1 /*
   2  * Copyright (c) 2001, 2017, 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_SHARED_GENOOPCLOSURES_INLINE_HPP
  26 #define SHARE_VM_GC_SHARED_GENOOPCLOSURES_INLINE_HPP
  27 
  28 #include "gc/serial/defNewGeneration.hpp"
  29 #include "gc/shared/cardTableRS.hpp"
  30 #include "gc/shared/genCollectedHeap.hpp"
  31 #include "gc/shared/genOopClosures.hpp"
  32 #include "gc/shared/generation.hpp"
  33 #include "gc/shared/space.hpp"
  34 #include "oops/access.inline.hpp"
  35 #include "oops/compressedOops.inline.hpp"
  36 
  37 inline OopsInGenClosure::OopsInGenClosure(Generation* gen) :
  38   ExtendedOopClosure(gen->ref_processor()), _orig_gen(gen), _rs(NULL) {
  39   set_generation(gen);
  40 }
  41 
  42 inline void OopsInGenClosure::set_generation(Generation* gen) {
  43   _gen = gen;
  44   _gen_boundary = _gen->reserved().start();
  45   // Barrier set for the heap, must be set after heap is initialized
  46   if (_rs == NULL) {
  47     _rs = GenCollectedHeap::heap()->rem_set();
  48   }
  49 }
  50 
  51 template <class T> inline void OopsInGenClosure::do_barrier(T* p) {
  52   assert(generation()->is_in_reserved(p), "expected ref in generation");
  53   T heap_oop = RawAccess<>::oop_load(p);
  54   assert(!CompressedOops::is_null(heap_oop), "expected non-null oop");
  55   oop obj = CompressedOops::decode_not_null(heap_oop);
  56   // If p points to a younger generation, mark the card.
  57   if ((HeapWord*)obj < _gen_boundary) {
  58     _rs->inline_write_ref_field_gc(p, obj);
  59   }
  60 }
  61 
  62 template <class T> inline void OopsInGenClosure::par_do_barrier(T* p) {
  63   assert(generation()->is_in_reserved(p), "expected ref in generation");
  64   T heap_oop = RawAccess<>::oop_load(p);
  65   assert(!CompressedOops::is_null(heap_oop), "expected non-null oop");
  66   oop obj = CompressedOops::decode_not_null(heap_oop);
  67   // If p points to a younger generation, mark the card.
  68   if ((HeapWord*)obj < gen_boundary()) {
  69     rs()->write_ref_field_gc_par(p, obj);
  70   }
  71 }
  72 
  73 inline void OopsInClassLoaderDataOrGenClosure::do_cld_barrier() {
  74   assert(_scanned_cld != NULL, "Must be");
  75   if (!_scanned_cld->has_modified_oops()) {
  76     _scanned_cld->record_modified_oops();
  77   }
  78 }
  79 
  80 // NOTE! Any changes made here should also be made
  81 // in FastScanClosure::do_oop_work()
  82 template <class T> inline void ScanClosure::do_oop_work(T* p) {
  83   T heap_oop = RawAccess<>::oop_load(p);
  84   // Should we copy the obj?
  85   if (!CompressedOops::is_null(heap_oop)) {
  86     oop obj = CompressedOops::decode_not_null(heap_oop);
  87     if ((HeapWord*)obj < _boundary) {
  88       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
  89       oop new_obj = obj->is_forwarded() ? obj->forwardee()
  90                                         : _g->copy_to_survivor_space(obj);
  91       RawAccess<OOP_NOT_NULL>::oop_store(p, new_obj);
  92     }
  93 
  94     if (is_scanning_a_cld()) {
  95       do_cld_barrier();
  96     } else if (_gc_barrier) {
  97       // Now call parent closure
  98       do_barrier(p);
  99     }
 100   }
 101 }
 102 
 103 inline void ScanClosure::do_oop_nv(oop* p)       { ScanClosure::do_oop_work(p); }
 104 inline void ScanClosure::do_oop_nv(narrowOop* p) { ScanClosure::do_oop_work(p); }
 105 
 106 // NOTE! Any changes made here should also be made
 107 // in ScanClosure::do_oop_work()
 108 template <class T> inline void FastScanClosure::do_oop_work(T* p) {
 109   T heap_oop = RawAccess<>::oop_load(p);
 110   // Should we copy the obj?
 111   if (!CompressedOops::is_null(heap_oop)) {
 112     oop obj = CompressedOops::decode_not_null(heap_oop);
 113     if ((HeapWord*)obj < _boundary) {
 114       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
 115       oop new_obj = obj->is_forwarded() ? obj->forwardee()
 116                                         : _g->copy_to_survivor_space(obj);
 117       RawAccess<OOP_NOT_NULL>::oop_store(p, new_obj);
 118       if (is_scanning_a_cld()) {
 119         do_cld_barrier();
 120       } else if (_gc_barrier) {
 121         // Now call parent closure
 122         do_barrier(p);
 123       }
 124     }
 125   }
 126 }
 127 
 128 inline void FastScanClosure::do_oop_nv(oop* p)       { FastScanClosure::do_oop_work(p); }
 129 inline void FastScanClosure::do_oop_nv(narrowOop* p) { FastScanClosure::do_oop_work(p); }
 130 
 131 template <class T> void FilteringClosure::do_oop_work(T* p) {
 132   T heap_oop = RawAccess<>::oop_load(p);
 133   if (!CompressedOops::is_null(heap_oop)) {
 134     oop obj = CompressedOops::decode_not_null(heap_oop);
 135     if ((HeapWord*)obj < _boundary) {
 136       _cl->do_oop(p);
 137     }
 138   }
 139 }
 140 
 141 void FilteringClosure::do_oop_nv(oop* p)       { FilteringClosure::do_oop_work(p); }
 142 void FilteringClosure::do_oop_nv(narrowOop* p) { FilteringClosure::do_oop_work(p); }
 143 
 144 // Note similarity to ScanClosure; the difference is that
 145 // the barrier set is taken care of outside this closure.
 146 template <class T> inline void ScanWeakRefClosure::do_oop_work(T* p) {
 147   oop obj = RawAccess<OOP_NOT_NULL>::oop_load(p);
 148   // weak references are sometimes scanned twice; must check
 149   // that to-space doesn't already contain this object
 150   if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
 151     oop new_obj = obj->is_forwarded() ? obj->forwardee()
 152                                       : _g->copy_to_survivor_space(obj);
 153     RawAccess<OOP_NOT_NULL>::oop_store(p, new_obj);
 154   }
 155 }
 156 
 157 inline void ScanWeakRefClosure::do_oop_nv(oop* p)       { ScanWeakRefClosure::do_oop_work(p); }
 158 inline void ScanWeakRefClosure::do_oop_nv(narrowOop* p) { ScanWeakRefClosure::do_oop_work(p); }
 159 
 160 #endif // SHARE_VM_GC_SHARED_GENOOPCLOSURES_INLINE_HPP