scalableleaheap.h

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#ifndef _SCALABLELEAHEAP_H_
#define _SCALABLELEAHEAP_H_

#include "heaplayers.h"

namespace ScalableHeapNS {

        template <int NumHeaps, class SuperHeap>
        class GlobalHeapWrapper : public SuperHeap {
        public:
                inline void * malloc (size_t sz) {
                        void * ptr = SuperHeap::malloc (sz);
                        if (ptr != NULL) {
                                assert (!isFree(ptr));
                        }
                        return ptr;
                }
                inline void free (void * ptr) {
                        // Set this object's heap to an unassigned heap (NumHeaps),
                        // then free it.
                        setHeap (ptr, NumHeaps); // This should be an unassigned heap number.
                        assert (getHeap(ptr) == NumHeaps);
                        setPrevHeap(getNext(ptr), NumHeaps);
                        assert (getPrevHeap(getNext(ptr)) == NumHeaps);
                        SuperHeap::free (ptr);
                }
        private:
                inline int remove (void *);
        };


  template <int Threshold, class Heap1, class Heap2>
  class TryHeap : public Heap2 {
  public:
          TryHeap (void)
                  : reserved (0)
          {}

    inline void * malloc (size_t sz) {
      void * ptr = heap1.malloc (sz);
      if (ptr == NULL) {
#if 1
                // Get a big chunk.
                size_t chunkSize = (Threshold / 2) > sz ? (Threshold / 2) : sz;
                ptr = Heap2::malloc (chunkSize);
                if (ptr == NULL) {
                        return NULL;
                }
                // Split it.
                void * splitPiece = CoalesceHeap<Heap2>::split (ptr, sz);
                assert (splitPiece != ptr);
                assert (!isFree(ptr));
                // Put the split piece on heap 1.
                if (splitPiece != NULL) {
                        reserved += getSize(splitPiece);
                        heap1.free (splitPiece);
                }
#else
                ptr = Heap2::malloc (sz);
#endif
          } else {
                  reserved -= getSize(ptr);
          }
//        assert (getHeap(ptr) == tid);
      return ptr;
    }
    inline void free (void * ptr) {
          reserved += getSize(ptr);
      heap1.free (ptr);
      if (reserved > Threshold) {
                // We've crossed the threshold.
                // Free objects from heap 1 and give them to heap 2.
                // Start big.
                size_t sz = Threshold / 2;
                while ((sz > sizeof(double)) && (reserved > Threshold / 2)) {
                  void * p = NULL;
                  while ((p == NULL) && (sz >= sizeof(double))) {
                        p = heap1.malloc (sz);
                        if (p == NULL) {
                          sz >>= 1;
                        }
                  }
                  if (p != NULL) {
                          reserved -= getSize(p);
                          Heap2::free (p);
                  }
                }
      }
    }

        
  private:
        inline int remove (void * ptr);
#if 0
        {
                assert (0);
                abort();
        }
#endif

    Heap1 heap1;
        int reserved;
  };


  template <int NumHeaps, int MmapThreshold, class BaseNullHeap, class BaseHeap>
  class SmallHeap : public
          ScalableHeapNS::TryHeap<MmapThreshold,
        MarkThreadHeap<NumHeaps, BaseNullHeap>,
        MarkThreadHeap<NumHeaps, GlobalHeapWrapper<NumHeaps, BaseHeap> > > {};

  template <int NumHeaps, int MmapThreshold, class BaseNullHeap, class BaseHeap>
  class MTHeap :
    public PHOThreadHeap<NumHeaps,
                     LockedHeap<SmallHeap<NumHeaps, MmapThreshold, BaseNullHeap, BaseHeap> > > {};

};

  
template <int NumHeaps, class BaseNullHeap, class BaseHeap, class Mmap>
class ScalableHeap :
public SelectMmapHeap<128 * 1024,
         ScalableHeapNS::MTHeap<NumHeaps, 128 * 1024, BaseNullHeap, BaseHeap>,
                    LockedHeap<Mmap> > {};
#endif

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