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 "utilities/globalDefinitions.hpp" 35 36 inline void PSScavenge::save_to_space_top_before_gc() { 37 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 38 _to_space_top_before_gc = heap->young_gen()->to_space()->top(); 39 } 40 41 template <class T> inline bool PSScavenge::should_scavenge(T* p) { 42 T heap_oop = oopDesc::load_heap_oop(p); 43 return PSScavenge::is_obj_in_young(heap_oop); 44 } 45 46 template <class T> 47 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) { 48 if (should_scavenge(p)) { 49 oop obj = oopDesc::load_decode_heap_oop_not_null(p); 50 // Skip objects copied to to_space since the scavenge started. 51 HeapWord* const addr = (HeapWord*)obj; 52 return addr < to_space_top_before_gc() || addr >= to_space->end(); 53 } 54 return false; 55 } 56 57 template <class T> 58 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) { 59 if (check_to_space) { 60 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 61 return should_scavenge(p, heap->young_gen()->to_space()); 62 } 63 return should_scavenge(p); 64 } 65 66 template<bool promote_immediately> 67 class PSRootsClosure: public OopClosure { 68 private: 69 PSPromotionManager* _promotion_manager; 70 71 protected: 72 template <class T> void do_oop_work(T *p) { 73 if (PSScavenge::should_scavenge(p)) { 74 // We never card mark roots, maybe call a func without test? 75 _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p); 76 } 77 } 78 public: 79 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { } 80 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); } 81 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); } 82 }; 83 84 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure; 85 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure; 86 87 // Scavenges a single oop in a Klass. 88 class PSScavengeFromKlassClosure: public OopClosure { 89 private: 90 PSPromotionManager* _pm; 91 // Used to redirty a scanned klass if it has oops 92 // pointing to the young generation after being scanned. 93 Klass* _scanned_klass; 94 public: 95 PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { } 96 void do_oop(narrowOop* p) { ShouldNotReachHere(); } 97 void do_oop(oop* p) { 98 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap(); 99 assert(!psh->is_in_reserved(p), "GC barrier needed"); 100 if (PSScavenge::should_scavenge(p)) { 101 assert(PSScavenge::should_scavenge(p, true), "revisiting object?"); 102 103 oop o = *p; 104 oop new_obj; 105 if (o->is_forwarded()) { 106 new_obj = o->forwardee(); 107 } else { 108 new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o); 109 } 110 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 111 112 if (PSScavenge::is_obj_in_young(new_obj)) { 113 do_klass_barrier(); 114 } 115 } 116 } 117 118 void set_scanned_klass(Klass* klass) { 119 assert(_scanned_klass == NULL || klass == NULL, "Should always only handling one klass at a time"); 120 _scanned_klass = klass; 121 } 122 123 private: 124 void do_klass_barrier() { 125 assert(_scanned_klass != NULL, "Should not be called without having a scanned klass"); 126 _scanned_klass->record_modified_oops(); 127 } 128 129 }; 130 131 // Scavenges the oop in a Klass. 132 class PSScavengeKlassClosure: public KlassClosure { 133 private: 134 PSScavengeFromKlassClosure _oop_closure; 135 protected: 136 public: 137 PSScavengeKlassClosure(PSPromotionManager* pm) : _oop_closure(pm) { } 138 void do_klass(Klass* klass) { 139 // If the klass has not been dirtied we know that there's 140 // no references into the young gen and we can skip it. 141 142 NOT_PRODUCT(ResourceMark rm); 143 log_develop_trace(gc, scavenge)("PSScavengeKlassClosure::do_klass " PTR_FORMAT ", %s, dirty: %s", 144 p2i(klass), 145 klass->external_name(), 146 klass->has_modified_oops() ? "true" : "false"); 147 148 if (klass->has_modified_oops()) { 149 // Clean the klass since we're going to scavenge all the metadata. 150 klass->clear_modified_oops(); 151 152 // Setup the promotion manager to redirty this klass 153 // if references are left in the young gen. 154 _oop_closure.set_scanned_klass(klass); 155 156 klass->oops_do(&_oop_closure); 157 158 _oop_closure.set_scanned_klass(NULL); 159 } 160 } 161 }; 162 163 #endif // SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP