jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp@2d160770d2e5

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, 2007, 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 #ifndef SERIALGC

    27 class DirtyCardQueueSet;

    29 // This barrier is specialized to use a logging barrier to support

    30 // snapshot-at-the-beginning marking.

    32 class G1SATBCardTableModRefBS: public CardTableModRefBSForCTRS {

    33 private:

    34   // Add "pre_val" to a set of objects that may have been disconnected from the

    35   // pre-marking object graph.

    36   static void enqueue(oop pre_val);

    38 public:

    39   G1SATBCardTableModRefBS(MemRegion whole_heap,

    40                           int max_covered_regions);

    42   bool is_a(BarrierSet::Name bsn) {

    43     return bsn == BarrierSet::G1SATBCT || CardTableModRefBS::is_a(bsn);

    44   }

    46   virtual bool has_write_ref_pre_barrier() { return true; }

    48   // This notes that we don't need to access any BarrierSet data

    49   // structures, so this can be called from a static context.

    50   template <class T> static void write_ref_field_pre_static(T* field, oop newVal) {

    51     T heap_oop = oopDesc::load_heap_oop(field);

    52     if (!oopDesc::is_null(heap_oop)) {

    53       enqueue(oopDesc::decode_heap_oop(heap_oop));

    54     }

    55   }

    57   // When we know the current java thread:

    58   template <class T> static void write_ref_field_pre_static(T* field, oop newVal,

    59                                                             JavaThread* jt);

    61   // We export this to make it available in cases where the static

    62   // type of the barrier set is known.  Note that it is non-virtual.

    63   template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) {

    64     write_ref_field_pre_static(field, newVal);

    65   }

    67   // These are the more general virtual versions.

    68   virtual void write_ref_field_pre_work(oop* field, oop new_val) {

    69     inline_write_ref_field_pre(field, new_val);

    70   }

    71   virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {

    72     inline_write_ref_field_pre(field, new_val);

    73   }

    74   virtual void write_ref_field_pre_work(void* field, oop new_val) {

    75     guarantee(false, "Not needed");

    76   }

    78   template <class T> void write_ref_array_pre_work(T* dst, int count);

    79   virtual void write_ref_array_pre(oop* dst, int count) {

    80     write_ref_array_pre_work(dst, count);

    81   }

    82   virtual void write_ref_array_pre(narrowOop* dst, int count) {

    83     write_ref_array_pre_work(dst, count);

    84   }

    85 };

    87 // Adds card-table logging to the post-barrier.

    88 // Usual invariant: all dirty cards are logged in the DirtyCardQueueSet.

    89 class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS {

    90  private:

    91   DirtyCardQueueSet& _dcqs;

    92  public:

    93   G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,

    94                                  int max_covered_regions);

    96   bool is_a(BarrierSet::Name bsn) {

    97     return bsn == BarrierSet::G1SATBCTLogging ||

    98       G1SATBCardTableModRefBS::is_a(bsn);

    99   }

   101   void write_ref_field_work(void* field, oop new_val);

   103   // Can be called from static contexts.

   104   static void write_ref_field_static(void* field, oop new_val);

   106   // NB: if you do a whole-heap invalidation, the "usual invariant" defined

   107   // above no longer applies.

   108   void invalidate(MemRegion mr, bool whole_heap = false);

   110   void write_region_work(MemRegion mr)    { invalidate(mr); }

   111   void write_ref_array_work(MemRegion mr) { invalidate(mr); }

   114 };

   117 #endif // SERIALGC

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp@2d160770d2e5

src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp