Oilpan: Implement bitmap marking

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index d0471e8e65a72f20f77f826261b864025b3970de..48bf7051a7483c3ac17a5ce5ea83858c03f4602f 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -456,18 +456,10 @@ private:
     bool m_parkedAllThreads; // False if we fail to park all threads
 };
 
-NO_SANITIZE_ADDRESS inline
-bool HeapObjectHeader::isMarked() const
-{
-    checkHeader();
-    return m_size & markBitMask;
-}
-
-NO_SANITIZE_ADDRESS inline
-void HeapObjectHeader::unmark()
+inline bool HeapObjectHeader::isMarked() const
 {
     checkHeader();
-    m_size &= ~markBitMask;
+    return pageHeaderFromObject(this)->objectIsMarked(reinterpret_cast<Address>(const_cast<HeapObjectHeader*>(this)));
 }
 
 NO_SANITIZE_ADDRESS inline
@@ -539,12 +531,6 @@ void FinalizedHeapObjectHeader::finalize()
 }
 
 template<typename Header>
-void LargeHeapObject<Header>::unmark()
-{
-    return heapObjectHeader()->unmark();
-}
-
-template<typename Header>
 bool LargeHeapObject<Header>::isMarked()
 {
     return heapObjectHeader()->isMarked();
@@ -1172,6 +1158,7 @@ OrphanedPagePool::~OrphanedPagePool()
 
 void OrphanedPagePool::addOrphanedPage(int index, BaseHeapPage* page)
 {
+    page->clearObjectMarkBitMap();
     page->markOrphaned();
     PoolEntry* entry = new PoolEntry(page, m_pool[index]);
     m_pool[index] = entry;
@@ -1414,7 +1401,6 @@ void ThreadHeap<Header>::sweepLargePages()
     for (LargeHeapObject<Header>* current = m_firstLargeHeapObject; current;) {
         if (current->isMarked()) {
             Heap::increaseMarkedObjectSize(current->size());
-            current->unmark();
             previousNext = &current->m_next;
             current = current->next();
         } else {
@@ -1496,20 +1482,31 @@ void ThreadHeap<Header>::makeConsistentForSweeping()
 }
 
 template<typename Header>
-void ThreadHeap<Header>::clearLiveAndMarkDead()
+void ThreadHeap<Header>::makeUnmarkedObjectsDead()
 {
     ASSERT(isConsistentForSweeping());
-    for (HeapPage<Header>* page = m_firstPage; page; page = page->next())
-        page->clearLiveAndMarkDead();
+    for (HeapPage<Header>* page = m_firstPage; page; page = page->next()) {
+        page->makeUnmarkedObjectsDead();
+    }
     for (LargeHeapObject<Header>* current = m_firstLargeHeapObject; current; current = current->next()) {
-        if (current->isMarked())
-            current->unmark();
-        else
+        if (!current->isMarked())
             current->setDeadMark();
     }
 }
 
 template<typename Header>
+void ThreadHeap<Header>::clearObjectMarkBitMaps()
+{
+    ASSERT(isConsistentForSweeping());
+    for (HeapPage<Header>* page = m_firstPage; page; page = page->next()) {
+        page->clearObjectMarkBitMap();
+    }
+    for (LargeHeapObject<Header>* current = m_firstLargeHeapObject; current; current = current->next()) {
+        current->clearObjectMarkBitMap();
+    }
+}
+
+template<typename Header>
 void ThreadHeap<Header>::clearFreeLists()
 {
     m_promptlyFreedCount = 0;
@@ -1549,6 +1546,12 @@ HeapPage<Header>::HeapPage(PageMemory* storage, ThreadHeap<Header>* heap, const
 }
 
 template<typename Header>
+void HeapPage<Header>::clearObjectMarkBitMap()
+{
+    memset(&m_objectMarkBitMap, 0, reservedForObjectMarkBitMap);
+}
+
+template<typename Header>
 void HeapPage<Header>::link(HeapPage** prevNext)
 {
     m_next = *prevNext;
@@ -1634,7 +1637,6 @@ void HeapPage<Header>::sweep(ThreadHeap<Header>* heap)
 
         if (startOfGap != headerAddress)
             heap->addToFreeList(startOfGap, headerAddress - startOfGap);
-        header->unmark();
         headerAddress += header->size();
         Heap::increaseMarkedObjectSize(header->size());
         startOfGap = headerAddress;
@@ -1644,7 +1646,7 @@ void HeapPage<Header>::sweep(ThreadHeap<Header>* heap)
 }
 
 template<typename Header>
-void HeapPage<Header>::clearLiveAndMarkDead()
+void HeapPage<Header>::makeUnmarkedObjectsDead()
 {
     for (Address headerAddress = payload(); headerAddress < end();) {
         Header* header = reinterpret_cast<Header*>(headerAddress);
@@ -1655,9 +1657,7 @@ void HeapPage<Header>::clearLiveAndMarkDead()
             headerAddress += header->size();
             continue;
         }
-        if (header->isMarked())
-            header->unmark();
-        else
+        if (!header->isMarked())
             header->setDeadMark();
         headerAddress += header->size();
     }