Enable concurrent sweeping. Added some extra debugging checks for concurrent sweeping.

src/spaces.cc

 // Copyright 2011 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 1124 matching lines @@
   }
 
   if (page->WasSwept()) {
     intptr_t size = free_list_.EvictFreeListItems(page);
     accounting_stats_.AllocateBytes(size);
     ASSERT_EQ(AreaSize(), static_cast<int>(size));
   } else {
     DecreaseUnsweptFreeBytes(page);
   }
 
+  // TODO(hpayer): This check is just used for debugging purpose and
+  // should be removed or turned into an assert after investigating the
+  // crash in concurrent sweeping.
+  CHECK(!free_list_.ContainsPageFreeListItems(page));
+
   if (Page::FromAllocationTop(allocation_info_.top()) == page) {
     allocation_info_.set_top(NULL);
     allocation_info_.set_limit(NULL);
   }
 
   if (unlink) {
     page->Unlink();
   }
   if (page->IsFlagSet(MemoryChunk::CONTAINS_ONLY_DATA)) {
     heap()->isolate()->memory_allocator()->Free(page);
@@ skipping 963 matching lines @@
     }
   }
   if (top_ == NULL) {
     end_ = NULL;
   }
   available_ -= sum;
   return sum;
 }
 
 
+bool FreeListCategory::ContainsPageFreeListItemsInList(Page* p) {
+  FreeListNode** n = &top_;
+  while (*n != NULL) {
+    if (Page::FromAddress((*n)->address()) == p) return true;
+    n = (*n)->next_address();
+  }
+  return false;
+}
+
+
 FreeListNode* FreeListCategory::PickNodeFromList(int *node_size) {
   FreeListNode* node = top_;
 
   if (node == NULL) return NULL;
 
   while (node != NULL &&
          Page::FromAddress(node->address())->IsEvacuationCandidate()) {
     available_ -= reinterpret_cast<FreeSpace*>(node)->Size();
     node = node->next();
   }
@@ skipping 307 matching lines @@
         large_list_.EvictFreeListItemsInList(p);
     p->set_available_in_small_free_list(0);
     p->set_available_in_medium_free_list(0);
     p->set_available_in_large_free_list(0);
   }
 
   return sum;
 }
 
 
+bool FreeList::ContainsPageFreeListItems(Page* p) {
+  return huge_list_.EvictFreeListItemsInList(p) ||
+         small_list_.EvictFreeListItemsInList(p) ||
+         medium_list_.EvictFreeListItemsInList(p) ||
+         large_list_.EvictFreeListItemsInList(p);
+}
+
+
 void FreeList::RepairLists(Heap* heap) {
   small_list_.RepairFreeList(heap);
   medium_list_.RepairFreeList(heap);
   large_list_.RepairFreeList(heap);
   huge_list_.RepairFreeList(heap);
 }
 
 
 #ifdef DEBUG
 intptr_t FreeListCategory::SumFreeList() {
@@ skipping 713 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal