1 /* 2 * Copyright (c) 2016, 2021, 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/shared/preservedMarks.inline.hpp" 27 #include "gc/shared/workerThread.hpp" 28 #include "gc/shared/workerUtils.hpp" 29 #include "memory/allocation.inline.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "oops/oop.inline.hpp" 32 #include "runtime/atomic.hpp" 33 #include "utilities/macros.hpp" 34 35 void PreservedMarks::restore() { 36 while (!_stack.is_empty()) { 37 const OopAndMarkWord elem = _stack.pop(); 38 elem.set_mark(); 39 } 40 assert_empty(); 41 } 42 43 void PreservedMarks::adjust_during_full_gc() { 44 StackIterator<OopAndMarkWord, mtGC> iter(_stack); 45 while (!iter.is_empty()) { 46 OopAndMarkWord* elem = iter.next_addr(); 47 48 oop obj = elem->get_oop(); 49 if (obj->is_forwarded()) { 50 elem->set_oop(obj->forwardee()); 51 } 52 } 53 } 54 55 void PreservedMarks::restore_and_increment(volatile size_t* const total_size_addr) { 56 const size_t stack_size = size(); 57 restore(); 58 // Only do the atomic add if the size is > 0. 59 if (stack_size > 0) { 60 Atomic::add(total_size_addr, stack_size); 61 } 62 } 63 64 #ifndef PRODUCT 65 void PreservedMarks::assert_empty() { 66 assert(_stack.is_empty(), "stack expected to be empty, size = " SIZE_FORMAT, 67 _stack.size()); 68 assert(_stack.cache_size() == 0, 69 "stack expected to have no cached segments, cache size = " SIZE_FORMAT, 70 _stack.cache_size()); 71 } 72 #endif // ndef PRODUCT 73 74 void PreservedMarksSet::init(uint num) { 75 assert(_stacks == nullptr && _num == 0, "do not re-initialize"); 76 assert(num > 0, "pre-condition"); 77 if (_in_c_heap) { 78 _stacks = NEW_C_HEAP_ARRAY(Padded<PreservedMarks>, num, mtGC); 79 } else { 80 _stacks = NEW_RESOURCE_ARRAY(Padded<PreservedMarks>, num); 81 } 82 for (uint i = 0; i < num; i += 1) { 83 ::new (_stacks + i) PreservedMarks(); 84 } 85 _num = num; 86 87 assert_empty(); 88 } 89 90 class RestorePreservedMarksTask : public WorkerTask { 91 PreservedMarksSet* const _preserved_marks_set; 92 SequentialSubTasksDone _sub_tasks; 93 volatile size_t _total_size; 94 #ifdef ASSERT 95 size_t _total_size_before; 96 #endif // ASSERT 97 98 public: 99 void work(uint worker_id) override { 100 uint task_id = 0; 101 while (_sub_tasks.try_claim_task(task_id)) { 102 _preserved_marks_set->get(task_id)->restore_and_increment(&_total_size); 103 } 104 } 105 106 RestorePreservedMarksTask(PreservedMarksSet* preserved_marks_set) 107 : WorkerTask("Restore Preserved Marks"), 108 _preserved_marks_set(preserved_marks_set), 109 _sub_tasks(preserved_marks_set->num()), 110 _total_size(0) 111 DEBUG_ONLY(COMMA _total_size_before(0)) { 112 #ifdef ASSERT 113 // This is to make sure the total_size we'll calculate below is correct. 114 for (uint i = 0; i < _preserved_marks_set->num(); ++i) { 115 _total_size_before += _preserved_marks_set->get(i)->size(); 116 } 117 #endif // ASSERT 118 } 119 120 ~RestorePreservedMarksTask() { 121 assert(_total_size == _total_size_before, "total_size = %zu before = %zu", _total_size, _total_size_before); 122 size_t mem_size = _total_size * (sizeof(oop) + sizeof(markWord)); 123 log_trace(gc)("Restored %zu marks, occupying %zu %s", _total_size, 124 byte_size_in_proper_unit(mem_size), 125 proper_unit_for_byte_size(mem_size)); 126 } 127 }; 128 129 void PreservedMarksSet::restore(WorkerThreads* workers) { 130 { 131 RestorePreservedMarksTask cl(this); 132 if (workers == nullptr) { 133 cl.work(0); 134 } else { 135 workers->run_task(&cl); 136 } 137 } 138 139 assert_empty(); 140 } 141 142 WorkerTask* PreservedMarksSet::create_task() { 143 return new RestorePreservedMarksTask(this); 144 } 145 146 void PreservedMarksSet::reclaim() { 147 assert_empty(); 148 149 for (uint i = 0; i < _num; i += 1) { 150 _stacks[i].~Padded<PreservedMarks>(); 151 } 152 153 if (_in_c_heap) { 154 FREE_C_HEAP_ARRAY(Padded<PreservedMarks>, _stacks); 155 } else { 156 // the array was resource-allocated, so nothing to do 157 } 158 _stacks = nullptr; 159 _num = 0; 160 } 161 162 #ifndef PRODUCT 163 void PreservedMarksSet::assert_empty() { 164 assert(_stacks != nullptr && _num > 0, "should have been initialized"); 165 for (uint i = 0; i < _num; i += 1) { 166 get(i)->assert_empty(); 167 } 168 } 169 #endif // ndef PRODUCT --- EOF ---