Push version 2.5.7 to trunk....

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 5846)
+++ src/heap.cc	(working copy)
@@ -38,7 +38,7 @@
 #include "mark-compact.h"
 #include "natives.h"
 #include "objects-visiting.h"
-#include "scanner.h"
+#include "scanner-base.h"
 #include "scopeinfo.h"
 #include "snapshot.h"
 #include "v8threads.h"
@@ -79,25 +79,34 @@
 // semispace_size_ should be a power of 2 and old_generation_size_ should be
 // a multiple of Page::kPageSize.
 #if defined(ANDROID)
-int Heap::max_semispace_size_  = 2*MB;
+static const int default_max_semispace_size_  = 2*MB;
 intptr_t Heap::max_old_generation_size_ = 192*MB;
 int Heap::initial_semispace_size_ = 128*KB;
 intptr_t Heap::code_range_size_ = 0;
 intptr_t Heap::max_executable_size_ = max_old_generation_size_;
 #elif defined(V8_TARGET_ARCH_X64)
-int Heap::max_semispace_size_  = 16*MB;
+static const int default_max_semispace_size_  = 16*MB;
 intptr_t Heap::max_old_generation_size_ = 1*GB;
 int Heap::initial_semispace_size_ = 1*MB;
 intptr_t Heap::code_range_size_ = 512*MB;
 intptr_t Heap::max_executable_size_ = 256*MB;
 #else
-int Heap::max_semispace_size_  = 8*MB;
+static const int default_max_semispace_size_  = 8*MB;
 intptr_t Heap::max_old_generation_size_ = 512*MB;
 int Heap::initial_semispace_size_ = 512*KB;
 intptr_t Heap::code_range_size_ = 0;
 intptr_t Heap::max_executable_size_ = 128*MB;
 #endif
 
+// Allow build-time customization of the max semispace size. Building
+// V8 with snapshots and a non-default max semispace size is much
+// easier if you can define it as part of the build environment.
+#if defined(V8_MAX_SEMISPACE_SIZE)
+int Heap::max_semispace_size_ = V8_MAX_SEMISPACE_SIZE;
+#else
+int Heap::max_semispace_size_ = default_max_semispace_size_;
+#endif
+
 // The snapshot semispace size will be the default semispace size if
 // snapshotting is used and will be the requested semispace size as
 // set up by ConfigureHeap otherwise.
@@ -395,7 +404,7 @@
   intptr_t total = 0;
   AllSpaces spaces;
   for (Space* space = spaces.next(); space != NULL; space = spaces.next()) {
-    total += space->Size();
+    total += space->SizeOfObjects();
   }
   return total;
 }
@@ -3240,7 +3249,8 @@
   const uc32 kMaxSupportedChar = 0xFFFF;
   // Count the number of characters in the UTF-8 string and check if
   // it is an ASCII string.
-  Access<Scanner::Utf8Decoder> decoder(Scanner::utf8_decoder());
+  Access<ScannerConstants::Utf8Decoder>
+      decoder(ScannerConstants::utf8_decoder());
   decoder->Reset(string.start(), string.length());
   int chars = 0;
   bool is_ascii = true;
@@ -4399,13 +4409,10 @@
       MemoryAllocator::Size() + MemoryAllocator::Available();
   *stats->os_error = OS::GetLastError();
   if (take_snapshot) {
-    HeapIterator iterator;
+    HeapIterator iterator(HeapIterator::kPreciseFiltering);
     for (HeapObject* obj = iterator.next();
          obj != NULL;
          obj = iterator.next()) {
-      // Note: snapshot won't be precise because IsFreeListNode returns true
-      // for any bytearray.
-      if (FreeListNode::IsFreeListNode(obj)) continue;
       InstanceType type = obj->map()->instance_type();
       ASSERT(0 <= type && type <= LAST_TYPE);
       stats->objects_per_type[type]++;
@@ -4760,10 +4767,20 @@
 }
 
 
-SpaceIterator::SpaceIterator() : current_space_(FIRST_SPACE), iterator_(NULL) {
+SpaceIterator::SpaceIterator()
+    : current_space_(FIRST_SPACE),
+      iterator_(NULL),
+      size_func_(NULL) {
 }
 
 
+SpaceIterator::SpaceIterator(HeapObjectCallback size_func)
+    : current_space_(FIRST_SPACE),
+      iterator_(NULL),
+      size_func_(size_func) {
+}
+
+
 SpaceIterator::~SpaceIterator() {
   // Delete active iterator if any.
   delete iterator_;
@@ -4798,25 +4815,25 @@
 
   switch (current_space_) {
     case NEW_SPACE:
-      iterator_ = new SemiSpaceIterator(Heap::new_space());
+      iterator_ = new SemiSpaceIterator(Heap::new_space(), size_func_);
       break;
     case OLD_POINTER_SPACE:
-      iterator_ = new HeapObjectIterator(Heap::old_pointer_space());
+      iterator_ = new HeapObjectIterator(Heap::old_pointer_space(), size_func_);
       break;
     case OLD_DATA_SPACE:
-      iterator_ = new HeapObjectIterator(Heap::old_data_space());
+      iterator_ = new HeapObjectIterator(Heap::old_data_space(), size_func_);
       break;
     case CODE_SPACE:
-      iterator_ = new HeapObjectIterator(Heap::code_space());
+      iterator_ = new HeapObjectIterator(Heap::code_space(), size_func_);
       break;
     case MAP_SPACE:
-      iterator_ = new HeapObjectIterator(Heap::map_space());
+      iterator_ = new HeapObjectIterator(Heap::map_space(), size_func_);
       break;
     case CELL_SPACE:
-      iterator_ = new HeapObjectIterator(Heap::cell_space());
+      iterator_ = new HeapObjectIterator(Heap::cell_space(), size_func_);
       break;
     case LO_SPACE:
-      iterator_ = new LargeObjectIterator(Heap::lo_space());
+      iterator_ = new LargeObjectIterator(Heap::lo_space(), size_func_);
       break;
   }
 
@@ -4826,11 +4843,58 @@
 }
 
 
-HeapIterator::HeapIterator() {
+class FreeListNodesFilter {
+ public:
+  FreeListNodesFilter() {
+    MarkFreeListNodes();
+  }
+
+  inline bool IsFreeListNode(HeapObject* object) {
+    if (object->IsMarked()) {
+      object->ClearMark();
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+ private:
+  void MarkFreeListNodes() {
+    Heap::old_pointer_space()->MarkFreeListNodes();
+    Heap::old_data_space()->MarkFreeListNodes();
+    MarkCodeSpaceFreeListNodes();
+    Heap::map_space()->MarkFreeListNodes();
+    Heap::cell_space()->MarkFreeListNodes();
+  }
+
+  void MarkCodeSpaceFreeListNodes() {
+    // For code space, using FreeListNode::IsFreeListNode is OK.
+    HeapObjectIterator iter(Heap::code_space());
+    for (HeapObject* obj = iter.next_object();
+         obj != NULL;
+         obj = iter.next_object()) {
+      if (FreeListNode::IsFreeListNode(obj)) obj->SetMark();
+    }
+  }
+
+  AssertNoAllocation no_alloc;
+};
+
+
+HeapIterator::HeapIterator()
+    : filtering_(HeapIterator::kNoFiltering),
+      filter_(NULL) {
   Init();
 }
 
 
+HeapIterator::HeapIterator(HeapIterator::FreeListNodesFiltering filtering)
+    : filtering_(filtering),
+      filter_(NULL) {
+  Init();
+}
+
+
 HeapIterator::~HeapIterator() {
   Shutdown();
 }
@@ -4838,20 +4902,44 @@
 
 void HeapIterator::Init() {
   // Start the iteration.
-  space_iterator_ = new SpaceIterator();
+  if (filtering_ == kPreciseFiltering) {
+    filter_ = new FreeListNodesFilter;
+    space_iterator_ =
+        new SpaceIterator(MarkCompactCollector::SizeOfMarkedObject);
+  } else {
+    space_iterator_ = new SpaceIterator;
+  }
   object_iterator_ = space_iterator_->next();
 }
 
 
 void HeapIterator::Shutdown() {
+#ifdef DEBUG
+  // Assert that in precise mode we have iterated through all
+  // objects. Otherwise, heap will be left in an inconsistent state.
+  if (filtering_ == kPreciseFiltering) {
+    ASSERT(object_iterator_ == NULL);
+  }
+#endif
   // Make sure the last iterator is deallocated.
   delete space_iterator_;
   space_iterator_ = NULL;
   object_iterator_ = NULL;
+  delete filter_;
+  filter_ = NULL;
 }
 
 
 HeapObject* HeapIterator::next() {
+  if (filter_ == NULL) return NextObject();
+
+  HeapObject* obj = NextObject();
+  while (obj != NULL && filter_->IsFreeListNode(obj)) obj = NextObject();
+  return obj;
+}
+
+
+HeapObject* HeapIterator::NextObject() {
   // No iterator means we are done.
   if (object_iterator_ == NULL) return NULL;