1 /*
   2  * Copyright (c) 2016, Red Hat, Inc. and/or its affiliates.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 
  25 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP
  26 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 
  30 class ShenandoahHeap;
  31 class ShenandoahHeapRegion;
  32 
  33 class ShenandoahCollectionSet : public CHeapObj<mtGC> {
  34   friend class ShenandoahHeap;
  35 private:
  36   size_t const          _map_size;
  37   size_t const          _region_size_bytes_shift;
  38   jbyte* const          _cset_map;
  39   // Bias cset map's base address for fast test if an oop is in cset
  40   jbyte* const          _biased_cset_map;
  41 
  42   ShenandoahHeap* const _heap;
  43 
  44   size_t                _garbage;
  45   size_t                _live_data;
  46   size_t                _used;
  47   size_t                _region_count;
  48 
  49   volatile jint         _current_index;
  50 public:
  51   ShenandoahCollectionSet(ShenandoahHeap* heap, HeapWord* heap_base);
  52 
  53   // Add region to collection set
  54   void add_region(ShenandoahHeapRegion* r);
  55 
  56   // Bring per-region statuses to consistency with this collection.
  57   // TODO: This is a transitional interface that bridges the gap between
  58   // region statuses and this collection. Should go away after we merge them.
  59   void update_region_status();
  60 
  61   // Remove region from collection set
  62   void remove_region(ShenandoahHeapRegion* r);
  63 
  64   // MT version
  65   ShenandoahHeapRegion* claim_next();
  66 
  67   // Single-thread version
  68   ShenandoahHeapRegion* next();
  69 
  70   size_t count()  const { return _region_count; }
  71   bool is_empty() const { return _region_count == 0; }
  72 
  73   void clear_current_index() {
  74     _current_index = 0;
  75   }
  76 
  77   inline bool is_in(ShenandoahHeapRegion* r) const;
  78   inline bool is_in(size_t region_number)    const;
  79   inline bool is_in(HeapWord* p)             const;
  80 
  81   void print_on(outputStream* out) const;
  82 
  83   size_t used()      const { return _used; }
  84   size_t live_data() const { return _live_data; }
  85   size_t garbage()   const { return _garbage;   }
  86   void clear();
  87 
  88 private:
  89   jbyte* biased_map_address() const {
  90     return _biased_cset_map;
  91   }
  92 };
  93 
  94 #endif //SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP