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 "oops/oop.inline.hpp" 40 #include "runtime/prefetch.inline.hpp" 41 42 template <class T> 43 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) { 44 // We're not going to even bother checking whether the object is 45 // already forwarded or not, as this usually causes an immediate 46 // stall. We'll try to prefetch the object (for write, given that 47 // we might need to install the forwarding reference) and we'll 48 // get back to it when pop it from the queue 49 Prefetch::write(obj->mark_addr_raw(), 0); 50 Prefetch::read(obj->mark_addr_raw(), (HeapWordSize*2)); 51 52 // slightly paranoid test; I'm trying to catch potential 53 // problems before we go into push_on_queue to know where the 54 // problem is coming from 55 assert((obj == RawAccess<>::oop_load(p)) || 56 (obj->is_forwarded() && 57 obj->forwardee() == RawAccess<>::oop_load(p)), 58 "p should still be pointing to obj or to its forwardee"); 59 60 _par_scan_state->push_on_queue(p); 61 } 62 63 template <class T> 64 inline void G1ScanClosureBase::handle_non_cset_obj_common(InCSetState const state, T* p, oop const obj) { 65 if (state.is_humongous()) { 66 _g1h->set_humongous_is_live(obj); 67 } 68 } 69 70 inline void G1ScanClosureBase::trim_queue_partially() { 71 _par_scan_state->trim_queue_partially(); 72 } 73 74 template <class T> 75 inline void G1ScanEvacuatedObjClosure::do_oop_work(T* p) { 76 T heap_oop = RawAccess<>::oop_load(p); 77 78 if (CompressedOops::is_null(heap_oop)) { 79 return; 80 } 81 oop obj = CompressedOops::decode_not_null(heap_oop); 82 const InCSetState state = _g1h->in_cset_state(obj); 83 if (state.is_in_cset()) { 84 prefetch_and_push(p, obj); 85 } else if (!HeapRegion::is_in_same_region(p, obj)) { 86 handle_non_cset_obj_common(state, p, obj); 87 assert(_scanning_in_young != Uninitialized, "Scan location has not been initialized."); 88 if (_scanning_in_young == True) { 89 return; 90 } 91 _par_scan_state->enqueue_card_if_tracked(p, obj); 92 } 93 } 94 95 template <class T> 96 inline void G1CMOopClosure::do_oop_work(T* p) { 97 _task->deal_with_reference(p); 98 } 99 100 template <class T> 101 inline void G1RootRegionScanClosure::do_oop_work(T* p) { 102 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p); 103 if (CompressedOops::is_null(heap_oop)) { 104 return; 105 } 106 oop obj = CompressedOops::decode_not_null(heap_oop); 107 _cm->mark_in_next_bitmap(_worker_id, obj); 108 } 109 110 template <class T> 111 inline static void check_obj_during_refinement(T* p, oop const obj) { 112 #ifdef ASSERT 113 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 114 // can't do because of races 115 // assert(oopDesc::is_oop_or_null(obj), "expected an oop"); 116 assert(check_obj_alignment(obj), "not oop aligned"); 117 assert(g1h->is_in_reserved(obj), "must be in heap"); 118 119 HeapRegion* from = g1h->heap_region_containing(p); 120 121 assert(from != NULL, "from region must be non-NULL"); 122 assert(from->is_in_reserved(p) || 123 (from->is_humongous() && 124 g1h->heap_region_containing(p)->is_humongous() && 125 from->humongous_start_region() == g1h->heap_region_containing(p)->humongous_start_region()), 126 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.", 127 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index()); 128 #endif // ASSERT 129 } 130 131 template <class T> 132 inline void G1ConcurrentRefineOopClosure::do_oop_work(T* p) { 133 T o = RawAccess<MO_VOLATILE>::oop_load(p); 134 if (CompressedOops::is_null(o)) { 135 return; 136 } 137 oop obj = CompressedOops::decode_not_null(o); 138 139 check_obj_during_refinement(p, obj); 140 141 if (HeapRegion::is_in_same_region(p, obj)) { 142 // Normally this closure should only be called with cross-region references. 143 // But since Java threads are manipulating the references concurrently and we 144 // reload the values things may have changed. 145 // Also this check lets slip through references from a humongous continues region 146 // to its humongous start region, as they are in different regions, and adds a 147 // remembered set entry. This is benign (apart from memory usage), as we never 148 // try to either evacuate or eager reclaim humonguous arrays of j.l.O. 149 return; 150 } 151 152 HeapRegionRemSet* to_rem_set = _g1h->heap_region_containing(obj)->rem_set(); 153 154 assert(to_rem_set != NULL, "Need per-region 'into' remsets."); 155 if (to_rem_set->is_tracked()) { 156 to_rem_set->add_reference(p, _worker_i); 157 } 158 } 159 160 template <class T> 161 inline void G1ScanObjsDuringUpdateRSClosure::do_oop_work(T* p) { 162 T o = RawAccess<>::oop_load(p); 163 if (CompressedOops::is_null(o)) { 164 return; 165 } 166 oop obj = CompressedOops::decode_not_null(o); 167 168 check_obj_during_refinement(p, obj); 169 170 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)); 171 const InCSetState state = _g1h->in_cset_state(obj); 172 if (state.is_in_cset()) { 173 // Since the source is always from outside the collection set, here we implicitly know 174 // that this is a cross-region reference too. 175 prefetch_and_push(p, obj); 176 } else if (!HeapRegion::is_in_same_region(p, obj)) { 177 handle_non_cset_obj_common(state, p, obj); 178 _par_scan_state->enqueue_card_if_tracked(p, obj); 179 } 180 } 181 182 template <class T> 183 inline void G1ScanObjsDuringScanRSClosure::do_oop_work(T* p) { 184 T heap_oop = RawAccess<>::oop_load(p); 185 if (CompressedOops::is_null(heap_oop)) { 186 return; 187 } 188 oop obj = CompressedOops::decode_not_null(heap_oop); 189 190 const InCSetState state = _g1h->in_cset_state(obj); 191 if (state.is_in_cset()) { 192 prefetch_and_push(p, obj); 193 } else if (!HeapRegion::is_in_same_region(p, obj)) { 194 handle_non_cset_obj_common(state, p, obj); 195 } 196 } 197 198 void G1ParCopyHelper::do_cld_barrier(oop new_obj) { 199 if (_g1h->heap_region_containing(new_obj)->is_young()) { 200 _scanned_cld->record_modified_oops(); 201 } 202 } 203 204 void G1ParCopyHelper::mark_object(oop obj) { 205 assert(!_g1h->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet"); 206 207 // We know that the object is not moving so it's safe to read its size. 208 _cm->mark_in_next_bitmap(_worker_id, obj); 209 } 210 211 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) { 212 assert(from_obj->is_forwarded(), "from obj should be forwarded"); 213 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee"); 214 assert(from_obj != to_obj, "should not be self-forwarded"); 215 216 assert(_g1h->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet"); 217 assert(!_g1h->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet"); 218 219 // The object might be in the process of being copied by another 220 // worker so we cannot trust that its to-space image is 221 // well-formed. So we have to read its size from its from-space 222 // image which we know should not be changing. 223 _cm->mark_in_next_bitmap(_worker_id, to_obj, from_obj->size()); 224 } 225 226 void G1ParCopyHelper::trim_queue_partially() { 227 _par_scan_state->trim_queue_partially(); 228 } 229 230 template <G1Barrier barrier, G1Mark do_mark_object> 231 template <class T> 232 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) { 233 T heap_oop = RawAccess<>::oop_load(p); 234 235 if (CompressedOops::is_null(heap_oop)) { 236 return; 237 } 238 239 oop obj = CompressedOops::decode_not_null(heap_oop); 240 241 assert(_worker_id == _par_scan_state->worker_id(), "sanity"); 242 243 const InCSetState state = _g1h->in_cset_state(obj); 244 if (state.is_in_cset()) { 245 oop forwardee; 246 markOop m = obj->mark_raw(); 247 if (m->is_marked()) { 248 forwardee = (oop) m->decode_pointer(); 249 } else { 250 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m); 251 } 252 assert(forwardee != NULL, "forwardee should not be NULL"); 253 RawAccess<IS_NOT_NULL>::oop_store(p, forwardee); 254 if (do_mark_object != G1MarkNone && forwardee != obj) { 255 // If the object is self-forwarded we don't need to explicitly 256 // mark it, the evacuation failure protocol will do so. 257 mark_forwarded_object(obj, forwardee); 258 } 259 260 if (barrier == G1BarrierCLD) { 261 do_cld_barrier(forwardee); 262 } 263 } else { 264 if (state.is_humongous()) { 265 _g1h->set_humongous_is_live(obj); 266 } 267 268 // The object is not in collection set. If we're a root scanning 269 // closure during an initial mark pause then attempt to mark the object. 270 if (do_mark_object == G1MarkFromRoot) { 271 mark_object(obj); 272 } 273 } 274 trim_queue_partially(); 275 } 276 277 template <class T> void G1RebuildRemSetClosure::do_oop_work(T* p) { 278 oop const obj = RawAccess<MO_VOLATILE>::oop_load(p); 279 if (obj == NULL) { 280 return; 281 } 282 283 if (HeapRegion::is_in_same_region(p, obj)) { 284 return; 285 } 286 287 HeapRegion* to = _g1h->heap_region_containing(obj); 288 HeapRegionRemSet* rem_set = to->rem_set(); 289 rem_set->add_reference(p, _worker_id); 290 } 291 292 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP