gst/gstelement.c: virutalize gst_element_set_state, use set_state member in class struct that was already added in 0....

Original commit message from CVS:
* gst/gstelement.c: (gst_element_class_init),
(gst_element_set_state), (gst_element_set_state_func):
virutalize gst_element_set_state, use set_state member in class
struct that was already added in 0.7 for this.
* gst/gstbin.c: (gst_bin_foreach), (set_kid_state_func),
(gst_bin_change_state):
make gst_bin_foreach works similar to other foreach functions, plug
memleaks in it. Make functions using it work with the new approach.
Document gst_bin_foreach, so it can be exported if we want to
* gst/gstbin.c: (gst_bin_class_init), (gst_bin_set_state):
use virtualized set_state to make set_state on bins set the state of
all its children.

ChangeLog

@@ -1,3 +1,18 @@
+2004-07-12  Benjamin Otte  <otte@gnome.org>
+
+	* gst/gstelement.c: (gst_element_class_init),
+	(gst_element_set_state), (gst_element_set_state_func):
+	  virutalize gst_element_set_state, use set_state member in class
+	  struct that was already added in 0.7 for this.
+	* gst/gstbin.c: (gst_bin_foreach), (set_kid_state_func), 
+	(gst_bin_change_state):
+	  make gst_bin_foreach works similar to other foreach functions, plug
+	  memleaks in it. Make functions using it work with the new approach.
+	  Document gst_bin_foreach, so it can be exported if we want to
+	* gst/gstbin.c: (gst_bin_class_init), (gst_bin_set_state):
+	  use virtualized set_state to make set_state on bins set the state of
+	  all its children.
+
 2004-07-12  Benjamin Otte  <otte@gnome.org>
 
 	* configure.ac:

gst/gstbin.c

@@ -32,6 +32,7 @@
 
 #include "gstscheduler.h"
 #include "gstindex.h"
+#include "gstutils.h"
 
 static GstElementDetails gst_bin_details = GST_ELEMENT_DETAILS ("Generic bin",
     "Generic/Bin",
@@ -56,6 +57,8 @@ static void gst_bin_add_func (GstBin * bin, GstElement * element);
 static void gst_bin_remove_func (GstBin * bin, GstElement * element);
 static void gst_bin_child_state_change_func (GstBin * bin,
     GstElementState oldstate, GstElementState newstate, GstElement * child);
+GstElementStateReturn gst_bin_set_state (GstElement * element,
+    GstElementState state);
 
 static GstClock *gst_bin_get_clock_func (GstElement * element);
 static void gst_bin_set_clock_func (GstElement * element, GstClock * clock);
@@ -161,6 +164,7 @@ gst_bin_class_init (GstBinClass * klass)
 #endif
 
   gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_bin_change_state);
+  gstelement_class->set_state = GST_DEBUG_FUNCPTR (gst_bin_set_state);
 #ifndef GST_DISABLE_INDEX
   gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index);
 #endif
@@ -707,57 +711,64 @@ gst_bin_child_state_change_func (GstBin * bin, GstElementState oldstate,
   GST_UNLOCK (bin);
 }
 
-typedef gint (*GstBinForeachFunc) (GstBin * bin, GstElement * element,
+typedef gboolean (*GstBinForeachFunc) (GstBin * bin, GstElement * element,
     gpointer data);
 
-/* Call FUNC on each child of BIN, in the order that they are in bin->children.
+/*
-
+ * gst_bin_foreach:
-   It is assumed that calling FUNC may alter the set of BIN's children. FUNC
+ * @bin: bin to traverse
-   will only be called on children that were in BIN when the gst_bin_foreach was
+ * @func: function to call on each child
-   called, and that are still in BIN when the child is reached.
+ * @data: user data handed to each function call
-
+ *
-   The return value semantics are a bit odd in this one:
+ * Calls @func on each child of the bin. If @func returns FALSE, 
-
+ * gst_bin_foreach() immediately returns.
-   If FUNC returns a nonnegative number, the number is added on to the eventual
+ * It is assumed that calling @func may alter the set of @bin's children. @func
-   return value of gst_bin_foreach, which starts at 0.
+ * will only be called on children that were in @bin when gst_bin_foreach() was
-
+ * called, and that are still in @bin when the child is reached.
-   If any FUNC returns a negative number, that value is immediately returned to
+ *
-   the caller. In that case, the child list might only be partially traversed.
+ * Returns: TRUE if @func always returned TRUE, FALSE otherwise
-*/
+ **/
-static gint
+static gboolean
 gst_bin_foreach (GstBin * bin, GstBinForeachFunc func, gpointer data)
 {
-  gint sum = 0;
+  GList *kids, *walk;
-  GList *kids = g_list_copy (bin->children);
 
-  while (kids) {
+  g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
-    GstElement *element = (GstElement *) kids->data;
+  g_return_val_if_fail (func != NULL, FALSE);
-    gint res = 0;
 
-    if (g_list_find (bin->children, element))
+  kids = g_list_copy (bin->children);
-      res = func (bin, element, data);
 
-    if (res < 0)
+  for (walk = kids; walk; walk = g_list_next (walk)) {
-      return res;
+    GstElement *element = (GstElement *) walk->data;
 
-    sum += res;
+    if (g_list_find (bin->children, element)) {
+      gboolean res = func (bin, element, data);
 
-    kids = kids->next;
+      if (!res) {
+        g_list_free (kids);
+        return FALSE;
+      }
+    }
   }
 
   g_list_free (kids);
-  return sum;
+  return TRUE;
 }
 
-static int
+typedef struct
-set_kid_state_func (GstBin * bin, GstElement * child, gpointer data)
 {
-  GstElementState old_child_state, pending;
+  GstElementState pending;
-
+  GstElementStateReturn result;
-  pending = (GstElementState) (GPOINTER_TO_INT (data));
+}
+SetKidStateData;
+static int
+set_kid_state_func (GstBin * bin, GstElement * child, gpointer user_data)
+{
+  GstElementState old_child_state;
+  SetKidStateData *data = user_data;
 
   if (GST_FLAG_IS_SET (child, GST_ELEMENT_LOCKED_STATE)) {
-    return 0;
+    return TRUE;
   }
 
   old_child_state = GST_STATE (child);
@@ -765,34 +776,35 @@ set_kid_state_func (GstBin * bin, GstElement * child, gpointer data)
   GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
       "changing state of child %s from current %s to pending %s",
       GST_ELEMENT_NAME (child), gst_element_state_get_name (old_child_state),
-      gst_element_state_get_name (pending));
+      gst_element_state_get_name (data->pending));
 
-  switch (gst_element_set_state (child, pending)) {
+  switch (gst_element_set_state (child, data->pending)) {
     case GST_STATE_FAILURE:
       GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
           "child '%s' failed to go to state %d(%s)",
           GST_ELEMENT_NAME (child),
-          pending, gst_element_state_get_name (pending));
+          data->pending, gst_element_state_get_name (data->pending));
 
       gst_element_set_state (child, old_child_state);
-      return -1;                /* error out to the caller */
+      return FALSE;             /* error out to the caller */
 
     case GST_STATE_ASYNC:
       GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
           "child '%s' is changing state asynchronously",
           GST_ELEMENT_NAME (child));
-      return 1;
+      data->result = GST_STATE_ASYNC;
+      return TRUE;
 
     case GST_STATE_SUCCESS:
       GST_CAT_DEBUG (GST_CAT_STATES,
           "child '%s' changed state to %d(%s) successfully",
-          GST_ELEMENT_NAME (child), pending,
+          GST_ELEMENT_NAME (child), data->pending,
-          gst_element_state_get_name (pending));
+          gst_element_state_get_name (data->pending));
-      return 0;
+      return TRUE;
 
     default:
       g_assert_not_reached ();
-      return -1;                /* satisfy gcc */
+      return FALSE;             /* satisfy gcc */
   }
 }
 
@@ -802,8 +814,7 @@ gst_bin_change_state (GstElement * element)
   GstBin *bin;
   GstElementStateReturn ret;
   GstElementState old_state, pending;
-  gint transition, kid_return;
+  SetKidStateData data;
-  gboolean have_async = FALSE;
 
   g_return_val_if_fail (GST_IS_BIN (element), GST_STATE_FAILURE);
 
@@ -811,7 +822,6 @@ gst_bin_change_state (GstElement * element)
 
   old_state = GST_STATE (element);
   pending = GST_STATE_PENDING (element);
-  transition = GST_STATE_TRANSITION (element);
 
   GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
       "changing state of children from %s to %s",
@@ -821,15 +831,11 @@ gst_bin_change_state (GstElement * element)
   if (pending == GST_STATE_VOID_PENDING)
     return GST_STATE_SUCCESS;
 
-  kid_return = gst_bin_foreach (bin, set_kid_state_func,
+  data.pending = pending;
-      GINT_TO_POINTER ((int) pending));
+  data.result = GST_STATE_SUCCESS;
-
+  if (!gst_bin_foreach (bin, set_kid_state_func, &data)) {
-  /* see gst_bin_foreach return value semantics above */
-  if (kid_return < 0) {
     GST_STATE_PENDING (element) = old_state;
     return GST_STATE_FAILURE;
-  } else if (kid_return > 0) {
-    have_async = TRUE;
   }
 
   GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
@@ -838,9 +844,10 @@ gst_bin_change_state (GstElement * element)
       gst_element_state_get_name (pending),
       gst_element_state_get_name (GST_STATE (element)));
 
-  if (have_async)
+  if (data.result == GST_STATE_ASYNC)
     ret = GST_STATE_ASYNC;
   else {
+    /* FIXME: this should have been done by the children already, no? */
     if (parent_class->change_state) {
       ret = parent_class->change_state (element);
     } else
@@ -849,6 +856,26 @@ gst_bin_change_state (GstElement * element)
   return ret;
 }
 
+GstElementStateReturn
+gst_bin_set_state (GstElement * element, GstElementState state)
+{
+  GstBin *bin = GST_BIN (element);
+
+  if (GST_STATE (bin) == state) {
+    SetKidStateData data;
+
+    data.pending = state;
+    data.result = GST_STATE_SUCCESS;
+    if (!gst_bin_foreach (bin, set_kid_state_func, &data)) {
+      return GST_STATE_FAILURE;
+    } else {
+      return data.result;
+    }
+  } else {
+    return GST_CALL_PARENT_WITH_DEFAULT (GST_ELEMENT_CLASS, set_state, (element,
+            state), GST_STATE_FAILURE);
+  }
+}
 
 static GstElementStateReturn
 gst_bin_change_state_norecurse (GstBin * bin)

gst/gstelement.c

@@ -76,6 +76,8 @@ static void gst_element_error_func (GstElement * element, GstElement * source,
     GError * error, gchar * debug);
 static void gst_element_found_tag_func (GstElement * element,
     GstElement * source, const GstTagList * tag_list);
+GstElementStateReturn gst_element_set_state_func (GstElement * element,
+    GstElementState state);
 
 #ifndef GST_DISABLE_LOADSAVE
 static xmlNodePtr gst_element_save_thyself (GstObject * object,
@@ -170,6 +172,7 @@ gst_element_class_init (GstElementClass * klass)
   klass->error = GST_DEBUG_FUNCPTR (gst_element_error_func);
   klass->found_tag = GST_DEBUG_FUNCPTR (gst_element_found_tag_func);
   klass->numpadtemplates = 0;
+  klass->set_state = GST_DEBUG_FUNCPTR (gst_element_set_state_func);
 
   klass->elementfactory = NULL;
 }
@@ -2719,43 +2722,33 @@ gst_element_wait_state_change (GstElement * element)
  */
 GstElementStateReturn
 gst_element_set_state (GstElement * element, GstElementState state)
+{
+  GstElementClass *klass = GST_ELEMENT_GET_CLASS (element);
+
+  g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
+  klass = GST_ELEMENT_GET_CLASS (element);
+  /* a set_state function is mandatory */
+  g_return_val_if_fail (klass->set_state, GST_STATE_FAILURE);
+  return klass->set_state (element, state);
+}
+
+GstElementStateReturn
+gst_element_set_state_func (GstElement * element, GstElementState state)
 {
   GstElementClass *oclass;
   GstElementState curpending;
   GstElementStateReturn return_val = GST_STATE_SUCCESS;
 
-  g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
   oclass = GST_ELEMENT_GET_CLASS (element);
 
-  /* for bins, we allow calls to change_state where old == new
-   * for elements, too many of them break with g_assert_not_reached(),
-   * so weed those out first.  This is done in gst-plugins CVS and can
-   * be fixed here after a new plugins release.
-   * FIXME: of course this file should not have ties to gstbin.h *at all*,
-   * but someone else added a function at the bottom using it.
-   * Fix this properly for 0.9 */
-
   /* start with the current state */
   curpending = GST_STATE (element);
 
   if (state == curpending) {
-    if (GST_IS_BIN (element)) {
+    GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
-      /* set current state on it again */
+        "element is already in requested state %s, returning",
-      GST_STATE_PENDING (element) = curpending;
+        gst_element_state_get_name (state));
-      GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
+    return GST_STATE_SUCCESS;
-          "%s is a bin, calling class state change on it for %s -> %s",
-          GST_OBJECT_NAME (element),
-          gst_element_state_get_name (curpending),
-          gst_element_state_get_name (state));
-      if (oclass->change_state)
-        return_val = (oclass->change_state) (element);
-      return return_val;
-    } else {
-      GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
-          "non-bin element is already in requested state %s, returning",
-          gst_element_state_get_name (state));
-      return GST_STATE_SUCCESS;
-    }
   }
 
   GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "setting state from %s to %s",