[oilpan]: optimize the way we allocate persistent handles in wrappers.

Source/platform/heap/ThreadState.h

Index: Source/platform/heap/ThreadState.h
diff --git a/Source/platform/heap/ThreadState.h b/Source/platform/heap/ThreadState.h
index 974007726c7e74740324394201e1e49fc7fc1af7..e89258c59b25ae547727db1777bb8cf05f5eaaf4 100644
--- a/Source/platform/heap/ThreadState.h
+++ b/Source/platform/heap/ThreadState.h
@@ -56,6 +56,7 @@ class HeapContainsCache;
 class HeapObjectHeader;
 class PageMemory;
 class PersistentNode;
+class WrapperPersistentRegion;
 class Visitor;
 class SafePointBarrier;
 class SafePointAwareMutexLocker;
@@ -528,6 +529,14 @@ public:
     BaseHeapPage* contains(void* pointer) { return contains(reinterpret_cast<Address>(pointer)); }
     BaseHeapPage* contains(const void* pointer) { return contains(const_cast<void*>(pointer)); }
 
+    WrapperPersistentRegion* wrapperRoots() const
+    {
+        ASSERT(m_liveWrapperPersistents);
+        return m_liveWrapperPersistents;
+    }
+    WrapperPersistentRegion* addWrapperPersistentRegion();
+    void removeWrapperPersistentRegion(WrapperPersistentRegion*);
+
     // List of persistent roots allocated on the given thread.
     PersistentNode* roots() const { return m_persistents.get(); }
 
@@ -652,6 +661,9 @@ private:
     static uint8_t s_mainThreadStateStorage[];
 
     ThreadIdentifier m_thread;
+    WrapperPersistentRegion* m_liveWrapperPersistents;
+    WrapperPersistentRegion* m_pooledWrapperPersistents;
+    size_t m_numPooledWrapperPersistentRegions;

[haraken, 2014/09/02 13:00:37]

m_numPooledWrapperPersistentRegions => m_numberOfPooledWrapperPersistentRegions
or m_pooledWrapperPersistentRegionsCount

Blink prefers a fully-qualified variable name.

[wibling-chromium, 2014/09/02 13:55:33]

Done.

     OwnPtr<PersistentNode> m_persistents;
     StackState m_stackState;
     intptr_t* m_startOfStack;