Don't take internal references on the context

We want applications to fully control the lifetime of a CoglContext
without having to worry that internal resources (such as the default
2d,3d and rectangle textures, or any caches we maintain) could result in
circular references that keep the context alive. We also want to avoid
making CoglContext into a special kind of object that isn't ref-counted
or that can't be used with object apis such as
cogl_object_set_user_data. Being able to reliably destroy the context is
important on platforms such as Android where you may be required
bring-up and tear-down a CoglContext numerous times throughout the
applications lifetime. A dissadvantage of this policy is that it is now
possible to leave other object such as framebuffers in an inconsistent
state if the context is unreferenced and destroyed. The documentation
states that all objects that directly or indirectly depend on a context
that has been destroyed will be left in an inconsistent state and must
not be accessed thereafter. Applications (such as Android applications)
that need to cleanly destroy and re-create Cogl resources should make
sure to manually unref these dependant objects before destroying the
context.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 23ce51beba1bb739a224e47614a59327dfbb65af)

1 files changed, 0 insertions, 4 deletions

diff --git a/cogl/cogl-gles2-context.c b/cogl/cogl-gles2-context.c
index 35857056..47f99b7c 100644
--- a/cogl/cogl-gles2-context.c
+++ b/cogl/cogl-gles2-context.c
@@ -1528,8 +1528,6 @@ _cogl_gles2_context_free (CoglGLES2Context *gles2_context)
                                  NULL);
     }
 
-  cogl_object_unref (gles2_context->context);
-
   g_free (gles2_context->vtable);
 
   g_free (gles2_context);
@@ -1601,7 +1599,6 @@ cogl_gles2_context_new (CoglContext *ctx, GError **error)
 
   gles2_ctx = g_malloc0 (sizeof (CoglGLES2Context));
 
-  cogl_object_ref (ctx);
   gles2_ctx->context = ctx;
 
   COGL_LIST_INIT (&gles2_ctx->foreign_offscreens);
@@ -1610,7 +1607,6 @@ cogl_gles2_context_new (CoglContext *ctx, GError **error)
   gles2_ctx->winsys = winsys->context_create_gles2_context (ctx, error);
   if (gles2_ctx->winsys == NULL)
     {
-      cogl_object_unref (gles2_ctx->context);
       g_free (gles2_ctx);
       return NULL;
     }