1/*
2 * Copyright (c) 2001, 2019, 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
21 * questions.
22 *
23 */
24
25#ifndef SHARE_RUNTIME_STATSAMPLER_HPP
26#define SHARE_RUNTIME_STATSAMPLER_HPP
27
28#include "runtime/perfData.hpp"
29#include "runtime/task.hpp"
30
31class StatSamplerTask;
32
33/*
34 * The StatSampler class is responsible for periodically updating
35 * sampled PerfData instances and writing the sampled values to the
36 * PerfData memory region.
37 *
38 * In addition it is also responsible for providing a home for
39 * PerfData instances that otherwise have no better home.
40 */
41class StatSampler : AllStatic {
42
43 friend class StatSamplerTask;
44
45 private:
46
47 static StatSamplerTask* _task;
48 static PerfDataList* _sampled;
49
50 static void collect_sample();
51 static void create_misc_perfdata();
52 static void create_sampled_perfdata();
53 static void sample_data(PerfDataList* list);
54 static const char* get_system_property(const char* name, TRAPS);
55 static void create_system_property_instrumentation(TRAPS);
56
57 public:
58 // Start/stop the sampler
59 static void engage();
60 static void disengage();
61
62 static bool is_active() { return _task != NULL; }
63
64 static void initialize();
65 static void destroy();
66};
67
68#endif // SHARE_RUNTIME_STATSAMPLER_HPP
69