object: add gst_clear_object()

This is based on g_clear_object(). Basically, you can use this instead
of using g_object_unref (which needs to be preceded by a NULL-check).

Fixes #275

diff --git a/gst/gstobject.c b/gst/gstobject.c
index 2199d1a..f5683a0 100644 (file)
--- a/gst/gstobject.c
+++ b/gst/gstobject.c
@@ -296,6 +296,30 @@ gst_object_ref_sink (gpointer object)
 }
 
 /**
+ * gst_clear_object: (skip)
+ * @object_ptr: a pointer to a #GstObject reference
+ *
+ * Clears a reference to a #GstObject.
+ *
+ * @object_ptr must not be %NULL.
+ *
+ * If the reference is %NULL then this function does nothing.
+ * Otherwise, the reference count of the object is decreased using
+ * gst_object_unref() and the pointer is set to %NULL.
+ *
+ * A macro is also included that allows this function to be used without
+ * pointer casts.
+ *
+ * Since: 1.16
+ **/
+#undef gst_clear_object
+void
+gst_clear_object (volatile GstObject ** object_ptr)
+{
+  g_clear_pointer (object_ptr, gst_object_unref);
+}
+
+/**
  * gst_object_replace:
  * @oldobj: (inout) (transfer full) (nullable): pointer to a place of
  *     a #GstObject to replace

diff --git a/gst/gstobject.h b/gst/gstobject.h
index fe5d95d..5fe5a18 100644 (file)
--- a/gst/gstobject.h
+++ b/gst/gstobject.h
@@ -255,6 +255,10 @@ GST_API
 void           gst_object_unref                (gpointer object);
 
 GST_API
+void        gst_clear_object (volatile GstObject **object_ptr);
+#define     gst_clear_object(object_ptr) g_clear_pointer ((object_ptr), gst_object_unref)
+
+GST_API
 gpointer        gst_object_ref_sink            (gpointer object);
 
 /* replace object pointer */