1 files changed, 25 insertions, 10 deletions

diff --git a/JavaScriptCore/wtf/HashTable.h b/JavaScriptCore/wtf/HashTable.h
index 4c7790a..3b283f8 100644
--- a/JavaScriptCore/wtf/HashTable.h
+++ b/JavaScriptCore/wtf/HashTable.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 David Levin <levin@chromium.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -24,6 +25,7 @@
 #include "FastMalloc.h"
 #include "HashTraits.h"
 #include <wtf/Assertions.h>
+#include <wtf/Threading.h>
 
 namespace WTF {
 
@@ -42,13 +44,19 @@ namespace WTF {
 
     struct HashTableStats {
         ~HashTableStats();
+        // All of the variables are accessed in ~HashTableStats when the static struct is destroyed.
+
+        // The following variables are all atomically incremented when modified.
         static int numAccesses;
-        static int numCollisions;
-        static int collisionGraph[4096];
-        static int maxCollisions;
         static int numRehashes;
         static int numRemoves;
         static int numReinserts;
+
+        // The following variables are only modified in the recordCollisionAtCount method within a mutex.
+        static int maxCollisions;
+        static int numCollisions;
+        static int collisionGraph[4096];
+
         static void recordCollisionAtCount(int count);
     };
 
@@ -201,6 +209,8 @@ namespace WTF {
 
 #if CHECK_HASHTABLE_ITERATORS
     public:
+        // Any modifications of the m_next or m_previous of an iterator that is in a linked list of a HashTable::m_iterator,
+        // should be guarded with m_table->m_mutex.
         mutable const HashTableType* m_table;
         mutable const_iterator* m_next;
         mutable const_iterator* m_previous;
@@ -397,7 +407,9 @@ namespace WTF {
 
 #if CHECK_HASHTABLE_ITERATORS
     public:
+        // All access to m_iterators should be guarded with m_mutex.
         mutable const_iterator* m_iterators;
+        mutable Mutex m_mutex;
 #endif
     };
 
@@ -466,7 +478,7 @@ namespace WTF {
             return 0;
 
 #if DUMP_HASHTABLE_STATS
-        ++HashTableStats::numAccesses;
+        atomicIncrement(&HashTableStats::numAccesses);
         int probeCount = 0;
 #endif
 
@@ -511,7 +523,7 @@ namespace WTF {
         int i = h & sizeMask;
 
 #if DUMP_HASHTABLE_STATS
-        ++HashTableStats::numAccesses;
+        atomicIncrement(&HashTableStats::numAccesses);
         int probeCount = 0;
 #endif
 
@@ -563,7 +575,7 @@ namespace WTF {
         int i = h & sizeMask;
 
 #if DUMP_HASHTABLE_STATS
-        ++HashTableStats::numAccesses;
+        atomicIncrement(&HashTableStats::numAccesses);
         int probeCount = 0;
 #endif
 
@@ -623,7 +635,7 @@ namespace WTF {
         int i = h & sizeMask;
 
 #if DUMP_HASHTABLE_STATS
-        ++HashTableStats::numAccesses;
+        atomicIncrement(&HashTableStats::numAccesses);
         int probeCount = 0;
 #endif
 
@@ -738,7 +750,7 @@ namespace WTF {
         ASSERT(!lookupForWriting(Extractor::extract(entry)).second);
         ASSERT(!isDeletedBucket(*(lookupForWriting(Extractor::extract(entry)).first)));
 #if DUMP_HASHTABLE_STATS
-        ++HashTableStats::numReinserts;
+        atomicIncrement(&HashTableStats::numReinserts);
 #endif
 
         Mover<ValueType, Traits::needsDestruction>::move(entry, *lookupForWriting(Extractor::extract(entry)).first);
@@ -801,7 +813,7 @@ namespace WTF {
     void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::remove(ValueType* pos)
     {
 #if DUMP_HASHTABLE_STATS
-        ++HashTableStats::numRemoves;
+        atomicIncrement(&HashTableStats::numRemoves);
 #endif
 
         deleteBucket(*pos);
@@ -887,7 +899,7 @@ namespace WTF {
 
 #if DUMP_HASHTABLE_STATS
         if (oldTableSize != 0)
-            ++HashTableStats::numRehashes;
+            atomicIncrement(&HashTableStats::numRehashes);
 #endif
 
         m_tableSize = newTableSize;
@@ -1016,6 +1028,7 @@ namespace WTF {
     template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
     void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::invalidateIterators()
     {
+        MutexLocker lock(m_mutex);
         const_iterator* next;
         for (const_iterator* p = m_iterators; p; p = next) {
             next = p->m_next;
@@ -1037,6 +1050,7 @@ namespace WTF {
         if (!table) {
             it->m_next = 0;
         } else {
+            MutexLocker lock(table->m_mutex);
             ASSERT(table->m_iterators != it);
             it->m_next = table->m_iterators;
             table->m_iterators = it;
@@ -1058,6 +1072,7 @@ namespace WTF {
             ASSERT(!it->m_next);
             ASSERT(!it->m_previous);
         } else {
+            MutexLocker lock(it->m_table->m_mutex);
             if (it->m_next) {
                 ASSERT(it->m_next->m_previous == it);
                 it->m_next->m_previous = it->m_previous;