jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/psScavenge.inline.hpp@4dfb2df418f2

6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

     1 /*

     2  * Copyright (c) 2002, 2011, 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 SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP

    26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP

    28 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp"

    29 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"

    30 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"

    31 #include "gc_implementation/parallelScavenge/psScavenge.hpp"

    33 inline void PSScavenge::save_to_space_top_before_gc() {

    34   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

    35   _to_space_top_before_gc = heap->young_gen()->to_space()->top();

    36 }

    38 template <class T> inline bool PSScavenge::should_scavenge(T* p) {

    39   T heap_oop = oopDesc::load_heap_oop(p);

    40   if (oopDesc::is_null(heap_oop)) return false;

    41   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);

    42   return PSScavenge::is_obj_in_young((HeapWord*)obj);

    43 }

    45 template <class T>

    46 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {

    47   if (should_scavenge(p)) {

    48     oop obj = oopDesc::load_decode_heap_oop_not_null(p);

    49     // Skip objects copied to to_space since the scavenge started.

    50     HeapWord* const addr = (HeapWord*)obj;

    51     return addr < to_space_top_before_gc() || addr >= to_space->end();

    52   }

    53   return false;

    54 }

    56 template <class T>

    57 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {

    58   if (check_to_space) {

    59     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

    60     return should_scavenge(p, heap->young_gen()->to_space());

    61   }

    62   return should_scavenge(p);

    63 }

    65 // Attempt to "claim" oop at p via CAS, push the new obj if successful

    66 // This version tests the oop* to make sure it is within the heap before

    67 // attempting marking.

    68 template <class T>

    69 inline void PSScavenge::copy_and_push_safe_barrier(PSPromotionManager* pm,

    70                                                    T*                  p) {

    71   assert(should_scavenge(p, true), "revisiting object?");

    73   oop o = oopDesc::load_decode_heap_oop_not_null(p);

    74   oop new_obj = o->is_forwarded()

    75         ? o->forwardee()

    76         : pm->copy_to_survivor_space(o);

    77   oopDesc::encode_store_heap_oop_not_null(p, new_obj);

    79   // We cannot mark without test, as some code passes us pointers

    80   // that are outside the heap.

    81   if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&

    82       Universe::heap()->is_in_reserved(p)) {

    83     if (PSScavenge::is_obj_in_young((HeapWord*)new_obj)) {

    84       card_table()->inline_write_ref_field_gc(p, new_obj);

    85     }

    86   }

    87 }

    89 class PSScavengeRootsClosure: public OopClosure {

    90  private:

    91   PSPromotionManager* _promotion_manager;

    93  protected:

    94   template <class T> void do_oop_work(T *p) {

    95     if (PSScavenge::should_scavenge(p)) {

    96       // We never card mark roots, maybe call a func without test?

    97       PSScavenge::copy_and_push_safe_barrier(_promotion_manager, p);

    98     }

    99   }

   100  public:

   101   PSScavengeRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }

   102   void do_oop(oop* p)       { PSScavengeRootsClosure::do_oop_work(p); }

   103   void do_oop(narrowOop* p) { PSScavengeRootsClosure::do_oop_work(p); }

   104 };

   106 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP

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

src/share/vm/gc_implementation/parallelScavenge/psScavenge.inline.hpp@4dfb2df418f2

src/share/vm/gc_implementation/parallelScavenge/psScavenge.inline.hpp