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 "runtime/atomic.hpp"
34 #include "utilities/growableArray.hpp"
35
36 // Use ShenandoahReentrantLock as ShenandoahNMethodLock
37 typedef ShenandoahReentrantLock<ShenandoahSimpleLock> ShenandoahNMethodLock;
38 typedef ShenandoahLocker<ShenandoahNMethodLock> ShenandoahNMethodLocker;
39
40 struct ShenandoahNMethodBarrier {
41 address _pc;
42 address _stub_addr;
43 int _gc_state_fast_index;
44 };
45
46 // ShenandoahNMethod tuple records the internal locations of oop slots within reclocation stream in
47 // the nmethod. This allows us to quickly scan the oops without doing the nmethod-internal scans,
48 // that sometimes involves parsing the machine code. Note it does not record the oops themselves,
49 // because it would then require handling these tuples as the new class of roots.
50 class ShenandoahNMethod : public CHeapObj<mtGC> {
51 private:
52 nmethod* const _nm;
53 oop** _oops;
54 int _oops_count;
55 ShenandoahNMethodBarrier* _barriers;
56 int _barriers_count;
57 bool _has_non_immed_oops;
58 bool _unregistered;
59 ShenandoahNMethodLock _lock;
60 ShenandoahNMethodLock _ic_lock;
61
62 public:
63 ShenandoahNMethod(nmethod *nm, GrowableArray<oop*>& oops, bool has_non_immed_oops, GrowableArray<ShenandoahNMethodBarrier>& barriers);
64 ~ShenandoahNMethod();
65
66 inline nmethod* nm() const;
67 inline ShenandoahNMethodLock* lock();
68 inline ShenandoahNMethodLock* ic_lock();
69 inline void oops_do(OopClosure* oops, bool fix_relocations = false);
70 // Update oops when the nmethod is re-registered
71 void update();
72
73 void update_barriers();
74
75 inline bool is_unregistered() const;
76
77 static ShenandoahNMethod* for_nmethod(nmethod* nm);
78 static inline ShenandoahNMethodLock* lock_for_nmethod(nmethod* nm);
79 static inline ShenandoahNMethodLock* ic_lock_for_nmethod(nmethod* nm);
80
81 static void heal_nmethod(nmethod* nm);
82 static inline void heal_nmethod_metadata(ShenandoahNMethod* nmethod_data);
83 static inline void disarm_nmethod(nmethod* nm);
84 static inline void disarm_nmethod_unlocked(nmethod* nm);
85
86 static inline ShenandoahNMethod* gc_data(nmethod* nm);
87 static inline void attach_gc_data(nmethod* nm, ShenandoahNMethod* gc_data);
88
89 static void assert_barriers(nmethod* nm, bool armed) NOT_DEBUG_RETURN;
90 void assert_correct() NOT_DEBUG_RETURN;
91 void assert_same_oops() NOT_DEBUG_RETURN;
92
93 private:
94 static void parse(nmethod* nm, GrowableArray<oop*>& oops, bool& _has_non_immed_oops, GrowableArray<ShenandoahNMethodBarrier>& barriers);
95 };
96
97 class ShenandoahNMethodTable;
98
99 // ShenandoahNMethodList holds registered nmethod data. The list is reference counted.
100 class ShenandoahNMethodList : public CHeapObj<mtGC> {
101 private:
102 ShenandoahNMethod** _list;
103 const int _size;
104 uint _ref_count;
105
106 private:
107 ~ShenandoahNMethodList();
108
109 public:
110 ShenandoahNMethodList(int size);
111
112 // Reference counting with CoceCache_lock held
113 ShenandoahNMethodList* acquire();
114 void release();
115
116 // Transfer content from other list to 'this' list, up to the limit
117 void transfer(ShenandoahNMethodList* const other, int limit);
118
119 inline int size() const;
120 inline ShenandoahNMethod** list() const;
121 inline ShenandoahNMethod* at(int index) const;
122 inline void set(int index, ShenandoahNMethod* snm);
123 };
124
125 // An opaque snapshot of current nmethod table for iteration
126 class ShenandoahNMethodTableSnapshot : public CHeapObj<mtGC> {
127 friend class ShenandoahNMethodTable;
128 private:
129 ShenandoahHeap* const _heap;
130 ShenandoahNMethodList* _list;
131 /* snapshot iteration limit */
132 int _limit;
133
134 shenandoah_padding(0);
135 Atomic<size_t> _claimed;
136 shenandoah_padding(1);
137
138 public:
139 ShenandoahNMethodTableSnapshot(ShenandoahNMethodTable* table);
140 ~ShenandoahNMethodTableSnapshot();
141
142 void parallel_nmethods_do(NMethodClosure *f);
143 void concurrent_nmethods_do(NMethodClosure* cl);
144 };
145
146 class ShenandoahNMethodTable : public CHeapObj<mtGC> {
147 friend class ShenandoahNMethodTableSnapshot;
148 private:
149 enum {
150 minSize = 1024
151 };
152
153 ShenandoahHeap* const _heap;
154 ShenandoahNMethodList* _list;
155
156 int _index;
157 ShenandoahLock _lock;
158 int _itr_cnt;
159
160 public:
161 ShenandoahNMethodTable();
162 ~ShenandoahNMethodTable();
163
164 void register_nmethod(nmethod* nm);
165 void unregister_nmethod(nmethod* nm);
166
167 bool contain(nmethod* nm) const;
168 int length() const { return _index; }
169
170 // Table iteration support
171 ShenandoahNMethodTableSnapshot* snapshot_for_iteration();
172 void finish_iteration(ShenandoahNMethodTableSnapshot* snapshot);
173
174 void assert_nmethods_correct() NOT_DEBUG_RETURN;
175 private:
176 // Rebuild table and replace current one
177 void rebuild(int size);
178
179 bool is_full() const {
180 assert(_index <= _list->size(), "Sanity");
181 return _index == _list->size();
182 }
183
184 ShenandoahNMethod* at(int index) const;
185 int index_of(nmethod* nm) const;
186 void remove(int index);
187 void append(ShenandoahNMethod* snm);
188
189 inline bool iteration_in_progress() const;
190 void wait_until_concurrent_iteration_done();
191
192 // Logging support
193 void log_register_nmethod(nmethod* nm);
194 void log_unregister_nmethod(nmethod* nm);
195 };
196
197 class ShenandoahConcurrentNMethodIterator {
198 private:
199 ShenandoahNMethodTable* const _table;
200 ShenandoahNMethodTableSnapshot* _table_snapshot;
201 uint _started_workers;
202 uint _finished_workers;
203
204 public:
205 ShenandoahConcurrentNMethodIterator(ShenandoahNMethodTable* table);
206
207 void nmethods_do(NMethodClosure* cl);
208 };
209
210 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHNMETHOD_HPP