1 /* 2 * Copyright (c) 2001, 2018, 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/shared/suspendibleThreadSet.hpp" 30 #include "logging/log.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "runtime/handles.inline.hpp" 33 #include "runtime/mutexLocker.hpp" 34 35 G1ConcurrentRefineThread::G1ConcurrentRefineThread(G1ConcurrentRefine* cr, uint worker_id) : 36 ConcurrentGCThread(), 37 _vtime_start(0.0), 38 _vtime_accum(0.0), 39 _worker_id(worker_id), 40 _active(false), 41 _monitor(NULL), 42 _cr(cr) 43 { 44 // Each thread has its own monitor. The i-th thread is responsible for signaling 45 // to thread i+1 if the number of buffers in the queue exceeds a threshold for this 46 // thread. Monitors are also used to wake up the threads during termination. 47 // The 0th (primary) worker is notified by mutator threads and has a special monitor. 48 if (!is_primary()) { 49 _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true, 50 Monitor::_safepoint_check_never); 51 } else { 52 _monitor = DirtyCardQ_CBL_mon; 53 } 54 55 // set name 56 set_name("G1 Refine#%d", worker_id); 57 create_and_start(); 58 } 59 60 void G1ConcurrentRefineThread::wait_for_completed_buffers() { 61 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 62 while (!should_terminate() && !is_active()) { 63 _monitor->wait(Mutex::_no_safepoint_check_flag); 64 } 65 } 66 67 bool G1ConcurrentRefineThread::is_active() { 68 DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set(); 69 return is_primary() ? dcqs.process_completed_buffers() : _active; 70 } 71 72 void G1ConcurrentRefineThread::activate() { 73 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 74 if (!is_primary()) { 75 set_active(true); 76 } else { 77 DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set(); 78 dcqs.set_process_completed_buffers(true); 79 } 80 _monitor->notify(); 81 } 82 83 void G1ConcurrentRefineThread::deactivate() { 84 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 85 if (!is_primary()) { 86 set_active(false); 87 } else { 88 DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set(); 89 dcqs.set_process_completed_buffers(false); 90 } 91 } 92 93 void G1ConcurrentRefineThread::run_service() { 94 _vtime_start = os::elapsedVTime(); 95 96 while (!should_terminate()) { 97 // Wait for work 98 wait_for_completed_buffers(); 99 if (should_terminate()) { 100 break; 101 } 102 103 size_t buffers_processed = 0; 104 log_debug(gc, refine)("Activated worker %d, on threshold: " SIZE_FORMAT ", current: " SIZE_FORMAT, 105 _worker_id, _cr->activation_threshold(_worker_id), 106 G1BarrierSet::dirty_card_queue_set().completed_buffers_num()); 107 108 { 109 SuspendibleThreadSetJoiner sts_join; 110 111 while (!should_terminate()) { 112 if (sts_join.should_yield()) { 113 sts_join.yield(); 114 continue; // Re-check for termination after yield delay. 115 } 116 117 if (!_cr->do_refinement_step(_worker_id)) { 118 break; 119 } 120 ++buffers_processed; 121 } 122 } 123 124 deactivate(); 125 log_debug(gc, refine)("Deactivated worker %d, off threshold: " SIZE_FORMAT 126 ", current: " SIZE_FORMAT ", processed: " SIZE_FORMAT, 127 _worker_id, _cr->deactivation_threshold(_worker_id), 128 G1BarrierSet::dirty_card_queue_set().completed_buffers_num(), 129 buffers_processed); 130 131 if (os::supports_vtime()) { 132 _vtime_accum = (os::elapsedVTime() - _vtime_start); 133 } else { 134 _vtime_accum = 0.0; 135 } 136 } 137 138 log_debug(gc, refine)("Stopping %d", _worker_id); 139 } 140 141 void G1ConcurrentRefineThread::stop_service() { 142 MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag); 143 _monitor->notify(); 144 }