1 /* 2 * Copyright (c) 2001, 2010, 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_MEMORY_GENOOPCLOSURES_HPP 26 #define SHARE_VM_MEMORY_GENOOPCLOSURES_HPP 27 28 #include "memory/iterator.hpp" 29 #include "oops/oop.hpp" 30 31 class Generation; 32 class HeapWord; 33 class CardTableRS; 34 class CardTableModRefBS; 35 class DefNewGeneration; 36 37 template<class E, unsigned int N> class GenericTaskQueue; 38 typedef GenericTaskQueue<oop, TASKQUEUE_SIZE> OopTaskQueue; 39 template<class T> class GenericTaskQueueSet; 40 typedef GenericTaskQueueSet<OopTaskQueue> OopTaskQueueSet; 41 42 // Closure for iterating roots from a particular generation 43 // Note: all classes deriving from this MUST call this do_barrier 44 // method at the end of their own do_oop method! 45 // Note: no do_oop defined, this is an abstract class. 46 47 class OopsInGenClosure : public OopClosure { 48 private: 49 Generation* _orig_gen; // generation originally set in ctor 50 Generation* _gen; // generation being scanned 51 52 protected: 53 // Some subtypes need access. 54 HeapWord* _gen_boundary; // start of generation 55 CardTableRS* _rs; // remembered set 56 57 // For assertions 58 Generation* generation() { return _gen; } 59 CardTableRS* rs() { return _rs; } 60 61 // Derived classes that modify oops so that they might be old-to-young 62 // pointers must call the method below. 63 template <class T> void do_barrier(T* p); 64 65 // Version for use by closures that may be called in parallel code. 66 template <class T> void par_do_barrier(T* p); 67 68 public: 69 OopsInGenClosure() : OopClosure(NULL), 70 _orig_gen(NULL), _gen(NULL), _gen_boundary(NULL), _rs(NULL) {}; 71 72 OopsInGenClosure(Generation* gen); 73 void set_generation(Generation* gen); 74 75 void reset_generation() { _gen = _orig_gen; } 76 77 // Problem with static closures: must have _gen_boundary set at some point, 78 // but cannot do this until after the heap is initialized. 79 void set_orig_generation(Generation* gen) { 80 _orig_gen = gen; 81 set_generation(gen); 82 } 83 84 HeapWord* gen_boundary() { return _gen_boundary; } 85 }; 86 87 // Closure for scanning DefNewGeneration. 88 // 89 // This closure will perform barrier store calls for ALL 90 // pointers in scanned oops. 91 class ScanClosure: public OopsInGenClosure { 92 protected: 93 DefNewGeneration* _g; 94 HeapWord* _boundary; 95 bool _gc_barrier; 96 template <class T> inline void do_oop_work(T* p); 97 public: 98 ScanClosure(DefNewGeneration* g, bool gc_barrier); 99 virtual void do_oop(oop* p); 100 virtual void do_oop(narrowOop* p); 101 inline void do_oop_nv(oop* p); 102 inline void do_oop_nv(narrowOop* p); 103 bool do_header() { return false; } 104 Prefetch::style prefetch_style() { 105 return Prefetch::do_write; 106 } 107 }; 108 109 // Closure for scanning DefNewGeneration. 110 // 111 // This closure only performs barrier store calls on 112 // pointers into the DefNewGeneration. This is less 113 // precise, but faster, than a ScanClosure 114 class FastScanClosure: public OopsInGenClosure { 115 protected: 116 DefNewGeneration* _g; 117 HeapWord* _boundary; 118 bool _gc_barrier; 119 template <class T> inline void do_oop_work(T* p); 120 public: 121 FastScanClosure(DefNewGeneration* g, bool gc_barrier); 122 virtual void do_oop(oop* p); 123 virtual void do_oop(narrowOop* p); 124 inline void do_oop_nv(oop* p); 125 inline void do_oop_nv(narrowOop* p); 126 bool do_header() { return false; } 127 Prefetch::style prefetch_style() { 128 return Prefetch::do_write; 129 } 130 }; 131 132 class FilteringClosure: public OopClosure { 133 private: 134 HeapWord* _boundary; 135 OopClosure* _cl; 136 protected: 137 template <class T> inline void do_oop_work(T* p) { 138 T heap_oop = oopDesc::load_heap_oop(p); 139 if (!oopDesc::is_null(heap_oop)) { 140 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 141 if ((HeapWord*)obj < _boundary) { 142 _cl->do_oop(p); 143 } 144 } 145 } 146 public: 147 FilteringClosure(HeapWord* boundary, OopClosure* cl) : 148 OopClosure(cl->_ref_processor), _boundary(boundary), 149 _cl(cl) {} 150 virtual void do_oop(oop* p); 151 virtual void do_oop(narrowOop* p); 152 inline void do_oop_nv(oop* p) { FilteringClosure::do_oop_work(p); } 153 inline void do_oop_nv(narrowOop* p) { FilteringClosure::do_oop_work(p); } 154 bool do_header() { return false; } 155 }; 156 157 // Closure for scanning DefNewGeneration's weak references. 158 // NOTE: very much like ScanClosure but not derived from 159 // OopsInGenClosure -- weak references are processed all 160 // at once, with no notion of which generation they were in. 161 class ScanWeakRefClosure: public OopClosure { 162 protected: 163 DefNewGeneration* _g; 164 HeapWord* _boundary; 165 template <class T> inline void do_oop_work(T* p); 166 public: 167 ScanWeakRefClosure(DefNewGeneration* g); 168 virtual void do_oop(oop* p); 169 virtual void do_oop(narrowOop* p); 170 inline void do_oop_nv(oop* p); 171 inline void do_oop_nv(narrowOop* p); 172 }; 173 174 class VerifyOopClosure: public OopClosure { 175 protected: 176 template <class T> inline void do_oop_work(T* p) { 177 oop obj = oopDesc::load_decode_heap_oop(p); 178 guarantee(obj->is_oop_or_null(), "invalid oop"); 179 } 180 public: 181 virtual void do_oop(oop* p); 182 virtual void do_oop(narrowOop* p); 183 static VerifyOopClosure verify_oop; 184 }; 185 186 #endif // SHARE_VM_MEMORY_GENOOPCLOSURES_HPP