Changeset 94445 in webkit for trunk/Source/JavaScriptCore/heap/NewSpace.h

Timestamp:

Sep 2, 2011, 1:41:59 PM (14 years ago)

Author:

[email protected]

Message:

Use bump allocator for initial property storage
​https://bugs.webkit.org/show_bug.cgi?id=67494

Reviewed by Gavin Barraclough.

Switch to a bump allocator for the initial out of line
property storage. This gives us slightly faster allocation
for short lived objects that need out of line storage at
the cost of an additional memcpy when the object survives
a GC pass.

No performance impact.

• JavaScriptCore.exp:
• heap/Heap.cpp:

(JSC::Heap::collect):

• heap/Heap.h:

(JSC::Heap::allocatePropertyStorage):
(JSC::Heap::inPropertyStorageNursary):

• heap/NewSpace.cpp:

(JSC::NewSpace::NewSpace):

• heap/NewSpace.h:

(JSC::NewSpace::resetPropertyStorageNursary):
(JSC::NewSpace::allocatePropertyStorage):
(JSC::NewSpace::inPropertyStorageNursary):

• jit/JITStubs.cpp:

(JSC::DEFINE_STUB_FUNCTION):

• runtime/JSObject.cpp:

(JSC::JSObject::allocatePropertyStorage):

• runtime/JSObject.h:

(JSC::JSObject::~JSObject):
(JSC::JSObject::putDirectInternal):
(JSC::JSObject::putDirectWithoutTransition):
(JSC::JSObject::putDirectFunctionWithoutTransition):
(JSC::JSObject::transitionTo):
(JSC::JSObject::visitChildrenDirect):

File:

• trunk/Source/JavaScriptCore/heap/NewSpace.h (modified) (4 diffs)

trunk/Source/JavaScriptCore/heap/NewSpace.h

@@ -47 +47 @@
     public:
         static const size_t maxCellSize = 1024;
+        static const ptrdiff_t PropertyStorageNurserySize = 1024 * 1024 * 4;
 
         struct SizeClass {
@@ -64 +65 @@
         SizeClass& sizeClassFor(size_t);
         void* allocate(SizeClass&);
+        inline void* allocatePropertyStorage(size_t);
+        inline bool inPropertyStorageNursery(void* ptr);
+        inline void resetPropertyStorageNursery();
+        
         void resetAllocator();
 
@@ -92 +97 @@
         SizeClass m_preciseSizeClasses[preciseCount];
         SizeClass m_impreciseSizeClasses[impreciseCount];
+        char* m_propertyStorageNursery;
+        char* m_propertyStorageAllocationPoint;
         size_t m_waterMark;
         size_t m_highWaterMark;
@@ -161 +168 @@
     }
 
+    inline void NewSpace::resetPropertyStorageNursery()
+    {
+        m_propertyStorageAllocationPoint = m_propertyStorageNursery;
+    }
+    
+    inline void* NewSpace::allocatePropertyStorage(size_t size)
+    {
+        char* result = m_propertyStorageAllocationPoint;
+        if (size > static_cast<size_t>(PropertyStorageNurserySize))
+            CRASH();
+        m_propertyStorageAllocationPoint += size;
+        if ((m_propertyStorageAllocationPoint - m_propertyStorageNursery) > PropertyStorageNurserySize) {
+            m_propertyStorageAllocationPoint = result;
+            return 0;
+        }
+        return result;
+    }
+
+    inline bool NewSpace::inPropertyStorageNursery(void* ptr)
+    {
+        char* addr = static_cast<char*>(ptr);
+        return static_cast<uintptr_t>(addr - m_propertyStorageNursery) < PropertyStorageNurserySize;
+    }
+    
     template <typename Functor> inline typename Functor::ReturnType NewSpace::forEachBlock(Functor& functor)
     {