Add functionality for finding code objects from a pc that points into...

src/heap.cc

 // Copyright 2009 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 86 matching lines @@
 // 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.
 int Heap::reserved_semispace_size_ = Heap::max_semispace_size_;
 
 List<Heap::GCPrologueCallbackPair> Heap::gc_prologue_callbacks_;
 List<Heap::GCEpilogueCallbackPair> Heap::gc_epilogue_callbacks_;
 
 GCCallback Heap::global_gc_prologue_callback_ = NULL;
 GCCallback Heap::global_gc_epilogue_callback_ = NULL;
+HeapObjectCallback Heap::gc_safe_size_of_old_object_ = NULL;
 
 // Variables set based on semispace_size_ and old_generation_size_ in
 // ConfigureHeap.
 
 // Will be 4 * reserved_semispace_size_ to ensure that young
 // generation can be aligned to its size.
 int Heap::survived_since_last_expansion_ = 0;
 int Heap::external_allocation_limit_ = 0;
 
 Heap::HeapState Heap::gc_state_ = NOT_IN_GC;
@@ skipping 69 matching lines @@
 bool Heap::HasBeenSetup() {
   return old_pointer_space_ != NULL &&
          old_data_space_ != NULL &&
          code_space_ != NULL &&
          map_space_ != NULL &&
          cell_space_ != NULL &&
          lo_space_ != NULL;
 }
 
 
+int Heap::GcSafeSizeOfOldObject(HeapObject* object) {
+  ASSERT(!Heap::InNewSpace(object));  // Code only works for old objects.
+  ASSERT(!MarkCompactCollector::are_map_pointers_encoded());
+  MapWord map_word = object->map_word();
+  map_word.ClearMark();
+  map_word.ClearOverflow();
+  return object->SizeFromMap(map_word.ToMap());
+}
+
+
+int Heap::GcSafeSizeOfOldObjectWithEncodedMap(HeapObject* object) {
+  ASSERT(!Heap::InNewSpace(object));  // Code only works for old objects.
+  ASSERT(MarkCompactCollector::are_map_pointers_encoded());
+  uint32_t marker = Memory::uint32_at(object->address());
+  if (marker == MarkCompactCollector::kSingleFreeEncoding) {
+    return kIntSize;
+  } else if (marker == MarkCompactCollector::kMultiFreeEncoding) {
+    return Memory::int_at(object->address() + kIntSize);
+  } else {
+    MapWord map_word = object->map_word();
+    Address map_address = map_word.DecodeMapAddress(Heap::map_space());
+    Map* map = reinterpret_cast<Map*>(HeapObject::FromAddress(map_address));
+    return object->SizeFromMap(map);
+  }
+}
+
+
 GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space) {
   // Is global GC requested?
   if (space != NEW_SPACE || FLAG_gc_global) {
     Counters::gc_compactor_caused_by_request.Increment();
     return MARK_COMPACTOR;
   }
 
   // Is enough data promoted to justify a global GC?
   if (OldGenerationPromotionLimitReached()) {
     Counters::gc_compactor_caused_by_promoted_data.Increment();
@@ skipping 529 matching lines @@
     mc_count_++;
   } else {
     ms_count_++;
   }
   tracer->set_full_gc_count(mc_count_ + ms_count_);
 
   MarkCompactPrologue(is_compacting);
 
   MarkCompactCollector::CollectGarbage();
 
-  MarkCompactEpilogue(is_compacting);
-
   LOG(ResourceEvent("markcompact", "end"));
 
   gc_state_ = NOT_IN_GC;
 
   Shrink();
 
   Counters::objs_since_last_full.Set(0);
 
   contexts_disposed_ = 0;
 }
 
 
 void Heap::MarkCompactPrologue(bool is_compacting) {
   // At any old GC clear the keyed lookup cache to enable collection of unused
   // maps.
   KeyedLookupCache::Clear();
   ContextSlotCache::Clear();
   DescriptorLookupCache::Clear();
 
   CompilationCache::MarkCompactPrologue();
 
-  Top::MarkCompactPrologue(is_compacting);
-  ThreadManager::MarkCompactPrologue(is_compacting);
-
   CompletelyClearInstanceofCache();
 
   if (is_compacting) FlushNumberStringCache();
 
   ClearNormalizedMapCaches();
 }
 
 
-void Heap::MarkCompactEpilogue(bool is_compacting) {
-  Top::MarkCompactEpilogue(is_compacting);
-  ThreadManager::MarkCompactEpilogue(is_compacting);
-}
-
-
 Object* Heap::FindCodeObject(Address a) {
   Object* obj = code_space_->FindObject(a);
   if (obj->IsFailure()) {
     obj = lo_space_->FindObject(a);
   }
   ASSERT(!obj->IsFailure());
   return obj;
 }
 
 
@@ skipping 3247 matching lines @@
   // size) and old-space-size if set or the initial values of semispace_size_
   // and old_generation_size_ otherwise.
   if (!heap_configured) {
     if (!ConfigureHeapDefault()) return false;
   }
 
   ScavengingVisitor::Initialize();
   NewSpaceScavenger::Initialize();
   MarkCompactCollector::Initialize();
 
+  MarkMapPointersAsEncoded(false);
+
   // Setup memory allocator and reserve a chunk of memory for new
   // space.  The chunk is double the size of the requested reserved
   // new space size to ensure that we can find a pair of semispaces that
   // are contiguous and aligned to their size.
   if (!MemoryAllocator::Setup(MaxReserved())) return false;
   void* chunk =
       MemoryAllocator::ReserveInitialChunk(4 * reserved_semispace_size_);
   if (chunk == NULL) return false;
 
   // Align the pair of semispaces to their size, which must be a power
@@ skipping 815 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal