1 /* 2 * Copyright (c) 2002, 2015, 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 #ifndef SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP 26 #define SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP 27 28 #include "gc/parallel/cardTableExtension.hpp" 29 #include "gc/parallel/parallelScavengeHeap.hpp" 30 #include "gc/parallel/psPromotionManager.inline.hpp" 31 #include "gc/parallel/psScavenge.hpp" 32 #include "logging/log.hpp" 33 #include "memory/iterator.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "utilities/globalDefinitions.hpp" 36 37 inline void PSScavenge::save_to_space_top_before_gc() { 38 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 39 _to_space_top_before_gc = heap->young_gen()->to_space()->top(); 40 } 41 42 template <class T> inline bool PSScavenge::should_scavenge(T* p) { 43 T heap_oop = oopDesc::load_heap_oop(p); 44 return PSScavenge::is_obj_in_young(heap_oop); 45 } 46 47 template <class T> 48 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) { 49 if (should_scavenge(p)) { 50 oop obj = oopDesc::load_decode_heap_oop_not_null(p); 51 // Skip objects copied to to_space since the scavenge started. 52 HeapWord* const addr = (HeapWord*)obj; 53 return addr < to_space_top_before_gc() || addr >= to_space->end(); 54 } 55 return false; 56 } 57 58 template <class T> 59 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) { 60 if (check_to_space) { 61 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 62 return should_scavenge(p, heap->young_gen()->to_space()); 63 } 64 return should_scavenge(p); 65 } 66 67 template<bool promote_immediately> 68 class PSRootsClosure: public OopClosure { 69 private: 70 PSPromotionManager* _promotion_manager; 71 72 protected: 73 template <class T> void do_oop_work(T *p) { 74 if (PSScavenge::should_scavenge(p)) { 75 // We never card mark roots, maybe call a func without test? 76 _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p); 77 } 78 } 79 public: 80 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { } 81 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); } 82 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); } 83 }; 84 85 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure; 86 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure; 87 88 // Scavenges a single oop in a Klass. 89 class PSScavengeFromKlassClosure: public OopClosure { 90 private: 91 PSPromotionManager* _pm; 92 // Used to redirty a scanned klass if it has oops 93 // pointing to the young generation after being scanned. 94 Klass* _scanned_klass; 95 public: 96 PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { } 97 void do_oop(narrowOop* p) { ShouldNotReachHere(); } 98 void do_oop(oop* p) { 99 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap(); 100 assert(!psh->is_in_reserved(p), "GC barrier needed"); 101 if (PSScavenge::should_scavenge(p)) { 102 assert(PSScavenge::should_scavenge(p, true), "revisiting object?"); 103 104 oop o = *p; 105 oop new_obj; 106 if (o->is_forwarded()) { 107 new_obj = o->forwardee(); 108 } else { 109 new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o); 110 } 111 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 112 113 if (PSScavenge::is_obj_in_young(new_obj)) { 114 do_klass_barrier(); 115 } 116 } 117 } 118 119 void set_scanned_klass(Klass* klass) { 120 assert(_scanned_klass == NULL || klass == NULL, "Should always only handling one klass at a time"); 121 _scanned_klass = klass; 122 } 123 124 private: 125 void do_klass_barrier() { 126 assert(_scanned_klass != NULL, "Should not be called without having a scanned klass"); 127 _scanned_klass->record_modified_oops(); 128 } 129 130 }; 131 132 // Scavenges the oop in a Klass. 133 class PSScavengeKlassClosure: public KlassClosure { 134 private: 135 PSScavengeFromKlassClosure _oop_closure; 136 protected: 137 public: 138 PSScavengeKlassClosure(PSPromotionManager* pm) : _oop_closure(pm) { } 139 void do_klass(Klass* klass) { 140 // If the klass has not been dirtied we know that there's 141 // no references into the young gen and we can skip it. 142 143 if (klass->has_modified_oops()) { 144 // Clean the klass since we're going to scavenge all the metadata. 145 klass->clear_modified_oops(); 146 147 // Setup the promotion manager to redirty this klass 148 // if references are left in the young gen. 149 _oop_closure.set_scanned_klass(klass); 150 151 klass->oops_do(&_oop_closure); 152 153 _oop_closure.set_scanned_klass(NULL); 154 } 155 } 156 }; 157 158 #endif // SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP