diff -r 71e347f905f2 -r 4a7fac7dd34a gstreamer_core/libs/gst/check/gstconsistencychecker.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gstreamer_core/libs/gst/check/gstconsistencychecker.c	Fri Apr 16 15:15:52 2010 +0300
@@ -0,0 +1,157 @@
+/* GStreamer
+ *
+ * unit testing helper lib
+ *
+ * Copyright (C) 2009 Edward Hervey <bilboed@bilboed.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:gstcheckconsistencychecker
+ * @short_description: Data flow consistency checker for GStreamer unit tests.
+ *
+ * These macros and functions are for internal use of the unit tests found
+ * inside the 'check' directories of various GStreamer packages.
+ *
+ * Since: 0.10.24
+ */
+
+#include "gstconsistencychecker.h"
+
+struct _GstStreamConsistency
+{
+  gboolean flushing;
+  gboolean newsegment;
+  gboolean eos;
+  gulong probeid;
+  GstPad *pad;
+};
+
+static gboolean
+source_pad_data_cb (GstPad * pad, GstMiniObject * data,
+    GstStreamConsistency * consist)
+{
+  if (GST_IS_BUFFER (data)) {
+    GST_DEBUG_OBJECT (pad, "Buffer %" GST_TIME_FORMAT,
+        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (GST_BUFFER (data))));
+    /* If an EOS went through, a buffer would be invalid */
+    fail_if (consist->eos, "Buffer received after EOS");
+    /* Buffers need to be preceded by a newsegment event */
+    fail_unless (consist->newsegment, "Buffer received without newsegment");
+  } else {
+    GstEvent *event = (GstEvent *) data;
+
+    GST_DEBUG_OBJECT (pad, "%s", GST_EVENT_TYPE_NAME (event));
+    switch (GST_EVENT_TYPE (event)) {
+      case GST_EVENT_FLUSH_START:
+        consist->flushing = TRUE;
+        break;
+      case GST_EVENT_FLUSH_STOP:
+        /* Receiving a flush-stop is only valid after receiving a flush-start */
+        fail_unless (consist->flushing,
+            "Received a FLUSH_STOP without a FLUSH_START");
+        fail_if (consist->eos, "Received a FLUSH_STOP after an EOS");
+        consist->flushing = FALSE;
+        break;
+      case GST_EVENT_NEWSEGMENT:
+        consist->newsegment = TRUE;
+        consist->eos = FALSE;
+        break;
+      case GST_EVENT_EOS:
+        /* FIXME : not 100% sure about whether two eos in a row is valid */
+        fail_if (consist->eos, "Received EOS just after another EOS");
+        consist->eos = TRUE;
+        consist->newsegment = FALSE;
+        break;
+      case GST_EVENT_TAG:
+        GST_DEBUG_OBJECT (pad, "tag %" GST_PTR_FORMAT, event->structure);
+      default:
+        if (GST_EVENT_IS_SERIALIZED (event) && GST_EVENT_IS_DOWNSTREAM (event)) {
+          fail_if (consist->eos, "Event received after EOS");
+          fail_unless (consist->newsegment, "Event received before newsegment");
+        }
+        /* FIXME : Figure out what to do for other events */
+        break;
+    }
+  }
+
+  return TRUE;
+}
+
+/**
+ * gst_consistency_checker_new:
+ * @pad: The #GstPad on which the dataflow will be checked.
+ *
+ * Sets up a data probe on the given pad which will raise assertions if the
+ * data flow is inconsistent.
+ *
+ * Currently only works for source pads.
+ *
+ * Returns: A #GstStreamConsistency structure used to track data flow.
+ *
+ * Since: 0.10.24
+ */
+
+GstStreamConsistency *
+gst_consistency_checker_new (GstPad * pad)
+{
+  GstStreamConsistency *consist;
+
+  g_return_val_if_fail (pad != NULL, NULL);
+
+  consist = g_new0 (GstStreamConsistency, 1);
+  consist->pad = g_object_ref (pad);
+  consist->probeid =
+      gst_pad_add_data_probe (pad, (GCallback) source_pad_data_cb, consist);
+
+  return consist;
+}
+
+/**
+ * gst_consistency_checker_reset:
+ * @consist: The #GstStreamConsistency to reset.
+ *
+ * Reset the stream checker's internal variables.
+ *
+ * Since: 0.10.24
+ */
+
+void
+gst_consistency_checker_reset (GstStreamConsistency * consist)
+{
+  consist->eos = FALSE;
+  consist->flushing = FALSE;
+  consist->newsegment = FALSE;
+}
+
+/**
+ * gst_consistency_checker_free:
+ * @consist: The #GstStreamConsistency to free.
+ *
+ * Frees the allocated data and probe associated with @consist.
+ *
+ * Since: 0.10.24
+ */
+
+void
+gst_consistency_checker_free (GstStreamConsistency * consist)
+{
+  /* Remove the data probe */
+  gst_pad_remove_data_probe (consist->pad, consist->probeid);
+  g_object_unref (consist->pad);
+  g_free (consist);
+}