1 /* 2 * Copyright (c) 2001, 2015, 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_HPP 26 #define SHARE_VM_GC_SHARED_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 class KlassRemSet; 37 38 template<class E, MEMFLAGS F, unsigned int N> class GenericTaskQueue; 39 typedef GenericTaskQueue<oop, mtGC, TASKQUEUE_SIZE> OopTaskQueue; 40 template<class T, MEMFLAGS F> class GenericTaskQueueSet; 41 typedef GenericTaskQueueSet<OopTaskQueue, mtGC> OopTaskQueueSet; 42 43 // Closure for iterating roots from a particular generation 44 // Note: all classes deriving from this MUST call this do_barrier 45 // method at the end of their own do_oop method! 46 // Note: no do_oop defined, this is an abstract class. 47 48 class OopsInGenClosure : public ExtendedOopClosure { 49 private: 50 Generation* _orig_gen; // generation originally set in ctor 51 Generation* _gen; // generation being scanned 52 53 protected: 54 // Some subtypes need access. 55 HeapWord* _gen_boundary; // start of generation 56 CardTableRS* _rs; // remembered set 57 58 // For assertions 59 Generation* generation() { return _gen; } 60 CardTableRS* rs() { return _rs; } 61 62 // Derived classes that modify oops so that they might be old-to-young 63 // pointers must call the method below. 64 template <class T> void do_barrier(T* p); 65 66 // Version for use by closures that may be called in parallel code. 67 template <class T> void par_do_barrier(T* p); 68 69 public: 70 OopsInGenClosure() : ExtendedOopClosure(NULL), 71 _orig_gen(NULL), _gen(NULL), _gen_boundary(NULL), _rs(NULL) {}; 72 73 OopsInGenClosure(Generation* gen); 74 void set_generation(Generation* gen); 75 76 void reset_generation() { _gen = _orig_gen; } 77 78 // Problem with static closures: must have _gen_boundary set at some point, 79 // but cannot do this until after the heap is initialized. 80 void set_orig_generation(Generation* gen) { 81 _orig_gen = gen; 82 set_generation(gen); 83 } 84 85 HeapWord* gen_boundary() { return _gen_boundary; } 86 87 }; 88 89 // Super class for scan closures. It contains code to dirty scanned Klasses. 90 class OopsInKlassOrGenClosure: public OopsInGenClosure { 91 Klass* _scanned_klass; 92 public: 93 OopsInKlassOrGenClosure(Generation* g) : OopsInGenClosure(g), _scanned_klass(NULL) {} 94 void set_scanned_klass(Klass* k) { 95 assert(k == NULL || _scanned_klass == NULL, "Must be"); 96 _scanned_klass = k; 97 } 98 bool is_scanning_a_klass() { return _scanned_klass != NULL; } 99 void do_klass_barrier(); 100 }; 101 102 // Closure for scanning DefNewGeneration. 103 // 104 // This closure will perform barrier store calls for ALL 105 // pointers in scanned oops. 106 class ScanClosure: public OopsInKlassOrGenClosure { 107 protected: 108 DefNewGeneration* _g; 109 HeapWord* _boundary; 110 bool _gc_barrier; 111 template <class T> inline void do_oop_work(T* p); 112 public: 113 ScanClosure(DefNewGeneration* g, bool gc_barrier); 114 virtual void do_oop(oop* p); 115 virtual void do_oop(narrowOop* p); 116 inline void do_oop_nv(oop* p); 117 inline void do_oop_nv(narrowOop* p); 118 }; 119 120 // Closure for scanning DefNewGeneration. 121 // 122 // This closure only performs barrier store calls on 123 // pointers into the DefNewGeneration. This is less 124 // precise, but faster, than a ScanClosure 125 class FastScanClosure: public OopsInKlassOrGenClosure { 126 protected: 127 DefNewGeneration* _g; 128 HeapWord* _boundary; 129 bool _gc_barrier; 130 template <class T> inline void do_oop_work(T* p); 131 public: 132 FastScanClosure(DefNewGeneration* g, bool gc_barrier); 133 virtual void do_oop(oop* p); 134 virtual void do_oop(narrowOop* p); 135 inline void do_oop_nv(oop* p); 136 inline void do_oop_nv(narrowOop* p); 137 }; 138 139 class KlassScanClosure: public KlassClosure { 140 OopsInKlassOrGenClosure* _scavenge_closure; 141 // true if the the modified oops state should be saved. 142 bool _accumulate_modified_oops; 143 public: 144 KlassScanClosure(OopsInKlassOrGenClosure* scavenge_closure, 145 KlassRemSet* klass_rem_set_policy); 146 void do_klass(Klass* k); 147 }; 148 149 class FilteringClosure: public ExtendedOopClosure { 150 private: 151 HeapWord* _boundary; 152 ExtendedOopClosure* _cl; 153 protected: 154 template <class T> inline void do_oop_work(T* p) { 155 T heap_oop = oopDesc::load_heap_oop(p); 156 if (!oopDesc::is_null(heap_oop)) { 157 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 158 if ((HeapWord*)obj < _boundary) { 159 _cl->do_oop(p); 160 } 161 } 162 } 163 public: 164 FilteringClosure(HeapWord* boundary, ExtendedOopClosure* cl) : 165 ExtendedOopClosure(cl->_ref_processor), _boundary(boundary), 166 _cl(cl) {} 167 virtual void do_oop(oop* p); 168 virtual void do_oop(narrowOop* p); 169 inline void do_oop_nv(oop* p) { FilteringClosure::do_oop_work(p); } 170 inline void do_oop_nv(narrowOop* p) { FilteringClosure::do_oop_work(p); } 171 virtual bool do_metadata() { return do_metadata_nv(); } 172 inline bool do_metadata_nv() { assert(!_cl->do_metadata(), "assumption broken, must change to 'return _cl->do_metadata()'"); return false; } 173 }; 174 175 // Closure for scanning DefNewGeneration's weak references. 176 // NOTE: very much like ScanClosure but not derived from 177 // OopsInGenClosure -- weak references are processed all 178 // at once, with no notion of which generation they were in. 179 class ScanWeakRefClosure: public OopClosure { 180 protected: 181 DefNewGeneration* _g; 182 HeapWord* _boundary; 183 template <class T> inline void do_oop_work(T* p); 184 public: 185 ScanWeakRefClosure(DefNewGeneration* g); 186 virtual void do_oop(oop* p); 187 virtual void do_oop(narrowOop* p); 188 inline void do_oop_nv(oop* p); 189 inline void do_oop_nv(narrowOop* p); 190 }; 191 192 #endif // SHARE_VM_GC_SHARED_GENOOPCLOSURES_HPP