gnulib set does not provide "get" operation, needed for dgrambuf.

Importing gnulib list instead.

16 files changed, 2473 insertions, 951 deletions

diff --git a/.gitignore b/.gitignore
index 07d4582..662c7f9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,7 +8,6 @@ mcastseed/compile
 mcastseed/config.guess
 mcastseed/config.h
 mcastseed/config.h.in
-mcastseed/config.h.in~
 mcastseed/config.log
 mcastseed/config.status
 mcastseed/config.sub
@@ -25,6 +24,7 @@ mcastseed/src/mcastleech
 mcastseed/src/random_speed_dd
 Makefile
 Makefile.in
+*~
 *.o
 *.a
 .deps
diff --git a/mcastseed/lib/Makefile.am b/mcastseed/lib/Makefile.am
index 17e7205..38faabe 100644
--- a/mcastseed/lib/Makefile.am
+++ b/mcastseed/lib/Makefile.am
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl rbtree-oset
+# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl rbtree-list
 
 AUTOMAKE_OPTIONS = 1.9.6 gnits
 
@@ -48,17 +48,17 @@ libgnu_a_LIBADD = $(gl_LIBOBJS)
 libgnu_a_DEPENDENCIES = $(gl_LIBOBJS)
 EXTRA_libgnu_a_SOURCES =
 
-## begin gnulib module oset
+## begin gnulib module list
 
-libgnu_a_SOURCES += gl_oset.h gl_oset.c
+libgnu_a_SOURCES += gl_list.h gl_list.c
 
-## end   gnulib module oset
+## end   gnulib module list
 
-## begin gnulib module rbtree-oset
+## begin gnulib module rbtree-list
 
-libgnu_a_SOURCES += gl_rbtree_oset.h gl_rbtree_oset.c gl_anytree_oset.h
+libgnu_a_SOURCES += gl_rbtree_list.h gl_rbtree_list.c gl_anyrbtree_list1.h gl_anyrbtree_list2.h gl_anytree_list1.h gl_anytree_list2.h
 
-## end   gnulib module rbtree-oset
+## end   gnulib module rbtree-list
 
 ## begin gnulib module stdbool
 
diff --git a/mcastseed/lib/gl_anyrbtree_list1.h b/mcastseed/lib/gl_anyrbtree_list1.h
new file mode 100644
index 0000000..0ae0715
--- /dev/null
+++ b/mcastseed/lib/gl_anyrbtree_list1.h
@@ -0,0 +1,76 @@
+/* Sequential list data type implemented by a binary tree.
+   Copyright (C) 2006, 2009-2016 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Common code of gl_rbtree_list.c and gl_rbtreehash_list.c.  */
+
+/* A red-black tree is a binary tree where every node is colored black or
+   red such that
+   1. The root is black.
+   2. No red node has a red parent.
+      Or equivalently: No red node has a red child.
+   3. All paths from the root down to any NULL endpoint contain the same
+      number of black nodes.
+   Let's call this the "black-height" bh of the tree.  It follows that every
+   such path contains exactly bh black and between 0 and bh red nodes.  (The
+   extreme cases are a path containing only black nodes, and a path colored
+   alternately black-red-black-red-...-black-red.)  The height of the tree
+   therefore is >= bh, <= 2*bh.
+ */
+
+/* -------------------------- gl_list_t Data Type -------------------------- */
+
+/* Color of a node.  */
+typedef enum color { BLACK, RED } color_t;
+
+/* Concrete list node implementation, valid for this file only.  */
+struct gl_list_node_impl
+{
+#if WITH_HASHTABLE
+  struct gl_hash_entry h;           /* hash table entry fields; must be first */
+#endif
+  struct gl_list_node_impl *left;   /* left branch, or NULL */
+  struct gl_list_node_impl *right;  /* right branch, or NULL */
+  /* Parent pointer, or NULL. The parent pointer is not needed for most
+     operations.  It is needed so that a gl_list_node_t can be returned
+     without memory allocation, on which the functions gl_list_remove_node,
+     gl_list_add_before, gl_list_add_after can be implemented.  */
+  struct gl_list_node_impl *parent;
+  color_t color;                    /* node's color */
+  size_t branch_size;               /* number of nodes in this branch,
+                                       = branchsize(left)+branchsize(right)+1 */
+  const void *value;
+};
+
+/* Concrete gl_list_impl type, valid for this file only.  */
+struct gl_list_impl
+{
+  struct gl_list_impl_base base;
+#if WITH_HASHTABLE
+  /* A hash table: managed as an array of collision lists.  */
+  struct gl_hash_entry **table;
+  size_t table_size;
+#endif
+  struct gl_list_node_impl *root;   /* root node or NULL */
+};
+
+/* A red-black tree of height h has a black-height bh >= ceil(h/2) and
+   therefore at least 2^ceil(h/2) - 1 elements.  So, h <= 116 (because a tree
+   of height h >= 117 would have at least 2^59 - 1 elements, and because even
+   on 64-bit machines,
+     sizeof (gl_list_node_impl) * (2^59 - 1) > 2^64
+   this would exceed the address space of the machine.  */
+#define MAXHEIGHT 116
diff --git a/mcastseed/lib/gl_rbtree_oset.c b/mcastseed/lib/gl_anyrbtree_list2.h
index 615b9ae..a0e2e43 100644
--- a/mcastseed/lib/gl_rbtree_oset.c
+++ b/mcastseed/lib/gl_anyrbtree_list2.h
@@ -1,4 +1,4 @@
-/* Ordered set data type implemented by a binary tree.
+/* Sequential list data type implemented by a binary tree.
    Copyright (C) 2006-2007, 2009-2016 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2006.
 
@@ -15,62 +15,143 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <config.h>
+/* Common code of gl_rbtree_list.c and gl_rbtreehash_list.c.  */
 
-/* Specification.  */
-#include "gl_rbtree_oset.h"
+/* -------------------------- gl_list_t Data Type -------------------------- */
 
-#include <stdlib.h>
+/* Create a subtree for count >= 1 elements.
+   Its black-height bh is passed as argument, with
+   2^bh - 1 <= count <= 2^(bh+1) - 1.  bh == 0 implies count == 1.
+   Its height is h where 2^(h-1) <= count <= 2^h - 1.
+   Return NULL upon out-of-memory.  */
+static gl_list_node_t
+create_subtree_with_contents (unsigned int bh,
+                              size_t count, const void **contents)
+{
+  size_t half1 = (count - 1) / 2;
+  size_t half2 = count / 2;
+  /* Note: half1 + half2 = count - 1.  */
+  gl_list_node_t node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+  if (node == NULL)
+    return NULL;
+
+  if (half1 > 0)
+    {
+      /* half1 > 0 implies count > 1, implies bh >= 1, implies
+           2^(bh-1) - 1 <= half1 <= 2^bh - 1.  */
+      node->left =
+        create_subtree_with_contents (bh - 1, half1, contents);
+      if (node->left == NULL)
+        goto fail1;
+      node->left->parent = node;
+    }
+  else
+    node->left = NULL;
+
+  node->value = contents[half1];
+
+  if (half2 > 0)
+    {
+      /* half2 > 0 implies count > 1, implies bh >= 1, implies
+           2^(bh-1) - 1 <= half2 <= 2^bh - 1.  */
+      node->right =
+       create_subtree_with_contents (bh - 1, half2, contents + half1 + 1);
+      if (node->right == NULL)
+        goto fail2;
+      node->right->parent = node;
+    }
+  else
+    node->right = NULL;
 
-/* A red-black tree is a binary tree where every node is colored black or
-   red such that
-   1. The root is black.
-   2. No red node has a red parent.
-      Or equivalently: No red node has a red child.
-   3. All paths from the root down to any NULL endpoint contain the same
-      number of black nodes.
-   Let's call this the "black-height" bh of the tree.  It follows that every
-   such path contains exactly bh black and between 0 and bh red nodes.  (The
-   extreme cases are a path containing only black nodes, and a path colored
-   alternately black-red-black-red-...-black-red.)  The height of the tree
-   therefore is >= bh, <= 2*bh.
- */
+  node->color = (bh == 0 ? RED : BLACK);
 
-/* -------------------------- gl_oset_t Data Type -------------------------- */
+  node->branch_size = count;
 
-/* Color of a node.  */
-typedef enum color { BLACK, RED } color_t;
+  return node;
 
-/* Tree node implementation, valid for this file only.  */
-struct gl_oset_node_impl
-{
-  struct gl_oset_node_impl *left;   /* left branch, or NULL */
-  struct gl_oset_node_impl *right;  /* right branch, or NULL */
-  /* Parent pointer, or NULL. The parent pointer is not needed for most
-     operations.  It is needed so that a gl_oset_node_t can be returned
-     without memory allocation, on which the functions gl_oset_remove_node,
-     gl_oset_add_before, gl_oset_add_after can be implemented.  */
-  struct gl_oset_node_impl *parent;
-  color_t color;                    /* node's color */
-  const void *value;
-};
-typedef struct gl_oset_node_impl * gl_oset_node_t;
-
-/* Concrete gl_oset_impl type, valid for this file only.  */
-struct gl_oset_impl
+ fail2:
+  if (node->left != NULL)
+    free_subtree (node->left);
+ fail1:
+  free (node);
+  return NULL;
+}
+
+static gl_list_t
+gl_tree_nx_create (gl_list_implementation_t implementation,
+                   gl_listelement_equals_fn equals_fn,
+                   gl_listelement_hashcode_fn hashcode_fn,
+                   gl_listelement_dispose_fn dispose_fn,
+                   bool allow_duplicates,
+                   size_t count, const void **contents)
 {
-  struct gl_oset_impl_base base;
-  struct gl_oset_node_impl *root;   /* root node or NULL */
-  size_t count;                     /* number of nodes */
-};
-
-/* A red-black tree of height h has a black-height bh >= ceil(h/2) and
-   therefore at least 2^ceil(h/2) - 1 elements.  So, h <= 116 (because a tree
-   of height h >= 117 would have at least 2^59 - 1 elements, and because even
-   on 64-bit machines,
-     sizeof (gl_oset_node_impl) * (2^59 - 1) > 2^64
-   this would exceed the address space of the machine.  */
-#define MAXHEIGHT 116
+  struct gl_list_impl *list =
+    (struct gl_list_impl *) malloc (sizeof (struct gl_list_impl));
+
+  if (list == NULL)
+    return NULL;
+
+  list->base.vtable = implementation;
+  list->base.equals_fn = equals_fn;
+  list->base.hashcode_fn = hashcode_fn;
+  list->base.dispose_fn = dispose_fn;
+  list->base.allow_duplicates = allow_duplicates;
+#if WITH_HASHTABLE
+  {
+    size_t estimate = xsum (count, count / 2); /* 1.5 * count */
+    if (estimate < 10)
+      estimate = 10;
+    list->table_size = next_prime (estimate);
+    if (size_overflow_p (xtimes (list->table_size, sizeof (gl_hash_entry_t))))
+      goto fail1;
+    list->table =
+      (gl_hash_entry_t *) calloc (list->table_size, sizeof (gl_hash_entry_t));
+    if (list->table == NULL)
+      goto fail1;
+  }
+#endif
+  if (count > 0)
+    {
+      /* Assuming 2^bh - 1 <= count <= 2^(bh+1) - 2, we create a tree whose
+         upper bh levels are black, and only the partially present lowest
+         level is red.  */
+      unsigned int bh;
+      {
+        size_t n;
+        for (n = count + 1, bh = 0; n > 1; n = n >> 1)
+          bh++;
+      }
+
+      list->root = create_subtree_with_contents (bh, count, contents);
+      if (list->root == NULL)
+        goto fail2;
+      list->root->parent = NULL;
+
+#if WITH_HASHTABLE
+      /* Now that the tree is built, node_position() works.  Now we can
+         add the nodes to the hash table.  */
+      if (add_nodes_to_buckets (list) < 0)
+        goto fail3;
+#endif
+    }
+  else
+    list->root = NULL;
+
+  return list;
+
+#if WITH_HASHTABLE
+ fail3:
+  free_subtree (list->root);
+#endif
+ fail2:
+#if WITH_HASHTABLE
+  free (list->table);
+ fail1:
+#endif
+  free (list);
+  return NULL;
+}
 
 /* Rotate left a subtree.
 
@@ -82,10 +163,12 @@ struct gl_oset_impl
 
    Change the tree structure, update the branch sizes.
    The caller must update the colors and register D as child of its parent.  */
-static gl_oset_node_t
-rotate_left (gl_oset_node_t b_node, gl_oset_node_t d_node)
+static gl_list_node_t
+rotate_left (gl_list_node_t b_node, gl_list_node_t d_node)
 {
-  gl_oset_node_t c_node = d_node->left;
+  gl_list_node_t a_node = b_node->left;
+  gl_list_node_t c_node = d_node->left;
+  gl_list_node_t e_node = d_node->right;
 
   b_node->right = c_node;
   d_node->left = b_node;
@@ -95,6 +178,12 @@ rotate_left (gl_oset_node_t b_node, gl_oset_node_t d_node)
   if (c_node != NULL)
     c_node->parent = b_node;
 
+  b_node->branch_size =
+    (a_node != NULL ? a_node->branch_size : 0)
+    + 1 + (c_node != NULL ? c_node->branch_size : 0);
+  d_node->branch_size =
+    b_node->branch_size + 1 + (e_node != NULL ? e_node->branch_size : 0);
+
   return d_node;
 }
 
@@ -108,10 +197,12 @@ rotate_left (gl_oset_node_t b_node, gl_oset_node_t d_node)
 
    Change the tree structure, update the branch sizes.
    The caller must update the colors and register B as child of its parent.  */
-static gl_oset_node_t
-rotate_right (gl_oset_node_t b_node, gl_oset_node_t d_node)
+static gl_list_node_t
+rotate_right (gl_list_node_t b_node, gl_list_node_t d_node)
 {
-  gl_oset_node_t c_node = b_node->right;
+  gl_list_node_t a_node = b_node->left;
+  gl_list_node_t c_node = b_node->right;
+  gl_list_node_t e_node = d_node->right;
 
   d_node->left = c_node;
   b_node->right = d_node;
@@ -121,6 +212,12 @@ rotate_right (gl_oset_node_t b_node, gl_oset_node_t d_node)
   if (c_node != NULL)
     c_node->parent = d_node;
 
+  d_node->branch_size =
+    (c_node != NULL ? c_node->branch_size : 0)
+    + 1 + (e_node != NULL ? e_node->branch_size : 0);
+  b_node->branch_size =
+    (a_node != NULL ? a_node->branch_size : 0) + 1 + d_node->branch_size;
+
   return b_node;
 }
 
@@ -128,15 +225,15 @@ rotate_right (gl_oset_node_t b_node, gl_oset_node_t d_node)
    Also assigns node->color.
    parent is the given node's parent, known to be non-NULL.  */
 static void
-rebalance_after_add (gl_oset_t set, gl_oset_node_t node, gl_oset_node_t parent)
+rebalance_after_add (gl_list_t list, gl_list_node_t node, gl_list_node_t parent)
 {
   for (;;)
     {
       /* At this point, parent = node->parent != NULL.
          Think of node->color being RED (although node->color is not yet
          assigned.)  */
-      gl_oset_node_t grandparent;
-      gl_oset_node_t uncle;
+      gl_list_node_t grandparent;
+      gl_list_node_t uncle;
 
       if (parent->color == BLACK)
         {
@@ -171,10 +268,10 @@ rebalance_after_add (gl_oset_t set, gl_oset_node_t node, gl_oset_node_t parent)
              to be RED too.
              In this case, recoloring is not sufficient.  Need to perform
              one or two rotations.  */
-          gl_oset_node_t *grandparentp;
+          gl_list_node_t *grandparentp;
 
           if (grandparent->parent == NULL)
-            grandparentp = &set->root;
+            grandparentp = &list->root;
           else if (grandparent->parent->left == grandparent)
             grandparentp = &grandparent->parent->left;
           else if (grandparent->parent->right == grandparent)
@@ -253,7 +350,7 @@ rebalance_after_add (gl_oset_t set, gl_oset_node_t node, gl_oset_node_t parent)
    a black node was removed.  CHILD is also black, or NULL.
    (CHILD can also be NULL.  But PARENT is non-NULL.)  */
 static void
-rebalance_after_remove (gl_oset_t set, gl_oset_node_t child, gl_oset_node_t parent)
+rebalance_after_remove (gl_list_t list, gl_list_node_t child, gl_list_node_t parent)
 {
   for (;;)
     {
@@ -261,10 +358,10 @@ rebalance_after_remove (gl_oset_t set, gl_oset_node_t child, gl_oset_node_t pare
          To make up, either look for a possibility to turn a RED to a BLACK
          node, or try to reduce the black-height tree of CHILD's sibling
          subtree as well.  */
-      gl_oset_node_t *parentp;
+      gl_list_node_t *parentp;
 
       if (parent->parent == NULL)
-        parentp = &set->root;
+        parentp = &list->root;
       else if (parent->parent->left == parent)
         parentp = &parent->parent->left;
       else if (parent->parent->right == parent)
@@ -274,7 +371,7 @@ rebalance_after_remove (gl_oset_t set, gl_oset_node_t child, gl_oset_node_t pare
 
       if (parent->left == child)
         {
-          gl_oset_node_t sibling = parent->right;
+          gl_list_node_t sibling = parent->right;
           /* sibling's black-height is >= 1.  In particular,
              sibling != NULL.
 
@@ -396,7 +493,7 @@ rebalance_after_remove (gl_oset_t set, gl_oset_node_t child, gl_oset_node_t pare
         }
       else if (parent->right == child)
         {
-          gl_oset_node_t sibling = parent->left;
+          gl_list_node_t sibling = parent->left;
           /* sibling's black-height is >= 1.  In particular,
              sibling != NULL.
 
@@ -535,118 +632,15 @@ rebalance_after_remove (gl_oset_t set, gl_oset_node_t child, gl_oset_node_t pare
     }
 }
 
-static gl_oset_node_t
-gl_tree_nx_add_first (gl_oset_t set, const void *elt)
-{
-  /* Create new node.  */
-  gl_oset_node_t new_node =
-    (struct gl_oset_node_impl *) malloc (sizeof (struct gl_oset_node_impl));
-
-  if (new_node == NULL)
-    return NULL;
-
-  new_node->left = NULL;
-  new_node->right = NULL;
-  new_node->value = elt;
-
-  /* Add it to the tree.  */
-  if (set->root == NULL)
-    {
-      new_node->color = BLACK;
-      set->root = new_node;
-      new_node->parent = NULL;
-    }
-  else
-    {
-      gl_oset_node_t node;
-
-      for (node = set->root; node->left != NULL; )
-        node = node->left;
-
-      node->left = new_node;
-      new_node->parent = node;
-
-      /* Color and rebalance.  */
-      rebalance_after_add (set, new_node, node);
-    }
-
-  set->count++;
-  return new_node;
-}
-
-static gl_oset_node_t
-gl_tree_nx_add_before (gl_oset_t set, gl_oset_node_t node, const void *elt)
-{
-  /* Create new node.  */
-  gl_oset_node_t new_node =
-    (struct gl_oset_node_impl *) malloc (sizeof (struct gl_oset_node_impl));
-
-  if (new_node == NULL)
-    return NULL;
-
-  new_node->left = NULL;
-  new_node->right = NULL;
-  new_node->value = elt;
-
-  /* Add it to the tree.  */
-  if (node->left == NULL)
-    node->left = new_node;
-  else
-    {
-      for (node = node->left; node->right != NULL; )
-        node = node->right;
-      node->right = new_node;
-    }
-  new_node->parent = node;
-
-  /* Color and rebalance.  */
-  rebalance_after_add (set, new_node, node);
-
-  set->count++;
-  return new_node;
-}
-
-static gl_oset_node_t
-gl_tree_nx_add_after (gl_oset_t set, gl_oset_node_t node, const void *elt)
-{
-  /* Create new node.  */
-  gl_oset_node_t new_node =
-    (struct gl_oset_node_impl *) malloc (sizeof (struct gl_oset_node_impl));
-
-  if (new_node == NULL)
-    return NULL;
-
-  new_node->left = NULL;
-  new_node->right = NULL;
-  new_node->value = elt;
-
-  /* Add it to the tree.  */
-  if (node->right == NULL)
-    node->right = new_node;
-  else
-    {
-      for (node = node->right; node->left != NULL; )
-        node = node->left;
-      node->left = new_node;
-    }
-  new_node->parent = node;
-
-  /* Color and rebalance.  */
-  rebalance_after_add (set, new_node, node);
-
-  set->count++;
-  return new_node;
-}
-
-static bool
-gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
+static void
+gl_tree_remove_node_from_tree (gl_list_t list, gl_list_node_t node)
 {
-  gl_oset_node_t parent = node->parent;
+  gl_list_node_t parent = node->parent;
 
   if (node->left == NULL)
     {
       /* Replace node with node->right.  */
-      gl_oset_node_t child = node->right;
+      gl_list_node_t child = node->right;
 
       if (child != NULL)
         {
@@ -656,7 +650,7 @@ gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
           child->color = BLACK;
         }
       if (parent == NULL)
-        set->root = child;
+        list->root = child;
       else
         {
           if (parent->left == node)
@@ -664,8 +658,16 @@ gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
           else /* parent->right == node */
             parent->right = child;
 
+          /* Update branch_size fields of the parent nodes.  */
+          {
+            gl_list_node_t p;
+
+            for (p = parent; p != NULL; p = p->parent)
+              p->branch_size--;
+          }
+
           if (child == NULL && node->color == BLACK)
-            rebalance_after_remove (set, child, parent);
+            rebalance_after_remove (list, child, parent);
         }
     }
   else if (node->right == NULL)
@@ -673,28 +675,36 @@ gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
       /* It is not absolutely necessary to treat this case.  But the more
          general case below is more complicated, hence slower.  */
       /* Replace node with node->left.  */
-      gl_oset_node_t child = node->left;
+      gl_list_node_t child = node->left;
 
       child->parent = parent;
       /* Since node->right == NULL, child must be RED and of height 1,
          hence node must have been BLACK.  Recolor the child.  */
       child->color = BLACK;
       if (parent == NULL)
-        set->root = child;
+        list->root = child;
       else
         {
           if (parent->left == node)
             parent->left = child;
           else /* parent->right == node */
             parent->right = child;
+
+          /* Update branch_size fields of the parent nodes.  */
+          {
+            gl_list_node_t p;
+
+            for (p = parent; p != NULL; p = p->parent)
+              p->branch_size--;
+          }
         }
     }
   else
     {
       /* Replace node with the rightmost element of the node->left subtree.  */
-      gl_oset_node_t subst;
-      gl_oset_node_t subst_parent;
-      gl_oset_node_t child;
+      gl_list_node_t subst;
+      gl_list_node_t subst_parent;
+      gl_list_node_t child;
       color_t removed_color;
 
       for (subst = node->left; subst->right != NULL; )
@@ -724,6 +734,14 @@ gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
           subst_parent->right = child;
         }
 
+      /* Update branch_size fields of the parent nodes.  */
+      {
+        gl_list_node_t p;
+
+        for (p = subst_parent; p != NULL; p = p->parent)
+          p->branch_size--;
+      }
+
       /* Copy subst into node's position.
          (This is safer than to copy subst's value into node, keep node in
          place, and free subst.)  */
@@ -735,9 +753,10 @@ gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
       subst->right = node->right;
       subst->right->parent = subst;
       subst->color = node->color;
+      subst->branch_size = node->branch_size;
       subst->parent = parent;
       if (parent == NULL)
-        set->root = subst;
+        list->root = subst;
       else if (parent->left == node)
         parent->left = subst;
       else /* parent->right == node */
@@ -752,63 +771,258 @@ gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
             /* Rebalancing starts at child's parent, that is subst_parent -
                except when subst_parent == node.  In this case, we need to use
                its replacement, subst.  */
-            rebalance_after_remove (set, child,
+            rebalance_after_remove (list, child,
                                     subst_parent != node ? subst_parent : subst);
         }
     }
-
-  set->count--;
-  if (set->base.dispose_fn != NULL)
-    set->base.dispose_fn (node->value);
-  free (node);
-  return true;
 }
 
-/* Generic binary tree code.  */
-#include "gl_anytree_oset.h"
+static gl_list_node_t
+gl_tree_nx_add_first (gl_list_t list, const void *elt)
+{
+  /* Create new node.  */
+  gl_list_node_t new_node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
 
-/* For debugging.  */
-static unsigned int
-check_invariants (gl_oset_node_t node, gl_oset_node_t parent, size_t *counterp)
+  if (new_node == NULL)
+    return NULL;
+
+  new_node->left = NULL;
+  new_node->right = NULL;
+  new_node->branch_size = 1;
+  new_node->value = elt;
+#if WITH_HASHTABLE
+  new_node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (new_node->value)
+     : (size_t)(uintptr_t) new_node->value);
+#endif
+
+  /* Add it to the tree.  */
+  if (list->root == NULL)
+    {
+      new_node->color = BLACK;
+      list->root = new_node;
+      new_node->parent = NULL;
+    }
+  else
+    {
+      gl_list_node_t node;
+
+      for (node = list->root; node->left != NULL; )
+        node = node->left;
+
+      node->left = new_node;
+      new_node->parent = node;
+
+      /* Update branch_size fields of the parent nodes.  */
+      {
+        gl_list_node_t p;
+
+        for (p = node; p != NULL; p = p->parent)
+          p->branch_size++;
+      }
+
+      /* Color and rebalance.  */
+      rebalance_after_add (list, new_node, node);
+    }
+
+#if WITH_HASHTABLE
+  /* Add node to the hash table.
+     Note that this is only possible _after_ the node has been added to the
+     tree structure, because add_to_bucket() uses node_position().  */
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
+  hash_resize_after_add (list);
+#endif
+
+  return new_node;
+}
+
+static gl_list_node_t
+gl_tree_nx_add_last (gl_list_t list, const void *elt)
 {
-  unsigned int left_blackheight =
-    (node->left != NULL ? check_invariants (node->left, node, counterp) : 0);
-  unsigned int right_blackheight =
-    (node->right != NULL ? check_invariants (node->right, node, counterp) : 0);
-
-  if (!(node->parent == parent))
-    abort ();
-  if (!(node->color == BLACK || node->color == RED))
-    abort ();
-  if (parent == NULL && !(node->color == BLACK))
-    abort ();
-  if (!(left_blackheight == right_blackheight))
-    abort ();
-
-  (*counterp)++;
-
-  return left_blackheight + (node->color == BLACK ? 1 : 0);
+  /* Create new node.  */
+  gl_list_node_t new_node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+
+  if (new_node == NULL)
+    return NULL;
+
+  new_node->left = NULL;
+  new_node->right = NULL;
+  new_node->branch_size = 1;
+  new_node->value = elt;
+#if WITH_HASHTABLE
+  new_node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (new_node->value)
+     : (size_t)(uintptr_t) new_node->value);
+#endif
+
+  /* Add it to the tree.  */
+  if (list->root == NULL)
+    {
+      new_node->color = BLACK;
+      list->root = new_node;
+      new_node->parent = NULL;
+    }
+  else
+    {
+      gl_list_node_t node;
+
+      for (node = list->root; node->right != NULL; )
+        node = node->right;
+
+      node->right = new_node;
+      new_node->parent = node;
+
+      /* Update branch_size fields of the parent nodes.  */
+      {
+        gl_list_node_t p;
+
+        for (p = node; p != NULL; p = p->parent)
+          p->branch_size++;
+      }
+
+      /* Color and rebalance.  */
+      rebalance_after_add (list, new_node, node);
+    }
+
+#if WITH_HASHTABLE
+  /* Add node to the hash table.
+     Note that this is only possible _after_ the node has been added to the
+     tree structure, because add_to_bucket() uses node_position().  */
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
+  hash_resize_after_add (list);
+#endif
+
+  return new_node;
 }
-void
-gl_rbtree_oset_check_invariants (gl_oset_t set)
+
+static gl_list_node_t
+gl_tree_nx_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
 {
-  size_t counter = 0;
-  if (set->root != NULL)
-    check_invariants (set->root, NULL, &counter);
-  if (!(set->count == counter))
-    abort ();
+  /* Create new node.  */
+  gl_list_node_t new_node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+
+  if (new_node == NULL)
+    return NULL;
+
+  new_node->left = NULL;
+  new_node->right = NULL;
+  new_node->branch_size = 1;
+  new_node->value = elt;
+#if WITH_HASHTABLE
+  new_node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (new_node->value)
+     : (size_t)(uintptr_t) new_node->value);
+#endif
+
+  /* Add it to the tree.  */
+  if (node->left == NULL)
+    node->left = new_node;
+  else
+    {
+      for (node = node->left; node->right != NULL; )
+        node = node->right;
+      node->right = new_node;
+    }
+  new_node->parent = node;
+
+  /* Update branch_size fields of the parent nodes.  */
+  {
+    gl_list_node_t p;
+
+    for (p = node; p != NULL; p = p->parent)
+      p->branch_size++;
+  }
+
+  /* Color and rebalance.  */
+  rebalance_after_add (list, new_node, node);
+
+#if WITH_HASHTABLE
+  /* Add node to the hash table.
+     Note that this is only possible _after_ the node has been added to the
+     tree structure, because add_to_bucket() uses node_position().  */
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
+  hash_resize_after_add (list);
+#endif
+
+  return new_node;
 }
 
-const struct gl_oset_implementation gl_rbtree_oset_implementation =
+static gl_list_node_t
+gl_tree_nx_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  /* Create new node.  */
+  gl_list_node_t new_node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+
+  if (new_node == NULL)
+    return NULL;
+
+  new_node->left = NULL;
+  new_node->right = NULL;
+  new_node->branch_size = 1;
+  new_node->value = elt;
+#if WITH_HASHTABLE
+  new_node->h.hashcode =
+    (list->base.hashcode_fn != NULL
+     ? list->base.hashcode_fn (new_node->value)
+     : (size_t)(uintptr_t) new_node->value);
+#endif
+
+  /* Add it to the tree.  */
+  if (node->right == NULL)
+    node->right = new_node;
+  else
+    {
+      for (node = node->right; node->left != NULL; )
+        node = node->left;
+      node->left = new_node;
+    }
+  new_node->parent = node;
+
+  /* Update branch_size fields of the parent nodes.  */
   {
-    gl_tree_nx_create_empty,
-    gl_tree_size,
-    gl_tree_search,
-    gl_tree_search_atleast,
-    gl_tree_nx_add,
-    gl_tree_remove,
-    gl_tree_oset_free,
-    gl_tree_iterator,
-    gl_tree_iterator_next,
-    gl_tree_iterator_free
-  };
+    gl_list_node_t p;
+
+    for (p = node; p != NULL; p = p->parent)
+      p->branch_size++;
+  }
+
+  /* Color and rebalance.  */
+  rebalance_after_add (list, new_node, node);
+
+#if WITH_HASHTABLE
+  /* Add node to the hash table.
+     Note that this is only possible _after_ the node has been added to the
+     tree structure, because add_to_bucket() uses node_position().  */
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
+  hash_resize_after_add (list);
+#endif
+
+  return new_node;
+}
diff --git a/mcastseed/lib/gl_anytree_list1.h b/mcastseed/lib/gl_anytree_list1.h
new file mode 100644
index 0000000..675f107
--- /dev/null
+++ b/mcastseed/lib/gl_anytree_list1.h
@@ -0,0 +1,41 @@
+/* Sequential list data type implemented by a binary tree.
+   Copyright (C) 2006, 2009-2016 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Common code of gl_avltree_list.c, gl_rbtree_list.c,
+                  gl_avltreehash_list.c, gl_rbtreehash_list.c.  */
+
+/* An item on the stack used for iterating across the elements.  */
+typedef struct
+{
+  gl_list_node_t node;
+  size_t rightp;
+} iterstack_item_t;
+
+/* A stack used for iterating across the elements.  */
+typedef iterstack_item_t iterstack_t[MAXHEIGHT];
+
+/* Free a non-empty subtree recursively.
+   This function is recursive and therefore not very fast.  */
+static void
+free_subtree (gl_list_node_t node)
+{
+  if (node->left != NULL)
+    free_subtree (node->left);
+  if (node->right != NULL)
+    free_subtree (node->right);
+  free (node);
+}
diff --git a/mcastseed/lib/gl_anytree_list2.h b/mcastseed/lib/gl_anytree_list2.h
new file mode 100644
index 0000000..7e6fe45
--- /dev/null
+++ b/mcastseed/lib/gl_anytree_list2.h
@@ -0,0 +1,940 @@
+/* Sequential list data type implemented by a binary tree.
+   Copyright (C) 2006-2016 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Common code of gl_avltree_list.c, gl_rbtree_list.c,
+                  gl_avltreehash_list.c, gl_rbtreehash_list.c.  */
+
+static gl_list_t
+gl_tree_nx_create_empty (gl_list_implementation_t implementation,
+                         gl_listelement_equals_fn equals_fn,
+                         gl_listelement_hashcode_fn hashcode_fn,
+                         gl_listelement_dispose_fn dispose_fn,
+                         bool allow_duplicates)
+{
+  struct gl_list_impl *list = (struct gl_list_impl *) malloc (sizeof (struct gl_list_impl));
+
+  if (list == NULL)
+    return NULL;
+
+  list->base.vtable = implementation;
+  list->base.equals_fn = equals_fn;
+  list->base.hashcode_fn = hashcode_fn;
+  list->base.dispose_fn = dispose_fn;
+  list->base.allow_duplicates = allow_duplicates;
+#if WITH_HASHTABLE
+  list->table_size = 11;
+  list->table =
+    (gl_hash_entry_t *) calloc (list->table_size, sizeof (gl_hash_entry_t));
+  if (list->table == NULL)
+    goto fail;
+#endif
+  list->root = NULL;
+
+  return list;
+
+#if WITH_HASHTABLE
+ fail:
+  free (list);
+  return NULL;
+#endif
+}
+
+static size_t
+gl_tree_size (gl_list_t list)
+{
+  return (list->root != NULL ? list->root->branch_size : 0);
+}
+
+static const void *
+gl_tree_node_value (gl_list_t list, gl_list_node_t node)
+{
+  return node->value;
+}
+
+static int
+gl_tree_node_nx_set_value (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+#if WITH_HASHTABLE
+  if (elt != node->value)
+    {
+      size_t new_hashcode =
+        (list->base.hashcode_fn != NULL
+         ? list->base.hashcode_fn (elt)
+         : (size_t)(uintptr_t) elt);
+
+      if (new_hashcode != node->h.hashcode)
+        {
+          remove_from_bucket (list, node);
+          node->value = elt;
+          node->h.hashcode = new_hashcode;
+          if (add_to_bucket (list, node) < 0)
+            {
+              /* Out of memory.  We removed node from a bucket but cannot add
+                 it to another bucket.  In order to avoid inconsistencies, we
+                 must remove node entirely from the list.  */
+              gl_tree_remove_node_from_tree (list, node);
+              free (node);
+              return -1;
+            }
+        }
+      else
+        node->value = elt;
+    }
+#else
+  node->value = elt;
+#endif
+  return 0;
+}
+
+static gl_list_node_t _GL_ATTRIBUTE_PURE
+gl_tree_next_node (gl_list_t list, gl_list_node_t node)
+{
+  if (node->right != NULL)
+    {
+      node = node->right;
+      while (node->left != NULL)
+        node = node->left;
+    }
+  else
+    {
+      while (node->parent != NULL && node->parent->right == node)
+        node = node->parent;
+      node = node->parent;
+    }
+  return node;
+}
+
+static gl_list_node_t _GL_ATTRIBUTE_PURE
+gl_tree_previous_node (gl_list_t list, gl_list_node_t node)
+{
+  if (node->left != NULL)
+    {
+      node = node->left;
+      while (node->right != NULL)
+        node = node->right;
+    }
+  else
+    {
+      while (node->parent != NULL && node->parent->left == node)
+        node = node->parent;
+      node = node->parent;
+    }
+  return node;
+}
+
+/* Return the node at the given position < gl_tree_size (list).  */
+static gl_list_node_t _GL_ATTRIBUTE_PURE
+node_at (gl_list_node_t root, size_t position)
+{
+  /* Here we know that root != NULL.  */
+  gl_list_node_t node = root;
+
+  for (;;)
+    {
+      if (node->left != NULL)
+        {
+          if (position < node->left->branch_size)
+            {
+              node = node->left;
+              continue;
+            }
+          position -= node->left->branch_size;
+        }
+      if (position == 0)
+        break;
+      position--;
+      node = node->right;
+    }
+  return node;
+}
+
+static const void * _GL_ATTRIBUTE_PURE
+gl_tree_get_at (gl_list_t list, size_t position)
+{
+  gl_list_node_t node = list->root;
+
+  if (!(node != NULL && position < node->branch_size))
+    /* Invalid argument.  */
+    abort ();
+  node = node_at (node, position);
+  return node->value;
+}
+
+static gl_list_node_t
+gl_tree_nx_set_at (gl_list_t list, size_t position, const void *elt)
+{
+  gl_list_node_t node = list->root;
+
+  if (!(node != NULL && position < node->branch_size))
+    /* Invalid argument.  */
+    abort ();
+  node = node_at (node, position);
+#if WITH_HASHTABLE
+  if (elt != node->value)
+    {
+      size_t new_hashcode =
+        (list->base.hashcode_fn != NULL
+         ? list->base.hashcode_fn (elt)
+         : (size_t)(uintptr_t) elt);
+
+      if (new_hashcode != node->h.hashcode)
+        {
+          remove_from_bucket (list, node);
+          node->value = elt;
+          node->h.hashcode = new_hashcode;
+          if (add_to_bucket (list, node) < 0)
+            {
+              /* Out of memory.  We removed node from a bucket but cannot add
+                 it to another bucket.  In order to avoid inconsistencies, we
+                 must remove node entirely from the list.  */
+              gl_tree_remove_node_from_tree (list, node);
+              free (node);
+              return NULL;
+            }
+        }
+      else
+        node->value = elt;
+    }
+#else
+  node->value = elt;
+#endif
+  return node;
+}
+
+#if !WITH_HASHTABLE
+
+static gl_list_node_t
+gl_tree_search_from_to (gl_list_t list, size_t start_index, size_t end_index,
+                        const void *elt)
+{
+  if (!(start_index <= end_index
+        && end_index <= (list->root != NULL ? list->root->branch_size : 0)))
+    /* Invalid arguments.  */
+    abort ();
+  {
+    gl_listelement_equals_fn equals = list->base.equals_fn;
+    /* Iterate across all elements.  */
+    gl_list_node_t node = list->root;
+    iterstack_t stack;
+    iterstack_item_t *stack_ptr = &stack[0];
+    size_t index = 0;
+
+    if (start_index == 0)
+      {
+        /* Consider all elements.  */
+        for (;;)
+          {
+            /* Descend on left branch.  */
+            for (;;)
+              {
+                if (node == NULL)
+                  break;
+                stack_ptr->node = node;
+                stack_ptr->rightp = 0;
+                node = node->left;
+                stack_ptr++;
+              }
+            /* Climb up again.  */
+            for (;;)
+              {
+                if (stack_ptr == &stack[0])
+                  return NULL;
+                stack_ptr--;
+                if (!stack_ptr->rightp)
+                  break;
+              }
+            node = stack_ptr->node;
+            /* Test against current element.  */
+            if (equals != NULL ? equals (elt, node->value) : elt == node->value)
+              return node;
+            index++;
+            if (index >= end_index)
+              return NULL;
+            /* Descend on right branch.  */
+            stack_ptr->rightp = 1;
+            node = node->right;
+            stack_ptr++;
+          }
+      }
+    else
+      {
+        /* Consider only elements at indices >= start_index.
+           In this case, rightp contains the difference between the start_index
+           for the parent node and the one for the child node (0 when the child
+           node is the parent's left child, > 0 when the child is the parent's
+           right child).  */
+        for (;;)
+          {
+            /* Descend on left branch.  */
+            for (;;)
+              {
+                if (node == NULL)
+                  break;
+                if (node->branch_size <= start_index)
+                  break;
+                stack_ptr->node = node;
+                stack_ptr->rightp = 0;
+                node = node->left;
+                stack_ptr++;
+              }
+            /* Climb up again.  */
+            for (;;)
+              {
+                if (stack_ptr == &stack[0])
+                  return NULL;
+                stack_ptr--;
+                if (!stack_ptr->rightp)
+                  break;
+                start_index += stack_ptr->rightp;
+              }
+            node = stack_ptr->node;
+            {
+              size_t left_branch_size1 =
+                (node->left != NULL ? node->left->branch_size : 0) + 1;
+              if (start_index < left_branch_size1)
+                {
+                  /* Test against current element.  */
+                  if (equals != NULL ? equals (elt, node->value) : elt == node->value)
+                    return node;
+                  /* Now that we have considered all indices < left_branch_size1,
+                     we can increment start_index.  */
+                  start_index = left_branch_size1;
+                }
+              index++;
+              if (index >= end_index)
+                return NULL;
+              /* Descend on right branch.  */
+              start_index -= left_branch_size1;
+              stack_ptr->rightp = left_branch_size1;
+            }
+            node = node->right;
+            stack_ptr++;
+          }
+      }
+  }
+}
+
+static size_t
+gl_tree_indexof_from_to (gl_list_t list, size_t start_index, size_t end_index,
+                         const void *elt)
+{
+  if (!(start_index <= end_index
+        && end_index <= (list->root != NULL ? list->root->branch_size : 0)))
+    /* Invalid arguments.  */
+    abort ();
+  {
+    gl_listelement_equals_fn equals = list->base.equals_fn;
+    /* Iterate across all elements.  */
+    gl_list_node_t node = list->root;
+    iterstack_t stack;
+    iterstack_item_t *stack_ptr = &stack[0];
+    size_t index = 0;
+
+    if (start_index == 0)
+      {
+        /* Consider all elements.  */
+        for (;;)
+          {
+            /* Descend on left branch.  */
+            for (;;)
+              {
+                if (node == NULL)
+                  break;
+                stack_ptr->node = node;
+                stack_ptr->rightp = 0;
+                node = node->left;
+                stack_ptr++;
+              }
+            /* Climb up again.  */
+            for (;;)
+              {
+                if (stack_ptr == &stack[0])
+                  return (size_t)(-1);
+                stack_ptr--;
+                if (!stack_ptr->rightp)
+                  break;
+              }
+            node = stack_ptr->node;
+            /* Test against current element.  */
+            if (equals != NULL ? equals (elt, node->value) : elt == node->value)
+              return index;
+            index++;
+            if (index >= end_index)
+              return (size_t)(-1);
+            /* Descend on right branch.  */
+            stack_ptr->rightp = 1;
+            node = node->right;
+            stack_ptr++;
+          }
+      }
+    else
+      {
+        /* Consider only elements at indices >= start_index.
+           In this case, rightp contains the difference between the start_index
+           for the parent node and the one for the child node (0 when the child
+           node is the parent's left child, > 0 when the child is the parent's
+           right child).  */
+        for (;;)
+          {
+            /* Descend on left branch.  */
+            for (;;)
+              {
+                if (node == NULL)
+                  break;
+                if (node->branch_size <= start_index)
+                  break;
+                stack_ptr->node = node;
+                stack_ptr->rightp = 0;
+                node = node->left;
+                stack_ptr++;
+              }
+            /* Climb up again.  */
+            for (;;)
+              {
+                if (stack_ptr == &stack[0])
+                  return (size_t)(-1);
+                stack_ptr--;
+                if (!stack_ptr->rightp)
+                  break;
+                start_index += stack_ptr->rightp;
+              }
+            node = stack_ptr->node;
+            {
+              size_t left_branch_size1 =
+                (node->left != NULL ? node->left->branch_size : 0) + 1;
+              if (start_index < left_branch_size1)
+                {
+                  /* Test against current element.  */
+                  if (equals != NULL ? equals (elt, node->value) : elt == node->value)
+                    return index;
+                  /* Now that we have considered all indices < left_branch_size1,
+                     we can increment start_index.  */
+                  start_index = left_branch_size1;
+                }
+              index++;
+              if (index >= end_index)
+                return (size_t)(-1);
+              /* Descend on right branch.  */
+              start_index -= left_branch_size1;
+              stack_ptr->rightp = left_branch_size1;
+            }
+            node = node->right;
+            stack_ptr++;
+          }
+      }
+  }
+}
+
+#endif
+
+static gl_list_node_t
+gl_tree_nx_add_at (gl_list_t list, size_t position, const void *elt)
+{
+  size_t count = (list->root != NULL ? list->root->branch_size : 0);
+
+  if (!(position <= count))
+    /* Invalid argument.  */
+    abort ();
+  if (position == count)
+    return gl_tree_nx_add_last (list, elt);
+  else
+    return gl_tree_nx_add_before (list, node_at (list->root, position), elt);
+}
+
+static bool
+gl_tree_remove_node (gl_list_t list, gl_list_node_t node)
+{
+#if WITH_HASHTABLE
+  /* Remove node from the hash table.
+     Note that this is only possible _before_ the node is removed from the
+     tree structure, because remove_from_bucket() uses node_position().  */
+  remove_from_bucket (list, node);
+#endif
+
+  gl_tree_remove_node_from_tree (list, node);
+
+  if (list->base.dispose_fn != NULL)
+    list->base.dispose_fn (node->value);
+  free (node);
+  return true;
+}
+
+static bool
+gl_tree_remove_at (gl_list_t list, size_t position)
+{
+  gl_list_node_t node = list->root;
+
+  if (!(node != NULL && position < node->branch_size))
+    /* Invalid argument.  */
+    abort ();
+  node = node_at (node, position);
+  return gl_tree_remove_node (list, node);
+}
+
+static bool
+gl_tree_remove (gl_list_t list, const void *elt)
+{
+  if (list->root != NULL)
+    {
+      gl_list_node_t node =
+        gl_tree_search_from_to (list, 0, list->root->branch_size, elt);
+
+      if (node != NULL)
+        return gl_tree_remove_node (list, node);
+    }
+  return false;
+}
+
+#if !WITH_HASHTABLE
+
+static void
+gl_tree_list_free (gl_list_t list)
+{
+  /* Iterate across all elements in post-order.  */
+  gl_list_node_t node = list->root;
+  iterstack_t stack;
+  iterstack_item_t *stack_ptr = &stack[0];
+
+  for (;;)
+    {
+      /* Descend on left branch.  */
+      for (;;)
+        {
+          if (node == NULL)
+            break;
+          stack_ptr->node = node;
+          stack_ptr->rightp = false;
+          node = node->left;
+          stack_ptr++;
+        }
+      /* Climb up again.  */
+      for (;;)
+        {
+          if (stack_ptr == &stack[0])
+            goto done_iterate;
+          stack_ptr--;
+          node = stack_ptr->node;
+          if (!stack_ptr->rightp)
+            break;
+          /* Free the current node.  */
+          if (list->base.dispose_fn != NULL)
+            list->base.dispose_fn (node->value);
+          free (node);
+        }
+      /* Descend on right branch.  */
+      stack_ptr->rightp = true;
+      node = node->right;
+      stack_ptr++;
+    }
+ done_iterate:
+  free (list);
+}
+
+#endif
+
+/* --------------------- gl_list_iterator_t Data Type --------------------- */
+
+static gl_list_iterator_t
+gl_tree_iterator (gl_list_t list)
+{
+  gl_list_iterator_t result;
+  gl_list_node_t node;
+
+  result.vtable = list->base.vtable;
+  result.list = list;
+  /* Start node is the leftmost node.  */
+  node = list->root;
+  if (node != NULL)
+    while (node->left != NULL)
+      node = node->left;
+  result.p = node;
+  /* End point is past the rightmost node.  */
+  result.q = NULL;
+#if defined GCC_LINT || defined lint
+  result.i = 0;
+  result.j = 0;
+  result.count = 0;
+#endif
+
+  return result;
+}
+
+static gl_list_iterator_t
+gl_tree_iterator_from_to (gl_list_t list, size_t start_index, size_t end_index)
+{
+  size_t count = (list->root != NULL ? list->root->branch_size : 0);
+  gl_list_iterator_t result;
+
+  if (!(start_index <= end_index && end_index <= count))
+    /* Invalid arguments.  */
+    abort ();
+  result.vtable = list->base.vtable;
+  result.list = list;
+  /* Start node is the node at position start_index.  */
+  result.p = (start_index < count ? node_at (list->root, start_index) : NULL);
+  /* End point is the node at position end_index.  */
+  result.q = (end_index < count ? node_at (list->root, end_index) : NULL);
+#if defined GCC_LINT || defined lint
+  result.i = 0;
+  result.j = 0;
+  result.count = 0;
+#endif
+
+  return result;
+}
+
+static bool
+gl_tree_iterator_next (gl_list_iterator_t *iterator,
+                       const void **eltp, gl_list_node_t *nodep)
+{
+  if (iterator->p != iterator->q)
+    {
+      gl_list_node_t node = (gl_list_node_t) iterator->p;
+      *eltp = node->value;
+      if (nodep != NULL)
+        *nodep = node;
+      /* Advance to the next node.  */
+      if (node->right != NULL)
+        {
+          node = node->right;
+          while (node->left != NULL)
+            node = node->left;
+        }
+      else
+        {
+          while (node->parent != NULL && node->parent->right == node)
+            node = node->parent;
+          node = node->parent;
+        }
+      iterator->p = node;
+      return true;
+    }
+  else
+    return false;
+}
+
+static void
+gl_tree_iterator_free (gl_list_iterator_t *iterator)
+{
+}
+
+/* ---------------------- Sorted gl_list_t Data Type ---------------------- */
+
+static gl_list_node_t
+gl_tree_sortedlist_search (gl_list_t list, gl_listelement_compar_fn compar,
+                           const void *elt)
+{
+  gl_list_node_t node;
+
+  for (node = list->root; node != NULL; )
+    {
+      int cmp = compar (node->value, elt);
+
+      if (cmp < 0)
+        node = node->right;
+      else if (cmp > 0)
+        node = node->left;
+      else /* cmp == 0 */
+        {
+          /* We have an element equal to ELT.  But we need the leftmost such
+             element.  */
+          gl_list_node_t found = node;
+          node = node->left;
+          for (; node != NULL; )
+            {
+              int cmp2 = compar (node->value, elt);
+
+              if (cmp2 < 0)
+                node = node->right;
+              else if (cmp2 > 0)
+                /* The list was not sorted.  */
+                abort ();
+              else /* cmp2 == 0 */
+                {
+                  found = node;
+                  node = node->left;
+                }
+            }
+          return found;
+        }
+    }
+  return NULL;
+}
+
+static gl_list_node_t
+gl_tree_sortedlist_search_from_to (gl_list_t list,
+                                   gl_listelement_compar_fn compar,
+                                   size_t low, size_t high,
+                                   const void *elt)
+{
+  gl_list_node_t node;
+
+  if (!(low <= high
+        && high <= (list->root != NULL ? list->root->branch_size : 0)))
+    /* Invalid arguments.  */
+    abort ();
+
+  for (node = list->root; node != NULL; )
+    {
+      size_t left_branch_size =
+        (node->left != NULL ? node->left->branch_size : 0);
+
+      if (low > left_branch_size)
+        {
+          low -= left_branch_size + 1;
+          high -= left_branch_size + 1;
+          node = node->right;
+        }
+      else if (high <= left_branch_size)
+        node = node->left;
+      else
+        {
+          /* Here low <= left_branch_size < high.  */
+          int cmp = compar (node->value, elt);
+
+          if (cmp < 0)
+            {
+              low = 0;
+              high -= left_branch_size + 1;
+              node = node->right;
+            }
+          else if (cmp > 0)
+            node = node->left;
+          else /* cmp == 0 */
+            {
+              /* We have an element equal to ELT.  But we need the leftmost
+                 such element.  */
+              gl_list_node_t found = node;
+              node = node->left;
+              for (; node != NULL; )
+                {
+                  size_t left_branch_size2 =
+                    (node->left != NULL ? node->left->branch_size : 0);
+
+                  if (low > left_branch_size2)
+                    {
+                      low -= left_branch_size2 + 1;
+                      node = node->right;
+                    }
+                  else
+                    {
+                      /* Here low <= left_branch_size2.  */
+                      int cmp2 = compar (node->value, elt);
+
+                      if (cmp2 < 0)
+                        {
+                          low = 0;
+                          node = node->right;
+                        }
+                      else if (cmp2 > 0)
+                        /* The list was not sorted.  */
+                        abort ();
+                      else /* cmp2 == 0 */
+                        {
+                          found = node;
+                          node = node->left;
+                        }
+                    }
+                }
+              return found;
+            }
+        }
+    }
+  return NULL;
+}
+
+static size_t
+gl_tree_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar,
+                            const void *elt)
+{
+  gl_list_node_t node;
+  size_t position;
+
+  for (node = list->root, position = 0; node != NULL; )
+    {
+      int cmp = compar (node->value, elt);
+
+      if (cmp < 0)
+        {
+          if (node->left != NULL)
+            position += node->left->branch_size;
+          position++;
+          node = node->right;
+        }
+      else if (cmp > 0)
+        node = node->left;
+      else /* cmp == 0 */
+        {
+          /* We have an element equal to ELT.  But we need the leftmost such
+             element.  */
+          size_t found_position =
+            position + (node->left != NULL ? node->left->branch_size : 0);
+          node = node->left;
+          for (; node != NULL; )
+            {
+              int cmp2 = compar (node->value, elt);
+
+              if (cmp2 < 0)
+                {
+                  if (node->left != NULL)
+                    position += node->left->branch_size;
+                  position++;
+                  node = node->right;
+                }
+              else if (cmp2 > 0)
+                /* The list was not sorted.  */
+                abort ();
+              else /* cmp2 == 0 */
+                {
+                  found_position =
+                    position
+                    + (node->left != NULL ? node->left->branch_size : 0);
+                  node = node->left;
+                }
+            }
+          return found_position;
+        }
+    }
+  return (size_t)(-1);
+}
+
+static size_t
+gl_tree_sortedlist_indexof_from_to (gl_list_t list,
+                                    gl_listelement_compar_fn compar,
+                                    size_t low, size_t high,
+                                    const void *elt)
+{
+  gl_list_node_t node;
+  size_t position;
+
+  if (!(low <= high
+        && high <= (list->root != NULL ? list->root->branch_size : 0)))
+    /* Invalid arguments.  */
+    abort ();
+
+  for (node = list->root, position = 0; node != NULL; )
+    {
+      size_t left_branch_size =
+        (node->left != NULL ? node->left->branch_size : 0);
+
+      if (low > left_branch_size)
+        {
+          low -= left_branch_size + 1;
+          high -= left_branch_size + 1;
+          position += left_branch_size + 1;
+          node = node->right;
+        }
+      else if (high <= left_branch_size)
+        node = node->left;
+      else
+        {
+          /* Here low <= left_branch_size < high.  */
+          int cmp = compar (node->value, elt);
+
+          if (cmp < 0)
+            {
+              low = 0;
+              high -= left_branch_size + 1;
+              position += left_branch_size + 1;
+              node = node->right;
+            }
+          else if (cmp > 0)
+            node = node->left;
+          else /* cmp == 0 */
+            {
+              /* We have an element equal to ELT.  But we need the leftmost
+                 such element.  */
+              size_t found_position =
+                position + (node->left != NULL ? node->left->branch_size : 0);
+              node = node->left;
+              for (; node != NULL; )
+                {
+                  size_t left_branch_size2 =
+                    (node->left != NULL ? node->left->branch_size : 0);
+
+                  if (low > left_branch_size2)
+                    {
+                      low -= left_branch_size2 + 1;
+                      node = node->right;
+                    }
+                  else
+                    {
+                      /* Here low <= left_branch_size2.  */
+                      int cmp2 = compar (node->value, elt);
+
+                      if (cmp2 < 0)
+                        {
+                          position += left_branch_size2 + 1;
+                          node = node->right;
+                        }
+                      else if (cmp2 > 0)
+                        /* The list was not sorted.  */
+                        abort ();
+                      else /* cmp2 == 0 */
+                        {
+                          found_position = position + left_branch_size2;
+                          node = node->left;
+                        }
+                    }
+                }
+              return found_position;
+            }
+        }
+    }
+  return (size_t)(-1);
+}
+
+static gl_list_node_t
+gl_tree_sortedlist_nx_add (gl_list_t list, gl_listelement_compar_fn compar,
+                           const void *elt)
+{
+  gl_list_node_t node = list->root;
+
+  if (node == NULL)
+    return gl_tree_nx_add_first (list, elt);
+
+  for (;;)
+    {
+      int cmp = compar (node->value, elt);
+
+      if (cmp < 0)
+        {
+          if (node->right == NULL)
+            return gl_tree_nx_add_after (list, node, elt);
+          node = node->right;
+        }
+      else if (cmp > 0)
+        {
+          if (node->left == NULL)
+            return gl_tree_nx_add_before (list, node, elt);
+          node = node->left;
+        }
+      else /* cmp == 0 */
+        return gl_tree_nx_add_before (list, node, elt);
+    }
+}
+
+static bool
+gl_tree_sortedlist_remove (gl_list_t list, gl_listelement_compar_fn compar,
+                           const void *elt)
+{
+  gl_list_node_t node = gl_tree_sortedlist_search (list, compar, elt);
+  if (node != NULL)
+    return gl_tree_remove_node (list, node);
+  else
+    return false;
+}
diff --git a/mcastseed/lib/gl_anytree_oset.h b/mcastseed/lib/gl_anytree_oset.h
deleted file mode 100644
index 127f4e3..0000000
--- a/mcastseed/lib/gl_anytree_oset.h
+++ /dev/null
@@ -1,297 +0,0 @@
-/* Ordered set data type implemented by a binary tree.
-   Copyright (C) 2006-2007, 2009-2016 Free Software Foundation, Inc.
-   Written by Bruno Haible <bruno@clisp.org>, 2006.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
-
-   This program 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 General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-/* Common code of gl_avltree_oset.c and gl_rbtree_oset.c.  */
-
-/* An item on the stack used for iterating across the elements.  */
-typedef struct
-{
-  gl_oset_node_t node;
-  bool rightp;
-} iterstack_item_t;
-
-/* A stack used for iterating across the elements.  */
-typedef iterstack_item_t iterstack_t[MAXHEIGHT];
-
-static gl_oset_t
-gl_tree_nx_create_empty (gl_oset_implementation_t implementation,
-                         gl_setelement_compar_fn compar_fn,
-                         gl_setelement_dispose_fn dispose_fn)
-{
-  struct gl_oset_impl *set =
-    (struct gl_oset_impl *) malloc (sizeof (struct gl_oset_impl));
-
-  if (set == NULL)
-    return NULL;
-
-  set->base.vtable = implementation;
-  set->base.compar_fn = compar_fn;
-  set->base.dispose_fn = dispose_fn;
-  set->root = NULL;
-  set->count = 0;
-
-  return set;
-}
-
-static size_t
-gl_tree_size (gl_oset_t set)
-{
-  return set->count;
-}
-
-static bool
-gl_tree_search (gl_oset_t set, const void *elt)
-{
-  gl_setelement_compar_fn compar = set->base.compar_fn;
-  gl_oset_node_t node;
-
-  for (node = set->root; node != NULL; )
-    {
-      int cmp = (compar != NULL
-                 ? compar (node->value, elt)
-                 : (node->value > elt ? 1 :
-                    node->value < elt ? -1 : 0));
-
-      if (cmp < 0)
-        node = node->right;
-      else if (cmp > 0)
-        node = node->left;
-      else /* cmp == 0 */
-        /* We have an element equal to ELT.  */
-        return true;
-    }
-  return false;
-}
-
-static bool
-gl_tree_search_atleast (gl_oset_t set,
-                        gl_setelement_threshold_fn threshold_fn,
-                        const void *threshold,
-                        const void **eltp)
-{
-  gl_oset_node_t node;
-
-  for (node = set->root; node != NULL; )
-    {
-      if (! threshold_fn (node->value, threshold))
-        node = node->right;
-      else
-        {
-          /* We have an element >= VALUE.  But we need the leftmost such
-             element.  */
-          gl_oset_node_t found = node;
-          node = node->left;
-          for (; node != NULL; )
-            {
-              if (! threshold_fn (node->value, threshold))
-                node = node->right;
-              else
-                {
-                  found = node;
-                  node = node->left;
-                }
-            }
-          *eltp = found->value;
-          return true;
-        }
-    }
-  return false;
-}
-
-static gl_oset_node_t
-gl_tree_search_node (gl_oset_t set, const void *elt)
-{
-  gl_setelement_compar_fn compar = set->base.compar_fn;
-  gl_oset_node_t node;
-
-  for (node = set->root; node != NULL; )
-    {
-      int cmp = (compar != NULL
-                 ? compar (node->value, elt)
-                 : (node->value > elt ? 1 :
-                    node->value < elt ? -1 : 0));
-
-      if (cmp < 0)
-        node = node->right;
-      else if (cmp > 0)
-        node = node->left;
-      else /* cmp == 0 */
-        /* We have an element equal to ELT.  */
-        return node;
-    }
-  return NULL;
-}
-
-static int
-gl_tree_nx_add (gl_oset_t set, const void *elt)
-{
-  gl_setelement_compar_fn compar;
-  gl_oset_node_t node = set->root;
-
-  if (node == NULL)
-    {
-      if (gl_tree_nx_add_first (set, elt) == NULL)
-        return -1;
-      return true;
-    }
-
-  compar = set->base.compar_fn;
-
-  for (;;)
-    {
-      int cmp = (compar != NULL
-                 ? compar (node->value, elt)
-                 : (node->value > elt ? 1 :
-                    node->value < elt ? -1 : 0));
-
-      if (cmp < 0)
-        {
-          if (node->right == NULL)
-            {
-              if (gl_tree_nx_add_after (set, node, elt) == NULL)
-                return -1;
-              return true;
-            }
-          node = node->right;
-        }
-      else if (cmp > 0)
-        {
-          if (node->left == NULL)
-            {
-              if (gl_tree_nx_add_before (set, node, elt) == NULL)
-                return -1;
-              return true;
-            }
-          node = node->left;
-        }
-      else /* cmp == 0 */
-        return false;
-    }
-}
-
-static bool
-gl_tree_remove (gl_oset_t set, const void *elt)
-{
-  gl_oset_node_t node = gl_tree_search_node (set, elt);
-
-  if (node != NULL)
-    return gl_tree_remove_node (set, node);
-  else
-    return false;
-}
-
-static void
-gl_tree_oset_free (gl_oset_t set)
-{
-  /* Iterate across all elements in post-order.  */
-  gl_oset_node_t node = set->root;
-  iterstack_t stack;
-  iterstack_item_t *stack_ptr = &stack[0];
-
-  for (;;)
-    {
-      /* Descend on left branch.  */
-      for (;;)
-        {
-          if (node == NULL)
-            break;
-          stack_ptr->node = node;
-          stack_ptr->rightp = false;
-          node = node->left;
-          stack_ptr++;
-        }
-      /* Climb up again.  */
-      for (;;)
-        {
-          if (stack_ptr == &stack[0])
-            goto done_iterate;
-          stack_ptr--;
-          node = stack_ptr->node;
-          if (!stack_ptr->rightp)
-            break;
-          /* Free the current node.  */
-          if (set->base.dispose_fn != NULL)
-            set->base.dispose_fn (node->value);
-          free (node);
-        }
-      /* Descend on right branch.  */
-      stack_ptr->rightp = true;
-      node = node->right;
-      stack_ptr++;
-    }
- done_iterate:
-  free (set);
-}
-
-/* --------------------- gl_oset_iterator_t Data Type --------------------- */
-
-static gl_oset_iterator_t
-gl_tree_iterator (gl_oset_t set)
-{
-  gl_oset_iterator_t result;
-  gl_oset_node_t node;
-
-  result.vtable = set->base.vtable;
-  result.set = set;
-  /* Start node is the leftmost node.  */
-  node = set->root;
-  if (node != NULL)
-    while (node->left != NULL)
-      node = node->left;
-  result.p = node;
-  /* End point is past the rightmost node.  */
-  result.q = NULL;
-#if defined GCC_LINT || defined lint
-  result.i = 0;
-  result.j = 0;
-  result.count = 0;
-#endif
-
-  return result;
-}
-
-static bool
-gl_tree_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
-{
-  if (iterator->p != iterator->q)
-    {
-      gl_oset_node_t node = (gl_oset_node_t) iterator->p;
-      *eltp = node->value;
-      /* Advance to the next node.  */
-      if (node->right != NULL)
-        {
-          node = node->right;
-          while (node->left != NULL)
-            node = node->left;
-        }
-      else
-        {
-          while (node->parent != NULL && node->parent->right == node)
-            node = node->parent;
-          node = node->parent;
-        }
-      iterator->p = node;
-      return true;
-    }
-  else
-    return false;
-}
-
-static void
-gl_tree_iterator_free (gl_oset_iterator_t *iterator)
-{
-}
diff --git a/mcastseed/lib/gl_list.c b/mcastseed/lib/gl_list.c
new file mode 100644
index 0000000..8793298
--- /dev/null
+++ b/mcastseed/lib/gl_list.c
@@ -0,0 +1,3 @@
+#include <config.h>
+#define GL_LIST_INLINE _GL_EXTERN_INLINE
+#include "gl_list.h"
diff --git a/mcastseed/lib/gl_list.h b/mcastseed/lib/gl_list.h
new file mode 100644
index 0000000..c9d05b0
--- /dev/null
+++ b/mcastseed/lib/gl_list.h
@@ -0,0 +1,841 @@
+/* Abstract sequential list data type.  -*- coding: utf-8 -*-
+   Copyright (C) 2006-2016 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef _GL_LIST_H
+#define _GL_LIST_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#ifndef _GL_INLINE_HEADER_BEGIN
+ #error "Please include config.h first."
+#endif
+_GL_INLINE_HEADER_BEGIN
+#ifndef GL_LIST_INLINE
+# define GL_LIST_INLINE _GL_INLINE
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* gl_list is an abstract list data type.  It can contain any number of
+   objects ('void *' or 'const void *' pointers) in any given order.
+   Duplicates are allowed, but can optionally be forbidden.
+
+   There are several implementations of this list datatype, optimized for
+   different operations or for memory.  You can start using the simplest list
+   implementation, GL_ARRAY_LIST, and switch to a different implementation
+   later, when you realize which operations are performed the most frequently.
+   The API of the different implementations is exactly the same; when
+   switching to a different implementation, you only have to change the
+   gl_list_create call.
+
+   The implementations are:
+     GL_ARRAY_LIST        a growable array
+     GL_CARRAY_LIST       a growable circular array
+     GL_LINKED_LIST       a linked list
+     GL_AVLTREE_LIST      a binary tree (AVL tree)
+     GL_RBTREE_LIST       a binary tree (red-black tree)
+     GL_LINKEDHASH_LIST   a hash table with a linked list
+     GL_AVLTREEHASH_LIST  a hash table with a binary tree (AVL tree)
+     GL_RBTREEHASH_LIST   a hash table with a binary tree (red-black tree)
+
+   The memory consumption is asymptotically the same: O(1) for every object
+   in the list.  When looking more closely at the average memory consumed
+   for an object, GL_ARRAY_LIST is the most compact representation, and
+   GL_LINKEDHASH_LIST and GL_TREEHASH_LIST need more memory.
+
+   The guaranteed average performance of the operations is, for a list of
+   n elements:
+
+   Operation                  ARRAY    LINKED    TREE    LINKEDHASH   TREEHASH
+                              CARRAY                   with|without with|without
+                                                         duplicates  duplicates
+
+   gl_list_size                O(1)     O(1)     O(1)      O(1)         O(1)
+   gl_list_node_value          O(1)     O(1)     O(1)      O(1)         O(1)
+   gl_list_node_set_value      O(1)     O(1)     O(1)      O(1)    O((log n)²)/O(1)
+   gl_list_next_node           O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_list_previous_node       O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_list_get_at              O(1)     O(n)   O(log n)    O(n)       O(log n)
+   gl_list_set_at              O(1)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_list_search              O(n)     O(n)     O(n)    O(n)/O(1)    O(log n)/O(1)
+   gl_list_search_from         O(n)     O(n)     O(n)    O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_search_from_to      O(n)     O(n)     O(n)    O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_indexof             O(n)     O(n)     O(n)      O(n)       O(log n)
+   gl_list_indexof_from        O(n)     O(n)     O(n)      O(n)    O((log n)²)/O(log n)
+   gl_list_indexof_from_to     O(n)     O(n)     O(n)      O(n)    O((log n)²)/O(log n)
+   gl_list_add_first         O(n)/O(1)  O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_last            O(1)     O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_before          O(n)     O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_after           O(n)     O(1)   O(log n)    O(1)    O((log n)²)/O(log n)
+   gl_list_add_at              O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_list_remove_node         O(n)     O(1)   O(log n)  O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_remove_at           O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_list_remove              O(n)     O(n)     O(n)    O(n)/O(1) O((log n)²)/O(log n)
+   gl_list_iterator            O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_list_iterator_from_to    O(1)     O(n)   O(log n)    O(n)       O(log n)
+   gl_list_iterator_next       O(1)     O(1)   O(log n)    O(1)       O(log n)
+   gl_sortedlist_search      O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_search_from O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_indexof     O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_indexof_fro O(log n)   O(n)   O(log n)    O(n)       O(log n)
+   gl_sortedlist_add           O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+   gl_sortedlist_remove        O(n)     O(n)   O(log n)    O(n)    O((log n)²)/O(log n)
+ */
+
+/* -------------------------- gl_list_t Data Type -------------------------- */
+
+/* Type of function used to compare two elements.
+   NULL denotes pointer comparison.  */
+typedef bool (*gl_listelement_equals_fn) (const void *elt1, const void *elt2);
+
+/* Type of function used to compute a hash code.
+   NULL denotes a function that depends only on the pointer itself.  */
+typedef size_t (*gl_listelement_hashcode_fn) (const void *elt);
+
+/* Type of function used to dispose an element once it's removed from a list.
+   NULL denotes a no-op.  */
+typedef void (*gl_listelement_dispose_fn) (const void *elt);
+
+struct gl_list_impl;
+/* Type representing an entire list.  */
+typedef struct gl_list_impl * gl_list_t;
+
+struct gl_list_node_impl;
+/* Type representing the position of an element in the list, in a way that
+   is more adapted to the list implementation than a plain index.
+   Note: It is invalidated by insertions and removals!  */
+typedef struct gl_list_node_impl * gl_list_node_t;
+
+struct gl_list_implementation;
+/* Type representing a list datatype implementation.  */
+typedef const struct gl_list_implementation * gl_list_implementation_t;
+
+#if 0 /* Unless otherwise specified, these are defined inline below.  */
+
+/* Create an empty list.
+   IMPLEMENTATION is one of GL_ARRAY_LIST, GL_CARRAY_LIST, GL_LINKED_LIST,
+   GL_AVLTREE_LIST, GL_RBTREE_LIST, GL_LINKEDHASH_LIST, GL_AVLTREEHASH_LIST,
+   GL_RBTREEHASH_LIST.
+   EQUALS_FN is an element comparison function or NULL.
+   HASHCODE_FN is an element hash code function or NULL.
+   DISPOSE_FN is an element disposal function or NULL.
+   ALLOW_DUPLICATES is false if duplicate elements shall not be allowed in
+   the list. The implementation may verify this at runtime.  */
+/* declared in gl_xlist.h */
+extern gl_list_t gl_list_create_empty (gl_list_implementation_t implementation,
+                                       gl_listelement_equals_fn equals_fn,
+                                       gl_listelement_hashcode_fn hashcode_fn,
+                                       gl_listelement_dispose_fn dispose_fn,
+                                       bool allow_duplicates);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_t gl_list_nx_create_empty (gl_list_implementation_t implementation,
+                                          gl_listelement_equals_fn equals_fn,
+                                          gl_listelement_hashcode_fn hashcode_fn,
+                                          gl_listelement_dispose_fn dispose_fn,
+                                          bool allow_duplicates);
+
+/* Create a list with given contents.
+   IMPLEMENTATION is one of GL_ARRAY_LIST, GL_CARRAY_LIST, GL_LINKED_LIST,
+   GL_AVLTREE_LIST, GL_RBTREE_LIST, GL_LINKEDHASH_LIST, GL_AVLTREEHASH_LIST,
+   GL_RBTREEHASH_LIST.
+   EQUALS_FN is an element comparison function or NULL.
+   HASHCODE_FN is an element hash code function or NULL.
+   DISPOSE_FN is an element disposal function or NULL.
+   ALLOW_DUPLICATES is false if duplicate elements shall not be allowed in
+   the list. The implementation may verify this at runtime.
+   COUNT is the number of initial elements.
+   CONTENTS[0..COUNT-1] is the initial contents.  */
+/* declared in gl_xlist.h */
+extern gl_list_t gl_list_create (gl_list_implementation_t implementation,
+                                 gl_listelement_equals_fn equals_fn,
+                                 gl_listelement_hashcode_fn hashcode_fn,
+                                 gl_listelement_dispose_fn dispose_fn,
+                                 bool allow_duplicates,
+                                 size_t count, const void **contents);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_t gl_list_nx_create (gl_list_implementation_t implementation,
+                                    gl_listelement_equals_fn equals_fn,
+                                    gl_listelement_hashcode_fn hashcode_fn,
+                                    gl_listelement_dispose_fn dispose_fn,
+                                    bool allow_duplicates,
+                                    size_t count, const void **contents);
+
+/* Return the current number of elements in a list.  */
+extern size_t gl_list_size (gl_list_t list);
+
+/* Return the element value represented by a list node.  */
+extern const void * gl_list_node_value (gl_list_t list, gl_list_node_t node);
+
+/* Replace the element value represented by a list node.  */
+/* declared in gl_xlist.h */
+extern void gl_list_node_set_value (gl_list_t list, gl_list_node_t node,
+                                    const void *elt);
+/* Likewise.  Return 0 upon success, -1 upon out-of-memory.  */
+extern int gl_list_node_nx_set_value (gl_list_t list, gl_list_node_t node,
+                                      const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Return the node immediately after the given node in the list, or NULL
+   if the given node is the last (rightmost) one in the list.  */
+extern gl_list_node_t gl_list_next_node (gl_list_t list, gl_list_node_t node);
+
+/* Return the node immediately before the given node in the list, or NULL
+   if the given node is the first (leftmost) one in the list.  */
+extern gl_list_node_t gl_list_previous_node (gl_list_t list, gl_list_node_t node);
+
+/* Return the element at a given position in the list.
+   POSITION must be >= 0 and < gl_list_size (list).  */
+extern const void * gl_list_get_at (gl_list_t list, size_t position);
+
+/* Replace the element at a given position in the list.
+   POSITION must be >= 0 and < gl_list_size (list).
+   Return its node.  */
+/* declared in gl_xlist.h */
+extern gl_list_node_t gl_list_set_at (gl_list_t list, size_t position,
+                                      const void *elt);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_node_t gl_list_nx_set_at (gl_list_t list, size_t position,
+                                         const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Search whether an element is already in the list.
+   Return its node if found, or NULL if not present in the list.  */
+extern gl_list_node_t gl_list_search (gl_list_t list, const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX.
+   Return its node if found, or NULL if not present in the list.  */
+extern gl_list_node_t gl_list_search_from (gl_list_t list, size_t start_index,
+                                           const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX and < END_INDEX.
+   Return its node if found, or NULL if not present in the list.  */
+extern gl_list_node_t gl_list_search_from_to (gl_list_t list,
+                                              size_t start_index,
+                                              size_t end_index,
+                                              const void *elt);
+
+/* Search whether an element is already in the list.
+   Return its position if found, or (size_t)(-1) if not present in the list.  */
+extern size_t gl_list_indexof (gl_list_t list, const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX.
+   Return its position if found, or (size_t)(-1) if not present in the list.  */
+extern size_t gl_list_indexof_from (gl_list_t list, size_t start_index,
+                                    const void *elt);
+
+/* Search whether an element is already in the list,
+   at a position >= START_INDEX and < END_INDEX.
+   Return its position if found, or (size_t)(-1) if not present in the list.  */
+extern size_t gl_list_indexof_from_to (gl_list_t list,
+                                       size_t start_index, size_t end_index,
+                                       const void *elt);
+
+/* Add an element as the first element of the list.
+   Return its node.  */
+/* declared in gl_xlist.h */
+extern gl_list_node_t gl_list_add_first (gl_list_t list, const void *elt);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_node_t gl_list_nx_add_first (gl_list_t list, const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Add an element as the last element of the list.
+   Return its node.  */
+/* declared in gl_xlist.h */
+extern gl_list_node_t gl_list_add_last (gl_list_t list, const void *elt);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_node_t gl_list_nx_add_last (gl_list_t list, const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Add an element before a given element node of the list.
+   Return its node.  */
+/* declared in gl_xlist.h */
+extern gl_list_node_t gl_list_add_before (gl_list_t list, gl_list_node_t node,
+                                          const void *elt);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_node_t gl_list_nx_add_before (gl_list_t list,
+                                             gl_list_node_t node,
+                                             const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Add an element after a given element node of the list.
+   Return its node.  */
+/* declared in gl_xlist.h */
+extern gl_list_node_t gl_list_add_after (gl_list_t list, gl_list_node_t node,
+                                         const void *elt);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_node_t gl_list_nx_add_after (gl_list_t list, gl_list_node_t node,
+                                            const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Add an element at a given position in the list.
+   POSITION must be >= 0 and <= gl_list_size (list).  */
+/* declared in gl_xlist.h */
+extern gl_list_node_t gl_list_add_at (gl_list_t list, size_t position,
+                                      const void *elt);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_node_t gl_list_nx_add_at (gl_list_t list, size_t position,
+                                         const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Remove an element from the list.
+   Return true.  */
+extern bool gl_list_remove_node (gl_list_t list, gl_list_node_t node);
+
+/* Remove an element at a given position from the list.
+   POSITION must be >= 0 and < gl_list_size (list).
+   Return true.  */
+extern bool gl_list_remove_at (gl_list_t list, size_t position);
+
+/* Search and remove an element from the list.
+   Return true if it was found and removed.  */
+extern bool gl_list_remove (gl_list_t list, const void *elt);
+
+/* Free an entire list.
+   (But this call does not free the elements of the list.)  */
+extern void gl_list_free (gl_list_t list);
+
+#endif /* End of inline and gl_xlist.h-defined functions.  */
+
+/* --------------------- gl_list_iterator_t Data Type --------------------- */
+
+/* Functions for iterating through a list.  */
+
+/* Type of an iterator that traverses a list.
+   This is a fixed-size struct, so that creation of an iterator doesn't need
+   memory allocation on the heap.  */
+typedef struct
+{
+  /* For fast dispatch of gl_list_iterator_next.  */
+  const struct gl_list_implementation *vtable;
+  /* For detecting whether the last returned element was removed.  */
+  gl_list_t list;
+  size_t count;
+  /* Other, implementation-private fields.  */
+  void *p; void *q;
+  size_t i; size_t j;
+} gl_list_iterator_t;
+
+#if 0 /* These are defined inline below.  */
+
+/* Create an iterator traversing a list.
+   The list contents must not be modified while the iterator is in use,
+   except for replacing or removing the last returned element.  */
+extern gl_list_iterator_t gl_list_iterator (gl_list_t list);
+
+/* Create an iterator traversing the element with indices i,
+   start_index <= i < end_index, of a list.
+   The list contents must not be modified while the iterator is in use,
+   except for replacing or removing the last returned element.  */
+extern gl_list_iterator_t gl_list_iterator_from_to (gl_list_t list,
+                                                    size_t start_index,
+                                                    size_t end_index);
+
+/* If there is a next element, store the next element in *ELTP, store its
+   node in *NODEP if NODEP is non-NULL, advance the iterator and return true.
+   Otherwise, return false.  */
+extern bool gl_list_iterator_next (gl_list_iterator_t *iterator,
+                                   const void **eltp, gl_list_node_t *nodep);
+
+/* Free an iterator.  */
+extern void gl_list_iterator_free (gl_list_iterator_t *iterator);
+
+#endif /* End of inline functions.  */
+
+/* ---------------------- Sorted gl_list_t Data Type ---------------------- */
+
+/* The following functions are for lists without duplicates where the
+   order is given by a sort criterion.  */
+
+/* Type of function used to compare two elements.  Same as for qsort().
+   NULL denotes pointer comparison.  */
+typedef int (*gl_listelement_compar_fn) (const void *elt1, const void *elt2);
+
+#if 0 /* Unless otherwise specified, these are defined inline below.  */
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Return its node if found, or NULL if not present in the list.
+   If the list contains several copies of ELT, the node of the leftmost one is
+   returned.  */
+extern gl_list_node_t gl_sortedlist_search (gl_list_t list,
+                                            gl_listelement_compar_fn compar,
+                                            const void *elt);
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Only list elements with indices >= START_INDEX and < END_INDEX are
+   considered; the implementation uses these bounds to minimize the number
+   of COMPAR invocations.
+   Return its node if found, or NULL if not present in the list.
+   If the list contains several copies of ELT, the node of the leftmost one is
+   returned.  */
+extern gl_list_node_t gl_sortedlist_search_from_to (gl_list_t list,
+                                                    gl_listelement_compar_fn compar,
+                                                    size_t start_index,
+                                                    size_t end_index,
+                                                    const void *elt);
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Return its position if found, or (size_t)(-1) if not present in the list.
+   If the list contains several copies of ELT, the position of the leftmost one
+   is returned.  */
+extern size_t gl_sortedlist_indexof (gl_list_t list,
+                                     gl_listelement_compar_fn compar,
+                                     const void *elt);
+
+/* Search whether an element is already in the list.
+   The list is assumed to be sorted with COMPAR.
+   Only list elements with indices >= START_INDEX and < END_INDEX are
+   considered; the implementation uses these bounds to minimize the number
+   of COMPAR invocations.
+   Return its position if found, or (size_t)(-1) if not present in the list.
+   If the list contains several copies of ELT, the position of the leftmost one
+   is returned.  */
+extern size_t gl_sortedlist_indexof_from_to (gl_list_t list,
+                                             gl_listelement_compar_fn compar,
+                                             size_t start_index,
+                                             size_t end_index,
+                                             const void *elt);
+
+/* Add an element at the appropriate position in the list.
+   The list is assumed to be sorted with COMPAR.
+   Return its node.  */
+/* declared in gl_xlist.h */
+extern gl_list_node_t gl_sortedlist_add (gl_list_t list,
+                                         gl_listelement_compar_fn compar,
+                                         const void *elt);
+/* Likewise.  Return NULL upon out-of-memory.  */
+extern gl_list_node_t gl_sortedlist_nx_add (gl_list_t list,
+                                            gl_listelement_compar_fn compar,
+                                            const void *elt)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+  ;
+
+/* Search and remove an element from the list.
+   The list is assumed to be sorted with COMPAR.
+   Return true if it was found and removed.
+   If the list contains several copies of ELT, only the leftmost one is
+   removed.  */
+extern bool gl_sortedlist_remove (gl_list_t list,
+                                  gl_listelement_compar_fn compar,
+                                  const void *elt);
+
+#endif /* End of inline and gl_xlist.h-defined functions.  */
+
+/* ------------------------ Implementation Details ------------------------ */
+
+struct gl_list_implementation
+{
+  /* gl_list_t functions.  */
+  gl_list_t (*nx_create_empty) (gl_list_implementation_t implementation,
+                                gl_listelement_equals_fn equals_fn,
+                                gl_listelement_hashcode_fn hashcode_fn,
+                                gl_listelement_dispose_fn dispose_fn,
+                                bool allow_duplicates);
+  gl_list_t (*nx_create) (gl_list_implementation_t implementation,
+                          gl_listelement_equals_fn equals_fn,
+                          gl_listelement_hashcode_fn hashcode_fn,
+                          gl_listelement_dispose_fn dispose_fn,
+                          bool allow_duplicates,
+                          size_t count, const void **contents);
+  size_t (*size) (gl_list_t list);
+  const void * (*node_value) (gl_list_t list, gl_list_node_t node);
+  int (*node_nx_set_value) (gl_list_t list, gl_list_node_t node,
+                            const void *elt);
+  gl_list_node_t (*next_node) (gl_list_t list, gl_list_node_t node);
+  gl_list_node_t (*previous_node) (gl_list_t list, gl_list_node_t node);
+  const void * (*get_at) (gl_list_t list, size_t position);
+  gl_list_node_t (*nx_set_at) (gl_list_t list, size_t position,
+                               const void *elt);
+  gl_list_node_t (*search_from_to) (gl_list_t list, size_t start_index,
+                                    size_t end_index, const void *elt);
+  size_t (*indexof_from_to) (gl_list_t list, size_t start_index,
+                             size_t end_index, const void *elt);
+  gl_list_node_t (*nx_add_first) (gl_list_t list, const void *elt);
+  gl_list_node_t (*nx_add_last) (gl_list_t list, const void *elt);
+  gl_list_node_t (*nx_add_before) (gl_list_t list, gl_list_node_t node,
+                                   const void *elt);
+  gl_list_node_t (*nx_add_after) (gl_list_t list, gl_list_node_t node,
+                                  const void *elt);
+  gl_list_node_t (*nx_add_at) (gl_list_t list, size_t position,
+                               const void *elt);
+  bool (*remove_node) (gl_list_t list, gl_list_node_t node);
+  bool (*remove_at) (gl_list_t list, size_t position);
+  bool (*remove_elt) (gl_list_t list, const void *elt);
+  void (*list_free) (gl_list_t list);
+  /* gl_list_iterator_t functions.  */
+  gl_list_iterator_t (*iterator) (gl_list_t list);
+  gl_list_iterator_t (*iterator_from_to) (gl_list_t list,
+                                          size_t start_index,
+                                          size_t end_index);
+  bool (*iterator_next) (gl_list_iterator_t *iterator,
+                         const void **eltp, gl_list_node_t *nodep);
+  void (*iterator_free) (gl_list_iterator_t *iterator);
+  /* Sorted gl_list_t functions.  */
+  gl_list_node_t (*sortedlist_search) (gl_list_t list,
+                                       gl_listelement_compar_fn compar,
+                                       const void *elt);
+  gl_list_node_t (*sortedlist_search_from_to) (gl_list_t list,
+                                               gl_listelement_compar_fn compar,
+                                               size_t start_index,
+                                               size_t end_index,
+                                               const void *elt);
+  size_t (*sortedlist_indexof) (gl_list_t list,
+                                gl_listelement_compar_fn compar,
+                                const void *elt);
+  size_t (*sortedlist_indexof_from_to) (gl_list_t list,
+                                        gl_listelement_compar_fn compar,
+                                        size_t start_index, size_t end_index,
+                                        const void *elt);
+  gl_list_node_t (*sortedlist_nx_add) (gl_list_t list,
+                                       gl_listelement_compar_fn compar,
+                                    const void *elt);
+  bool (*sortedlist_remove) (gl_list_t list,
+                             gl_listelement_compar_fn compar,
+                             const void *elt);
+};
+
+struct gl_list_impl_base
+{
+  const struct gl_list_implementation *vtable;
+  gl_listelement_equals_fn equals_fn;
+  gl_listelement_hashcode_fn hashcode_fn;
+  gl_listelement_dispose_fn dispose_fn;
+  bool allow_duplicates;
+};
+
+/* Define all functions of this file as accesses to the
+   struct gl_list_implementation.  */
+
+GL_LIST_INLINE gl_list_t
+gl_list_nx_create_empty (gl_list_implementation_t implementation,
+                         gl_listelement_equals_fn equals_fn,
+                         gl_listelement_hashcode_fn hashcode_fn,
+                         gl_listelement_dispose_fn dispose_fn,
+                         bool allow_duplicates)
+{
+  return implementation->nx_create_empty (implementation, equals_fn,
+                                          hashcode_fn, dispose_fn,
+                                          allow_duplicates);
+}
+
+GL_LIST_INLINE gl_list_t
+gl_list_nx_create (gl_list_implementation_t implementation,
+                   gl_listelement_equals_fn equals_fn,
+                   gl_listelement_hashcode_fn hashcode_fn,
+                   gl_listelement_dispose_fn dispose_fn,
+                   bool allow_duplicates,
+                   size_t count, const void **contents)
+{
+  return implementation->nx_create (implementation, equals_fn, hashcode_fn,
+                                    dispose_fn, allow_duplicates, count,
+                                    contents);
+}
+
+GL_LIST_INLINE size_t
+gl_list_size (gl_list_t list)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->size (list);
+}
+
+GL_LIST_INLINE const void *
+gl_list_node_value (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->node_value (list, node);
+}
+
+GL_LIST_INLINE int
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_list_node_nx_set_value (gl_list_t list, gl_list_node_t node,
+                           const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->node_nx_set_value (list, node, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+gl_list_next_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->next_node (list, node);
+}
+
+GL_LIST_INLINE gl_list_node_t
+gl_list_previous_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->previous_node (list, node);
+}
+
+GL_LIST_INLINE const void *
+gl_list_get_at (gl_list_t list, size_t position)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->get_at (list, position);
+}
+
+GL_LIST_INLINE gl_list_node_t
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_list_nx_set_at (gl_list_t list, size_t position, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->nx_set_at (list, position, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+gl_list_search (gl_list_t list, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->search_from_to (list, 0, size, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+gl_list_search_from (gl_list_t list, size_t start_index, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->search_from_to (list, start_index, size, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+gl_list_search_from_to (gl_list_t list, size_t start_index, size_t end_index,
+                        const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->search_from_to (list, start_index, end_index, elt);
+}
+
+GL_LIST_INLINE size_t
+gl_list_indexof (gl_list_t list, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->indexof_from_to (list, 0, size, elt);
+}
+
+GL_LIST_INLINE size_t
+gl_list_indexof_from (gl_list_t list, size_t start_index, const void *elt)
+{
+  size_t size = ((const struct gl_list_impl_base *) list)->vtable->size (list);
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->indexof_from_to (list, start_index, size, elt);
+}
+
+GL_LIST_INLINE size_t
+gl_list_indexof_from_to (gl_list_t list, size_t start_index, size_t end_index,
+                         const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->indexof_from_to (list, start_index, end_index, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_list_nx_add_first (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->nx_add_first (list, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_list_nx_add_last (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->nx_add_last (list, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_list_nx_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->nx_add_before (list, node, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_list_nx_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->nx_add_after (list, node, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_list_nx_add_at (gl_list_t list, size_t position, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->nx_add_at (list, position, elt);
+}
+
+GL_LIST_INLINE bool
+gl_list_remove_node (gl_list_t list, gl_list_node_t node)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->remove_node (list, node);
+}
+
+GL_LIST_INLINE bool
+gl_list_remove_at (gl_list_t list, size_t position)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->remove_at (list, position);
+}
+
+GL_LIST_INLINE bool
+gl_list_remove (gl_list_t list, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->remove_elt (list, elt);
+}
+
+GL_LIST_INLINE void
+gl_list_free (gl_list_t list)
+{
+  ((const struct gl_list_impl_base *) list)->vtable->list_free (list);
+}
+
+GL_LIST_INLINE gl_list_iterator_t
+gl_list_iterator (gl_list_t list)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->iterator (list);
+}
+
+GL_LIST_INLINE gl_list_iterator_t
+gl_list_iterator_from_to (gl_list_t list, size_t start_index, size_t end_index)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->iterator_from_to (list, start_index, end_index);
+}
+
+GL_LIST_INLINE bool
+gl_list_iterator_next (gl_list_iterator_t *iterator,
+                       const void **eltp, gl_list_node_t *nodep)
+{
+  return iterator->vtable->iterator_next (iterator, eltp, nodep);
+}
+
+GL_LIST_INLINE void
+gl_list_iterator_free (gl_list_iterator_t *iterator)
+{
+  iterator->vtable->iterator_free (iterator);
+}
+
+GL_LIST_INLINE gl_list_node_t
+gl_sortedlist_search (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->sortedlist_search (list, compar, elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+gl_sortedlist_search_from_to (gl_list_t list, gl_listelement_compar_fn compar, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->sortedlist_search_from_to (list, compar, start_index, end_index,
+                                      elt);
+}
+
+GL_LIST_INLINE size_t
+gl_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->sortedlist_indexof (list, compar, elt);
+}
+
+GL_LIST_INLINE size_t
+gl_sortedlist_indexof_from_to (gl_list_t list, gl_listelement_compar_fn compar, size_t start_index, size_t end_index, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->sortedlist_indexof_from_to (list, compar, start_index, end_index,
+                                       elt);
+}
+
+GL_LIST_INLINE gl_list_node_t
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+  __attribute__ ((__warn_unused_result__))
+#endif
+gl_sortedlist_nx_add (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->sortedlist_nx_add (list, compar, elt);
+}
+
+GL_LIST_INLINE bool
+gl_sortedlist_remove (gl_list_t list, gl_listelement_compar_fn compar, const void *elt)
+{
+  return ((const struct gl_list_impl_base *) list)->vtable
+         ->sortedlist_remove (list, compar, elt);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+_GL_INLINE_HEADER_END
+
+#endif /* _GL_LIST_H */
diff --git a/mcastseed/lib/gl_oset.c b/mcastseed/lib/gl_oset.c
deleted file mode 100644
index 21f731a..0000000
--- a/mcastseed/lib/gl_oset.c
+++ /dev/null
@@ -1,3 +0,0 @@
-#include <config.h>
-#define GL_OSET_INLINE _GL_EXTERN_INLINE
-#include "gl_oset.h"
diff --git a/mcastseed/lib/gl_oset.h b/mcastseed/lib/gl_oset.h
deleted file mode 100644
index ffca315..0000000
--- a/mcastseed/lib/gl_oset.h
+++ /dev/null
@@ -1,293 +0,0 @@
-/* Abstract ordered set data type.
-   Copyright (C) 2006-2007, 2009-2016 Free Software Foundation, Inc.
-   Written by Bruno Haible <bruno@clisp.org>, 2006.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
-
-   This program 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 General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-#ifndef _GL_OSET_H
-#define _GL_OSET_H
-
-#include <stdbool.h>
-#include <stddef.h>
-
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
-_GL_INLINE_HEADER_BEGIN
-#ifndef GL_OSET_INLINE
-# define GL_OSET_INLINE _GL_INLINE
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-
-/* gl_oset is an abstract ordered set data type.  It can contain any number
-   of objects ('void *' or 'const void *' pointers) in the order of a given
-   comparator function.  Duplicates (in the sense of the comparator) are
-   forbidden.
-
-   There are several implementations of this ordered set datatype, optimized
-   for different operations or for memory.  You can start using the simplest
-   ordered set implementation, GL_ARRAY_OSET, and switch to a different
-   implementation later, when you realize which operations are performed
-   the most frequently.  The API of the different implementations is exactly
-   the same; when switching to a different implementation, you only have to
-   change the gl_oset_create call.
-
-   The implementations are:
-     GL_ARRAY_OSET        a growable array
-     GL_AVLTREE_OSET      a binary tree (AVL tree)
-     GL_RBTREE_OSET       a binary tree (red-black tree)
-
-   The memory consumption is asymptotically the same: O(1) for every object
-   in the set.  When looking more closely at the average memory consumed
-   for an object, GL_ARRAY_OSET is the most compact representation, and
-   GL_AVLTREE_OSET, GL_RBTREE_OSET need more memory.
-
-   The guaranteed average performance of the operations is, for a set of
-   n elements:
-
-   Operation                  ARRAY     TREE
-
-   gl_oset_size                O(1)     O(1)
-   gl_oset_add                 O(n)   O(log n)
-   gl_oset_remove              O(n)   O(log n)
-   gl_oset_search            O(log n) O(log n)
-   gl_oset_search_atleast    O(log n) O(log n)
-   gl_oset_iterator            O(1)   O(log n)
-   gl_oset_iterator_next       O(1)   O(log n)
- */
-
-/* -------------------------- gl_oset_t Data Type -------------------------- */
-
-/* Type of function used to compare two elements.  Same as for qsort().
-   NULL denotes pointer comparison.  */
-typedef int (*gl_setelement_compar_fn) (const void *elt1, const void *elt2);
-
-/* Type of function used to dispose an element once it's removed from a set.
-   NULL denotes a no-op.  */
-typedef void (*gl_setelement_dispose_fn) (const void *elt);
-
-/* Type of function used to compare an element with a threshold.
-   Return true if the element is greater or equal than the threshold.  */
-typedef bool (*gl_setelement_threshold_fn) (const void *elt, const void *threshold);
-
-struct gl_oset_impl;
-/* Type representing an entire ordered set.  */
-typedef struct gl_oset_impl * gl_oset_t;
-
-struct gl_oset_implementation;
-/* Type representing a ordered set datatype implementation.  */
-typedef const struct gl_oset_implementation * gl_oset_implementation_t;
-
-#if 0 /* Unless otherwise specified, these are defined inline below.  */
-
-/* Create an empty set.
-   IMPLEMENTATION is one of GL_ARRAY_OSET, GL_AVLTREE_OSET, GL_RBTREE_OSET.
-   COMPAR_FN is an element comparison function or NULL.
-   DISPOSE_FN is an element disposal function or NULL.  */
-/* declared in gl_xoset.h */
-extern gl_oset_t gl_oset_create_empty (gl_oset_implementation_t implementation,
-                                       gl_setelement_compar_fn compar_fn,
-                                       gl_setelement_dispose_fn dispose_fn);
-/* Likewise.  Return NULL upon out-of-memory.  */
-extern gl_oset_t gl_oset_nx_create_empty (gl_oset_implementation_t implementation,
-                                          gl_setelement_compar_fn compar_fn,
-                                          gl_setelement_dispose_fn dispose_fn);
-
-/* Return the current number of elements in an ordered set.  */
-extern size_t gl_oset_size (gl_oset_t set);
-
-/* Search whether an element is already in the ordered set.
-   Return true if found, or false if not present in the set.  */
-extern bool gl_oset_search (gl_oset_t set, const void *elt);
-
-/* Search the least element in the ordered set that compares greater or equal
-   to the given THRESHOLD.  The representation of the THRESHOLD is defined
-   by the THRESHOLD_FN.
-   Return true and store the found element in *ELTP if found, otherwise return
-   false.  */
-extern bool gl_oset_search_atleast (gl_oset_t set,
-                                    gl_setelement_threshold_fn threshold_fn,
-                                    const void *threshold,
-                                    const void **eltp);
-
-/* Add an element to an ordered set.
-   Return true if it was not already in the set and added, false otherwise.  */
-/* declared in gl_xoset.h */
-extern bool gl_oset_add (gl_oset_t set, const void *elt);
-/* Likewise.  Return -1 upon out-of-memory.  */
-extern int gl_oset_nx_add (gl_oset_t set, const void *elt)
-#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
-  __attribute__ ((__warn_unused_result__))
-#endif
-  ;
-
-/* Remove an element from an ordered set.
-   Return true if it was found and removed.  */
-extern bool gl_oset_remove (gl_oset_t set, const void *elt);
-
-/* Free an entire ordered set.
-   (But this call does not free the elements of the set.)  */
-extern void gl_oset_free (gl_oset_t set);
-
-#endif /* End of inline and gl_xlist.h-defined functions.  */
-
-/* --------------------- gl_oset_iterator_t Data Type --------------------- */
-
-/* Functions for iterating through an ordered set.  */
-
-/* Type of an iterator that traverses an ordered set.
-   This is a fixed-size struct, so that creation of an iterator doesn't need
-   memory allocation on the heap.  */
-typedef struct
-{
-  /* For fast dispatch of gl_oset_iterator_next.  */
-  const struct gl_oset_implementation *vtable;
-  /* For detecting whether the last returned element was removed.  */
-  gl_oset_t set;
-  size_t count;
-  /* Other, implementation-private fields.  */
-  void *p; void *q;
-  size_t i; size_t j;
-} gl_oset_iterator_t;
-
-#if 0 /* These are defined inline below.  */
-
-/* Create an iterator traversing an ordered set.
-   The set's contents must not be modified while the iterator is in use,
-   except for removing the last returned element.  */
-extern gl_oset_iterator_t gl_oset_iterator (gl_oset_t set);
-
-/* If there is a next element, store the next element in *ELTP, advance the
-   iterator and return true.  Otherwise, return false.  */
-extern bool gl_oset_iterator_next (gl_oset_iterator_t *iterator,
-                                   const void **eltp);
-
-/* Free an iterator.  */
-extern void gl_oset_iterator_free (gl_oset_iterator_t *iterator);
-
-#endif /* End of inline functions.  */
-
-/* ------------------------ Implementation Details ------------------------ */
-
-struct gl_oset_implementation
-{
-  /* gl_oset_t functions.  */
-  gl_oset_t (*nx_create_empty) (gl_oset_implementation_t implementation,
-                                gl_setelement_compar_fn compar_fn,
-                                gl_setelement_dispose_fn dispose_fn);
-  size_t (*size) (gl_oset_t set);
-  bool (*search) (gl_oset_t set, const void *elt);
-  bool (*search_atleast) (gl_oset_t set,
-                          gl_setelement_threshold_fn threshold_fn,
-                          const void *threshold, const void **eltp);
-  int (*nx_add) (gl_oset_t set, const void *elt);
-  bool (*remove_elt) (gl_oset_t set, const void *elt);
-  void (*oset_free) (gl_oset_t set);
-  /* gl_oset_iterator_t functions.  */
-  gl_oset_iterator_t (*iterator) (gl_oset_t set);
-  bool (*iterator_next) (gl_oset_iterator_t *iterator, const void **eltp);
-  void (*iterator_free) (gl_oset_iterator_t *iterator);
-};
-
-struct gl_oset_impl_base
-{
-  const struct gl_oset_implementation *vtable;
-  gl_setelement_compar_fn compar_fn;
-  gl_setelement_dispose_fn dispose_fn;
-};
-
-/* Define all functions of this file as accesses to the
-   struct gl_oset_implementation.  */
-
-GL_OSET_INLINE gl_oset_t
-gl_oset_nx_create_empty (gl_oset_implementation_t implementation,
-                         gl_setelement_compar_fn compar_fn,
-                         gl_setelement_dispose_fn dispose_fn)
-{
-  return implementation->nx_create_empty (implementation, compar_fn,
-                                          dispose_fn);
-}
-
-GL_OSET_INLINE size_t
-gl_oset_size (gl_oset_t set)
-{
-  return ((const struct gl_oset_impl_base *) set)->vtable->size (set);
-}
-
-GL_OSET_INLINE bool
-gl_oset_search (gl_oset_t set, const void *elt)
-{
-  return ((const struct gl_oset_impl_base *) set)->vtable->search (set, elt);
-}
-
-GL_OSET_INLINE bool
-gl_oset_search_atleast (gl_oset_t set,
-                        gl_setelement_threshold_fn threshold_fn,
-                        const void *threshold, const void **eltp)
-{
-  return ((const struct gl_oset_impl_base *) set)->vtable
-         ->search_atleast (set, threshold_fn, threshold, eltp);
-}
-
-GL_OSET_INLINE int
-#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
-  __attribute__ ((__warn_unused_result__))
-#endif
-gl_oset_nx_add (gl_oset_t set, const void *elt)
-{
-  return ((const struct gl_oset_impl_base *) set)->vtable->nx_add (set, elt);
-}
-
-GL_OSET_INLINE bool
-gl_oset_remove (gl_oset_t set, const void *elt)
-{
-  return ((const struct gl_oset_impl_base *) set)->vtable
-         ->remove_elt (set, elt);
-}
-
-GL_OSET_INLINE void
-gl_oset_free (gl_oset_t set)
-{
-  ((const struct gl_oset_impl_base *) set)->vtable->oset_free (set);
-}
-
-GL_OSET_INLINE gl_oset_iterator_t
-gl_oset_iterator (gl_oset_t set)
-{
-  return ((const struct gl_oset_impl_base *) set)->vtable->iterator (set);
-}
-
-GL_OSET_INLINE bool
-gl_oset_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
-{
-  return iterator->vtable->iterator_next (iterator, eltp);
-}
-
-GL_OSET_INLINE void
-gl_oset_iterator_free (gl_oset_iterator_t *iterator)
-{
-  iterator->vtable->iterator_free (iterator);
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-_GL_INLINE_HEADER_END
-
-#endif /* _GL_OSET_H */
diff --git a/mcastseed/lib/gl_rbtree_list.c b/mcastseed/lib/gl_rbtree_list.c
new file mode 100644
index 0000000..5d621f1
--- /dev/null
+++ b/mcastseed/lib/gl_rbtree_list.c
@@ -0,0 +1,102 @@
+/* Sequential list data type implemented by a binary tree.
+   Copyright (C) 2006, 2008-2016 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "gl_rbtree_list.h"
+
+#include <stdlib.h>
+
+/* -------------------------- gl_list_t Data Type -------------------------- */
+
+/* Generic red-black tree code.  */
+#include "gl_anyrbtree_list1.h"
+
+/* Generic binary tree code.  */
+#include "gl_anytree_list1.h"
+
+/* Generic red-black tree code.  */
+#include "gl_anyrbtree_list2.h"
+
+/* Generic binary tree code.  */
+#include "gl_anytree_list2.h"
+
+/* For debugging.  */
+static unsigned int
+check_invariants (gl_list_node_t node, gl_list_node_t parent)
+{
+  unsigned int left_blackheight =
+    (node->left != NULL ? check_invariants (node->left, node) : 0);
+  unsigned int right_blackheight =
+    (node->right != NULL ? check_invariants (node->right, node) : 0);
+
+  if (!(node->parent == parent))
+    abort ();
+  if (!(node->branch_size
+        == (node->left != NULL ? node->left->branch_size : 0)
+           + 1 + (node->right != NULL ? node->right->branch_size : 0)))
+    abort ();
+  if (!(node->color == BLACK || node->color == RED))
+    abort ();
+  if (parent == NULL && !(node->color == BLACK))
+    abort ();
+  if (!(left_blackheight == right_blackheight))
+    abort ();
+
+  return left_blackheight + (node->color == BLACK ? 1 : 0);
+}
+void
+gl_rbtree_list_check_invariants (gl_list_t list)
+{
+  if (list->root != NULL)
+    check_invariants (list->root, NULL);
+}
+
+const struct gl_list_implementation gl_rbtree_list_implementation =
+  {
+    gl_tree_nx_create_empty,
+    gl_tree_nx_create,
+    gl_tree_size,
+    gl_tree_node_value,
+    gl_tree_node_nx_set_value,
+    gl_tree_next_node,
+    gl_tree_previous_node,
+    gl_tree_get_at,
+    gl_tree_nx_set_at,
+    gl_tree_search_from_to,
+    gl_tree_indexof_from_to,
+    gl_tree_nx_add_first,
+    gl_tree_nx_add_last,
+    gl_tree_nx_add_before,
+    gl_tree_nx_add_after,
+    gl_tree_nx_add_at,
+    gl_tree_remove_node,
+    gl_tree_remove_at,
+    gl_tree_remove,
+    gl_tree_list_free,
+    gl_tree_iterator,
+    gl_tree_iterator_from_to,
+    gl_tree_iterator_next,
+    gl_tree_iterator_free,
+    gl_tree_sortedlist_search,
+    gl_tree_sortedlist_search_from_to,
+    gl_tree_sortedlist_indexof,
+    gl_tree_sortedlist_indexof_from_to,
+    gl_tree_sortedlist_nx_add,
+    gl_tree_sortedlist_remove
+  };
diff --git a/mcastseed/lib/gl_rbtree_oset.h b/mcastseed/lib/gl_rbtree_list.h
index 850e8b4..8cb9d11 100644
--- a/mcastseed/lib/gl_rbtree_oset.h
+++ b/mcastseed/lib/gl_rbtree_list.h
@@ -1,4 +1,4 @@
-/* Ordered set data type implemented by a binary tree.
+/* Sequential list data type implemented by a binary tree.
    Copyright (C) 2006, 2009-2016 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2006.
 
@@ -15,20 +15,20 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#ifndef _GL_RBTREE_OSET_H
-#define _GL_RBTREE_OSET_H
+#ifndef _GL_RBTREE_LIST_H
+#define _GL_RBTREE_LIST_H
 
-#include "gl_oset.h"
+#include "gl_list.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-extern const struct gl_oset_implementation gl_rbtree_oset_implementation;
-#define GL_RBTREE_OSET &gl_rbtree_oset_implementation
+extern const struct gl_list_implementation gl_rbtree_list_implementation;
+#define GL_RBTREE_LIST &gl_rbtree_list_implementation
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* _GL_RBTREE_OSET_H */
+#endif /* _GL_RBTREE_LIST_H */
diff --git a/mcastseed/m4/gnulib-cache.m4 b/mcastseed/m4/gnulib-cache.m4
index ec5cc21..d75ad4f 100644
--- a/mcastseed/m4/gnulib-cache.m4
+++ b/mcastseed/m4/gnulib-cache.m4
@@ -27,12 +27,12 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl rbtree-oset
+#   gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl rbtree-list
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([])
 gl_MODULES([
-  rbtree-oset
+  rbtree-list
 ])
 gl_AVOID([])
 gl_SOURCE_BASE([lib])
diff --git a/mcastseed/m4/gnulib-comp.m4 b/mcastseed/m4/gnulib-comp.m4
index 136b568..b809eea 100644
--- a/mcastseed/m4/gnulib-comp.m4
+++ b/mcastseed/m4/gnulib-comp.m4
@@ -42,8 +42,8 @@ AC_DEFUN([gl_EARLY],
   AC_REQUIRE([gl_PROG_AR_RANLIB])
 
   # Code from module extern-inline:
-  # Code from module oset:
-  # Code from module rbtree-oset:
+  # Code from module list:
+  # Code from module rbtree-list:
   # Code from module stdbool:
 ])
 
@@ -205,15 +205,17 @@ AC_DEFUN([gltests_LIBSOURCES], [
 # This macro records the list of files which have been installed by
 # gnulib-tool and may be removed by future gnulib-tool invocations.
 AC_DEFUN([gl_FILE_LIST], [
-  lib/gl_anytree_oset.h
-  lib/gl_oset.c
-  lib/gl_oset.h
-  lib/gl_rbtree_oset.c
-  lib/gl_rbtree_oset.h
+  lib/gl_anyrbtree_list1.h
+  lib/gl_anyrbtree_list2.h
+  lib/gl_anytree_list1.h
+  lib/gl_anytree_list2.h
+  lib/gl_list.c
+  lib/gl_list.h
+  lib/gl_rbtree_list.c
+  lib/gl_rbtree_list.h
   lib/stdbool.in.h
   m4/00gnulib.m4
   m4/extern-inline.m4
   m4/gnulib-common.m4
-  m4/onceonly.m4
   m4/stdbool.m4
 ])
diff --git a/mcastseed/m4/onceonly.m4 b/mcastseed/m4/onceonly.m4
deleted file mode 100644
index c0c9e2c..0000000
--- a/mcastseed/m4/onceonly.m4
+++ /dev/null
@@ -1,104 +0,0 @@
-# onceonly.m4 serial 9
-dnl Copyright (C) 2002-2003, 2005-2006, 2008-2016 Free Software Foundation,
-dnl Inc.
-dnl
-dnl This file is free software; you can redistribute it and/or modify
-dnl it under the terms of the GNU General Public License as published by
-dnl the Free Software Foundation; either version 3 of the License, or
-dnl (at your option) any later version.
-dnl
-dnl This file is distributed in the hope that it will be useful,
-dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
-dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-dnl GNU General Public License for more details.
-dnl
-dnl You should have received a copy of the GNU General Public License
-dnl along with this file.  If not, see <http://www.gnu.org/licenses/>.
-dnl
-dnl As a special exception to the GNU General Public License,
-dnl this file may be distributed as part of a program
-dnl that contains a configuration script generated by Autoconf, under
-dnl the same distribution terms as the rest of that program.
-
-dnl This file defines some "once only" variants of standard autoconf macros.
-dnl   AC_CHECK_HEADERS_ONCE          like  AC_CHECK_HEADERS
-dnl   AC_CHECK_FUNCS_ONCE            like  AC_CHECK_FUNCS
-dnl   AC_CHECK_DECLS_ONCE            like  AC_CHECK_DECLS
-dnl   AC_REQUIRE([AC_FUNC_STRCOLL])  like  AC_FUNC_STRCOLL
-dnl The advantage is that the check for each of the headers/functions/decls
-dnl will be put only once into the 'configure' file. It keeps the size of
-dnl the 'configure' file down, and avoids redundant output when 'configure'
-dnl is run.
-dnl The drawback is that the checks cannot be conditionalized. If you write
-dnl   if some_condition; then gl_CHECK_HEADERS(stdlib.h); fi
-dnl inside an AC_DEFUNed function, the gl_CHECK_HEADERS macro call expands to
-dnl empty, and the check will be inserted before the body of the AC_DEFUNed
-dnl function.
-
-dnl The original code implemented AC_CHECK_HEADERS_ONCE and AC_CHECK_FUNCS_ONCE
-dnl in terms of AC_DEFUN and AC_REQUIRE. This implementation uses diversions to
-dnl named sections DEFAULTS and INIT_PREPARE in order to check all requested
-dnl headers at once, thus reducing the size of 'configure'. It is known to work
-dnl with autoconf 2.57..2.62 at least . The size reduction is ca. 9%.
-
-dnl Autoconf version 2.59 plus gnulib is required; this file is not needed
-dnl with Autoconf 2.60 or greater. But note that autoconf's implementation of
-dnl AC_CHECK_DECLS_ONCE expects a comma-separated list of symbols as first
-dnl argument!
-AC_PREREQ([2.59])
-
-# AC_CHECK_HEADERS_ONCE(HEADER1 HEADER2 ...) is a once-only variant of
-# AC_CHECK_HEADERS(HEADER1 HEADER2 ...).
-AC_DEFUN([AC_CHECK_HEADERS_ONCE], [
-  :
-  m4_foreach_w([gl_HEADER_NAME], [$1], [
-    AC_DEFUN([gl_CHECK_HEADER_]m4_quote(m4_translit(gl_HEADER_NAME,
-                                                    [./-], [___])), [
-      m4_divert_text([INIT_PREPARE],
-        [gl_header_list="$gl_header_list gl_HEADER_NAME"])
-      gl_HEADERS_EXPANSION
-      AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_HEADER_NAME])),
-        [Define to 1 if you have the <]m4_defn([gl_HEADER_NAME])[> header file.])
-    ])
-    AC_REQUIRE([gl_CHECK_HEADER_]m4_quote(m4_translit(gl_HEADER_NAME,
-                                                      [./-], [___])))
-  ])
-])
-m4_define([gl_HEADERS_EXPANSION], [
-  m4_divert_text([DEFAULTS], [gl_header_list=])
-  AC_CHECK_HEADERS([$gl_header_list])
-  m4_define([gl_HEADERS_EXPANSION], [])
-])
-
-# AC_CHECK_FUNCS_ONCE(FUNC1 FUNC2 ...) is a once-only variant of
-# AC_CHECK_FUNCS(FUNC1 FUNC2 ...).
-AC_DEFUN([AC_CHECK_FUNCS_ONCE], [
-  :
-  m4_foreach_w([gl_FUNC_NAME], [$1], [
-    AC_DEFUN([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME]), [
-      m4_divert_text([INIT_PREPARE],
-        [gl_func_list="$gl_func_list gl_FUNC_NAME"])
-      gl_FUNCS_EXPANSION
-      AH_TEMPLATE(AS_TR_CPP([HAVE_]m4_defn([gl_FUNC_NAME])),
-        [Define to 1 if you have the ']m4_defn([gl_FUNC_NAME])[' function.])
-    ])
-    AC_REQUIRE([gl_CHECK_FUNC_]m4_defn([gl_FUNC_NAME]))
-  ])
-])
-m4_define([gl_FUNCS_EXPANSION], [
-  m4_divert_text([DEFAULTS], [gl_func_list=])
-  AC_CHECK_FUNCS([$gl_func_list])
-  m4_define([gl_FUNCS_EXPANSION], [])
-])
-
-# AC_CHECK_DECLS_ONCE(DECL1 DECL2 ...) is a once-only variant of
-# AC_CHECK_DECLS(DECL1, DECL2, ...).
-AC_DEFUN([AC_CHECK_DECLS_ONCE], [
-  :
-  m4_foreach_w([gl_DECL_NAME], [$1], [
-    AC_DEFUN([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME]), [
-      AC_CHECK_DECLS(m4_defn([gl_DECL_NAME]))
-    ])
-    AC_REQUIRE([gl_CHECK_DECL_]m4_defn([gl_DECL_NAME]))
-  ])
-])