1 /* 2 * Copyright (c) 2001, 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_G1_G1OOPCLOSURES_INLINE_HPP 26 #define SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP 27 28 #include "gc/g1/concurrentMark.inline.hpp" 29 #include "gc/g1/g1CollectedHeap.hpp" 30 #include "gc/g1/g1OopClosures.hpp" 31 #include "gc/g1/g1ParScanThreadState.inline.hpp" 32 #include "gc/g1/g1RemSet.hpp" 33 #include "gc/g1/g1RemSet.inline.hpp" 34 #include "gc/g1/heapRegion.inline.hpp" 35 #include "gc/g1/heapRegionRemSet.hpp" 36 #include "memory/iterator.inline.hpp" 37 #include "runtime/prefetch.inline.hpp" 38 39 /* 40 * This really ought to be an inline function, but apparently the C++ 41 * compiler sometimes sees fit to ignore inline declarations. Sigh. 42 */ 43 44 template <class T> 45 inline void FilterIntoCSClosure::do_oop_nv(T* p) { 46 T heap_oop = oopDesc::load_heap_oop(p); 47 if (!oopDesc::is_null(heap_oop) && 48 _g1->is_in_cset_or_humongous(oopDesc::decode_heap_oop_not_null(heap_oop))) { 49 _oc->do_oop(p); 50 } 51 } 52 53 template <class T> 54 inline void FilterOutOfRegionClosure::do_oop_nv(T* p) { 55 T heap_oop = oopDesc::load_heap_oop(p); 56 if (!oopDesc::is_null(heap_oop)) { 57 HeapWord* obj_hw = (HeapWord*)oopDesc::decode_heap_oop_not_null(heap_oop); 58 if (obj_hw < _r_bottom || obj_hw >= _r_end) { 59 _oc->do_oop(p); 60 } 61 } 62 } 63 64 // This closure is applied to the fields of the objects that have just been copied. 65 template <class T> 66 inline void G1ParScanClosure::do_oop_nv(T* p) { 67 T heap_oop = oopDesc::load_heap_oop(p); 68 69 if (!oopDesc::is_null(heap_oop)) { 70 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 71 const InCSetState state = _g1->in_cset_state(obj); 72 if (state.is_in_cset()) { 73 // We're not going to even bother checking whether the object is 74 // already forwarded or not, as this usually causes an immediate 75 // stall. We'll try to prefetch the object (for write, given that 76 // we might need to install the forwarding reference) and we'll 77 // get back to it when pop it from the queue 78 Prefetch::write(obj->mark_addr(), 0); 79 Prefetch::read(obj->mark_addr(), (HeapWordSize*2)); 80 81 // slightly paranoid test; I'm trying to catch potential 82 // problems before we go into push_on_queue to know where the 83 // problem is coming from 84 assert((obj == oopDesc::load_decode_heap_oop(p)) || 85 (obj->is_forwarded() && 86 obj->forwardee() == oopDesc::load_decode_heap_oop(p)), 87 "p should still be pointing to obj or to its forwardee"); 88 89 _par_scan_state->push_on_queue(p); 90 } else { 91 if (state.is_humongous()) { 92 _g1->set_humongous_is_live(obj); 93 } 94 _par_scan_state->update_rs(_from, p); 95 } 96 } 97 } 98 99 template <class T> 100 inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) { 101 T heap_oop = oopDesc::load_heap_oop(p); 102 103 if (!oopDesc::is_null(heap_oop)) { 104 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 105 if (_g1->is_in_cset_or_humongous(obj)) { 106 Prefetch::write(obj->mark_addr(), 0); 107 Prefetch::read(obj->mark_addr(), (HeapWordSize*2)); 108 109 // Place on the references queue 110 _par_scan_state->push_on_queue(p); 111 } else { 112 assert(!_g1->obj_in_cs(obj), "checking"); 113 } 114 } 115 } 116 117 template <class T> 118 inline void G1CMOopClosure::do_oop_nv(T* p) { 119 oop obj = oopDesc::load_decode_heap_oop(p); 120 if (_cm->verbose_high()) { 121 gclog_or_tty->print_cr("[%u] we're looking at location " 122 "*" PTR_FORMAT " = " PTR_FORMAT, 123 _task->worker_id(), p2i(p), p2i((void*) obj)); 124 } 125 _task->deal_with_reference(obj); 126 } 127 128 template <class T> 129 inline void G1RootRegionScanClosure::do_oop_nv(T* p) { 130 T heap_oop = oopDesc::load_heap_oop(p); 131 if (!oopDesc::is_null(heap_oop)) { 132 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 133 HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj); 134 _cm->grayRoot(obj, obj->size(), _worker_id, hr); 135 } 136 } 137 138 template <class T> 139 inline void G1Mux2Closure::do_oop_nv(T* p) { 140 // Apply first closure; then apply the second. 141 _c1->do_oop(p); 142 _c2->do_oop(p); 143 } 144 145 template <class T> 146 inline void G1TriggerClosure::do_oop_nv(T* p) { 147 // Record that this closure was actually applied (triggered). 148 _triggered = true; 149 } 150 151 template <class T> 152 inline void G1InvokeIfNotTriggeredClosure::do_oop_nv(T* p) { 153 if (!_trigger_cl->triggered()) { 154 _oop_cl->do_oop(p); 155 } 156 } 157 158 template <class T> 159 inline void G1UpdateRSOrPushRefOopClosure::do_oop_nv(T* p) { 160 oop obj = oopDesc::load_decode_heap_oop(p); 161 if (obj == NULL) { 162 return; 163 } 164 165 #ifdef ASSERT 166 // can't do because of races 167 // assert(obj == NULL || obj->is_oop(), "expected an oop"); 168 169 // Do the safe subset of is_oop 170 #ifdef CHECK_UNHANDLED_OOPS 171 oopDesc* o = obj.obj(); 172 #else 173 oopDesc* o = obj; 174 #endif // CHECK_UNHANDLED_OOPS 175 assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned"); 176 assert(_g1->is_in_reserved(obj), "must be in heap"); 177 #endif // ASSERT 178 179 assert(_from != NULL, "from region must be non-NULL"); 180 assert(_from->is_in_reserved(p), "p is not in from"); 181 182 HeapRegion* to = _g1->heap_region_containing(obj); 183 if (_from == to) { 184 // Normally this closure should only be called with cross-region references. 185 // But since Java threads are manipulating the references concurrently and we 186 // reload the values things may have changed. 187 return; 188 } 189 190 // The _record_refs_into_cset flag is true during the RSet 191 // updating part of an evacuation pause. It is false at all 192 // other times: 193 // * rebuilding the remembered sets after a full GC 194 // * during concurrent refinement. 195 // * updating the remembered sets of regions in the collection 196 // set in the event of an evacuation failure (when deferred 197 // updates are enabled). 198 199 if (_record_refs_into_cset && to->in_collection_set()) { 200 // We are recording references that point into the collection 201 // set and this particular reference does exactly that... 202 // If the referenced object has already been forwarded 203 // to itself, we are handling an evacuation failure and 204 // we have already visited/tried to copy this object 205 // there is no need to retry. 206 if (!self_forwarded(obj)) { 207 assert(_push_ref_cl != NULL, "should not be null"); 208 // Push the reference in the refs queue of the G1ParScanThreadState 209 // instance for this worker thread. 210 _push_ref_cl->do_oop(p); 211 } 212 213 // Deferred updates to the CSet are either discarded (in the normal case), 214 // or processed (if an evacuation failure occurs) at the end 215 // of the collection. 216 // See G1RemSet::cleanup_after_oops_into_collection_set_do(). 217 } else { 218 // We either don't care about pushing references that point into the 219 // collection set (i.e. we're not during an evacuation pause) _or_ 220 // the reference doesn't point into the collection set. Either way 221 // we add the reference directly to the RSet of the region containing 222 // the referenced object. 223 assert(to->rem_set() != NULL, "Need per-region 'into' remsets."); 224 to->rem_set()->add_reference(p, _worker_i); 225 } 226 } 227 228 template <class T> 229 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) { 230 if (_g1->heap_region_containing(new_obj)->is_young()) { 231 _scanned_klass->record_modified_oops(); 232 } 233 } 234 235 void G1ParCopyHelper::mark_object(oop obj) { 236 assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet"); 237 238 // We know that the object is not moving so it's safe to read its size. 239 _cm->grayRoot(obj, (size_t) obj->size(), _worker_id); 240 } 241 242 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) { 243 assert(from_obj->is_forwarded(), "from obj should be forwarded"); 244 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee"); 245 assert(from_obj != to_obj, "should not be self-forwarded"); 246 247 assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet"); 248 assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet"); 249 250 // The object might be in the process of being copied by another 251 // worker so we cannot trust that its to-space image is 252 // well-formed. So we have to read its size from its from-space 253 // image which we know should not be changing. 254 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id); 255 } 256 257 template <G1Barrier barrier, G1Mark do_mark_object> 258 template <class T> 259 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) { 260 T heap_oop = oopDesc::load_heap_oop(p); 261 262 if (oopDesc::is_null(heap_oop)) { 263 return; 264 } 265 266 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 267 268 assert(_worker_id == _par_scan_state->worker_id(), "sanity"); 269 270 const InCSetState state = _g1->in_cset_state(obj); 271 if (state.is_in_cset()) { 272 oop forwardee; 273 markOop m = obj->mark(); 274 if (m->is_marked()) { 275 forwardee = (oop) m->decode_pointer(); 276 } else { 277 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m); 278 } 279 assert(forwardee != NULL, "forwardee should not be NULL"); 280 oopDesc::encode_store_heap_oop(p, forwardee); 281 if (do_mark_object != G1MarkNone && forwardee != obj) { 282 // If the object is self-forwarded we don't need to explicitly 283 // mark it, the evacuation failure protocol will do so. 284 mark_forwarded_object(obj, forwardee); 285 } 286 287 if (barrier == G1BarrierKlass) { 288 do_klass_barrier(p, forwardee); 289 } 290 } else { 291 if (state.is_humongous()) { 292 _g1->set_humongous_is_live(obj); 293 } 294 // The object is not in collection set. If we're a root scanning 295 // closure during an initial mark pause then attempt to mark the object. 296 if (do_mark_object == G1MarkFromRoot) { 297 mark_object(obj); 298 } 299 } 300 } 301 302 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP