v8: make GCTracer persistent.

src/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/cpu-profiler.h"
@@ skipping 30 matching lines @@
 #endif
       sweep_precisely_(false),
       reduce_memory_footprint_(false),
       abort_incremental_marking_(false),
       marking_parity_(ODD_MARKING_PARITY),
       compacting_(false),
       was_marked_incrementally_(false),
       sweeping_pending_(false),
       pending_sweeper_jobs_semaphore_(0),
       sequential_sweeping_(false),
-      tracer_(NULL),
       migration_slots_buffer_(NULL),
       heap_(heap),
       code_flusher_(NULL),
       have_code_to_deoptimize_(false) { }
 
 #ifdef VERIFY_HEAP
 class VerifyMarkingVisitor: public ObjectVisitor {
  public:
   explicit VerifyMarkingVisitor(Heap* heap) : heap_(heap) {}
 
@@ skipping 371 matching lines @@
 #endif
 
   Finish();
 
   if (marking_parity_ == EVEN_MARKING_PARITY) {
     marking_parity_ = ODD_MARKING_PARITY;
   } else {
     ASSERT(marking_parity_ == ODD_MARKING_PARITY);
     marking_parity_ = EVEN_MARKING_PARITY;
   }
-
-  tracer_ = NULL;
 }
 
 
 #ifdef VERIFY_HEAP
 void MarkCompactCollector::VerifyMarkbitsAreClean(PagedSpace* space) {
   PageIterator it(space);
 
   while (it.has_next()) {
     Page* p = it.next();
     CHECK(p->markbits()->IsClean());
@@ skipping 483 matching lines @@
       p->ClearFlag(MemoryChunk::RESCAN_ON_EVACUATION);
     }
     compacting_ = false;
     evacuation_candidates_.Rewind(0);
     invalidated_code_.Rewind(0);
   }
   ASSERT_EQ(0, evacuation_candidates_.length());
 }
 
 
-void MarkCompactCollector::Prepare(GCTracer* tracer) {
+void MarkCompactCollector::Prepare() {
   was_marked_incrementally_ = heap()->incremental_marking()->IsMarking();
 
-  // Rather than passing the tracer around we stash it in a static member
-  // variable.
-  tracer_ = tracer;
-
 #ifdef DEBUG
   ASSERT(state_ == IDLE);
   state_ = PREPARE_GC;
 #endif
 
   ASSERT(!FLAG_never_compact || !FLAG_always_compact);
 
   if (IsConcurrentSweepingInProgress()) {
     // Instead of waiting we could also abort the sweeper threads here.
     WaitUntilSweepingCompleted();
@@ skipping 1318 matching lines @@
         code->CodeIterateBody(visitor);
       }
       ProcessMarkingDeque();
       return;
     }
   }
 }
 
 
 void MarkCompactCollector::MarkLiveObjects() {
-  GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_MARK);
+  GCTracer::Scope gc_scope(heap()->tracer(), GCTracer::Scope::MC_MARK);
   // The recursive GC marker detects when it is nearing stack overflow,
   // and switches to a different marking system.  JS interrupts interfere
   // with the C stack limit check.
   PostponeInterruptsScope postpone(isolate());
 
   bool incremental_marking_overflowed = false;
   IncrementalMarking* incremental_marking = heap_->incremental_marking();
   if (was_marked_incrementally_) {
     // Finalize the incremental marking and check whether we had an overflow.
     // Both markers use grey color to mark overflowed objects so
@@ skipping 430 matching lines @@
         entries, g, starts.at(g), starts.at(g + 1), new_number_of_entries);
     new_number_of_entries += survived;
   }
   for (int i = new_number_of_entries; i < number_of_entries; i++) {
     entries->clear_at(i);
   }
 }
 
 
 void MarkCompactCollector::ProcessWeakCollections() {
-  GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_WEAKCOLLECTION_PROCESS);
+  GCTracer::Scope gc_scope(heap()->tracer(),
+                           GCTracer::Scope::MC_WEAKCOLLECTION_PROCESS);
   Object* weak_collection_obj = heap()->encountered_weak_collections();
   while (weak_collection_obj != Smi::FromInt(0)) {
     JSWeakCollection* weak_collection =
         reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
     ASSERT(MarkCompactCollector::IsMarked(weak_collection));
     if (weak_collection->table()->IsHashTable()) {
       ObjectHashTable* table = ObjectHashTable::cast(weak_collection->table());
       Object** anchor = reinterpret_cast<Object**>(table->address());
       for (int i = 0; i < table->Capacity(); i++) {
         if (MarkCompactCollector::IsMarked(HeapObject::cast(table->KeyAt(i)))) {
           Object** key_slot =
               table->RawFieldOfElementAt(ObjectHashTable::EntryToIndex(i));
           RecordSlot(anchor, key_slot, *key_slot);
           Object** value_slot =
               table->RawFieldOfElementAt(ObjectHashTable::EntryToValueIndex(i));
           MarkCompactMarkingVisitor::MarkObjectByPointer(
               this, anchor, value_slot);
         }
       }
     }
     weak_collection_obj = weak_collection->next();
   }
 }
 
 
 void MarkCompactCollector::ClearWeakCollections() {
-  GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_WEAKCOLLECTION_CLEAR);
+  GCTracer::Scope gc_scope(heap()->tracer(),
+                           GCTracer::Scope::MC_WEAKCOLLECTION_CLEAR);
   Object* weak_collection_obj = heap()->encountered_weak_collections();
   while (weak_collection_obj != Smi::FromInt(0)) {
     JSWeakCollection* weak_collection =
         reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
     ASSERT(MarkCompactCollector::IsMarked(weak_collection));
     if (weak_collection->table()->IsHashTable()) {
       ObjectHashTable* table = ObjectHashTable::cast(weak_collection->table());
       for (int i = 0; i < table->Capacity(); i++) {
         HeapObject* key = HeapObject::cast(table->KeyAt(i));
         if (!MarkCompactCollector::IsMarked(key)) {
@@ skipping 653 matching lines @@
     }
   }
   invalidated_code_.Rewind(0);
 }
 
 
 void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
   Heap::RelocationLock relocation_lock(heap());
 
   bool code_slots_filtering_required;
-  { GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_SWEEP_NEWSPACE);
+  { GCTracer::Scope gc_scope(heap()->tracer(),
+                             GCTracer::Scope::MC_SWEEP_NEWSPACE);
     code_slots_filtering_required = MarkInvalidatedCode();
     EvacuateNewSpace();
   }
 
-  { GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_EVACUATE_PAGES);
+  { GCTracer::Scope gc_scope(heap()->tracer(),
+                             GCTracer::Scope::MC_EVACUATE_PAGES);
     EvacuatePages();
   }
 
   // Second pass: find pointers to new space and update them.
   PointersUpdatingVisitor updating_visitor(heap());
 
-  { GCTracer::Scope gc_scope(tracer_,
+  { GCTracer::Scope gc_scope(heap()->tracer(),
                              GCTracer::Scope::MC_UPDATE_NEW_TO_NEW_POINTERS);
     // Update pointers in to space.
     SemiSpaceIterator to_it(heap()->new_space()->bottom(),
                             heap()->new_space()->top());
     for (HeapObject* object = to_it.Next();
          object != NULL;
          object = to_it.Next()) {
       Map* map = object->map();
       object->IterateBody(map->instance_type(),
                           object->SizeFromMap(map),
                           &updating_visitor);
     }
   }
 
-  { GCTracer::Scope gc_scope(tracer_,
+  { GCTracer::Scope gc_scope(heap()->tracer(),
                              GCTracer::Scope::MC_UPDATE_ROOT_TO_NEW_POINTERS);
     // Update roots.
     heap_->IterateRoots(&updating_visitor, VISIT_ALL_IN_SWEEP_NEWSPACE);
   }
 
-  { GCTracer::Scope gc_scope(tracer_,
+  { GCTracer::Scope gc_scope(heap()->tracer(),
                              GCTracer::Scope::MC_UPDATE_OLD_TO_NEW_POINTERS);
     StoreBufferRebuildScope scope(heap_,
                                   heap_->store_buffer(),
                                   &Heap::ScavengeStoreBufferCallback);
     heap_->store_buffer()->IteratePointersToNewSpaceAndClearMaps(
         &UpdatePointer);
   }
 
-  { GCTracer::Scope gc_scope(tracer_,
+  { GCTracer::Scope gc_scope(heap()->tracer(),
                              GCTracer::Scope::MC_UPDATE_POINTERS_TO_EVACUATED);
     SlotsBuffer::UpdateSlotsRecordedIn(heap_,
                                        migration_slots_buffer_,
                                        code_slots_filtering_required);
     if (FLAG_trace_fragmentation) {
       PrintF("  migration slots buffer: %d\n",
              SlotsBuffer::SizeOfChain(migration_slots_buffer_));
     }
 
     if (compacting_ && was_marked_incrementally_) {
       // It's difficult to filter out slots recorded for large objects.
       LargeObjectIterator it(heap_->lo_space());
       for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
         // LargeObjectSpace is not swept yet thus we have to skip
         // dead objects explicitly.
         if (!IsMarked(obj)) continue;
 
         Page* p = Page::FromAddress(obj->address());
         if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
           obj->Iterate(&updating_visitor);
           p->ClearFlag(Page::RESCAN_ON_EVACUATION);
         }
       }
     }
   }
 
   int npages = evacuation_candidates_.length();
   { GCTracer::Scope gc_scope(
-      tracer_, GCTracer::Scope::MC_UPDATE_POINTERS_BETWEEN_EVACUATED);
+      heap()->tracer(), GCTracer::Scope::MC_UPDATE_POINTERS_BETWEEN_EVACUATED);
     for (int i = 0; i < npages; i++) {
       Page* p = evacuation_candidates_[i];
       ASSERT(p->IsEvacuationCandidate() ||
              p->IsFlagSet(Page::RESCAN_ON_EVACUATION));
 
       if (p->IsEvacuationCandidate()) {
         SlotsBuffer::UpdateSlotsRecordedIn(heap_,
                                            p->slots_buffer(),
                                            code_slots_filtering_required);
         if (FLAG_trace_fragmentation) {
@@ skipping 39 matching lines @@
             }
             break;
           default:
             UNREACHABLE();
             break;
         }
       }
     }
   }
 
-  GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_UPDATE_MISC_POINTERS);
+  GCTracer::Scope gc_scope(heap()->tracer(),
+                           GCTracer::Scope::MC_UPDATE_MISC_POINTERS);
 
   // Update pointers from cells.
   HeapObjectIterator cell_iterator(heap_->cell_space());
   for (HeapObject* cell = cell_iterator.Next();
        cell != NULL;
        cell = cell_iterator.Next()) {
     if (cell->IsCell()) {
       Cell::BodyDescriptor::IterateBody(cell, &updating_visitor);
     }
   }
@@ skipping 614 matching lines @@
            AllocationSpaceName(space->identity()),
            pages_swept);
   }
 
   // Give pages that are queued to be freed back to the OS.
   heap()->FreeQueuedChunks();
 }
 
 
 void MarkCompactCollector::SweepSpaces() {
-  GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_SWEEP);
+  GCTracer::Scope gc_scope(heap()->tracer(), GCTracer::Scope::MC_SWEEP);
 #ifdef DEBUG
   state_ = SWEEP_SPACES;
 #endif
   SweeperType how_to_sweep = CONSERVATIVE;
   if (AreSweeperThreadsActivated()) {
     if (FLAG_parallel_sweeping) how_to_sweep = PARALLEL_CONSERVATIVE;
     if (FLAG_concurrent_sweeping) how_to_sweep = CONCURRENT_CONSERVATIVE;
   }
   if (sweep_precisely_) how_to_sweep = PRECISE;
 
   MoveEvacuationCandidatesToEndOfPagesList();
 
   // Noncompacting collections simply sweep the spaces to clear the mark
   // bits and free the nonlive blocks (for old and map spaces).  We sweep
   // the map space last because freeing non-live maps overwrites them and
   // the other spaces rely on possibly non-live maps to get the sizes for
   // non-live objects.
-  { GCTracer::Scope sweep_scope(tracer_, GCTracer::Scope::MC_SWEEP_OLDSPACE);
+  { GCTracer::Scope sweep_scope(heap()->tracer(),
+                                GCTracer::Scope::MC_SWEEP_OLDSPACE);
     { SequentialSweepingScope scope(this);
       SweepSpace(heap()->old_pointer_space(), how_to_sweep);
       SweepSpace(heap()->old_data_space(), how_to_sweep);
     }
 
     if (how_to_sweep == PARALLEL_CONSERVATIVE ||
         how_to_sweep == CONCURRENT_CONSERVATIVE) {
       StartSweeperThreads();
     }
 
     if (how_to_sweep == PARALLEL_CONSERVATIVE) {
       WaitUntilSweepingCompleted();
     }
   }
   RemoveDeadInvalidatedCode();
 
-  { GCTracer::Scope sweep_scope(tracer_, GCTracer::Scope::MC_SWEEP_CODE);
+  { GCTracer::Scope sweep_scope(heap()->tracer(),
+                                GCTracer::Scope::MC_SWEEP_CODE);
     SweepSpace(heap()->code_space(), PRECISE);
   }
 
-  { GCTracer::Scope sweep_scope(tracer_, GCTracer::Scope::MC_SWEEP_CELL);
+  { GCTracer::Scope sweep_scope(heap()->tracer(),
+                                GCTracer::Scope::MC_SWEEP_CELL);
     SweepSpace(heap()->cell_space(), PRECISE);
     SweepSpace(heap()->property_cell_space(), PRECISE);
   }
 
   EvacuateNewSpaceAndCandidates();
 
   // ClearNonLiveTransitions depends on precise sweeping of map space to
   // detect whether unmarked map became dead in this collection or in one
   // of the previous ones.
-  { GCTracer::Scope sweep_scope(tracer_, GCTracer::Scope::MC_SWEEP_MAP);
+  { GCTracer::Scope sweep_scope(heap()->tracer(),
+                                GCTracer::Scope::MC_SWEEP_MAP);
     SweepSpace(heap()->map_space(), PRECISE);
   }
 
   // Deallocate unmarked objects and clear marked bits for marked objects.
   heap_->lo_space()->FreeUnmarkedObjects();
 
   // Deallocate evacuated candidate pages.
   ReleaseEvacuationCandidates();
 }
 
@@ skipping 230 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal