1/*
2 * Copyright (c) 2014, 2016, Oracle and/or its affiliates. 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
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23 */
24
25#ifndef SHARE_VM_GC_G1_G1STRINGDEDUPTHREAD_HPP
26#define SHARE_VM_GC_G1_G1STRINGDEDUPTHREAD_HPP
27
28#include "gc/g1/g1StringDedupStat.hpp"
29#include "gc/shared/concurrentGCThread.hpp"
30
31//
32// The deduplication thread is where the actual deduplication occurs. It waits for
33// deduplication candidates to appear on the deduplication queue, removes them from
34// the queue and tries to deduplicate them. It uses the deduplication hashtable to
35// find identical, already existing, character arrays on the heap. The thread runs
36// concurrently with the Java application but participates in safepoints to allow
37// the GC to adjust and unlink oops from the deduplication queue and table.
38//
39class G1StringDedupThread: public ConcurrentGCThread {
40private:
41  static G1StringDedupThread* _thread;
42
43  G1StringDedupThread();
44  ~G1StringDedupThread();
45
46  void print_start(const G1StringDedupStat& last_stat);
47  void print_end(const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat);
48
49  void run_service();
50  void stop_service();
51
52public:
53  static void create();
54
55  static G1StringDedupThread* thread();
56
57  void deduplicate_shared_strings(G1StringDedupStat& stat);
58};
59
60#endif // SHARE_VM_GC_G1_G1STRINGDEDUPTHREAD_HPP
61