1 /* 2 * Copyright (c) 2000, 2008, 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 inline void MarkSweep::mark_object(oop obj) { 26 // some marks may contain information we need to preserve so we store them away 27 // and overwrite the mark. We'll restore it at the end of markSweep. 28 markOop mark = obj->mark(); 29 obj->set_mark(markOopDesc::prototype()->set_marked()); 30 31 if (mark->must_be_preserved(obj)) { 32 preserve_mark(obj, mark); 33 } 34 } 35 36 template <class T> inline void MarkSweep::follow_root(T* p) { 37 assert(!Universe::heap()->is_in_reserved(p), 38 "roots shouldn't be things within the heap"); 39 #ifdef VALIDATE_MARK_SWEEP 40 if (ValidateMarkSweep) { 41 guarantee(!_root_refs_stack->contains(p), "should only be in here once"); 42 _root_refs_stack->push(p); 43 } 44 #endif 45 T heap_oop = oopDesc::load_heap_oop(p); 46 if (!oopDesc::is_null(heap_oop)) { 47 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 48 if (!obj->mark()->is_marked()) { 49 mark_object(obj); 50 obj->follow_contents(); 51 } 52 } 53 follow_stack(); 54 } 55 56 template <class T> inline void MarkSweep::mark_and_follow(T* p) { 57 // assert(Universe::heap()->is_in_reserved(p), "should be in object space"); 58 T heap_oop = oopDesc::load_heap_oop(p); 59 if (!oopDesc::is_null(heap_oop)) { 60 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 61 if (!obj->mark()->is_marked()) { 62 mark_object(obj); 63 obj->follow_contents(); 64 } 65 } 66 } 67 68 template <class T> inline void MarkSweep::mark_and_push(T* p) { 69 // assert(Universe::heap()->is_in_reserved(p), "should be in object space"); 70 T heap_oop = oopDesc::load_heap_oop(p); 71 if (!oopDesc::is_null(heap_oop)) { 72 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 73 if (!obj->mark()->is_marked()) { 74 mark_object(obj); 75 _marking_stack->push(obj); 76 } 77 } 78 } 79 80 void MarkSweep::push_objarray(oop obj, size_t index) { 81 ObjArrayTask task(obj, index); 82 assert(task.is_valid(), "bad ObjArrayTask"); 83 _objarray_stack->push(task); 84 } 85 86 template <class T> inline void MarkSweep::adjust_pointer(T* p, bool isroot) { 87 T heap_oop = oopDesc::load_heap_oop(p); 88 if (!oopDesc::is_null(heap_oop)) { 89 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 90 oop new_obj = oop(obj->mark()->decode_pointer()); 91 assert(new_obj != NULL || // is forwarding ptr? 92 obj->mark() == markOopDesc::prototype() || // not gc marked? 93 (UseBiasedLocking && obj->mark()->has_bias_pattern()) || 94 // not gc marked? 95 obj->is_shared(), // never forwarded? 96 "should be forwarded"); 97 if (new_obj != NULL) { 98 assert(Universe::heap()->is_in_reserved(new_obj), 99 "should be in object space"); 100 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 101 } 102 } 103 VALIDATE_MARK_SWEEP_ONLY(track_adjusted_pointer(p, isroot)); 104 } 105 106 template <class T> inline void MarkSweep::KeepAliveClosure::do_oop_work(T* p) { 107 #ifdef VALIDATE_MARK_SWEEP 108 if (ValidateMarkSweep) { 109 if (!Universe::heap()->is_in_reserved(p)) { 110 _root_refs_stack->push(p); 111 } else { 112 _other_refs_stack->push(p); 113 } 114 } 115 #endif 116 mark_and_push(p); 117 }