1 /*
   2  * Copyright (c) 2001, 2016, 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_GC_G1_CONCURRENTG1REFINETHREAD_HPP
  26 #define SHARE_VM_GC_G1_CONCURRENTG1REFINETHREAD_HPP
  27 
  28 #include "gc/shared/concurrentGCThread.hpp"
  29 
  30 // Forward Decl.
  31 class CardTableEntryClosure;
  32 class ConcurrentG1Refine;
  33 
  34 // One or more G1 Concurrent Refinement Threads may be active if concurrent
  35 // refinement is in progress.
  36 class ConcurrentG1RefineThread: public ConcurrentGCThread {
  37   friend class VMStructs;
  38   friend class G1CollectedHeap;
  39 
  40   double _vtime_start;  // Initial virtual time.
  41   double _vtime_accum;  // Accumulated virtual time.
  42   uint _worker_id;
  43   uint _worker_id_offset;
  44 
  45   // The refinement threads collection is linked list. A predecessor can activate a successor
  46   // when the number of the rset update buffer crosses a certain threshold. A successor
  47   // would self-deactivate when the number of the buffers falls below the threshold.
  48   bool _active;
  49   ConcurrentG1RefineThread* _next;
  50   Monitor* _monitor;
  51   ConcurrentG1Refine* _cg1r;
  52 
  53   // The closure applied to completed log buffers.
  54   CardTableEntryClosure* _refine_closure;
  55 
  56   size_t _thread_threshold_step;
  57   // This thread activation threshold
  58   size_t _threshold;
  59   // This thread deactivation threshold
  60   size_t _deactivation_threshold;
  61 
  62   void wait_for_completed_buffers();
  63 
  64   void set_active(bool x) { _active = x; }
  65   bool is_active();
  66   void activate();
  67   void deactivate();
  68 
  69   bool is_primary() { return (_worker_id == 0); }
  70 
  71   void run_service();
  72   void stop_service();
  73 
  74 public:
  75   virtual void run();
  76   // Constructor
  77   ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread* next,
  78                            CardTableEntryClosure* refine_closure,
  79                            uint worker_id_offset, uint worker_id);
  80 
  81   void initialize();
  82 
  83   // Total virtual time so far.
  84   double vtime_accum() { return _vtime_accum; }
  85 
  86   ConcurrentG1Refine* cg1r() { return _cg1r;     }
  87 
  88   // shutdown
  89   void stop();
  90 };
  91 
  92 #endif // SHARE_VM_GC_G1_CONCURRENTG1REFINETHREAD_HPP
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