1 /* 2 * Copyright (c) 2016, 2023, 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/slidingForwarding.inline.hpp" 28 #include "gc/shared/workerThread.hpp" 29 #include "gc/shared/workerUtils.hpp" 30 #include "memory/allocation.inline.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "oops/oop.inline.hpp" 33 #include "runtime/atomic.hpp" 34 #include "utilities/macros.hpp" 35 36 void PreservedMarks::restore() { 37 while (!_stack.is_empty()) { 38 const OopAndMarkWord elem = _stack.pop(); 39 elem.set_mark(); 40 } 41 assert_empty(); 42 } 43 44 template <bool ALT_FWD> 45 void PreservedMarks::adjust_during_full_gc_impl() { 46 StackIterator<OopAndMarkWord, mtGC> iter(_stack); 47 while (!iter.is_empty()) { 48 OopAndMarkWord* elem = iter.next_addr(); 49 50 oop obj = elem->get_oop(); 51 if (obj->is_forwarded()) { 52 elem->set_oop(SlidingForwarding::forwardee<ALT_FWD>(obj)); 53 } 54 } 55 } 56 57 void PreservedMarks::adjust_during_full_gc() { 58 if (UseAltGCForwarding) { 59 adjust_during_full_gc_impl<true>(); 60 } else { 61 adjust_during_full_gc_impl<false>(); 62 } 63 } 64 65 void PreservedMarks::restore_and_increment(volatile size_t* const total_size_addr) { 66 const size_t stack_size = size(); 67 restore(); 68 // Only do the atomic add if the size is > 0. 69 if (stack_size > 0) { 70 Atomic::add(total_size_addr, stack_size); 71 } 72 } 73 74 #ifndef PRODUCT 75 void PreservedMarks::assert_empty() { 76 assert(_stack.is_empty(), "stack expected to be empty, size = " SIZE_FORMAT, 77 _stack.size()); 78 assert(_stack.cache_size() == 0, 79 "stack expected to have no cached segments, cache size = " SIZE_FORMAT, 80 _stack.cache_size()); 81 } 82 #endif // ndef PRODUCT 83 84 void PreservedMarksSet::init(uint num) { 85 assert(_stacks == nullptr && _num == 0, "do not re-initialize"); 86 assert(num > 0, "pre-condition"); 87 if (_in_c_heap) { 88 _stacks = NEW_C_HEAP_ARRAY(Padded<PreservedMarks>, num, mtGC); 89 } else { 90 _stacks = NEW_RESOURCE_ARRAY(Padded<PreservedMarks>, num); 91 } 92 for (uint i = 0; i < num; i += 1) { 93 ::new (_stacks + i) PreservedMarks(); 94 } 95 _num = num; 96 97 assert_empty(); 98 } 99 100 class RestorePreservedMarksTask : public WorkerTask { 101 PreservedMarksSet* const _preserved_marks_set; 102 SequentialSubTasksDone _sub_tasks; 103 volatile size_t _total_size; 104 #ifdef ASSERT 105 size_t _total_size_before; 106 #endif // ASSERT 107 108 public: 109 void work(uint worker_id) override { 110 uint task_id = 0; 111 while (_sub_tasks.try_claim_task(task_id)) { 112 _preserved_marks_set->get(task_id)->restore_and_increment(&_total_size); 113 } 114 } 115 116 RestorePreservedMarksTask(PreservedMarksSet* preserved_marks_set) 117 : WorkerTask("Restore Preserved Marks"), 118 _preserved_marks_set(preserved_marks_set), 119 _sub_tasks(preserved_marks_set->num()), 120 _total_size(0) 121 DEBUG_ONLY(COMMA _total_size_before(0)) { 122 #ifdef ASSERT 123 // This is to make sure the total_size we'll calculate below is correct. 124 for (uint i = 0; i < _preserved_marks_set->num(); ++i) { 125 _total_size_before += _preserved_marks_set->get(i)->size(); 126 } 127 #endif // ASSERT 128 } 129 130 ~RestorePreservedMarksTask() { 131 assert(_total_size == _total_size_before, "total_size = %zu before = %zu", _total_size, _total_size_before); 132 size_t mem_size = _total_size * (sizeof(oop) + sizeof(markWord)); 133 log_trace(gc)("Restored %zu marks, occupying %zu %s", _total_size, 134 byte_size_in_proper_unit(mem_size), 135 proper_unit_for_byte_size(mem_size)); 136 } 137 }; 138 139 void PreservedMarksSet::restore(WorkerThreads* workers) { 140 { 141 RestorePreservedMarksTask cl(this); 142 if (workers == nullptr) { 143 cl.work(0); 144 } else { 145 workers->run_task(&cl); 146 } 147 } 148 149 assert_empty(); 150 } 151 152 WorkerTask* PreservedMarksSet::create_task() { 153 return new RestorePreservedMarksTask(this); 154 } 155 156 void PreservedMarksSet::reclaim() { 157 assert_empty(); 158 159 for (uint i = 0; i < _num; i += 1) { 160 _stacks[i].~Padded<PreservedMarks>(); 161 } 162 163 if (_in_c_heap) { 164 FREE_C_HEAP_ARRAY(Padded<PreservedMarks>, _stacks); 165 } else { 166 // the array was resource-allocated, so nothing to do 167 } 168 _stacks = nullptr; 169 _num = 0; 170 } 171 172 #ifndef PRODUCT 173 void PreservedMarksSet::assert_empty() { 174 assert(_stacks != nullptr && _num > 0, "should have been initialized"); 175 for (uint i = 0; i < _num; i += 1) { 176 get(i)->assert_empty(); 177 } 178 } 179 #endif // ndef PRODUCT --- EOF ---