);
     }
+    if (self->weakreflist) {
+        PyObject_ClearWeakRefs((PyObject *)self);
+    }
     Py_TYPE(self)->tp_free(self);
 }
 
@@ -1289,6 +1293,7 @@ static PyTypeObject pgTexture_Type = {
     .tp_basicsize = sizeof(pgTextureObject),
     .tp_dealloc = (destructor)texture_dealloc,
     .tp_doc = DOC_SDL2_VIDEO_TEXTURE,
+    .tp_weaklistoffset = offsetof(pgTextureObject, weakreflist),
     .tp_methods = texture_methods,
     .tp_init = (initproc)texture_init,
     .tp_new = PyType_GenericNew,

test/render_test.py

@@ -1,4 +1,6 @@
+import gc
 import unittest
+import weakref
 
 import pygame
 import pygame._render as _render
@@ -465,6 +467,13 @@ def test_draw(self):
         for x in range(64, 82):
             self.assertEqual(pygame.Color(80, 120, 160, 255), result.get_at((x, 50)))
 
+    def test_garbage_collection(self):
+        reference = weakref.ref(self.texture)
+        self.assertTrue(reference() is self.texture)
+        del self.texture
+        gc.collect()
+        self.assertIsNone(reference())
+
     def test_update(self):
         surface = pygame.Surface((100, 100))
         surface.fill(pygame.Color(80, 120, 160, 128))