1 /* 2 * Copyright (c) 1997, 2014, 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 "compiler/compileBroker.hpp" 27 #include "gc_implementation/shared/gcTimer.hpp" 28 #include "gc_implementation/shared/gcTrace.hpp" 29 #include "gc_implementation/shared/markSweep.inline.hpp" 30 #include "gc_interface/collectedHeap.inline.hpp" 31 #include "oops/methodData.hpp" 32 #include "oops/objArrayKlass.inline.hpp" 33 #include "oops/oop.inline.hpp" 34 35 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 36 37 uint MarkSweep::_total_invocations = 0; 38 39 Stack<oop, mtGC> MarkSweep::_marking_stack; 40 Stack<ObjArrayTask, mtGC> MarkSweep::_objarray_stack; 41 42 Stack<oop, mtGC> MarkSweep::_preserved_oop_stack; 43 Stack<markOop, mtGC> MarkSweep::_preserved_mark_stack; 44 size_t MarkSweep::_preserved_count = 0; 45 size_t MarkSweep::_preserved_count_max = 0; 46 PreservedMark* MarkSweep::_preserved_marks = NULL; 47 ReferenceProcessor* MarkSweep::_ref_processor = NULL; 48 STWGCTimer* MarkSweep::_gc_timer = NULL; 49 SerialOldTracer* MarkSweep::_gc_tracer = NULL; 50 51 MarkSweep::FollowRootClosure MarkSweep::follow_root_closure; 52 53 void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); } 54 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); } 55 56 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure; 57 MarkSweep::FollowKlassClosure MarkSweep::follow_klass_closure; 58 MarkSweep::AdjustKlassClosure MarkSweep::adjust_klass_closure; 59 60 void MarkSweep::MarkAndPushClosure::do_oop(oop* p) { mark_and_push(p); } 61 void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); } 62 63 void MarkSweep::FollowKlassClosure::do_klass(Klass* klass) { 64 klass->oops_do(&MarkSweep::mark_and_push_closure); 65 } 66 void MarkSweep::AdjustKlassClosure::do_klass(Klass* klass) { 67 klass->oops_do(&MarkSweep::adjust_pointer_closure); 68 } 69 70 void MarkSweep::follow_class_loader(ClassLoaderData* cld) { 71 cld->oops_do(&MarkSweep::mark_and_push_closure, &MarkSweep::follow_klass_closure, true); 72 } 73 74 void MarkSweep::follow_stack() { 75 do { 76 while (!_marking_stack.is_empty()) { 77 oop obj = _marking_stack.pop(); 78 assert (obj->is_gc_marked(), "p must be marked"); 79 obj->follow_contents(); 80 } 81 // Process ObjArrays one at a time to avoid marking stack bloat. 82 if (!_objarray_stack.is_empty()) { 83 ObjArrayTask task = _objarray_stack.pop(); 84 ObjArrayKlass* k = (ObjArrayKlass*)task.obj()->klass(); 85 k->oop_follow_contents(task.obj(), task.index()); 86 } 87 } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty()); 88 } 89 90 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure; 91 92 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); } 93 94 // We preserve the mark which should be replaced at the end and the location 95 // that it will go. Note that the object that this markOop belongs to isn't 96 // currently at that address but it will be after phase4 97 void MarkSweep::preserve_mark(oop obj, markOop mark) { 98 // We try to store preserved marks in the to space of the new generation since 99 // this is storage which should be available. Most of the time this should be 100 // sufficient space for the marks we need to preserve but if it isn't we fall 101 // back to using Stacks to keep track of the overflow. 102 if (_preserved_count < _preserved_count_max) { 103 _preserved_marks[_preserved_count++].init(obj, mark); 104 } else { 105 _preserved_mark_stack.push(mark); 106 _preserved_oop_stack.push(obj); 107 } 108 } 109 110 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure; 111 112 void MarkSweep::AdjustPointerClosure::do_oop(oop* p) { adjust_pointer(p); } 113 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p); } 114 115 void MarkSweep::adjust_marks() { 116 assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(), 117 "inconsistent preserved oop stacks"); 118 119 // adjust the oops we saved earlier 120 for (size_t i = 0; i < _preserved_count; i++) { 121 _preserved_marks[i].adjust_pointer(); 122 } 123 124 // deal with the overflow stack 125 StackIterator<oop, mtGC> iter(_preserved_oop_stack); 126 while (!iter.is_empty()) { 127 oop* p = iter.next_addr(); 128 adjust_pointer(p); 129 } 130 } 131 132 void MarkSweep::restore_marks() { 133 assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(), 134 "inconsistent preserved oop stacks"); 135 if (PrintGC && Verbose) { 136 gclog_or_tty->print_cr("Restoring " SIZE_FORMAT " marks", 137 _preserved_count + _preserved_oop_stack.size()); 138 } 139 140 // restore the marks we saved earlier 141 for (size_t i = 0; i < _preserved_count; i++) { 142 _preserved_marks[i].restore(); 143 } 144 145 // deal with the overflow 146 while (!_preserved_oop_stack.is_empty()) { 147 oop obj = _preserved_oop_stack.pop(); 148 markOop mark = _preserved_mark_stack.pop(); 149 obj->set_mark(mark); 150 } 151 } 152 153 MarkSweep::IsAliveClosure MarkSweep::is_alive; 154 155 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); } 156 157 MarkSweep::KeepAliveClosure MarkSweep::keep_alive; 158 159 void MarkSweep::KeepAliveClosure::do_oop(oop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); } 160 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); } 161 162 void marksweep_init() { 163 MarkSweep::_gc_timer = new (ResourceObj::C_HEAP, mtGC) STWGCTimer(); 164 MarkSweep::_gc_tracer = new (ResourceObj::C_HEAP, mtGC) SerialOldTracer(); 165 } 166 167 #ifndef PRODUCT 168 169 void MarkSweep::trace(const char* msg) { 170 if (TraceMarkSweep) 171 gclog_or_tty->print("%s", msg); 172 } 173 174 #endif