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
  21  * questions.
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  23  */
  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 
  35 inline OopsInGenClosure::OopsInGenClosure(Generation* gen) :
  36   ExtendedOopClosure(gen->ref_processor()), _orig_gen(gen), _rs(NULL) {
  37   set_generation(gen);
  38 }
  39 
  40 inline void OopsInGenClosure::set_generation(Generation* gen) {
  41   _gen = gen;
  42   _gen_boundary = _gen->reserved().start();
  43   // Barrier set for the heap, must be set after heap is initialized
  44   if (_rs == NULL) {
  45     _rs = GenCollectedHeap::heap()->rem_set();
  46   }
  47 }
  48 
  49 template <class T> inline void OopsInGenClosure::do_barrier(T* p) {
  50   assert(generation()->is_in_reserved(p), "expected ref in generation");
  51   T heap_oop = oopDesc::load_heap_oop(p);
  52   assert(!oopDesc::is_null(heap_oop), "expected non-null oop");
  53   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  54   // If p points to a younger generation, mark the card.
  55   if ((HeapWord*)obj < _gen_boundary) {
  56     _rs->inline_write_ref_field_gc(p, obj);
  57   }
  58 }
  59 
  60 template <class T> inline void OopsInGenClosure::par_do_barrier(T* p) {
  61   assert(generation()->is_in_reserved(p), "expected ref in generation");
  62   T heap_oop = oopDesc::load_heap_oop(p);
  63   assert(!oopDesc::is_null(heap_oop), "expected non-null oop");
  64   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  65   // If p points to a younger generation, mark the card.
  66   if ((HeapWord*)obj < gen_boundary()) {
  67     rs()->write_ref_field_gc_par(p, obj);
  68   }
  69 }
  70 
  71 inline void OopsInClassLoaderDataOrGenClosure::do_cld_barrier() {
  72   assert(_scanned_cld != NULL, "Must be");
  73   if (!_scanned_cld->has_modified_oops()) {
  74     _scanned_cld->record_modified_oops();
  75   }
  76 }
  77 
  78 // NOTE! Any changes made here should also be made
  79 // in FastScanClosure::do_oop_work()
  80 template <class T> inline void ScanClosure::do_oop_work(T* p) {
  81   T heap_oop = oopDesc::load_heap_oop(p);
  82   // Should we copy the obj?
  83   if (!oopDesc::is_null(heap_oop)) {
  84     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  85     if ((HeapWord*)obj < _boundary) {
  86       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
  87       oop new_obj = obj->is_forwarded() ? obj->forwardee()
  88                                         : _g->copy_to_survivor_space(obj);
  89       oopDesc::encode_store_heap_oop_not_null(p, new_obj);
  90     }
  91 
  92     if (is_scanning_a_cld()) {
  93       do_cld_barrier();
  94     } else if (_gc_barrier) {
  95       // Now call parent closure
  96       do_barrier(p);
  97     }
  98   }
  99 }
 100 
 101 inline void ScanClosure::do_oop_nv(oop* p)       { ScanClosure::do_oop_work(p); }
 102 inline void ScanClosure::do_oop_nv(narrowOop* p) { ScanClosure::do_oop_work(p); }
 103 
 104 // NOTE! Any changes made here should also be made
 105 // in ScanClosure::do_oop_work()
 106 template <class T> inline void FastScanClosure::do_oop_work(T* p) {
 107   T heap_oop = oopDesc::load_heap_oop(p);
 108   // Should we copy the obj?
 109   if (!oopDesc::is_null(heap_oop)) {
 110     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 111     if ((HeapWord*)obj < _boundary) {
 112       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
 113       oop new_obj = obj->is_forwarded() ? obj->forwardee()
 114                                         : _g->copy_to_survivor_space(obj);
 115       oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 116       if (is_scanning_a_cld()) {
 117         do_cld_barrier();
 118       } else if (_gc_barrier) {
 119         // Now call parent closure
 120         do_barrier(p);
 121       }
 122     }
 123   }
 124 }
 125 
 126 inline void FastScanClosure::do_oop_nv(oop* p)       { FastScanClosure::do_oop_work(p); }
 127 inline void FastScanClosure::do_oop_nv(narrowOop* p) { FastScanClosure::do_oop_work(p); }
 128 
 129 template <class T> void FilteringClosure::do_oop_work(T* p) {
 130   T heap_oop = oopDesc::load_heap_oop(p);
 131   if (!oopDesc::is_null(heap_oop)) {
 132     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 133     if ((HeapWord*)obj < _boundary) {
 134       _cl->do_oop(p);
 135     }
 136   }
 137 }
 138 
 139 void FilteringClosure::do_oop_nv(oop* p)       { FilteringClosure::do_oop_work(p); }
 140 void FilteringClosure::do_oop_nv(narrowOop* p) { FilteringClosure::do_oop_work(p); }
 141 
 142 // Note similarity to ScanClosure; the difference is that
 143 // the barrier set is taken care of outside this closure.
 144 template <class T> inline void ScanWeakRefClosure::do_oop_work(T* p) {
 145   assert(!oopDesc::is_null(*p), "null weak reference?");
 146   oop obj = oopDesc::load_decode_heap_oop_not_null(p);
 147   // weak references are sometimes scanned twice; must check
 148   // that to-space doesn't already contain this object
 149   if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
 150     oop new_obj = obj->is_forwarded() ? obj->forwardee()
 151                                       : _g->copy_to_survivor_space(obj);
 152     oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 153   }
 154 }
 155 
 156 inline void ScanWeakRefClosure::do_oop_nv(oop* p)       { ScanWeakRefClosure::do_oop_work(p); }
 157 inline void ScanWeakRefClosure::do_oop_nv(narrowOop* p) { ScanWeakRefClosure::do_oop_work(p); }
 158 
 159 #endif // SHARE_VM_GC_SHARED_GENOOPCLOSURES_INLINE_HPP
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