glcontext: detect the sharegroup case where the context are in different chains

In the end they will lead to the same root context in the tree so check that
for equality.
This commit is contained in:
Matthew Waters 2014-09-29 00:24:28 +10:00 committed by Tim-Philipp Müller
parent 14f297b61c
commit 817417c005

View file

@ -581,14 +581,33 @@ gst_gl_context_get_window (GstGLContext * context)
}
static gboolean
_share_group_descendant (GstGLContext * context, GstGLContext * other_context)
_share_group_descendant (GstGLContext * context, GstGLContext * other_context,
GstGLContext ** root)
{
GstGLContext *next = gst_object_ref (context);
while (next != NULL) {
GstGLContext *prev;
/* given a context tree where --> means "has other gl context":
*
* a-->b-->c-->d
* / /
* e /
* /
* f-->g
*
* return TRUE if @other_context is a descendant of @context
*
* e.g. [a, b], [f, d], [e, c] are all descendants
* but [b, a], [f, d], [e, f] are not descendants. Provide the root node (d)
* so that we can check if two chains end up at the end with the same
* GstGLContext
*/
while (next != NULL) {
if (next == other_context) {
gst_object_unref (next);
if (root)
*root = NULL;
return TRUE;
}
@ -597,6 +616,9 @@ _share_group_descendant (GstGLContext * context, GstGLContext * other_context)
gst_object_unref (prev);
}
if (root != NULL)
*root = prev;
return FALSE;
}
@ -613,12 +635,16 @@ _share_group_descendant (GstGLContext * context, GstGLContext * other_context)
gboolean
gst_gl_context_can_share (GstGLContext * context, GstGLContext * other_context)
{
GstGLContext *root1, *root2;
g_return_val_if_fail (GST_GL_IS_CONTEXT (context), FALSE);
g_return_val_if_fail (GST_GL_IS_CONTEXT (other_context), FALSE);
/* check if the contexts are descendants or the root nodes are the same */
return context == other_context
|| _share_group_descendant (context, other_context)
|| _share_group_descendant (other_context, context);
|| _share_group_descendant (context, other_context, &root1)
|| _share_group_descendant (other_context, context, &root2)
|| ((root1 != NULL || root2 != NULL) && root1 == root2);
}
/**