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