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 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 disarm_nmethod(nmethod* nm);
71
72 static inline ShenandoahNMethod* gc_data(nmethod* nm);
73 static inline void attach_gc_data(nmethod* nm, ShenandoahNMethod* gc_data);
74
75 void assert_alive_and_correct() NOT_DEBUG_RETURN;
76 void assert_same_oops(bool allow_dead = false) NOT_DEBUG_RETURN;
77 static void assert_no_oops(nmethod* nm, bool allow_dea = false) NOT_DEBUG_RETURN;
78
79 private:
80 bool has_non_immed_oops() const { return _has_non_immed_oops; }
81 static void detect_reloc_oops(nmethod* nm, GrowableArray<oop*>& oops, bool& _has_non_immed_oops);
82 };
83
84 class ShenandoahNMethodTable;
85
86 // ShenandoahNMethodList holds registered nmethod data. The list is reference counted.
87 class ShenandoahNMethodList : public CHeapObj<mtGC> {
88 private:
89 ShenandoahNMethod** _list;
90 const int _size;
91 uint _ref_count;
92
93 private:
94 ~ShenandoahNMethodList();
95
96 public:
97 ShenandoahNMethodList(int size);
98
99 // Reference counting with CoceCache_lock held
100 ShenandoahNMethodList* acquire();
101 void release();
102
103 // Transfer content from other list to 'this' list, up to the limit
104 void transfer(ShenandoahNMethodList* const other, int limit);
105
106 inline int size() const;
107 inline ShenandoahNMethod** list() const;
108 inline ShenandoahNMethod* at(int index) const;
109 inline void set(int index, ShenandoahNMethod* snm);
110 };
111
112 // An opaque snapshot of current nmethod table for iteration
113 class ShenandoahNMethodTableSnapshot : public CHeapObj<mtGC> {
114 friend class ShenandoahNMethodTable;
115 private:
116 ShenandoahHeap* const _heap;
117 ShenandoahNMethodList* _list;
118 /* snapshot iteration limit */
119 int _limit;
120
121 shenandoah_padding(0);
122 volatile size_t _claimed;
123 shenandoah_padding(1);
124
125 public:
126 ShenandoahNMethodTableSnapshot(ShenandoahNMethodTable* table);
127 ~ShenandoahNMethodTableSnapshot();
128
129 template<bool CSET_FILTER>
130 void parallel_blobs_do(CodeBlobClosure *f);
131
132 void concurrent_nmethods_do(NMethodClosure* cl);
133 };
134
135 class ShenandoahNMethodTable : public CHeapObj<mtGC> {
136 friend class ShenandoahNMethodTableSnapshot;
137 private:
138 enum {
139 minSize = 1024
140 };
141
142 ShenandoahHeap* const _heap;
143 ShenandoahNMethodList* _list;
144
145 int _index;
146 ShenandoahLock _lock;
147 int _itr_cnt;
148
149 public:
150 ShenandoahNMethodTable();
151 ~ShenandoahNMethodTable();
152
153 void register_nmethod(nmethod* nm);
154 void unregister_nmethod(nmethod* nm);
155 void flush_nmethod(nmethod* nm);
156
157 bool contain(nmethod* nm) const;
158 int length() const { return _index; }
159
160 // Table iteration support
161 ShenandoahNMethodTableSnapshot* snapshot_for_iteration();
162 void finish_iteration(ShenandoahNMethodTableSnapshot* snapshot);
163
164 void assert_nmethods_alive_and_correct() NOT_DEBUG_RETURN;
165 private:
166 // Rebuild table and replace current one
167 void rebuild(int size);
168
169 bool is_full() const {
170 assert(_index <= _list->size(), "Sanity");
171 return _index == _list->size();
172 }
173
174 ShenandoahNMethod* at(int index) const;
175 int index_of(nmethod* nm) const;
176 void remove(int index);
177 void append(ShenandoahNMethod* snm);
178
179 inline bool iteration_in_progress() const;
180 void wait_until_concurrent_iteration_done();
181
182 // Logging support
183 void log_register_nmethod(nmethod* nm);
184 void log_unregister_nmethod(nmethod* nm);
185 void log_flush_nmethod(nmethod* nm);
186 };
187
188 class ShenandoahConcurrentNMethodIterator {
189 private:
190 ShenandoahNMethodTable* const _table;
191 ShenandoahNMethodTableSnapshot* _table_snapshot;
192
193 public:
194 ShenandoahConcurrentNMethodIterator(ShenandoahNMethodTable* table);
195
196 void nmethods_do_begin();
197 void nmethods_do(NMethodClosure* cl);
198 void nmethods_do_end();
199 };
200
201 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHNMETHOD_HPP