Changeset 181214 in webkit for trunk/Source/JavaScriptCore/runtime/WeakGCMap.h

Timestamp:

Mar 7, 2015, 2:20:54 PM (10 years ago)

Author:

[email protected]

Message:

Unreviewed, rolling out r181010.
​https://bugs.webkit.org/show_bug.cgi?id=142442

Broke media/video-src-invalid-poster.html (Requested by kling
on #webkit).

Reverted changeset:

"Stale entries in WeakGCMaps are keeping tons of WeakBlocks
alive unnecessarily."
​https://bugs.webkit.org/show_bug.cgi?id=142115
​http://trac.webkit.org/changeset/181010

File:

• trunk/Source/JavaScriptCore/runtime/WeakGCMap.h (modified) (5 diffs)

trunk/Source/JavaScriptCore/runtime/WeakGCMap.h

@@ -1 +1 @@
 /*
- * 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
@@ -48 +48 @@
     typedef typename HashMapType::const_iterator const_iterator;
 
-    explicit WeakGCMap(VM&);
-    ~WeakGCMap();
+    WeakGCMap()
+        : m_gcThreshold(minGCThreshold)
+    {
+    }
 
     ValueArg* get(const KeyType& key) const
@@ -58 +60 @@
     AddResult set(const KeyType& key, ValueType value)
     {
+        gcMapIfNeeded();
         return m_map.set(key, WTF::move(value));
     }
@@ -63 +66 @@
     ALWAYS_INLINE AddResult add(const KeyType& key, ValueType value)
     {
+        gcMapIfNeeded();
         AddResult addResult = m_map.fastAdd(key, nullptr);
         if (!addResult.iterator->value) { // New value or found a zombie value.
@@ -100 +104 @@
     }
 
-    void pruneStaleEntries();
+private:
+    static const int minGCThreshold = 3;
 
-private:
+    NEVER_INLINE void gcMap()
+    {
+        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 gcMapIfNeeded()
+    {
+        if (m_map.size() < m_gcThreshold)
+            return;
+
+        gcMap();
+        m_gcThreshold = std::max(minGCThreshold, m_map.size() * 2 - 1);
+    }
+
     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