1 /*
2 * Copyright (c) 2001, 2018, 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 CardTableBarrierSet;
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 class loader data.
85 class OopsInClassLoaderDataOrGenClosure: public OopsInGenClosure {
86 ClassLoaderData* _scanned_cld;
87 public:
88 OopsInClassLoaderDataOrGenClosure(Generation* g) : OopsInGenClosure(g), _scanned_cld(NULL) {}
89 void set_scanned_cld(ClassLoaderData* cld) {
90 assert(cld == NULL || _scanned_cld == NULL, "Must be");
91 _scanned_cld = cld;
92 }
93 bool is_scanning_a_cld() { return _scanned_cld != NULL; }
94 void do_cld_barrier();
95 };
96
97 #if INCLUDE_SERIALGC
98
99 // Closure for scanning DefNewGeneration.
100 //
101 // This closure will perform barrier store calls for ALL
102 // pointers in scanned oops.
103 class ScanClosure: public OopsInClassLoaderDataOrGenClosure {
104 protected:
105 DefNewGeneration* _g;
106 HeapWord* _boundary;
107 bool _gc_barrier;
108 template <class T> inline void do_oop_work(T* p);
109 public:
110 ScanClosure(DefNewGeneration* g, bool gc_barrier);
111 virtual void do_oop(oop* p);
112 virtual void do_oop(narrowOop* p);
113 inline void do_oop_nv(oop* p);
114 inline void do_oop_nv(narrowOop* p);
115 };
116
117 // Closure for scanning DefNewGeneration.
118 //
119 // This closure only performs barrier store calls on
120 // pointers into the DefNewGeneration. This is less
121 // precise, but faster, than a ScanClosure
122 class FastScanClosure: public OopsInClassLoaderDataOrGenClosure {
123 protected:
124 DefNewGeneration* _g;
125 HeapWord* _boundary;
126 bool _gc_barrier;
127 template <class T> inline void do_oop_work(T* p);
128 public:
129 FastScanClosure(DefNewGeneration* g, bool gc_barrier);
130 virtual void do_oop(oop* p);
131 virtual void do_oop(narrowOop* p);
132 inline void do_oop_nv(oop* p);
133 inline void do_oop_nv(narrowOop* p);
134 };
135
136 #endif // INCLUDE_SERIALGC
137
138 class CLDScanClosure: public CLDClosure {
139 OopsInClassLoaderDataOrGenClosure* _scavenge_closure;
140 // true if the the modified oops state should be saved.
141 bool _accumulate_modified_oops;
142 public:
143 CLDScanClosure(OopsInClassLoaderDataOrGenClosure* scavenge_closure,
144 bool accumulate_modified_oops) :
145 _scavenge_closure(scavenge_closure), _accumulate_modified_oops(accumulate_modified_oops) {}
146 void do_cld(ClassLoaderData* cld);
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 public:
156 FilteringClosure(HeapWord* boundary, ExtendedOopClosure* cl) :
157 ExtendedOopClosure(cl->ref_discoverer()), _boundary(boundary),
158 _cl(cl) {}
159 virtual void do_oop(oop* p);
160 virtual void do_oop(narrowOop* p);
161 inline void do_oop_nv(oop* p);
162 inline void do_oop_nv(narrowOop* p);
163 virtual bool do_metadata() { return do_metadata_nv(); }
164 inline bool do_metadata_nv() { assert(!_cl->do_metadata(), "assumption broken, must change to 'return _cl->do_metadata()'"); return false; }
165 };
166
167 #if INCLUDE_SERIALGC
168
169 // Closure for scanning DefNewGeneration's weak references.
170 // NOTE: very much like ScanClosure but not derived from
171 // OopsInGenClosure -- weak references are processed all
172 // at once, with no notion of which generation they were in.
173 class ScanWeakRefClosure: public OopClosure {
174 protected:
175 DefNewGeneration* _g;
176 HeapWord* _boundary;
177 template <class T> inline void do_oop_work(T* p);
178 public:
179 ScanWeakRefClosure(DefNewGeneration* g);
180 virtual void do_oop(oop* p);
181 virtual void do_oop(narrowOop* p);
182 inline void do_oop_nv(oop* p);
183 inline void do_oop_nv(narrowOop* p);
184 };
185
186 #endif // INCLUDE_SERIALGC
187
188 #endif // SHARE_VM_GC_SHARED_GENOOPCLOSURES_HPP