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 36 G1ConcurrentRefineThread::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 61 void G1ConcurrentRefineThread::wait_for_completed_buffers() { 62 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 63 while (!should_terminate() && !is_active()) { 64 _monitor->wait(Mutex::_no_safepoint_check_flag); 65 } 66 } 67 68 bool G1ConcurrentRefineThread::is_active() { 69 G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set(); 70 return is_primary() ? dcqs.process_completed_buffers() : _active; 71 } 72 73 void G1ConcurrentRefineThread::activate() { 74 MutexLockerEx 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 84 void G1ConcurrentRefineThread::deactivate() { 85 MutexLockerEx 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 94 void 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 } 141 142 void G1ConcurrentRefineThread::stop_service() { 143 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 144 _monitor->notify(); 145 }