Parallel and concurrent sweeping.

src/mark-compact.h

Index: src/mark-compact.h
diff --git a/src/mark-compact.h b/src/mark-compact.h
index 9a0b014d633d6a069f288c9341cd9eac38531a66..1595c3bff0d260c4fc9ce909a18671e1d7cd5b7d 100644
--- a/src/mark-compact.h
+++ b/src/mark-compact.h
@@ -587,9 +587,15 @@ class MarkCompactCollector {
   enum SweeperType {
     CONSERVATIVE,
     LAZY_CONSERVATIVE,
+    PARALLEL_CONSERVATIVE,
     PRECISE
   };
 
+  enum SweepingParallelism {
+    SWEEP_SEQUENTIALLY,
+    SWEEP_IN_PARALLEL
+  };
+
 #ifdef VERIFY_HEAP
   void VerifyMarkbitsAreClean();
   static void VerifyMarkbitsAreClean(PagedSpace* space);
@@ -598,7 +604,10 @@ class MarkCompactCollector {
 
   // Sweep a single page from the given space conservatively.
   // Return a number of reclaimed bytes.
-  static intptr_t SweepConservatively(PagedSpace* space, Page* p);
+  template<SweepingParallelism type>
+  static intptr_t SweepConservatively(PagedSpace* space,
+                                      FreeList* free_list,
+                                      Page* p);
 
   INLINE(static bool ShouldSkipEvacuationSlotRecording(Object** anchor)) {
     return Page::FromAddress(reinterpret_cast<Address>(anchor))->
@@ -664,6 +673,16 @@ class MarkCompactCollector {
 
   MarkingParity marking_parity() { return marking_parity_; }
 
+  void SweepInParallel(PagedSpace* space,
+                       FreeList* private_free_list,
+                       FreeList* free_list);
+
+  void WaitUntilSweepingCompleted();
+
+  intptr_t StealMemoryFromSweeperThreads(PagedSpace* space);
+
+  bool AreSweeperThreadsActivated();
+
  private:
   MarkCompactCollector();
   ~MarkCompactCollector();
@@ -672,6 +691,7 @@ class MarkCompactCollector {
   void RemoveDeadInvalidatedCode();
   void ProcessInvalidatedCode(ObjectVisitor* visitor);
 
+  void StartSweeperThreads();
 
 #ifdef DEBUG
   enum CollectorState {
@@ -836,6 +856,8 @@ class MarkCompactCollector {
 
   void SweepSpace(PagedSpace* space, SweeperType sweeper);
 
+  void PrepareParallelSweeping(PagedSpace* space);

[Michael Starzinger, 2013/01/30 11:01:19]

The implementation of this method is gone, let's also drop the declaration.

[Hannes Payer (out of office), 2013/01/30 12:07:32]

Done.

+
 #ifdef DEBUG
   friend class MarkObjectVisitor;
   static void VisitObject(HeapObject* obj);