1 /* 2 * Copyright (c) 2001, 2017, 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/common/suspendibleThreadSet.hpp" 27 #include "gc/g1/concurrentG1Refine.hpp" 28 #include "gc/g1/concurrentG1RefineThread.hpp" 29 #include "gc/g1/g1CollectedHeap.inline.hpp" 30 #include "gc/g1/g1RemSet.hpp" 31 #include "logging/log.hpp" 32 #include "memory/resourceArea.hpp" 33 #include "runtime/handles.inline.hpp" 34 #include "runtime/mutexLocker.hpp" 35 36 ConcurrentG1RefineThread:: 37 ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread *next, 38 uint worker_id_offset, uint worker_id, 39 size_t activate, size_t deactivate) : 40 ConcurrentGCThread(), 41 _worker_id_offset(worker_id_offset), 42 _worker_id(worker_id), 43 _active(false), 44 _next(next), 45 _monitor(NULL), 46 _cg1r(cg1r), 47 _vtime_accum(0.0), 48 _activation_threshold(activate), 49 _deactivation_threshold(deactivate) 50 { 51 52 // Each thread has its own monitor. The i-th thread is responsible for signaling 53 // to thread i+1 if the number of buffers in the queue exceeds a threshold for this 54 // thread. Monitors are also used to wake up the threads during termination. 55 // The 0th (primary) worker is notified by mutator threads and has a special monitor. 56 if (!is_primary()) { 57 _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true, 58 Monitor::_safepoint_check_never); 59 } else { 60 _monitor = DirtyCardQ_CBL_mon; 61 } 62 63 // set name 64 set_name("G1 Refine#%d", worker_id); 65 create_and_start(); 66 } 67 68 void ConcurrentG1RefineThread::update_thresholds(size_t activate, 69 size_t deactivate) { 70 assert(deactivate < activate, "precondition"); 71 _activation_threshold = activate; 72 _deactivation_threshold = deactivate; 73 } 74 75 void ConcurrentG1RefineThread::wait_for_completed_buffers() { 76 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 77 while (!should_terminate() && !is_active()) { 78 _monitor->wait(Mutex::_no_safepoint_check_flag); 79 } 80 } 81 82 bool ConcurrentG1RefineThread::is_active() { 83 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); 84 return is_primary() ? dcqs.process_completed_buffers() : _active; 85 } 86 87 void ConcurrentG1RefineThread::activate() { 88 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 89 if (!is_primary()) { 90 set_active(true); 91 } else { 92 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); 93 dcqs.set_process_completed(true); 94 } 95 _monitor->notify(); 96 } 97 98 void ConcurrentG1RefineThread::deactivate() { 99 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 100 if (!is_primary()) { 101 set_active(false); 102 } else { 103 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); 104 dcqs.set_process_completed(false); 105 } 106 } 107 108 void ConcurrentG1RefineThread::run_service() { 109 _vtime_start = os::elapsedVTime(); 110 111 while (!should_terminate()) { 112 // Wait for work 113 wait_for_completed_buffers(); 114 if (should_terminate()) { 115 break; 116 } 117 118 size_t buffers_processed = 0; 119 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); 120 log_debug(gc, refine)("Activated %d, on threshold: " SIZE_FORMAT ", current: " SIZE_FORMAT, 121 _worker_id, _activation_threshold, dcqs.completed_buffers_num()); 122 123 { 124 SuspendibleThreadSetJoiner sts_join; 125 126 while (!should_terminate()) { 127 if (sts_join.should_yield()) { 128 sts_join.yield(); 129 continue; // Re-check for termination after yield delay. 130 } 131 132 size_t curr_buffer_num = dcqs.completed_buffers_num(); 133 // If the number of the buffers falls down into the yellow zone, 134 // that means that the transition period after the evacuation pause has ended. 135 if (dcqs.completed_queue_padding() > 0 && curr_buffer_num <= cg1r()->yellow_zone()) { 136 dcqs.set_completed_queue_padding(0); 137 } 138 139 // Check if we need to activate the next thread. 140 if ((_next != NULL) && 141 !_next->is_active() && 142 (curr_buffer_num > _next->_activation_threshold)) { 143 _next->activate(); 144 } 145 146 // Process the next buffer, if there are enough left. 147 if (!dcqs.refine_completed_buffer_concurrently(_worker_id + _worker_id_offset, _deactivation_threshold)) { 148 break; // Deactivate, number of buffers fell below threshold. 149 } 150 ++buffers_processed; 151 } 152 } 153 154 deactivate(); 155 log_debug(gc, refine)("Deactivated %d, off threshold: " SIZE_FORMAT 156 ", current: " SIZE_FORMAT ", processed: " SIZE_FORMAT, 157 _worker_id, _deactivation_threshold, 158 dcqs.completed_buffers_num(), 159 buffers_processed); 160 161 if (os::supports_vtime()) { 162 _vtime_accum = (os::elapsedVTime() - _vtime_start); 163 } else { 164 _vtime_accum = 0.0; 165 } 166 } 167 168 log_debug(gc, refine)("Stopping %d", _worker_id); 169 } 170 171 void ConcurrentG1RefineThread::stop_service() { 172 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 173 _monitor->notify(); 174 }