1 /*
2 * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHSTRINGDEDUP_HPP
25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHSTRINGDEDUP_HPP
26
27 #include "classfile/javaClasses.hpp"
28 #include "gc_implementation/shenandoah/shenandoahPhaseTimings.hpp"
29 #include "memory/iterator.hpp"
30 #include "utilities/ostream.hpp"
31
32 #define STRDEDUP_TIME_FORMAT_MS "%.3fms"
33 #define STRDEDUP_TIME_PARAM_MS(time) ((time) * MILLIUNITS)
34
35 class ShenandoahStrDedupStats VALUE_OBJ_CLASS_SPEC {
36 private:
37 // Counters
38 volatile size_t _inspected;
39 volatile size_t _deduped;
40 volatile size_t _skipped;
41 volatile size_t _known;
42
43 size_t _idle;
44 size_t _exec;
45 size_t _block;
46
47 // Time spent by the deduplication thread in different phases
48 double _start_concurrent;
49 double _end_concurrent;
50 double _start_phase;
51 double _idle_elapsed;
52 double _exec_elapsed;
53 double _block_elapsed;
54
55 size_t _table_expanded_count;
56 size_t _table_shrinked_count;
57 size_t _table_rehashed_count;
58
59 public:
60 ShenandoahStrDedupStats();
61
62 void inc_inspected() { assert_thread(); _inspected ++; }
63 void inc_skipped() { assert_thread(); _skipped ++; }
64 void inc_known() { assert_thread(); _known ++; }
65 void inc_deduped() {
66 assert_thread();
67 _deduped ++;
68 }
69
70 void atomic_inc_inspected(size_t count);
71 void atomic_inc_deduped(size_t count);
72 void atomic_inc_skipped(size_t count);
73 void atomic_inc_known(size_t count);
74
75 void mark_idle();
76 void mark_exec();
77 void mark_block();
78 void mark_unblock();
79 void mark_done();
80
81 void inc_table_expanded();
82 void inc_table_shrinked();
83 void inc_table_rehashed();
84
85 void update(const ShenandoahStrDedupStats& sts);
86
87 void print_statistics(outputStream* out) const;
88
89 private:
90 void assert_thread() PRODUCT_RETURN;
91 };
92
93 class ShenandoahStrDedupQueue;
94 class ShenandoahStrDedupQueueSet;
95 class ShenandoahStrDedupTable;
96 class ShenandoahStrDedupThread;
97
98 class ShenandoahStringDedup : AllStatic {
99 friend class ShenandoahStrDedupStats;
100
101 private:
102 static ShenandoahStrDedupQueueSet* _queues;
103 static ShenandoahStrDedupTable* _table;
104 static ShenandoahStrDedupThread* _thread;
105 static bool _enabled;
106 static ShenandoahStrDedupStats _stats;
107
108 public:
109 // Initialize string deduplication.
110 static void initialize();
111
112 static bool is_enabled() { return _enabled; }
113
114 // Enqueue a string to worker's local string dedup queue
115 static void enqueue_candidate(oop java_string, ShenandoahStrDedupQueue* q);
116
117 // Get string dedup queue associated to specific worker id
118 static ShenandoahStrDedupQueue* queue(uint worker_id);
119
120 // Deduplicate a string, the call is lock-free
121 static bool deduplicate(oop java_string, bool update_counter = true);
122
123 // Parallel scan string dedup queues/table
124 static void clear_claimed();
125
126 static void parallel_oops_do(ShenandoahPhaseTimings::Phase phase, OopClosure* cl, uint worker_id);
127
128 // For verification only
129 static void oops_do_slow(OopClosure* cl);
130
131 static void threads_do(ThreadClosure* tc);
132
133 static void print_worker_threads_on(outputStream* out) { }
134
135 static ShenandoahStrDedupStats& dedup_stats() { return _stats; }
136
137 // Parallel cleanup string dedup queues/table
138 static void parallel_cleanup();
139
140 static void stop();
141
142 static inline bool is_candidate(oop obj) {
143 return java_lang_String::is_instance(obj) &&
144 java_lang_String::value(obj) != NULL;
145 }
146
147 static void print_statistics(outputStream* out);
148 };
149
150 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHSTRINGDEDUP_HPP