src/share/vm/gc_implementation/g1/concurrentMarkThread.hpp

Mon, 02 Aug 2010 12:51:43 -0700

author
johnc
date
Mon, 02 Aug 2010 12:51:43 -0700
changeset 2060
2d160770d2e5
parent 1907
c18cbe5936b8
child 2195
4e0094bc41fa
permissions
-rw-r--r--

6814437: G1: remove the _new_refs array
Summary: The per-worker _new_refs array is used to hold references that point into the collection set. It is populated during RSet updating and subsequently processed. In the event of an evacuation failure it processed again to recreate the RSets of regions in the collection set. Remove the per-worker _new_refs array by processing the references directly. Use a DirtyCardQueue to hold the cards containing the references so that the RSets of regions in the collection set can be recreated when handling an evacuation failure.
Reviewed-by: iveresov, jmasa, tonyp

     1 /*
     2  * Copyright (c) 2001, 2009, 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  */
    25 // The Concurrent Mark GC Thread (could be several in the future).
    26 // This is copied from the Concurrent Mark Sweep GC Thread
    27 // Still under construction.
    29 class ConcurrentMark;
    31 class ConcurrentMarkThread: public ConcurrentGCThread {
    32   friend class VMStructs;
    34   double _vtime_start;  // Initial virtual time.
    35   double _vtime_accum;  // Accumulated virtual time.
    37   double _vtime_mark_accum;
    38   double _vtime_count_accum;
    40  public:
    41   virtual void run();
    43  private:
    44   ConcurrentMark*                  _cm;
    45   volatile bool                    _started;
    46   volatile bool                    _in_progress;
    48   void sleepBeforeNextCycle();
    50   static SurrogateLockerThread*         _slt;
    52  public:
    53   // Constructor
    54   ConcurrentMarkThread(ConcurrentMark* cm);
    56   static void makeSurrogateLockerThread(TRAPS);
    57   static SurrogateLockerThread* slt() { return _slt; }
    59   // Printing
    60   void print_on(outputStream* st) const;
    61   void print() const;
    63   // Total virtual time so far.
    64   double vtime_accum();
    65   // Marking virtual time so far
    66   double vtime_mark_accum();
    67   // Counting virtual time so far.
    68   double vtime_count_accum() { return _vtime_count_accum; }
    70   ConcurrentMark* cm()     { return _cm; }
    72   void set_started()       { _started = true;  }
    73   void clear_started()     { _started = false; }
    74   bool started()           { return _started;  }
    76   void set_in_progress()   { _in_progress = true;  }
    77   void clear_in_progress() { _in_progress = false; }
    78   bool in_progress()       { return _in_progress;  }
    80   // This flag returns true from the moment a marking cycle is
    81   // initiated (during the initial-mark pause when started() is set)
    82   // to the moment when the cycle completes (just after the next
    83   // marking bitmap has been cleared and in_progress() is
    84   // cleared). While this flag is true we will not start another cycle
    85   // so that cycles do not overlap. We cannot use just in_progress()
    86   // as the CM thread might take some time to wake up before noticing
    87   // that started() is set and set in_progress().
    88   bool during_cycle()      { return started() || in_progress(); }
    90   // Yield for GC
    91   void            yield();
    93   // shutdown
    94   void stop();
    95 };

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