diff options
| author | suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp> | 2011-01-09 23:09:36 +0900 |
|---|---|---|
| committer | suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp> | 2011-01-09 23:09:36 +0900 |
| commit | 5e7ad208e35643e18deb505465604e2ed3b149cf (patch) | |
| tree | 53ccd8d1580ca9b3c2530557aa82df776ea1b90c /src | |
| parent | 38b272ffbbdaae276d636aec4ef84af407d16181 (diff) | |
[cache] Fix Savannah bug #31923, patch drafted by Harsha.
When a node comparator changes the cached nodes during the
search of a node matching with queried properties, the
pointers obtained before the functon should be updated to
prevent the dereference to freed or reallocated nodes.
To minimize the rescan of the linked list, the update is
executed when the comparator notifies the change of cached
nodes. This change depends previous change:
38b272ffbbdaae276d636aec4ef84af407d16181
* src/cache/ftccache.h (FTC_CACHE_LOOKUP_CMP): Rescan the
top node if the cached nodes are changed.
* src/cache/ftccache.c (FTC_Cache_Lookup): Ditto.
Diffstat (limited to 'src')
| -rw-r--r-- | src/cache/ftccache.c | 23 | ||||
| -rw-r--r-- | src/cache/ftccache.h | 24 |
2 files changed, 47 insertions, 0 deletions
diff --git a/src/cache/ftccache.c b/src/cache/ftccache.c index 9a525601..ad1c5c30 100644 --- a/src/cache/ftccache.c +++ b/src/cache/ftccache.c @@ -498,7 +498,11 @@ if ( cache == NULL || anode == NULL ) return FTC_Err_Invalid_Argument; + /* Go to the `top' node of the list sharing same masked hash */ bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); + + /* Lookup a node with exactly same hash and queried properties. */ + /* NOTE: _nodcomp() may change the linked list to reduce memory. */ for (;;) { node = *pnode; @@ -512,6 +516,25 @@ pnode = &node->link; } + if ( list_changed ) + { + /* Update bucket by modified linked list */ + bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); + + /* Update pnode by modified linked list */ + while ( *pnode != node ) + { + if ( *pnode == NULL ) + { + FT_ERROR(("oops!!! node missing")); + goto NewNode; + } + else + pnode = &((*pnode)->link); + } + } + + /* Reorder the list to move the found node to the `top' */ if ( node != *bucket ) { *pnode = node->link; diff --git a/src/cache/ftccache.h b/src/cache/ftccache.h index b6b40a01..d696621e 100644 --- a/src/cache/ftccache.h +++ b/src/cache/ftccache.h @@ -224,8 +224,12 @@ FT_BEGIN_HEADER \ error = FTC_Err_Ok; \ node = NULL; \ + \ + /* Go to the `top' node of the list sharing same masked hash */ \ _bucket = _pnode = FTC_NODE__TOP_FOR_HASH( _cache, _hash ); \ \ + /* Lookup a node with exactly same hash and queried properties. */ \ + /* NOTE: _nodcomp() may change the linked list to reduce memory. */ \ for (;;) \ { \ _node = *_pnode; \ @@ -239,6 +243,25 @@ FT_BEGIN_HEADER _pnode = &_node->link; \ } \ \ + if ( _list_changed ) \ + { \ + /* Update _bucket by possibly modified linked list */ \ + _bucket = _pnode = FTC_NODE__TOP_FOR_HASH( _cache, _hash ); \ + \ + /* Update _pnode by possibly modified linked list */ \ + while ( *_pnode != _node ) \ + { \ + if ( *_pnode == NULL ) \ + { \ + FT_ERROR(("oops!!! node missing")); \ + goto _NewNode; \ + } \ + else \ + _pnode = &((*_pnode)->link); \ + } \ + } \ + \ + /* Reorder the list to move the found node to the `top' */ \ if ( _node != *_bucket ) \ { \ *_pnode = _node->link; \ @@ -246,6 +269,7 @@ FT_BEGIN_HEADER *_bucket = _node; \ } \ \ + /* Update MRU list */ \ { \ FTC_Manager _manager = _cache->manager; \ void* _nl = &_manager->nodes_list; \ |