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