1 /* 2 * Copyright (c) 2001, 2018, 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_G1_G1OOPCLOSURES_INLINE_HPP 26 #define SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP 27 28 #include "gc/g1/g1CollectedHeap.hpp" 29 #include "gc/g1/g1ConcurrentMark.inline.hpp" 30 #include "gc/g1/g1OopClosures.hpp" 31 #include "gc/g1/g1ParScanThreadState.inline.hpp" 32 #include "gc/g1/g1RemSet.hpp" 33 #include "gc/g1/heapRegion.inline.hpp" 34 #include "gc/g1/heapRegionRemSet.hpp" 35 #include "memory/iterator.inline.hpp" 36 #include "oops/access.inline.hpp" 37 #include "oops/compressedOops.inline.hpp" 38 #include "oops/oopsHierarchy.hpp" 39 #include "runtime/prefetch.inline.hpp" 40 41 template <class T> 42 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) { 43 // We're not going to even bother checking whether the object is 44 // already forwarded or not, as this usually causes an immediate 45 // stall. We'll try to prefetch the object (for write, given that 46 // we might need to install the forwarding reference) and we'll 47 // get back to it when pop it from the queue 48 Prefetch::write(obj->mark_addr(), 0); 49 Prefetch::read(obj->mark_addr(), (HeapWordSize*2)); 50 51 // slightly paranoid test; I'm trying to catch potential 52 // problems before we go into push_on_queue to know where the 53 // problem is coming from 54 assert((obj == RawAccess<>::oop_load(p)) || 55 (obj->is_forwarded() && 56 obj->forwardee() == RawAccess<>::oop_load(p)), 57 "p should still be pointing to obj or to its forwardee"); 58 59 _par_scan_state->push_on_queue(p); 60 } 61 62 template <class T> 63 inline void G1ScanClosureBase::handle_non_cset_obj_common(InCSetState const state, T* p, oop const obj) { 64 if (state.is_humongous()) { 65 _g1h->set_humongous_is_live(obj); 66 } 67 } 68 69 template <class T> 70 inline void G1ScanEvacuatedObjClosure::do_oop_nv(T* p) { 71 T heap_oop = RawAccess<>::oop_load(p); 72 73 if (CompressedOops::is_null(heap_oop)) { 74 return; 75 } 76 oop obj = CompressedOops::decode_not_null(heap_oop); 77 const InCSetState state = _g1h->in_cset_state(obj); 78 if (state.is_in_cset()) { 79 prefetch_and_push(p, obj); 80 } else { 81 if (HeapRegion::is_in_same_region(p, obj)) { 82 return; 83 } 84 handle_non_cset_obj_common(state, p, obj); 85 _par_scan_state->update_rs(_from, p, obj); 86 } 87 } 88 89 template <class T> 90 inline void G1CMOopClosure::do_oop_nv(T* p) { 91 _task->deal_with_reference(p); 92 } 93 94 template <class T> 95 inline void G1RootRegionScanClosure::do_oop_nv(T* p) { 96 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p); 97 if (CompressedOops::is_null(heap_oop)) { 98 return; 99 } 100 oop obj = CompressedOops::decode_not_null(heap_oop); 101 _cm->mark_in_next_bitmap(_worker_id, obj); 102 } 103 104 template <class T> 105 inline static void check_obj_during_refinement(T* p, oop const obj) { 106 #ifdef ASSERT 107 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 108 // can't do because of races 109 // assert(oopDesc::is_oop_or_null(obj), "expected an oop"); 110 assert(check_obj_alignment(obj), "not oop aligned"); 111 assert(g1h->is_in_reserved(obj), "must be in heap"); 112 113 HeapRegion* from = g1h->heap_region_containing(p); 114 115 assert(from != NULL, "from region must be non-NULL"); 116 assert(from->is_in_reserved(p) || 117 (from->is_humongous() && 118 g1h->heap_region_containing(p)->is_humongous() && 119 from->humongous_start_region() == g1h->heap_region_containing(p)->humongous_start_region()), 120 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.", 121 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index()); 122 #endif // ASSERT 123 } 124 125 template <class T> 126 inline void G1ConcurrentRefineOopClosure::do_oop_nv(T* p) { 127 T o = RawAccess<MO_VOLATILE>::oop_load(p); 128 if (CompressedOops::is_null(o)) { 129 return; 130 } 131 oop obj = CompressedOops::decode_not_null(o); 132 133 check_obj_during_refinement(p, obj); 134 135 if (HeapRegion::is_in_same_region(p, obj)) { 136 // Normally this closure should only be called with cross-region references. 137 // But since Java threads are manipulating the references concurrently and we 138 // reload the values things may have changed. 139 // Also this check lets slip through references from a humongous continues region 140 // to its humongous start region, as they are in different regions, and adds a 141 // remembered set entry. This is benign (apart from memory usage), as we never 142 // try to either evacuate or eager reclaim humonguous arrays of j.l.O. 143 return; 144 } 145 146 HeapRegionRemSet* to_rem_set = _g1->heap_region_containing(obj)->rem_set(); 147 148 assert(to_rem_set != NULL, "Need per-region 'into' remsets."); 149 if (to_rem_set->is_tracked()) { 150 to_rem_set->add_reference(p, _worker_i); 151 } 152 } 153 154 template <class T> 155 inline void G1ScanObjsDuringUpdateRSClosure::do_oop_nv(T* p) { 156 T o = RawAccess<>::oop_load(p); 157 if (CompressedOops::is_null(o)) { 158 return; 159 } 160 oop obj = CompressedOops::decode_not_null(o); 161 162 check_obj_during_refinement(p, obj); 163 164 assert(!_g1h->is_in_cset((HeapWord*)p), "Oop originates from " PTR_FORMAT " (region: %u) which is in the collection set.", p2i(p), _g1h->addr_to_region((HeapWord*)p)); 165 const InCSetState state = _g1h->in_cset_state(obj); 166 if (state.is_in_cset()) { 167 // Since the source is always from outside the collection set, here we implicitly know 168 // that this is a cross-region reference too. 169 prefetch_and_push(p, obj); 170 } else { 171 HeapRegion* to = _g1h->heap_region_containing(obj); 172 if (_from == to) { 173 return; 174 } 175 handle_non_cset_obj_common(state, p, obj); 176 to->rem_set()->add_reference(p, _worker_i); 177 } 178 } 179 180 template <class T> 181 inline void G1ScanObjsDuringScanRSClosure::do_oop_nv(T* p) { 182 T heap_oop = RawAccess<>::oop_load(p); 183 if (CompressedOops::is_null(heap_oop)) { 184 return; 185 } 186 oop obj = CompressedOops::decode_not_null(heap_oop); 187 188 const InCSetState state = _g1h->in_cset_state(obj); 189 if (state.is_in_cset()) { 190 prefetch_and_push(p, obj); 191 } else { 192 if (HeapRegion::is_in_same_region(p, obj)) { 193 return; 194 } 195 handle_non_cset_obj_common(state, p, obj); 196 } 197 } 198 199 void G1ParCopyHelper::do_cld_barrier(oop new_obj) { 200 if (_g1h->heap_region_containing(new_obj)->is_young()) { 201 _scanned_cld->record_modified_oops(); 202 } 203 } 204 205 void G1ParCopyHelper::mark_object(oop obj) { 206 assert(!_g1h->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet"); 207 208 // We know that the object is not moving so it's safe to read its size. 209 _cm->mark_in_next_bitmap(_worker_id, obj); 210 } 211 212 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) { 213 assert(from_obj->is_forwarded(), "from obj should be forwarded"); 214 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee"); 215 assert(from_obj != to_obj, "should not be self-forwarded"); 216 217 assert(_g1h->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet"); 218 assert(!_g1h->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet"); 219 220 // The object might be in the process of being copied by another 221 // worker so we cannot trust that its to-space image is 222 // well-formed. So we have to read its size from its from-space 223 // image which we know should not be changing. 224 _cm->mark_in_next_bitmap(_worker_id, to_obj, from_obj->size()); 225 } 226 227 template <G1Barrier barrier, G1Mark do_mark_object> 228 template <class T> 229 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) { 230 T heap_oop = RawAccess<>::oop_load(p); 231 232 if (CompressedOops::is_null(heap_oop)) { 233 return; 234 } 235 236 oop obj = CompressedOops::decode_not_null(heap_oop); 237 238 assert(_worker_id == _par_scan_state->worker_id(), "sanity"); 239 240 const InCSetState state = _g1h->in_cset_state(obj); 241 if (state.is_in_cset()) { 242 oop forwardee; 243 markOop m = obj->mark(); 244 if (m->is_marked()) { 245 forwardee = (oop) m->decode_pointer(); 246 } else { 247 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m); 248 } 249 assert(forwardee != NULL, "forwardee should not be NULL"); 250 RawAccess<>::oop_store(p, forwardee); 251 if (do_mark_object != G1MarkNone && forwardee != obj) { 252 // If the object is self-forwarded we don't need to explicitly 253 // mark it, the evacuation failure protocol will do so. 254 mark_forwarded_object(obj, forwardee); 255 } 256 257 if (barrier == G1BarrierCLD) { 258 do_cld_barrier(forwardee); 259 } 260 } else { 261 if (state.is_humongous()) { 262 _g1h->set_humongous_is_live(obj); 263 } 264 265 // The object is not in collection set. If we're a root scanning 266 // closure during an initial mark pause then attempt to mark the object. 267 if (do_mark_object == G1MarkFromRoot) { 268 mark_object(obj); 269 } 270 } 271 } 272 273 template <class T> void G1RebuildRemSetClosure::do_oop_nv(T* p) { 274 oop const obj = RawAccess<MO_VOLATILE>::oop_load(p); 275 if (obj == NULL) { 276 return; 277 } 278 279 if (HeapRegion::is_in_same_region(p, obj)) { 280 return; 281 } 282 283 HeapRegion* to = _g1h->heap_region_containing(obj); 284 HeapRegionRemSet* rem_set = to->rem_set(); 285 rem_set->add_reference(p, _worker_id); 286 } 287 288 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP