1 /*
2 * Copyright (c) 2019, 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 static void heal_nmethod(nmethod* nm);
69 static inline void disarm_nmethod(nmethod* nm);
70
71 static inline ShenandoahNMethod* gc_data(nmethod* nm);
72 static inline void attach_gc_data(nmethod* nm, ShenandoahNMethod* gc_data);
73
74 void assert_alive_and_correct() NOT_DEBUG_RETURN;
75 void assert_same_oops(bool allow_dead = false) NOT_DEBUG_RETURN;
76 static void assert_no_oops(nmethod* nm, bool allow_dea = false) NOT_DEBUG_RETURN;
77
78 private:
79 bool has_non_immed_oops() const { return _has_non_immed_oops; }
80 static void detect_reloc_oops(nmethod* nm, GrowableArray<oop*>& oops, bool& _has_non_immed_oops);
81 };
82
83 class ShenandoahNMethodTable;
84
85 // An opaque snapshot of current nmethod table for iteration
86 class ShenandoahNMethodTableSnapshot : public CHeapObj<mtGC> {
87 friend class ShenandoahNMethodTable;
88 private:
89 ShenandoahHeap* const _heap;
90 ShenandoahNMethodTable* _table;
91 ShenandoahNMethod** const _array;
92 const int _length;
93
94 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
95 volatile size_t _claimed;
96 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
97
98 public:
99 ShenandoahNMethodTableSnapshot(ShenandoahNMethodTable* table);
100
101 template<bool CSET_FILTER>
102 void parallel_blobs_do(CodeBlobClosure *f);
103
104 void concurrent_nmethods_do(NMethodClosure* cl);
105 };
106
107 class ShenandoahNMethodTable : public CHeapObj<mtGC> {
108 friend class ShenandoahNMethodTableSnapshot;
109 private:
110 enum {
111 minSize = 1024
112 };
113
114 ShenandoahHeap* const _heap;
115 ShenandoahNMethod** _array;
116 int _size;
117 int _index;
118 ShenandoahLock _lock;
119 bool _iteration_in_progress;
120
121 public:
122 ShenandoahNMethodTable();
123 ~ShenandoahNMethodTable();
124
125 void register_nmethod(nmethod* nm);
126 void unregister_nmethod(nmethod* nm);
127 void flush_nmethod(nmethod* nm);
128
129 bool contain(nmethod* nm) const;
130 int length() const { return _index; }
131
132 // Table iteration support
133 ShenandoahNMethodTableSnapshot* snapshot_for_iteration();
134 void finish_iteration(ShenandoahNMethodTableSnapshot* snapshot);
135
136 void assert_nmethods_alive_and_correct() NOT_DEBUG_RETURN;
137 private:
138 // Rebuild table and replace current one
139 void rebuild(int size);
140
141 bool is_full() const {
142 assert(_index <= _size, "Sanity");
143 return _index == _size;
144 }
145
146 ShenandoahNMethod* at(int index) const;
147 int index_of(nmethod* nm) const;
148 void remove(int index);
149 void append(ShenandoahNMethod* snm);
150
151 inline bool iteration_in_progress() const;
152 void wait_until_concurrent_iteration_done();
153
154 // Logging support
155 void log_register_nmethod(nmethod* nm);
156 void log_unregister_nmethod(nmethod* nm);
157 void log_flush_nmethod(nmethod* nm);
158 };
159
160 class ShenandoahConcurrentNMethodIterator {
161 private:
162 ShenandoahNMethodTable* const _table;
163 ShenandoahNMethodTableSnapshot* _table_snapshot;
164
165 public:
166 ShenandoahConcurrentNMethodIterator(ShenandoahNMethodTable* table);
167
168 void nmethods_do_begin();
169 void nmethods_do(NMethodClosure* cl);
170 void nmethods_do_end();
171 };
172
173 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHNMETHOD_HPP