Favor free list allocation to bump pointer allocation.

runtime/vm/freelist.h

Index: runtime/vm/freelist.h
diff --git a/runtime/vm/freelist.h b/runtime/vm/freelist.h
index 7edc4fea48d724973b16a9cb777623758965f687..711c3666d698e5b9a9dddd726f71695441686c43 100644
--- a/runtime/vm/freelist.h
+++ b/runtime/vm/freelist.h
@@ -5,6 +5,8 @@
 #ifndef VM_FREELIST_H_
 #define VM_FREELIST_H_
 
+#include <bitset>

[siva, 2012/07/19 19:38:23]

The compiler uses our BitVector class for all these kinds of bitmap needs.
This comes back to the generic question do we use our home brewed data
structures or the stl ones.

[cshapiro, 2012/07/19 22:34:29]

With regard to our off-line discussion, this is a distinct type whose behavior
is sufficiently different from BitVector to justify its existence.

+
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/raw_object.h"
@@ -78,6 +80,10 @@ class FreeList {
 
   void Reset();
 
+  intptr_t Length(int index) const;
+
+  void Print() const;
+
  private:
   static const int kNumLists = 128;
 
@@ -88,6 +94,8 @@ class FreeList {
 
   void SplitElementAfterAndEnqueue(FreeListElement* element, intptr_t size);
 
+  std::bitset<kNumLists + 1> free_map_;
+
   FreeListElement* free_lists_[kNumLists + 1];
 
   DISALLOW_COPY_AND_ASSIGN(FreeList);