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.
  22  *
  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 OopsInKlassOrGenClosure::do_klass_barrier() {
  72   assert(_scanned_klass != NULL, "Must be");
  73   _scanned_klass->record_modified_oops();
  74 }
  75 
  76 // NOTE! Any changes made here should also be made
  77 // in FastScanClosure::do_oop_work()
  78 template <class T> inline void ScanClosure::do_oop_work(T* p) {
  79   T heap_oop = oopDesc::load_heap_oop(p);
  80   // Should we copy the obj?
  81   if (!oopDesc::is_null(heap_oop)) {
  82     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  83     if ((HeapWord*)obj < _boundary) {
  84       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
  85       oop new_obj = obj->is_forwarded() ? obj->forwardee()
  86                                         : _g->copy_to_survivor_space(obj);
  87       oopDesc::encode_store_heap_oop_not_null(p, new_obj);
  88     }
  89 
  90     if (is_scanning_a_klass()) {
  91       do_klass_barrier();
  92     } else if (_gc_barrier) {
  93       // Now call parent closure
  94       do_barrier(p);
  95     }
  96   }
  97 }
  98 
  99 inline void ScanClosure::do_oop_nv(oop* p)       { ScanClosure::do_oop_work(p); }
 100 inline void ScanClosure::do_oop_nv(narrowOop* p) { ScanClosure::do_oop_work(p); }
 101 
 102 // NOTE! Any changes made here should also be made
 103 // in ScanClosure::do_oop_work()
 104 template <class T> inline void FastScanClosure::do_oop_work(T* p) {
 105   T heap_oop = oopDesc::load_heap_oop(p);
 106   // Should we copy the obj?
 107   if (!oopDesc::is_null(heap_oop)) {
 108     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 109     if ((HeapWord*)obj < _boundary) {
 110       assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
 111       oop new_obj = obj->is_forwarded() ? obj->forwardee()
 112                                         : _g->copy_to_survivor_space(obj);
 113       oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 114       if (is_scanning_a_klass()) {
 115         do_klass_barrier();
 116       } else if (_gc_barrier) {
 117         // Now call parent closure
 118         do_barrier(p);
 119       }
 120     }
 121   }
 122 }
 123 
 124 inline void FastScanClosure::do_oop_nv(oop* p)       { FastScanClosure::do_oop_work(p); }
 125 inline void FastScanClosure::do_oop_nv(narrowOop* p) { FastScanClosure::do_oop_work(p); }
 126 
 127 template <class T> void FilteringClosure::do_oop_work(T* p) {
 128   T heap_oop = oopDesc::load_heap_oop(p);
 129   if (!oopDesc::is_null(heap_oop)) {
 130     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 131     if ((HeapWord*)obj < _boundary) {
 132       _cl->do_oop(p);
 133     }
 134   }
 135 }
 136 
 137 void FilteringClosure::do_oop_nv(oop* p)       { FilteringClosure::do_oop_work(p); }
 138 void FilteringClosure::do_oop_nv(narrowOop* p) { FilteringClosure::do_oop_work(p); }
 139 
 140 // Note similarity to ScanClosure; the difference is that
 141 // the barrier set is taken care of outside this closure.
 142 template <class T> inline void ScanWeakRefClosure::do_oop_work(T* p) {
 143   assert(!oopDesc::is_null(*p), "null weak reference?");
 144   oop obj = oopDesc::load_decode_heap_oop_not_null(p);
 145   // weak references are sometimes scanned twice; must check
 146   // that to-space doesn't already contain this object
 147   if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
 148     oop new_obj = obj->is_forwarded() ? obj->forwardee()
 149                                       : _g->copy_to_survivor_space(obj);
 150     oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 151   }
 152 }
 153 
 154 inline void ScanWeakRefClosure::do_oop_nv(oop* p)       { ScanWeakRefClosure::do_oop_work(p); }
 155 inline void ScanWeakRefClosure::do_oop_nv(narrowOop* p) { ScanWeakRefClosure::do_oop_work(p); }
 156 
 157 #endif // SHARE_VM_GC_SHARED_GENOOPCLOSURES_INLINE_HPP