webkitgtk-2.4.9webkitgtk-2.4.9

1 files changed, 45 insertions, 27 deletions

diff --git a/Source/JavaScriptCore/runtime/WeakGCMap.h b/Source/JavaScriptCore/runtime/WeakGCMap.h
index 16d3d4400..d9c1fb63e 100644
--- a/Source/JavaScriptCore/runtime/WeakGCMap.h
+++ b/Source/JavaScriptCore/runtime/WeakGCMap.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009, 2015 Apple Inc. All rights reserved.
+ * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -37,7 +37,6 @@ namespace JSC {
 template<typename KeyArg, typename ValueArg, typename HashArg = typename DefaultHash<KeyArg>::Hash,
     typename KeyTraitsArg = HashTraits<KeyArg>>
 class WeakGCMap {
-    WTF_MAKE_FAST_ALLOCATED;
     typedef Weak<ValueArg> ValueType;
     typedef HashMap<KeyArg, ValueType, HashArg, KeyTraitsArg> HashMapType;
 
@@ -47,8 +46,10 @@ public:
     typedef typename HashMapType::iterator iterator;
     typedef typename HashMapType::const_iterator const_iterator;
 
-    explicit WeakGCMap(VM&);
-    ~WeakGCMap();
+    WeakGCMap()
+        : m_gcThreshold(minGCThreshold)
+    {
+    }
 
     ValueArg* get(const KeyType& key) const
     {
@@ -57,7 +58,19 @@ public:
 
     AddResult set(const KeyType& key, ValueType value)
     {
-        return m_map.set(key, WTF::move(value));
+        gcMapIfNeeded();
+        return m_map.set(key, std::move(value));
+    }
+
+    AddResult add(const KeyType& key, ValueType value)
+    {
+        gcMapIfNeeded();
+        AddResult addResult = m_map.add(key, nullptr);
+        if (!addResult.iterator->value) { // New value or found a zombie value.
+            addResult.isNewEntry = true;
+            addResult.iterator->value = std::move(value);
+        }
+        return addResult;
     }
 
     bool remove(const KeyType& key)
@@ -70,17 +83,6 @@ public:
         m_map.clear();
     }
 
-    bool isEmpty() const
-    {
-        const_iterator it = m_map.begin();
-        const_iterator end = m_map.end();
-        while (it != end) {
-            if (it->value)
-                return true;
-        }
-        return false;
-    }
-
     iterator find(const KeyType& key)
     {
         iterator it = m_map.find(key);
@@ -95,27 +97,43 @@ public:
         return const_cast<WeakGCMap*>(this)->find(key);
     }
 
-    template<typename Functor>
-    void forEach(Functor functor)
+    bool contains(const KeyType& key) const
     {
-        for (auto& pair : m_map) {
-            if (pair.value)
-                functor(pair.key, pair.value.get());
-        }
+        return find(key) != m_map.end();
     }
 
-    bool contains(const KeyType& key) const
+private:
+    static const int minGCThreshold = 3;
+
+    void gcMap()
     {
-        return find(key) != m_map.end();
+        Vector<KeyType, 4> zombies;
+
+        for (iterator it = m_map.begin(), end = m_map.end(); it != end; ++it) {
+            if (!it->value)
+                zombies.append(it->key);
+        }
+
+        for (size_t i = 0; i < zombies.size(); ++i)
+            m_map.remove(zombies[i]);
     }
 
-    void pruneStaleEntries();
+    void gcMapIfNeeded()
+    {
+        if (m_map.size() < m_gcThreshold)
+            return;
+
+        gcMap();
+        m_gcThreshold = std::max(minGCThreshold, m_map.size() * 2 - 1);
+    }
 
-private:
     HashMapType m_map;
-    VM& m_vm;
+    int m_gcThreshold;
 };
 
+template<typename KeyArg, typename RawMappedArg, typename HashArg, typename KeyTraitsArg>
+const int WeakGCMap<KeyArg, RawMappedArg, HashArg, KeyTraitsArg>::minGCThreshold;
+
 } // namespace JSC
 
 #endif // WeakGCMap_h