Remove sequential sweeping mode and perform lazy sweeping when no sweeper threads are active.

src/mark-compact.h

 // 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.
 
 #ifndef V8_MARK_COMPACT_H_
 #define V8_MARK_COMPACT_H_
 
 #include "src/compiler-intrinsics.h"
 #include "src/spaces.h"
 
@@ skipping 552 matching lines @@
   static inline bool IsMarked(Object* obj);
 
   inline Heap* heap() const { return heap_; }
   inline Isolate* isolate() const;
 
   CodeFlusher* code_flusher() { return code_flusher_; }
   inline bool is_code_flushing_enabled() const { return code_flusher_ != NULL; }
   void EnableCodeFlushing(bool enable);
 
   enum SweeperType {
-    CONSERVATIVE,
     PARALLEL_CONSERVATIVE,
     CONCURRENT_CONSERVATIVE,
     PRECISE
   };
 
   enum SweepingParallelism {
     SWEEP_ON_MAIN_THREAD,
     SWEEP_IN_PARALLEL
   };
 
@@ skipping 82 matching lines @@
   int SweepInParallel(PagedSpace* space, int required_freed_bytes);
 
   void WaitUntilSweepingCompleted();
 
   bool IsSweepingCompleted();
 
   void RefillFreeList(PagedSpace* space);
 
   bool AreSweeperThreadsActivated();
 
-  // If a paged space is passed in, this method checks if the given space is
-  // swept concurrently. Otherwise, this method checks if concurrent sweeping
-  // is in progress right now on any space.
-  bool IsConcurrentSweepingInProgress(PagedSpace* space = NULL);
+  // Checks if sweeping is in progress right now on any space.
+  bool sweeping_pending() { return sweeping_pending_; }

[Jarin, 2014/07/11 07:40:52]

Nit: so why is not this called IsSweepingInProgress (or some such)?

[Hannes Payer (out of office), 2014/07/11 09:36:13]

It is a true getter now. Anyhow, I renamed the variable to
sweeping_in_progress_.

 
   void set_sequential_sweeping(bool sequential_sweeping) {
     sequential_sweeping_ = sequential_sweeping;
   }
 
   bool sequential_sweeping() const {
     return sequential_sweeping_;
   }
 
   // Mark the global table which maps weak objects to dependent code without
@@ skipping 295 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_H_