Parallel and concurrent sweeping.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 9281fa9d72e354bfc4e16d035bcc14e71eb7a158..1d13f6713fafc9a96b677b4f3b9dc7a0f5176a28 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1082,6 +1082,14 @@ class Heap {
   inline bool CollectGarbage(AllocationSpace space,
                              const char* gc_reason = NULL);
 
+  void StartParallelSweeping(SweeperType sweeper_type);
+  void WaitUntilParallelSweepingCompleted();
+  void StealMemoryFromSweeperThreads(PagedSpace* space);
+  void FinalizeParallelSweeping();
+  bool IsConcurrentSweepingActivated();
+  bool AreSweepingThreadsActivated();
+  bool IsConcurrentSweepingPending();

[Michael Starzinger, 2013/01/24 17:15:54]

We should try to move most of that functionality into MarkCompact and minimize
the entry points in Heap. IMHO parallel sweeping should be considered a
subsystem of MarkCompact.

[Hannes Payer (out of office), 2013/01/25 10:46:49]

Done.

+
   static const int kNoGCFlags = 0;
   static const int kSweepPreciselyMask = 1;
   static const int kReduceMemoryFootprintMask = 2;
@@ -1567,7 +1575,18 @@ class Heap {
            old_pointer_space()->IsSweepingComplete();
   }
 
+  void SweepInParallel(PagedSpace* paged_space,

[Michael Starzinger, 2013/01/24 17:15:54]

This dispatcher should not be necessary.

[Hannes Payer (out of office), 2013/01/25 10:46:49]

Done.

+                       SweeperType sweeper_type,
+                       FreeList* private_free_list,
+                       FreeList* free_list) {
+    mark_compact_collector()->SweepInParallel(paged_space,
+                                              sweeper_type,
+                                              private_free_list,
+                                              free_list);
+  }
+
   bool AdvanceSweepers(int step_size) {

[Michael Starzinger, 2013/01/24 17:15:54]

This is still being called from the idle notification. For both modes it should
be a NOP.

[Hannes Payer (out of office), 2013/01/25 10:46:49]

Done.

+    ASSERT(!FLAG_parallel_sweeping && !FLAG_concurrent_sweeping);
     bool sweeping_complete = old_data_space()->AdvanceSweeper(step_size);
     sweeping_complete &= old_pointer_space()->AdvanceSweeper(step_size);
     return sweeping_complete;