Set unswept free bytes for concurent sweeper.

BUG=

Review URL: https://codereview.chromium.org/12184016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13776 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mark-compact.cc

@@ -557,6 +557,8 @@ void MarkCompactCollector::WaitUntilSweepingCompleted() {
     sweeping_pending_ = false;
     StealMemoryFromSweeperThreads(heap()->paged_space(OLD_DATA_SPACE));
     StealMemoryFromSweeperThreads(heap()->paged_space(OLD_POINTER_SPACE));
+    heap()->paged_space(OLD_DATA_SPACE)->ResetUnsweptFreeBytes();
+    heap()->paged_space(OLD_POINTER_SPACE)->ResetUnsweptFreeBytes();
   }
 }
 
@@ -567,6 +569,8 @@ intptr_t MarkCompactCollector::
   for (int i = 0; i < FLAG_sweeper_threads; i++) {
     freed_bytes += heap()->isolate()->sweeper_threads()[i]->StealMemory(space);
   }
+  space->AddToAccountingStats(freed_bytes);
+  space->DecrementUnsweptFreeBytes(freed_bytes);
   return freed_bytes;
 }
 
@@ -3843,6 +3847,7 @@ void MarkCompactCollector::SweepSpace(PagedSpace* space, SweeperType sweeper) {
                  reinterpret_cast<intptr_t>(p));
         }
         p->set_parallel_sweeping(1);
+        space->IncreaseUnsweptFreeBytes(p);
         break;
       }
       case PRECISE: {

src/spaces.h

@@ -1630,6 +1630,11 @@ class PagedSpace : public Space {
     accounting_stats_.ClearSizeWaste();
   }
 
+  // Increases the number of available bytes of that space.
+  void AddToAccountingStats(intptr_t bytes) {
+    accounting_stats_.DeallocateBytes(bytes);
+  }
+
   // Available bytes without growing.  These are the bytes on the free list.
   // The bytes in the linear allocation area are not included in this total
   // because updating the stats would slow down allocation.  New pages are
@@ -1749,11 +1754,19 @@ class PagedSpace : public Space {
     unswept_free_bytes_ += (p->area_size() - p->LiveBytes());
   }
 
+  void DecrementUnsweptFreeBytes(int by) {
+    unswept_free_bytes_ -= by;
+  }
+
   void DecreaseUnsweptFreeBytes(Page* p) {
     ASSERT(ShouldBeSweptLazily(p));
     unswept_free_bytes_ -= (p->area_size() - p->LiveBytes());
   }
 
+  void ResetUnsweptFreeBytes() {
+    unswept_free_bytes_ = 0;
+  }
+
   bool AdvanceSweeper(intptr_t bytes_to_sweep);
 
   // When parallel sweeper threads are active this function waits
@@ -1787,10 +1800,6 @@ class PagedSpace : public Space {
  protected:
   FreeList* free_list() { return &free_list_; }
 
-  void AddToAccountingStats(intptr_t bytes) {
-    accounting_stats_.DeallocateBytes(bytes);
-  }
-
   int area_size_;
 
   // Maximum capacity of this space.

src/sweeper-thread.cc

@@ -76,17 +76,15 @@ void SweeperThread::Run() {
 
 
 intptr_t SweeperThread::StealMemory(PagedSpace* space) {
-  intptr_t free_bytes = 0;
   if (space->identity() == OLD_POINTER_SPACE) {
-    free_bytes = space->free_list()->Concatenate(&free_list_old_pointer_space_);
-    space->AddToAccountingStats(free_bytes);
+    return space->free_list()->Concatenate(&free_list_old_pointer_space_);
   } else if (space->identity() == OLD_DATA_SPACE) {
-    free_bytes = space->free_list()->Concatenate(&free_list_old_data_space_);
-    space->AddToAccountingStats(free_bytes);
+    return space->free_list()->Concatenate(&free_list_old_data_space_);
   }
-  return free_bytes;
+  return 0;
 }
 
+
 void SweeperThread::Stop() {
   Release_Store(&stop_thread_, static_cast<AtomicWord>(true));
   start_sweeping_semaphore_->Signal();