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 "memory/allocation.hpp"
32 #include "utilities/growableArray.hpp"
33
34 // ShenandoahNMethod tuple records the internal locations of oop slots within reclocation stream in
35 // the nmethod. This allows us to quickly scan the oops without doing the nmethod-internal scans,
36 // that sometimes involves parsing the machine code. Note it does not record the oops themselves,
37 // because it would then require handling these tuples as the new class of roots.
38 class ShenandoahNMethod : public CHeapObj<mtGC> {
39 private:
40 nmethod* const _nm;
41 oop** _oops;
42 int _oops_count;
43 bool _has_non_immed_oops;
44 bool _unregistered;
45 ShenandoahReentrantLock _lock;
46
47 public:
48 ShenandoahNMethod(nmethod *nm, GrowableArray<oop*>& oops, bool has_non_immed_oops);
49 ~ShenandoahNMethod();
50
51 inline nmethod* nm() const;
52 inline ShenandoahReentrantLock* lock();
53 void oops_do(OopClosure* oops, bool fix_relocations = false);
54 // Update oops when the nmethod is re-registered
55 void update();
56
57 bool has_cset_oops(ShenandoahHeap* heap);
58
59 inline int oop_count() const;
60 inline bool has_oops() const;
61
62 inline void mark_unregistered();
63 inline bool is_unregistered() const;
64
65 static ShenandoahNMethod* for_nmethod(nmethod* nm);
66 static inline ShenandoahReentrantLock* lock_for_nmethod(nmethod* nm);
67
68 // Keep nmethod's metadata alive
69 static void keep_metadata_alive(nmethod* nm);
70
71 static void heal_nmethod(nmethod* nm);
72 static inline void disarm_nmethod(nmethod* nm);
73
74 static inline ShenandoahNMethod* gc_data(nmethod* nm);
75 static inline void attach_gc_data(nmethod* nm, ShenandoahNMethod* gc_data);
76
77 void assert_alive_and_correct() NOT_DEBUG_RETURN;
78 void assert_same_oops(bool allow_dead = false) NOT_DEBUG_RETURN;
79 static void assert_no_oops(nmethod* nm, bool allow_dea = false) NOT_DEBUG_RETURN;
80
81 private:
82 bool has_non_immed_oops() const { return _has_non_immed_oops; }
83 static void detect_reloc_oops(nmethod* nm, GrowableArray<oop*>& oops, bool& _has_non_immed_oops);
84 };
85
86 class ShenandoahNMethodTable;
87
88 // An opaque snapshot of current nmethod table for iteration
89 class ShenandoahNMethodTableSnapshot : public CHeapObj<mtGC> {
90 friend class ShenandoahNMethodTable;
91 private:
92 ShenandoahHeap* const _heap;
93 ShenandoahNMethodTable* _table;
94 ShenandoahNMethod** const _array;
95 const int _length;
96
97 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
98 volatile size_t _claimed;
99 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
100
101 public:
102 ShenandoahNMethodTableSnapshot(ShenandoahNMethodTable* table);
103
104 template<bool CSET_FILTER>
105 void parallel_blobs_do(CodeBlobClosure *f);
106
107 void concurrent_nmethods_do(NMethodClosure* cl);
108 };
109
110 class ShenandoahNMethodTable : public CHeapObj<mtGC> {
111 friend class ShenandoahNMethodTableSnapshot;
112 private:
113 enum {
114 minSize = 1024
115 };
116
117 ShenandoahHeap* const _heap;
118 ShenandoahNMethod** _array;
119 int _size;
120 int _index;
121 ShenandoahLock _lock;
122 bool _iteration_in_progress;
123
124 public:
125 ShenandoahNMethodTable();
126 ~ShenandoahNMethodTable();
127
128 void register_nmethod(nmethod* nm);
129 void unregister_nmethod(nmethod* nm);
130 void flush_nmethod(nmethod* nm);
131
132 bool contain(nmethod* nm) const;
133 int length() const { return _index; }
134
135 // Table iteration support
136 ShenandoahNMethodTableSnapshot* snapshot_for_iteration();
137 void finish_iteration(ShenandoahNMethodTableSnapshot* snapshot);
138
139 void assert_nmethods_alive_and_correct() NOT_DEBUG_RETURN;
140 private:
141 // Rebuild table and replace current one
142 void rebuild(int size);
143
144 bool is_full() const {
145 assert(_index <= _size, "Sanity");
146 return _index == _size;
147 }
148
149 ShenandoahNMethod* at(int index) const;
150 int index_of(nmethod* nm) const;
151 void remove(int index);
152 void append(ShenandoahNMethod* snm);
153
154 inline bool iteration_in_progress() const;
155 void wait_until_concurrent_iteration_done();
156
157 // Logging support
158 void log_register_nmethod(nmethod* nm);
159 void log_unregister_nmethod(nmethod* nm);
160 void log_flush_nmethod(nmethod* nm);
161 };
162
163 class ShenandoahConcurrentNMethodIterator {
164 private:
165 ShenandoahNMethodTable* const _table;
166 ShenandoahNMethodTableSnapshot* _table_snapshot;
167
168 public:
169 ShenandoahConcurrentNMethodIterator(ShenandoahNMethodTable* table);
170
171 void nmethods_do_begin();
172 void nmethods_do(NMethodClosure* cl);
173 void nmethods_do_end();
174 };
175
176 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHNMETHOD_HPP