From de635d089f10816668957ac08b19ae78761d7ab2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian.droege@collabora.co.uk>
Date: Mon, 17 Sep 2012 13:09:58 +0200
Subject: [PATCH] pad: Add parent parameter to the link and unlink functions

Fixes part of bug #683995.
---
 gst/gstpad.c                  | 29 +++++++++++++++++++++++++----
 gst/gstpad.h                  | 10 ++++++++--
 tests/check/gst/gstghostpad.c |  8 ++++----
 3 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/gst/gstpad.c b/gst/gstpad.c
index 60f1d6e918..04c285e46c 100644
--- a/gst/gstpad.c
+++ b/gst/gstpad.c
@@ -1836,11 +1836,23 @@ gst_pad_unlink (GstPad * srcpad, GstPad * sinkpad)
     goto not_linked_together;
 
   if (GST_PAD_UNLINKFUNC (srcpad)) {
-    GST_PAD_UNLINKFUNC (srcpad) (srcpad);
+    GstObject *tmpparent;
+
+    ACQUIRE_PARENT (srcpad, tmpparent, no_src_parent);
+
+    GST_PAD_UNLINKFUNC (srcpad) (srcpad, tmpparent);
+    RELEASE_PARENT (parent);
   }
+no_src_parent:
   if (GST_PAD_UNLINKFUNC (sinkpad)) {
-    GST_PAD_UNLINKFUNC (sinkpad) (sinkpad);
+    GstObject *tmpparent;
+
+    ACQUIRE_PARENT (sinkpad, tmpparent, no_sink_parent);
+
+    GST_PAD_UNLINKFUNC (sinkpad) (sinkpad, tmpparent);
+    RELEASE_PARENT (parent);
   }
+no_sink_parent:
 
   /* first clear peers */
   GST_PAD_PEER (srcpad) = NULL;
@@ -2210,13 +2222,22 @@ gst_pad_link_full (GstPad * srcpad, GstPad * sinkpad, GstPadLinkCheck flags)
     GST_OBJECT_UNLOCK (srcpad);
 
     if (srcfunc) {
+      GstObject *tmpparent;
+
+      ACQUIRE_PARENT (srcpad, tmpparent, no_parent);
       /* this one will call the peer link function */
-      result = srcfunc (srcpad, sinkpad);
+      result = srcfunc (srcpad, tmpparent, sinkpad);
+      RELEASE_PARENT (tmpparent);
     } else if (sinkfunc) {
+      GstObject *tmpparent;
+
+      ACQUIRE_PARENT (sinkpad, tmpparent, no_parent);
       /* if no source link function, we need to call the sink link
        * function ourselves. */
-      result = sinkfunc (sinkpad, srcpad);
+      result = sinkfunc (sinkpad, tmpparent, srcpad);
+      RELEASE_PARENT (tmpparent);
     }
+  no_parent:
 
     GST_OBJECT_LOCK (srcpad);
     GST_OBJECT_LOCK (sinkpad);
diff --git a/gst/gstpad.h b/gst/gstpad.h
index f14e7fe403..c6ac927359 100644
--- a/gst/gstpad.h
+++ b/gst/gstpad.h
@@ -396,20 +396,26 @@ typedef gboolean		(*GstPadQueryFunction)		(GstPad *pad, GstObject *parent,
 /**
  * GstPadLinkFunction:
  * @pad: the #GstPad that is linked.
+ * @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
+ *          @parent is guaranteed to be not-NULL and remain valid during the
+ *          execution of this function.
  * @peer: the peer #GstPad of the link
  *
  * Function signature to handle a new link on the pad.
  *
  * Returns: the result of the link with the specified peer.
  */
-typedef GstPadLinkReturn	(*GstPadLinkFunction)		(GstPad *pad, GstPad *peer);
+typedef GstPadLinkReturn	(*GstPadLinkFunction)		(GstPad *pad, GstObject *parent, GstPad *peer);
 /**
  * GstPadUnlinkFunction:
  * @pad: the #GstPad that is linked.
+ * @parent: the parent of @pad. If the #GST_PAD_FLAG_NEED_PARENT flag is set,
+ *          @parent is guaranteed to be not-NULL and remain valid during the
+ *          execution of this function.
  *
  * Function signature to handle a unlinking the pad prom its peer.
  */
-typedef void			(*GstPadUnlinkFunction)		(GstPad *pad);
+typedef void			(*GstPadUnlinkFunction)		(GstPad *pad, GstObject *parent);
 
 
 /* misc */
diff --git a/tests/check/gst/gstghostpad.c b/tests/check/gst/gstghostpad.c
index af3c0af6e9..c93cc20882 100644
--- a/tests/check/gst/gstghostpad.c
+++ b/tests/check/gst/gstghostpad.c
@@ -802,7 +802,7 @@ static gint linked_count2;
 static gint unlinked_count2;
 
 static GstPadLinkReturn
-pad_linked1 (GstPad * pad, GstPad * peer)
+pad_linked1 (GstPad * pad, GstObject * parent, GstPad * peer)
 {
   linked_count1++;
 
@@ -810,13 +810,13 @@ pad_linked1 (GstPad * pad, GstPad * peer)
 }
 
 static void
-pad_unlinked1 (GstPad * pad)
+pad_unlinked1 (GstPad * pad, GstObject * parent)
 {
   unlinked_count1++;
 }
 
 static GstPadLinkReturn
-pad_linked2 (GstPad * pad, GstPad * peer)
+pad_linked2 (GstPad * pad, GstObject * parent, GstPad * peer)
 {
   linked_count2++;
 
@@ -824,7 +824,7 @@ pad_linked2 (GstPad * pad, GstPad * peer)
 }
 
 static void
-pad_unlinked2 (GstPad * pad)
+pad_unlinked2 (GstPad * pad, GstObject * parent)
 {
   unlinked_count2++;
 }