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#include "precompiled.hpp"
26#include "gc/g1/g1BarrierSet.hpp"
27#include "gc/g1/g1ConcurrentRefine.hpp"
28#include "gc/g1/g1ConcurrentRefineThread.hpp"
29#include "gc/g1/g1DirtyCardQueue.hpp"
30#include "gc/shared/suspendibleThreadSet.hpp"
31#include "logging/log.hpp"
32#include "memory/resourceArea.hpp"
33#include "runtime/handles.inline.hpp"
34#include "runtime/mutexLocker.hpp"
35
36G1ConcurrentRefineThread::G1ConcurrentRefineThread(G1ConcurrentRefine* cr, uint worker_id) :
37 ConcurrentGCThread(),
38 _vtime_start(0.0),
39 _vtime_accum(0.0),
40 _worker_id(worker_id),
41 _active(false),
42 _monitor(NULL),
43 _cr(cr)
44{
45 // Each thread has its own monitor. The i-th thread is responsible for signaling
46 // to thread i+1 if the number of buffers in the queue exceeds a threshold for this
47 // thread. Monitors are also used to wake up the threads during termination.
48 // The 0th (primary) worker is notified by mutator threads and has a special monitor.
49 if (!is_primary()) {
50 _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true,
51 Monitor::_safepoint_check_never);
52 } else {
53 _monitor = DirtyCardQ_CBL_mon;
54 }
55
56 // set name
57 set_name("G1 Refine#%d", worker_id);
58 create_and_start();
59}
60
61void G1ConcurrentRefineThread::wait_for_completed_buffers() {
62 MonitorLocker ml(_monitor, Mutex::_no_safepoint_check_flag);
63 while (!should_terminate() && !is_active()) {
64 ml.wait();
65 }
66}
67
68bool G1ConcurrentRefineThread::is_active() {
69 G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set();
70 return is_primary() ? dcqs.process_completed_buffers() : _active;
71}
72
73void G1ConcurrentRefineThread::activate() {
74 MutexLocker x(_monitor, Mutex::_no_safepoint_check_flag);
75 if (!is_primary()) {
76 set_active(true);
77 } else {
78 G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set();
79 dcqs.set_process_completed_buffers(true);
80 }
81 _monitor->notify();
82}
83
84void G1ConcurrentRefineThread::deactivate() {
85 MutexLocker x(_monitor, Mutex::_no_safepoint_check_flag);
86 if (!is_primary()) {
87 set_active(false);
88 } else {
89 G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set();
90 dcqs.set_process_completed_buffers(false);
91 }
92}
93
94void G1ConcurrentRefineThread::run_service() {
95 _vtime_start = os::elapsedVTime();
96
97 while (!should_terminate()) {
98 // Wait for work
99 wait_for_completed_buffers();
100 if (should_terminate()) {
101 break;
102 }
103
104 size_t buffers_processed = 0;
105 log_debug(gc, refine)("Activated worker %d, on threshold: " SIZE_FORMAT ", current: " SIZE_FORMAT,
106 _worker_id, _cr->activation_threshold(_worker_id),
107 G1BarrierSet::dirty_card_queue_set().completed_buffers_num());
108
109 {
110 SuspendibleThreadSetJoiner sts_join;
111
112 while (!should_terminate()) {
113 if (sts_join.should_yield()) {
114 sts_join.yield();
115 continue; // Re-check for termination after yield delay.
116 }
117
118 if (!_cr->do_refinement_step(_worker_id)) {
119 break;
120 }
121 ++buffers_processed;
122 }
123 }
124
125 deactivate();
126 log_debug(gc, refine)("Deactivated worker %d, off threshold: " SIZE_FORMAT
127 ", current: " SIZE_FORMAT ", processed: " SIZE_FORMAT,
128 _worker_id, _cr->deactivation_threshold(_worker_id),
129 G1BarrierSet::dirty_card_queue_set().completed_buffers_num(),
130 buffers_processed);
131
132 if (os::supports_vtime()) {
133 _vtime_accum = (os::elapsedVTime() - _vtime_start);
134 } else {
135 _vtime_accum = 0.0;
136 }
137 }
138
139 log_debug(gc, refine)("Stopping %d", _worker_id);
140}
141
142void G1ConcurrentRefineThread::stop_service() {
143 MutexLocker x(_monitor, Mutex::_no_safepoint_check_flag);
144 _monitor->notify();
145}
146