commit bbd695c71e0bf518f582e84524e1cdeb3de3896c
author Mathieu Chartier <mathieuc@google.com> Wed Apr 16 09:48:48 2014 -0700
committer Mathieu Chartier <mathieuc@google.com> Thu Apr 17 19:01:34 2014 -0700
tree 6fe6a128b629abc6a396a192b2e8da1180afeded
parent a092ee404ababbf8fc945111dc4a571284c9f02f

Replace ObjectSet with LargeObjectBitmap.

Speeds up large object marking since large objects no longer required
a lock. Changed the GCs to use the heap bitmap for marking objects
which aren't in the fast path. This eliminates the need for a
MarkLargeObject function.

Maps before (10 GC iterations):
Mean partial time: 180ms
Mean sticky time: 151ms

Maps after:
Mean partial time: 161ms
Mean sticky time: 101ms

Note: the GC durations are long due to recent ergonomic changes and
because the fast bulk free hasn't yet been enabled. Over 50% of the
GC time is spent in RosAllocSpace::FreeList.

Bug: 13571028

Change-Id: Id8f94718aeaa13052672ccbae1e8edf77d653f62

runtime/gc/space/space.h

diff --git a/runtime/gc/space/space.h b/runtime/gc/space/space.h
index 2b27f87..0a87a16 100644
--- a/runtime/gc/space/space.h
+++ b/runtime/gc/space/space.h
@@ -173,10 +173,11 @@
 
  protected:
   struct SweepCallbackContext {
-    bool swap_bitmaps;
-    Heap* heap;
-    space::Space* space;
-    Thread* self;
+   public:
+    SweepCallbackContext(bool swap_bitmaps, space::Space* space);
+    const bool swap_bitmaps;
+    space::Space* const space;
+    Thread* const self;
     size_t freed_objects;
     size_t freed_bytes;
   };
@@ -313,15 +314,15 @@
 // is suitable for use for large primitive arrays.
 class DiscontinuousSpace : public Space {
  public:
-  accounting::ObjectSet* GetLiveObjects() const {
-    return live_objects_.get();
+  accounting::LargeObjectBitmap* GetLiveBitmap() const {
+    return live_bitmap_.get();
   }
 
-  accounting::ObjectSet* GetMarkObjects() const {
-    return mark_objects_.get();
+  accounting::LargeObjectBitmap* GetMarkBitmap() const {
+    return mark_bitmap_.get();
   }
 
-  virtual bool IsDiscontinuousSpace() const {
+  virtual bool IsDiscontinuousSpace() const OVERRIDE {
     return true;
   }
 
@@ -330,8 +331,8 @@
  protected:
   DiscontinuousSpace(const std::string& name, GcRetentionPolicy gc_retention_policy);
 
-  UniquePtr<accounting::ObjectSet> live_objects_;
-  UniquePtr<accounting::ObjectSet> mark_objects_;
+  UniquePtr<accounting::LargeObjectBitmap> live_bitmap_;
+  UniquePtr<accounting::LargeObjectBitmap> mark_bitmap_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DiscontinuousSpace);