Ticket #2060: 0001-PR2060-RBTree-updating-min-and-max-on-extract-path.patch

File 0001-PR2060-RBTree-updating-min-and-max-on-extract-path.patch, 2.1 KB (added by Gedare Bloom, on 05/02/12 at 18:17:31)

Bugfix

  • cpukit/score/src/rbtreeextract.c 

    From ddbe30f3a3e25ce260c1560af51664e0dc9a6289 Mon Sep 17 00:00:00 2001
From: Gedare Bloom <gedare@rtems.org>
Date: Wed, 2 May 2012 15:04:58 -0400
Subject: [PATCH] PR2060: RBTree: updating min and max on extract path

During node extraction from a red-black tree the min and max values are updated
incorrectly. We need to use the successor/predecessor functions to find the
next/previous node when we remove the min/max from the tree.
---
 cpukit/score/src/rbtreeextract.c |   26 +++++++++-----------------
 1 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/cpukit/score/src/rbtreeextract.c b/cpukit/score/src/rbtreeextract.c
index 4071361..9a0a18b 100644
    a b void _RBTree_Extract_unprotected( 
    108108
    109109  /* check if min needs to be updated */
    110110  if (the_node == the_rbtree->first[RBT_LEFT]) {
    111     if (the_node->child[RBT_RIGHT])
    112       the_rbtree->first[RBT_LEFT] = the_node->child[RBT_RIGHT];
    113     else {
    114       the_rbtree->first[RBT_LEFT] = the_node->parent;
    115       if(_RBTree_Are_nodes_equal((RBTree_Node *)the_rbtree,
    116             the_rbtree->first[RBT_LEFT]))
    117         the_rbtree->first[RBT_LEFT] = NULL;
    118     }
     111    RBTree_Node *next;
     112    next = _RBTree_Successor_unprotected(the_rbtree, the_node);
     113    the_rbtree->first[RBT_LEFT] = next;
    119114  }
    120   /* check if max needs to be updated: note, min can equal max (1 element) */
     115
     116  /* Check if max needs to be updated. min=max for 1 element trees so
     117   * do not use else if here. */
    121118  if (the_node == the_rbtree->first[RBT_RIGHT]) {
    122     if (the_node->child[RBT_LEFT])
    123       the_rbtree->first[RBT_RIGHT] = the_node->child[RBT_LEFT];
    124     else {
    125       the_rbtree->first[RBT_RIGHT] = the_node->parent;
    126       if(_RBTree_Are_nodes_equal((RBTree_Node *)the_rbtree,
    127             the_rbtree->first[RBT_RIGHT]))
    128         the_rbtree->first[RBT_RIGHT] = NULL;
    129     }
     119    RBTree_Node *previous;
     120    previous = _RBTree_Predecessor_unprotected(the_rbtree, the_node);
     121    the_rbtree->first[RBT_RIGHT] = previous;
    130122  }
    131123
    132124  /* if the_node has at most one non-null child then it is safe to proceed