1 /*
   2  * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
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  24 
  25 #ifndef SHARE_VM_JFR_LEAKPROFILER_CHAINS_BITSET_HPP
  26 #define SHARE_VM_JFR_LEAKPROFILER_CHAINS_BITSET_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "oops/oopsHierarchy.hpp"
  30 #include "utilities/bitMap.inline.hpp"
  31 
  32 class JfrVirtualMemory;
  33 class MemRegion;
  34 
  35 class BitSet : public CHeapObj<mtTracing> {
  36  private:
  37   JfrVirtualMemory* _vmm;
  38   const HeapWord* const _region_start;
  39   BitMap _bits;
  40   const size_t _region_size;
  41 
  42  public:
  43   BitSet(const MemRegion& covered_region);
  44   ~BitSet();
  45 
  46   bool initialize();
  47 
  48   BitMap::idx_t mark_obj(const HeapWord* addr) {
  49     const BitMap::idx_t bit = addr_to_bit(addr);
  50     _bits.set_bit(bit);
  51     return bit;
  52   }
  53 
  54   BitMap::idx_t mark_obj(oop obj) {
  55     return mark_obj((HeapWord*)obj);
  56   }
  57 
  58   bool is_marked(const HeapWord* addr) const {
  59     return is_marked(addr_to_bit(addr));
  60   }
  61 
  62   bool is_marked(oop obj) const {
  63     return is_marked((HeapWord*)obj);
  64   }
  65 
  66   BitMap::idx_t size() const {
  67     return _bits.size();
  68   }
  69 
  70   BitMap::idx_t addr_to_bit(const HeapWord* addr) const {
  71     return pointer_delta(addr, _region_start) >> LogMinObjAlignment;
  72   }
  73 
  74   bool is_marked(const BitMap::idx_t bit) const {
  75     return _bits.at(bit);
  76   }
  77 };
  78 
  79 #endif  // SHARE_VM_JFR_LEAKPROFILER_CHAINS_BITSET_HPP