rev 10309 : 8150390: Move rs length sampling data to the sampling thread
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   1 /*
   2  * Copyright (c) 2015, 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
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_G1_YOUNGLIST_HPP
  26 #define SHARE_VM_GC_G1_YOUNGLIST_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/globals.hpp"
  30 
  31 class YoungList : public CHeapObj<mtGC> {
  32 private:
  33   G1CollectedHeap* _g1h;
  34 
  35   HeapRegion* _head;
  36 
  37   HeapRegion* _survivor_head;
  38   HeapRegion* _survivor_tail;
  39 
  40   HeapRegion* _curr;
  41 
  42   uint        _length;
  43   uint        _survivor_length;
  44 
  45   size_t      _last_sampled_rs_lengths;
  46   size_t      _sampled_rs_lengths;
  47 
  48   void         empty_list(HeapRegion* list);
  49 
  50 public:
  51   YoungList(G1CollectedHeap* g1h);
  52 
  53   void         push_region(HeapRegion* hr);
  54   void         add_survivor_region(HeapRegion* hr);
  55 
  56   void         empty_list();
  57   bool         is_empty() { return _length == 0; }
  58   uint         length() { return _length; }
  59   uint         eden_length() { return length() - survivor_length(); }
  60   uint         survivor_length() { return _survivor_length; }
  61 
  62   // Currently we do not keep track of the used byte sum for the
  63   // young list and the survivors and it'd be quite a lot of work to
  64   // do so. When we'll eventually replace the young list with
  65   // instances of HeapRegionLinkedList we'll get that for free. So,
  66   // we'll report the more accurate information then.
  67   size_t       eden_used_bytes() {
  68     assert(length() >= survivor_length(), "invariant");
  69     return (size_t) eden_length() * HeapRegion::GrainBytes;
  70   }
  71   size_t       survivor_used_bytes() {
  72     return (size_t) survivor_length() * HeapRegion::GrainBytes;
  73   }
  74 
  75   void rs_length_sampling_init();
  76   bool rs_length_sampling_more();
  77   void rs_length_sampling_next();
  78 
  79   void reset_sampled_info() {
  80     _last_sampled_rs_lengths =   0;
  81   }
  82   size_t sampled_rs_lengths() { return _last_sampled_rs_lengths; }
  83 
  84   // for development purposes
  85   void reset_auxilary_lists();
  86   void clear() { _head = NULL; _length = 0; }
  87 
  88   void clear_survivors() {
  89     _survivor_head    = NULL;
  90     _survivor_tail    = NULL;
  91     _survivor_length  = 0;
  92   }
  93 
  94   HeapRegion* first_region() { return _head; }
  95   HeapRegion* first_survivor_region() { return _survivor_head; }
  96   HeapRegion* last_survivor_region() { return _survivor_tail; }
  97 
  98   // debugging
  99   bool          check_list_well_formed();
 100   bool          check_list_empty(bool check_sample = true);
 101   void          print();
 102 };
 103 
 104 #endif // SHARE_VM_GC_G1_YOUNGLIST_HPP
--- EOF ---