r134080 causes heap problem on linux systems where PAGESIZE != 4096

https://bugs.webkit.org/show_bug.cgi?id=102828

Patch by Balazs Kilvady <kilvadyb@homejinni.com> on 2013-01-18
Reviewed by Mark Hahnenberg.

Make MarkStackSegment::blockSize as the capacity of segments of a MarkStackArray.

* JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCoreExports.def:
* heap/MarkStack.cpp:
(JSC):
(JSC::MarkStackArray::MarkStackArray):
(JSC::MarkStackArray::expand):
(JSC::MarkStackArray::donateSomeCellsTo):
(JSC::MarkStackArray::stealSomeCellsFrom):
* heap/MarkStack.h:
(JSC::MarkStackSegment::data):
(CapacityFromSize):
(MarkStackArray):
* heap/MarkStackInlines.h:
(JSC::MarkStackArray::setTopForFullSegment):
(JSC::MarkStackArray::append):
(JSC::MarkStackArray::isEmpty):
(JSC::MarkStackArray::size):
* runtime/Options.h:
(JSC):

Change-Id: I4663100b6b8b054bed03c0c6eb01bb9274a1b264
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140195 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>

1 files changed, 5 insertions, 11 deletions

diff --git a/Source/JavaScriptCore/heap/MarkStack.h b/Source/JavaScriptCore/heap/MarkStack.h
index 2a7f04450..c97b6a735 100644
--- a/Source/JavaScriptCore/heap/MarkStack.h
+++ b/Source/JavaScriptCore/heap/MarkStack.h
@@ -75,16 +75,6 @@ public:
     {
         return bitwise_cast<const JSCell**>(this + 1);
     }
-    
-    static size_t capacityFromSize(size_t size)
-    {
-        return (size - sizeof(MarkStackSegment)) / sizeof(const JSCell*);
-    }
-    
-    static size_t sizeFromCapacity(size_t capacity)
-    {
-        return sizeof(MarkStackSegment) + capacity * sizeof(const JSCell*);
-    }
 
     static const size_t blockSize = 4 * KB;
 
@@ -111,6 +101,10 @@ public:
     bool isEmpty();
 
 private:
+    template <size_t size> struct CapacityFromSize {
+        static const size_t value = (size - sizeof(MarkStackSegment)) / sizeof(const JSCell*);
+    };
+
     JS_EXPORT_PRIVATE void expand();
     
     size_t postIncTop();
@@ -124,7 +118,7 @@ private:
     DoublyLinkedList<MarkStackSegment> m_segments;
     BlockAllocator& m_blockAllocator;
 
-    size_t m_segmentCapacity;
+    JS_EXPORT_PRIVATE static const size_t s_segmentCapacity = CapacityFromSize<MarkStackSegment::blockSize>::value;
     size_t m_top;
     size_t m_numberOfSegments;