- Pass the knowledge whether the old GC is compacting to the GC prologue and ...

src/heap.cc

 // Copyright 2006-2008 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 401 matching lines @@
   FlatStringReader::PostGarbageCollectionProcessing();
 }
 
 
 void Heap::MarkCompact(GCTracer* tracer) {
   gc_state_ = MARK_COMPACT;
   mc_count_++;
   tracer->set_full_gc_count(mc_count_);
   LOG(ResourceEvent("markcompact", "begin"));
 
-  MarkCompactPrologue();
+  MarkCompactCollector::Prepare(tracer);
 
-  MarkCompactCollector::CollectGarbage(tracer);
+  bool is_compacting = MarkCompactCollector::IsCompacting();
 
-  MarkCompactEpilogue();
+  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);
 }
 
 
-void Heap::MarkCompactPrologue() {
+void Heap::MarkCompactPrologue(bool is_compacting) {
+  // At any old GC clear the keyed lookup cache to enable collection of unused
+  // maps.
   ClearKeyedLookupCache();
+
   CompilationCache::MarkCompactPrologue();
   RegExpImpl::OldSpaceCollectionPrologue();
-  Top::MarkCompactPrologue();
-  ThreadManager::MarkCompactPrologue();
+
+  Top::MarkCompactPrologue(is_compacting);
+  ThreadManager::MarkCompactPrologue(is_compacting);
 }
 
 
-void Heap::MarkCompactEpilogue() {
-  Top::MarkCompactEpilogue();
-  ThreadManager::MarkCompactEpilogue();
+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 1134 matching lines @@
   } else {
     filler->set_map(Heap::byte_array_map());
     ByteArray::cast(filler)->set_length(ByteArray::LengthFor(size));
   }
 }
 
 
 Object* Heap::CreateCode(const CodeDesc& desc,
                          ScopeInfo<>* sinfo,
                          Code::Flags flags,
-                         Code** self_reference) {
+                         Handle<Object> self_reference) {
   // Compute size
   int body_size = RoundUp(desc.instr_size + desc.reloc_size, kObjectAlignment);
   int sinfo_size = 0;
   if (sinfo != NULL) sinfo_size = sinfo->Serialize(NULL);
   int obj_size = Code::SizeFor(body_size, sinfo_size);
   Object* result;
   if (obj_size > MaxHeapObjectSize()) {
     result = lo_space_->AllocateRawCode(obj_size);
   } else {
     result = code_space_->AllocateRaw(obj_size);
   }
 
   if (result->IsFailure()) return result;
 
   // Initialize the object
   HeapObject::cast(result)->set_map(code_map());
   Code* code = Code::cast(result);
   code->set_instruction_size(desc.instr_size);
   code->set_relocation_size(desc.reloc_size);
   code->set_sinfo_size(sinfo_size);
   code->set_flags(flags);
   code->set_ic_flag(Code::IC_TARGET_IS_ADDRESS);
-  // Allow self references to created code object.
-  if (self_reference != NULL) {
-    *self_reference = code;
+  // Allow self references to created code object by patching the handle to
+  // point to the newly allocated Code object.
+  if (!self_reference.is_null()) {
+    *(self_reference.location()) = code;
   }
   // Migrate generated code.
   // The generated code can contain Object** values (typically from handles)
   // that are dereferenced during the copy to point directly to the actual heap
   // objects. These pointers can include references to the code object itself,
   // through the self_reference parameter.
   code->CopyFrom(desc);
   if (sinfo != NULL) sinfo->Serialize(code);  // write scope info
   LOG(CodeAllocateEvent(code, desc.origin));
 
@@ skipping 1660 matching lines @@
 #ifdef DEBUG
 bool Heap::GarbageCollectionGreedyCheck() {
   ASSERT(FLAG_gc_greedy);
   if (Bootstrapper::IsActive()) return true;
   if (disallow_allocation_failure()) return true;
   return CollectGarbage(0, NEW_SPACE);
 }
 #endif
 
 } }  // namespace v8::internal