Refactor incremental marking to use static visitor.

src/incremental-marking.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 13 matching lines @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "v8.h"
 
 #include "incremental-marking.h"
 
 #include "code-stubs.h"
 #include "compilation-cache.h"
+#include "objects-visiting.h"
+#include "objects-visiting-inl.h"
 #include "v8conversions.h"
 
 namespace v8 {
 namespace internal {
 
 
 IncrementalMarking::IncrementalMarking(Heap* heap)
     : heap_(heap),
       state_(STOPPED),
       marking_deque_memory_(NULL),
@@ skipping 109 matching lines @@
     MarkBit obj_bit = Marking::MarkBitFrom(obj);
     if (Marking::IsBlack(obj_bit)) {
       // Object is not going to be rescanned.  We need to record the slot.
       heap_->mark_compact_collector()->RecordRelocSlot(rinfo,
                                                        Code::cast(value));
     }
   }
 }
 
 
-class IncrementalMarkingMarkingVisitor : public ObjectVisitor {
+class IncrementalMarkingMarkingVisitor
+    : public StaticMarkingVisitor<IncrementalMarkingMarkingVisitor> {
  public:
-  IncrementalMarkingMarkingVisitor(Heap* heap,
-                                   IncrementalMarking* incremental_marking)
-      : heap_(heap),
-        incremental_marking_(incremental_marking) {
+  static void Initialize() {
+    StaticMarkingVisitor<IncrementalMarkingMarkingVisitor>::Initialize();
+
+    table_.Register(kVisitSharedFunctionInfo, &VisitSharedFunctionInfo);
+
+    table_.Register(kVisitJSFunction, &VisitJSFunction);
+
+    table_.Register(kVisitJSRegExp, &VisitJSRegExp);
   }
 
-  void VisitEmbeddedPointer(RelocInfo* rinfo) {
+  static inline void VisitEmbeddedPointer(Heap* heap, RelocInfo* rinfo) {
     ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
     Object* target = rinfo->target_object();
     if (target->NonFailureIsHeapObject()) {
-      heap_->mark_compact_collector()->RecordRelocSlot(rinfo, target);
-      MarkObject(target);
+      heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+      MarkObject(heap, target);
     }
   }
 
-  void VisitCodeTarget(RelocInfo* rinfo) {
+  static inline void VisitCodeTarget(Heap* heap, RelocInfo* rinfo) {
     ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
     Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
     if (FLAG_cleanup_code_caches_at_gc && target->is_inline_cache_stub()
-        && (target->ic_age() != heap_->global_ic_age())) {
+        && (target->ic_age() != heap->global_ic_age())) {
       IC::Clear(rinfo->pc());
       target = Code::GetCodeFromTargetAddress(rinfo->target_address());
     }
-    heap_->mark_compact_collector()->RecordRelocSlot(rinfo, Code::cast(target));
-    MarkObject(target);
+    heap->mark_compact_collector()->RecordRelocSlot(rinfo, Code::cast(target));
+    MarkObject(heap, target);
   }
 
-  void VisitDebugTarget(RelocInfo* rinfo) {
-    ASSERT((RelocInfo::IsJSReturn(rinfo->rmode()) &&
-            rinfo->IsPatchedReturnSequence()) ||
-           (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
-            rinfo->IsPatchedDebugBreakSlotSequence()));
-    Object* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
-    heap_->mark_compact_collector()->RecordRelocSlot(rinfo, Code::cast(target));
-    MarkObject(target);
+  static void VisitCode(Map* map, HeapObject* object) {
+    Heap* heap = map->GetHeap();
+    Code* code = reinterpret_cast<Code*>(object);
+    code->CodeIterateBody<IncrementalMarkingMarkingVisitor>(heap);
   }
 
-  void VisitCodeEntry(Address entry_address) {
-    Object* target = Code::GetObjectFromEntryAddress(entry_address);
-    heap_->mark_compact_collector()->
-        RecordCodeEntrySlot(entry_address, Code::cast(target));
-    MarkObject(target);
+  static void VisitJSWeakMap(Map* map, HeapObject* object) {
+    Heap* heap = map->GetHeap();
+    VisitPointers(heap,
+                  HeapObject::RawField(object, JSWeakMap::kPropertiesOffset),
+                  HeapObject::RawField(object, JSWeakMap::kSize));
   }
 
-  void VisitSharedFunctionInfo(SharedFunctionInfo* shared) {
-    if (shared->ic_age() != heap_->global_ic_age()) {
-      shared->ResetForNewContext(heap_->global_ic_age());
+  static void VisitSharedFunctionInfo(Map* map, HeapObject* object) {
+    Heap* heap = map->GetHeap();
+    SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
+    if (shared->ic_age() != heap->global_ic_age()) {
+      shared->ResetForNewContext(heap->global_ic_age());
+    }
+    FixedBodyVisitor<IncrementalMarkingMarkingVisitor,
+                     SharedFunctionInfo::BodyDescriptor,
+                     void>::Visit(map, object);
+  }
+
+  static inline void VisitJSFunction(Map* map, HeapObject* object) {
+    Heap* heap = map->GetHeap();
+    // Iterate over all fields in the body but take care in dealing with
+    // the code entry.
+    VisitPointers(heap,
+                  HeapObject::RawField(object, JSFunction::kPropertiesOffset),
+                  HeapObject::RawField(object, JSFunction::kCodeEntryOffset));
+    VisitCodeEntry(heap, object->address() + JSFunction::kCodeEntryOffset);
+    VisitPointers(heap,
+                  HeapObject::RawField(object,
+                      JSFunction::kCodeEntryOffset + kPointerSize),
+                  HeapObject::RawField(object, JSFunction::kSize));
+  }
+
+  INLINE(static void VisitPointer(Heap* heap, Object** p)) {
+    Object* obj = *p;
+    if (obj->NonFailureIsHeapObject()) {
+      heap->mark_compact_collector()->RecordSlot(p, p, obj);
+      MarkObject(heap, obj);
     }
   }
 
-  void VisitPointer(Object** p) {
-    Object* obj = *p;
-    if (obj->NonFailureIsHeapObject()) {
-      heap_->mark_compact_collector()->RecordSlot(p, p, obj);
-      MarkObject(obj);
-    }
-  }
-
-  void VisitPointers(Object** start, Object** end) {
+  INLINE(static void VisitPointers(Heap* heap, Object** start, Object** end)) {
     for (Object** p = start; p < end; p++) {
       Object* obj = *p;
       if (obj->NonFailureIsHeapObject()) {
-        heap_->mark_compact_collector()->RecordSlot(start, p, obj);
-        MarkObject(obj);
+        heap->mark_compact_collector()->RecordSlot(start, p, obj);
+        MarkObject(heap, obj);
       }
     }
   }
 
- private:
-  // Mark object pointed to by p.
-  INLINE(void MarkObject(Object* obj)) {
+  INLINE(static void MarkObject(Heap* heap, Object* obj)) {
     HeapObject* heap_object = HeapObject::cast(obj);
     MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
     if (mark_bit.data_only()) {
-      if (incremental_marking_->MarkBlackOrKeepGrey(mark_bit)) {
+      if (heap->incremental_marking()->MarkBlackOrKeepGrey(mark_bit)) {
         MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
                                               heap_object->Size());
       }
     } else if (Marking::IsWhite(mark_bit)) {
-      incremental_marking_->WhiteToGreyAndPush(heap_object, mark_bit);
+      heap->incremental_marking()->WhiteToGreyAndPush(heap_object, mark_bit);
     }
   }
-
-  Heap* heap_;
-  IncrementalMarking* incremental_marking_;
 };
 
 
 class IncrementalMarkingRootMarkingVisitor : public ObjectVisitor {
  public:
   IncrementalMarkingRootMarkingVisitor(Heap* heap,
                                        IncrementalMarking* incremental_marking)
       : heap_(heap),
         incremental_marking_(incremental_marking) {
   }
@@ skipping 23 matching lines @@
         incremental_marking_->WhiteToGreyAndPush(heap_object, mark_bit);
       }
     }
   }
 
   Heap* heap_;
   IncrementalMarking* incremental_marking_;
 };
 
 
+void IncrementalMarking::Initialize() {
+  IncrementalMarkingMarkingVisitor::Initialize();
+}
+
+
 void IncrementalMarking::SetOldSpacePageFlags(MemoryChunk* chunk,
                                               bool is_marking,
                                               bool is_compacting) {
   if (is_marking) {
     chunk->SetFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
     chunk->SetFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
 
     // It's difficult to filter out slots recorded for large objects.
     if (chunk->owner()->identity() == LO_SPACE &&
         chunk->size() > static_cast<size_t>(Page::kPageSize) &&
@@ skipping 313 matching lines @@
     }
   }
   marking_deque_.set_top(new_top);
 
   steps_took_since_last_gc_ = 0;
   steps_count_since_last_gc_ = 0;
   longest_step_ = 0.0;
 }
 
 
-void IncrementalMarking::VisitGlobalContext(Context* ctx, ObjectVisitor* v) {
-  v->VisitPointers(
-      HeapObject::RawField(
-          ctx, Context::MarkCompactBodyDescriptor::kStartOffset),
-      HeapObject::RawField(
-          ctx, Context::MarkCompactBodyDescriptor::kEndOffset));
-
-  MarkCompactCollector* collector = heap_->mark_compact_collector();
-  for (int idx = Context::FIRST_WEAK_SLOT;
-       idx < Context::GLOBAL_CONTEXT_SLOTS;
-       ++idx) {
-    Object** slot =
-        HeapObject::RawField(ctx, FixedArray::OffsetOfElementAt(idx));
-    collector->RecordSlot(slot, slot, *slot);
-  }
-}
-
-
 void IncrementalMarking::Hurry() {
   if (state() == MARKING) {
     double start = 0.0;
     if (FLAG_trace_incremental_marking) {
       PrintF("[IncrementalMarking] Hurry\n");
       start = OS::TimeCurrentMillis();
     }
     // TODO(gc) hurry can mark objects it encounters black as mutator
     // was stopped.
     Map* filler_map = heap_->one_pointer_filler_map();
     Map* global_context_map = heap_->global_context_map();
-    IncrementalMarkingMarkingVisitor marking_visitor(heap_, this);
     while (!marking_deque_.IsEmpty()) {
       HeapObject* obj = marking_deque_.Pop();
 
       // Explicitly skip one word fillers. Incremental markbit patterns are
       // correct only for objects that occupy at least two words.
       Map* map = obj->map();
       if (map == filler_map) {
         continue;
       } else if (map == global_context_map) {
         // Global contexts have weak fields.
-        VisitGlobalContext(Context::cast(obj), &marking_visitor);
+        IncrementalMarkingMarkingVisitor::VisitGlobalContext(map, obj);
       } else if (map->instance_type() == MAP_TYPE) {
         Map* map = Map::cast(obj);
         heap_->ClearCacheOnMap(map);
 
         // When map collection is enabled we have to mark through map's
         // transitions and back pointers in a special way to make these links
         // weak.  Only maps for subclasses of JSReceiver can have transitions.
         STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
         if (FLAG_collect_maps &&
             map->instance_type() >= FIRST_JS_RECEIVER_TYPE) {
           marker_.MarkMapContents(map);
         } else {
-          marking_visitor.VisitPointers(
+          IncrementalMarkingMarkingVisitor::VisitPointers(
+              heap_,
               HeapObject::RawField(map, Map::kPointerFieldsBeginOffset),
               HeapObject::RawField(map, Map::kPointerFieldsEndOffset));
         }
       } else {
-        obj->Iterate(&marking_visitor);
+        MarkBit map_mark_bit = Marking::MarkBitFrom(map);
+        if (Marking::IsWhite(map_mark_bit)) {
+          WhiteToGreyAndPush(map, map_mark_bit);
+        }
+        IncrementalMarkingMarkingVisitor::IterateBody(map, obj);
       }
 
       MarkBit mark_bit = Marking::MarkBitFrom(obj);
       ASSERT(!Marking::IsBlack(mark_bit));
       Marking::MarkBlack(mark_bit);
       MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
     }
     state_ = COMPLETE;
     if (FLAG_trace_incremental_marking) {
       double end = OS::TimeCurrentMillis();
@@ skipping 113 matching lines @@
   }
 
   if (state_ == SWEEPING) {
     if (heap_->AdvanceSweepers(static_cast<int>(bytes_to_process))) {
       bytes_scanned_ = 0;
       StartMarking(PREVENT_COMPACTION);
     }
   } else if (state_ == MARKING) {
     Map* filler_map = heap_->one_pointer_filler_map();
     Map* global_context_map = heap_->global_context_map();
-    IncrementalMarkingMarkingVisitor marking_visitor(heap_, this);
     while (!marking_deque_.IsEmpty() && bytes_to_process > 0) {
       HeapObject* obj = marking_deque_.Pop();
 
       // Explicitly skip one word fillers. Incremental markbit patterns are
       // correct only for objects that occupy at least two words.
       Map* map = obj->map();
       if (map == filler_map) continue;
 
       int size = obj->SizeFromMap(map);
       bytes_to_process -= size;
       MarkBit map_mark_bit = Marking::MarkBitFrom(map);
       if (Marking::IsWhite(map_mark_bit)) {
         WhiteToGreyAndPush(map, map_mark_bit);
       }
 
       // TODO(gc) switch to static visitor instead of normal visitor.
       if (map == global_context_map) {
         // Global contexts have weak fields.
         Context* ctx = Context::cast(obj);
 
         // We will mark cache black with a separate pass
         // when we finish marking.
         MarkObjectGreyDoNotEnqueue(ctx->normalized_map_cache());
 
-        VisitGlobalContext(ctx, &marking_visitor);
+        IncrementalMarkingMarkingVisitor::VisitGlobalContext(map, ctx);
       } else if (map->instance_type() == MAP_TYPE) {
         Map* map = Map::cast(obj);
         heap_->ClearCacheOnMap(map);
 
         // When map collection is enabled we have to mark through map's
         // transitions and back pointers in a special way to make these links
         // weak.  Only maps for subclasses of JSReceiver can have transitions.
         STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
         if (FLAG_collect_maps &&
             map->instance_type() >= FIRST_JS_RECEIVER_TYPE) {
           marker_.MarkMapContents(map);
         } else {
-          marking_visitor.VisitPointers(
+          IncrementalMarkingMarkingVisitor::VisitPointers(
+              heap_,
               HeapObject::RawField(map, Map::kPointerFieldsBeginOffset),
               HeapObject::RawField(map, Map::kPointerFieldsEndOffset));
         }
       } else if (map->instance_type() == JS_FUNCTION_TYPE) {
-        marking_visitor.VisitPointers(
+        IncrementalMarkingMarkingVisitor::VisitPointers(
+            heap_,
             HeapObject::RawField(obj, JSFunction::kPropertiesOffset),
             HeapObject::RawField(obj, JSFunction::kCodeEntryOffset));
 
-        marking_visitor.VisitCodeEntry(
-            obj->address() + JSFunction::kCodeEntryOffset);
+        IncrementalMarkingMarkingVisitor::VisitCodeEntry(
+            heap_, obj->address() + JSFunction::kCodeEntryOffset);
 
-        marking_visitor.VisitPointers(
+        IncrementalMarkingMarkingVisitor::VisitPointers(
+            heap_,
             HeapObject::RawField(obj,
                                  JSFunction::kCodeEntryOffset + kPointerSize),
             HeapObject::RawField(obj,
                                  JSFunction::kNonWeakFieldsEndOffset));

[Toon Verwaest, 2012/07/23 13:10:21]

Is this the same as IncrementalMarkingMarkingVisitor::VisitJSFunction?

[Michael Starzinger, 2012/07/25 08:21:33]

Done. Yes, it's should be the same. Changed so that the static visitor is used
here as well.

       } else {
-        obj->IterateBody(map->instance_type(), size, &marking_visitor);
+        IncrementalMarkingMarkingVisitor::IterateBody(map, obj);
       }
 
       MarkBit obj_mark_bit = Marking::MarkBitFrom(obj);
       SLOW_ASSERT(Marking::IsGrey(obj_mark_bit) ||
                   (obj->IsFiller() && Marking::IsWhite(obj_mark_bit)));
       Marking::MarkBlack(obj_mark_bit);
       MemoryChunk::IncrementLiveBytesFromGC(obj->address(), size);
     }
     if (marking_deque_.IsEmpty()) MarkingComplete(action);
   }
@@ skipping 90 matching lines @@
   allocation_marking_factor_ = kInitialAllocationMarkingFactor;
   bytes_scanned_ = 0;
 }
 
 
 int64_t IncrementalMarking::SpaceLeftInOldSpace() {
   return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSizeOfObjects();
 }
 
 } }  // namespace v8::internal