1 /* 2 * Copyright (c) 2002, 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 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP 27 28 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp" 29 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" 30 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp" 31 #include "gc_implementation/parallelScavenge/psScavenge.hpp" 32 #include "memory/iterator.hpp" 33 #include "utilities/globalDefinitions.hpp" 34 35 inline void PSScavenge::save_to_space_top_before_gc() { 36 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); 37 _to_space_top_before_gc = heap->young_gen()->to_space()->top(); 38 } 39 40 template <class T> inline bool PSScavenge::should_scavenge(T* p) { 41 T heap_oop = oopDesc::load_heap_oop(p); 42 return PSScavenge::is_obj_in_young(heap_oop); 43 } 44 45 template <class T> 46 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) { 47 if (should_scavenge(p)) { 48 oop obj = oopDesc::load_decode_heap_oop_not_null(p); 49 // Skip objects copied to to_space since the scavenge started. 50 HeapWord* const addr = (HeapWord*)obj; 51 return addr < to_space_top_before_gc() || addr >= to_space->end(); 52 } 53 return false; 54 } 55 56 template <class T> 57 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) { 58 if (check_to_space) { 59 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); 60 return should_scavenge(p, heap->young_gen()->to_space()); 61 } 62 return should_scavenge(p); 63 } 64 65 template<bool promote_immediately> 66 class PSRootsClosure: public OopClosure { 67 private: 68 PSPromotionManager* _promotion_manager; 69 70 protected: 71 template <class T> void do_oop_work(T *p) { 72 if (PSScavenge::should_scavenge(p)) { 73 // We never card mark roots, maybe call a func without test? 74 _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p); 75 } 76 } 77 public: 78 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { } 79 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); } 80 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); } 81 }; 82 83 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure; 84 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure; 85 86 // Scavenges a single oop in a Klass. 87 class PSScavengeFromKlassClosure: public OopClosure { 88 private: 89 PSPromotionManager* _pm; 90 // Used to redirty a scanned klass if it has oops 91 // pointing to the young generation after being scanned. 92 Klass* _scanned_klass; 93 public: 94 PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { } 95 void do_oop(narrowOop* p) { ShouldNotReachHere(); } 96 void do_oop(oop* p) { 97 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap(); 98 assert(!psh->is_in_reserved(p), "GC barrier needed"); 99 if (PSScavenge::should_scavenge(p)) { 100 assert(!Universe::heap()->is_in_reserved(p), "Not from meta-data?"); 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 #ifndef PRODUCT 143 if (TraceScavenge) { 144 ResourceMark rm; 145 gclog_or_tty->print_cr("PSScavengeKlassClosure::do_klass " PTR_FORMAT ", %s, dirty: %s", 146 p2i(klass), 147 klass->external_name(), 148 klass->has_modified_oops() ? "true" : "false"); 149 } 150 #endif 151 152 if (klass->has_modified_oops()) { 153 // Clean the klass since we're going to scavenge all the metadata. 154 klass->clear_modified_oops(); 155 156 // Setup the promotion manager to redirty this klass 157 // if references are left in the young gen. 158 _oop_closure.set_scanned_klass(klass); 159 160 klass->oops_do(&_oop_closure); 161 162 _oop_closure.set_scanned_klass(NULL); 163 } 164 } 165 }; 166 167 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP