1 /* 2 * Copyright (c) 2018, 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 "classfile/symbolTable.hpp" 27 #include "classfile/stringTable.hpp" 28 #include "code/codeCache.hpp" 29 #include "gc/shared/parallelCleaning.hpp" 30 #include "logging/log.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "logging/log.hpp" 33 34 StringDedupCleaningTask::StringDedupCleaningTask(BoolObjectClosure* is_alive, 35 OopClosure* keep_alive, 36 bool resize_table) : 37 AbstractGangTask("String Dedup Cleaning"), 38 _dedup_closure(is_alive, keep_alive) { 39 40 if (StringDedup::is_enabled()) { 41 StringDedup::gc_prologue(resize_table); 42 } 43 } 44 45 StringDedupCleaningTask::~StringDedupCleaningTask() { 46 if (StringDedup::is_enabled()) { 47 StringDedup::gc_epilogue(); 48 } 49 } 50 51 void StringDedupCleaningTask::work(uint worker_id) { 52 if (StringDedup::is_enabled()) { 53 StringDedup::parallel_unlink(&_dedup_closure, worker_id); 54 } 55 } 56 57 CodeCacheUnloadingTask::CodeCacheUnloadingTask(uint num_workers, BoolObjectClosure* is_alive, bool unloading_occurred) : 58 _unloading_scope(is_alive), 59 _unloading_occurred(unloading_occurred), 60 _num_workers(num_workers), 61 _first_nmethod(NULL), 62 _claimed_nmethod(NULL) { 63 // Get first alive nmethod 64 CompiledMethodIterator iter(CompiledMethodIterator::only_alive); 65 if(iter.next()) { 66 _first_nmethod = iter.method(); 67 } 68 _claimed_nmethod = _first_nmethod; 69 } 70 71 CodeCacheUnloadingTask::~CodeCacheUnloadingTask() { 72 CodeCache::verify_clean_inline_caches(); 73 CodeCache::verify_icholder_relocations(); 74 } 75 76 void CodeCacheUnloadingTask::claim_nmethods(CompiledMethod** claimed_nmethods, int *num_claimed_nmethods) { 77 CompiledMethod* first; 78 CompiledMethodIterator last(CompiledMethodIterator::only_alive); 79 80 do { 81 *num_claimed_nmethods = 0; 82 83 first = _claimed_nmethod; 84 last = CompiledMethodIterator(CompiledMethodIterator::only_alive, first); 85 86 if (first != NULL) { 87 88 for (int i = 0; i < MaxClaimNmethods; i++) { 89 if (!last.next()) { 90 break; 91 } 92 claimed_nmethods[i] = last.method(); 93 (*num_claimed_nmethods)++; 94 } 95 } 96 97 } while (Atomic::cmpxchg(last.method(), &_claimed_nmethod, first) != first); 98 } 99 100 void CodeCacheUnloadingTask::work(uint worker_id) { 101 // The first nmethods is claimed by the first worker. 102 if (worker_id == 0 && _first_nmethod != NULL) { 103 _first_nmethod->do_unloading(_unloading_occurred); 104 _first_nmethod = NULL; 105 } 106 107 int num_claimed_nmethods; 108 CompiledMethod* claimed_nmethods[MaxClaimNmethods]; 109 110 while (true) { 111 claim_nmethods(claimed_nmethods, &num_claimed_nmethods); 112 113 if (num_claimed_nmethods == 0) { 114 break; 115 } 116 117 for (int i = 0; i < num_claimed_nmethods; i++) { 118 claimed_nmethods[i]->do_unloading(_unloading_occurred); 119 } 120 } 121 } 122 123 KlassCleaningTask::KlassCleaningTask() : 124 _clean_klass_tree_claimed(0), 125 _klass_iterator() { 126 } 127 128 bool KlassCleaningTask::claim_clean_klass_tree_task() { 129 if (_clean_klass_tree_claimed) { 130 return false; 131 } 132 133 return Atomic::cmpxchg(1, &_clean_klass_tree_claimed, 0) == 0; 134 } 135 136 InstanceKlass* KlassCleaningTask::claim_next_klass() { 137 Klass* klass; 138 do { 139 klass =_klass_iterator.next_klass(); 140 } while (klass != NULL && !klass->is_instance_klass()); 141 142 // this can be null so don't call InstanceKlass::cast 143 return static_cast<InstanceKlass*>(klass); 144 } 145 146 void KlassCleaningTask::work() { 147 ResourceMark rm; 148 149 // One worker will clean the subklass/sibling klass tree. 150 if (claim_clean_klass_tree_task()) { 151 Klass::clean_subklass_tree(); 152 } 153 154 // All workers will help cleaning the classes, 155 InstanceKlass* klass; 156 while ((klass = claim_next_klass()) != NULL) { 157 clean_klass(klass); 158 } 159 }