1 /*
2 * Copyright (c) 2019, 2020, Red Hat, Inc. 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_GC_SHENANDOAH_SHENANDOAHNMETHOD_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHNMETHOD_HPP
27
28 #include "code/nmethod.hpp"
29 #include "gc/shenandoah/shenandoahHeap.hpp"
30 #include "gc/shenandoah/shenandoahLock.hpp"
31 #include "gc/shenandoah/shenandoahPadding.hpp"
32 #include "memory/allocation.hpp"
33 #include "utilities/growableArray.hpp"
34
35 // ShenandoahNMethod tuple records the internal locations of oop slots within reclocation stream in
36 // the nmethod. This allows us to quickly scan the oops without doing the nmethod-internal scans,
37 // that sometimes involves parsing the machine code. Note it does not record the oops themselves,
38 // because it would then require handling these tuples as the new class of roots.
39 class ShenandoahNMethod : public CHeapObj<mtGC> {
40 private:
41 nmethod* const _nm;
42 oop** _oops;
43 int _oops_count;
44 bool _has_non_immed_oops;
45 bool _unregistered;
46 ShenandoahReentrantLock _lock;
47
48 public:
49 ShenandoahNMethod(nmethod *nm, GrowableArray<oop*>& oops, bool has_non_immed_oops);
50 ~ShenandoahNMethod();
51
52 inline nmethod* nm() const;
53 inline ShenandoahReentrantLock* lock();
54 inline void oops_do(OopClosure* oops, bool fix_relocations = false);
55 // Update oops when the nmethod is re-registered
56 void update();
57
58 bool has_cset_oops(ShenandoahHeap* heap);
59
60 inline int oop_count() const;
61 inline bool has_oops() const;
62
63 inline void mark_unregistered();
64 inline bool is_unregistered() const;
65
66 static ShenandoahNMethod* for_nmethod(nmethod* nm);
67 static inline ShenandoahReentrantLock* lock_for_nmethod(nmethod* nm);
68
69 static void heal_nmethod(nmethod* nm);
70 static inline void heal_nmethod_metadata(ShenandoahNMethod* nmethod_data);
71 static inline void disarm_nmethod(nmethod* nm);
72
73 static inline ShenandoahNMethod* gc_data(nmethod* nm);
74 static inline void attach_gc_data(nmethod* nm, ShenandoahNMethod* gc_data);
75
76 void assert_alive_and_correct() NOT_DEBUG_RETURN;
77 void assert_same_oops(bool allow_dead = false) NOT_DEBUG_RETURN;
78 static void assert_no_oops(nmethod* nm, bool allow_dea = false) NOT_DEBUG_RETURN;
79
80 private:
81 bool has_non_immed_oops() const { return _has_non_immed_oops; }
82 static void detect_reloc_oops(nmethod* nm, GrowableArray<oop*>& oops, bool& _has_non_immed_oops);
83 };
84
85 class ShenandoahNMethodTable;
86
87 // ShenandoahNMethodList holds registered nmethod data. The list is reference counted.
88 class ShenandoahNMethodList : public CHeapObj<mtGC> {
89 private:
90 ShenandoahNMethod** _list;
91 const int _size;
92 uint _ref_count;
93
94 private:
95 ~ShenandoahNMethodList();
96
97 public:
98 ShenandoahNMethodList(int size);
99
100 // Reference counting with CoceCache_lock held
101 ShenandoahNMethodList* acquire();
102 void release();
103
104 // Transfer content from other list to 'this' list, up to the limit
105 void transfer(ShenandoahNMethodList* const other, int limit);
106
107 inline int size() const;
108 inline ShenandoahNMethod** list() const;
109 inline ShenandoahNMethod* at(int index) const;
110 inline void set(int index, ShenandoahNMethod* snm);
111 };
112
113 // An opaque snapshot of current nmethod table for iteration
114 class ShenandoahNMethodTableSnapshot : public CHeapObj<mtGC> {
115 friend class ShenandoahNMethodTable;
116 private:
117 ShenandoahHeap* const _heap;
118 ShenandoahNMethodList* _list;
119 /* snapshot iteration limit */
120 int _limit;
121
122 shenandoah_padding(0);
123 volatile size_t _claimed;
124 shenandoah_padding(1);
125
126 public:
127 ShenandoahNMethodTableSnapshot(ShenandoahNMethodTable* table);
128 ~ShenandoahNMethodTableSnapshot();
129
130 void parallel_blobs_do(CodeBlobClosure *f);
131 void concurrent_nmethods_do(NMethodClosure* cl);
132 };
133
134 class ShenandoahNMethodTable : public CHeapObj<mtGC> {
135 friend class ShenandoahNMethodTableSnapshot;
136 private:
137 enum {
138 minSize = 1024
139 };
140
141 ShenandoahHeap* const _heap;
142 ShenandoahNMethodList* _list;
143
144 int _index;
145 ShenandoahLock _lock;
146 int _itr_cnt;
147
148 public:
149 ShenandoahNMethodTable();
150 ~ShenandoahNMethodTable();
151
152 void register_nmethod(nmethod* nm);
153 void unregister_nmethod(nmethod* nm);
154 void flush_nmethod(nmethod* nm);
155
156 bool contain(nmethod* nm) const;
157 int length() const { return _index; }
158
159 // Table iteration support
160 ShenandoahNMethodTableSnapshot* snapshot_for_iteration();
161 void finish_iteration(ShenandoahNMethodTableSnapshot* snapshot);
162
163 void assert_nmethods_alive_and_correct() NOT_DEBUG_RETURN;
164 private:
165 // Rebuild table and replace current one
166 void rebuild(int size);
167
168 bool is_full() const {
169 assert(_index <= _list->size(), "Sanity");
170 return _index == _list->size();
171 }
172
173 ShenandoahNMethod* at(int index) const;
174 int index_of(nmethod* nm) const;
175 void remove(int index);
176 void append(ShenandoahNMethod* snm);
177
178 inline bool iteration_in_progress() const;
179 void wait_until_concurrent_iteration_done();
180
181 // Logging support
182 void log_register_nmethod(nmethod* nm);
183 void log_unregister_nmethod(nmethod* nm);
184 void log_flush_nmethod(nmethod* nm);
185 };
186
187 class ShenandoahConcurrentNMethodIterator {
188 private:
189 ShenandoahNMethodTable* const _table;
190 ShenandoahNMethodTableSnapshot* _table_snapshot;
191
192 public:
193 ShenandoahConcurrentNMethodIterator(ShenandoahNMethodTable* table);
194
195 void nmethods_do_begin();
196 void nmethods_do(NMethodClosure* cl);
197 void nmethods_do_end();
198 };
199
200 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHNMETHOD_HPP