1 /* 2 * Copyright (c) 2014, 2019, 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_GC_G1_G1PARSCANTHREADSTATE_INLINE_HPP 26 #define SHARE_GC_G1_G1PARSCANTHREADSTATE_INLINE_HPP 27 28 #include "gc/g1/g1CollectedHeap.inline.hpp" 29 #include "gc/g1/g1OopStarChunkedList.inline.hpp" 30 #include "gc/g1/g1ParScanThreadState.hpp" 31 #include "gc/g1/g1RemSet.hpp" 32 #include "oops/access.inline.hpp" 33 #include "oops/oop.inline.hpp" 34 35 template <class T> void G1ParScanThreadState::do_oop_evac(T* p) { 36 // Reference should not be NULL here as such are never pushed to the task queue. 37 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p); 38 39 // Although we never intentionally push references outside of the collection 40 // set, due to (benign) races in the claim mechanism during RSet scanning more 41 // than one thread might claim the same card. So the same card may be 42 // processed multiple times, and so we might get references into old gen here. 43 // So we need to redo this check. 44 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj); 45 // References pushed onto the work stack should never point to a humongous region 46 // as they are not added to the collection set due to above precondition. 47 assert(!region_attr.is_humongous(), 48 "Obj " PTR_FORMAT " should not refer to humongous region %u from " PTR_FORMAT, 49 p2i(obj), _g1h->addr_to_region(cast_from_oop<HeapWord*>(obj)), p2i(p)); 50 51 if (!region_attr.is_in_cset()) { 52 // In this case somebody else already did all the work. 53 return; 54 } 55 56 markWord m = obj->mark_raw(); 57 if (m.is_marked()) { 58 obj = (oop) m.decode_pointer(); 59 } else { 60 obj = copy_to_survivor_space(region_attr, obj, m); 61 } 62 RawAccess<IS_NOT_NULL>::oop_store(p, obj); 63 64 assert(obj != NULL, "Must be"); 65 if (HeapRegion::is_in_same_region(p, obj)) { 66 return; 67 } 68 HeapRegion* from = _g1h->heap_region_containing(p); 69 if (!from->is_young()) { 70 enqueue_card_if_tracked(_g1h->region_attr(obj), p, obj); 71 } 72 } 73 74 template <class T> inline void G1ParScanThreadState::push_on_queue(T* ref) { 75 assert(verify_ref(ref), "sanity"); 76 _refs->push(ref); 77 } 78 79 inline void G1ParScanThreadState::do_oop_partial_array(oop* p) { 80 assert(has_partial_array_mask(p), "invariant"); 81 oop from_obj = clear_partial_array_mask(p); 82 83 assert(_g1h->is_in_reserved(from_obj), "must be in heap."); 84 assert(from_obj->is_objArray(), "must be obj array"); 85 objArrayOop from_obj_array = objArrayOop(from_obj); 86 // The from-space object contains the real length. 87 int length = from_obj_array->length(); 88 89 assert(from_obj->is_forwarded(), "must be forwarded"); 90 oop to_obj = from_obj->forwardee(); 91 assert(from_obj != to_obj, "should not be chunking self-forwarded objects"); 92 objArrayOop to_obj_array = objArrayOop(to_obj); 93 // We keep track of the next start index in the length field of the 94 // to-space object. 95 int next_index = to_obj_array->length(); 96 assert(0 <= next_index && next_index < length, 97 "invariant, next index: %d, length: %d", next_index, length); 98 99 int start = next_index; 100 int end = length; 101 int remainder = end - start; 102 // We'll try not to push a range that's smaller than ParGCArrayScanChunk. 103 if (remainder > 2 * ParGCArrayScanChunk) { 104 end = start + ParGCArrayScanChunk; 105 to_obj_array->set_length(end); 106 // Push the remainder before we process the range in case another 107 // worker has run out of things to do and can steal it. 108 oop* from_obj_p = set_partial_array_mask(from_obj); 109 push_on_queue(from_obj_p); 110 } else { 111 assert(length == end, "sanity"); 112 // We'll process the final range for this object. Restore the length 113 // so that the heap remains parsable in case of evacuation failure. 114 to_obj_array->set_length(end); 115 } 116 117 HeapRegion* hr = _g1h->heap_region_containing(to_obj); 118 G1ScanInYoungSetter x(&_scanner, hr->is_young()); 119 // Process indexes [start,end). It will also process the header 120 // along with the first chunk (i.e., the chunk with start == 0). 121 // Note that at this point the length field of to_obj_array is not 122 // correct given that we are using it to keep track of the next 123 // start index. oop_iterate_range() (thankfully!) ignores the length 124 // field and only relies on the start / end parameters. It does 125 // however return the size of the object which will be incorrect. So 126 // we have to ignore it even if we wanted to use it. 127 to_obj_array->oop_iterate_range(&_scanner, start, end); 128 } 129 130 inline void G1ParScanThreadState::deal_with_reference(oop* ref_to_scan) { 131 if (!has_partial_array_mask(ref_to_scan)) { 132 do_oop_evac(ref_to_scan); 133 } else { 134 do_oop_partial_array(ref_to_scan); 135 } 136 } 137 138 inline void G1ParScanThreadState::deal_with_reference(narrowOop* ref_to_scan) { 139 assert(!has_partial_array_mask(ref_to_scan), "NarrowOop* elements should never be partial arrays."); 140 do_oop_evac(ref_to_scan); 141 } 142 143 inline void G1ParScanThreadState::dispatch_reference(StarTask ref) { 144 assert(verify_task(ref), "sanity"); 145 if (ref.is_narrow()) { 146 deal_with_reference((narrowOop*)ref); 147 } else { 148 deal_with_reference((oop*)ref); 149 } 150 } 151 152 void G1ParScanThreadState::steal_and_trim_queue(RefToScanQueueSet *task_queues) { 153 StarTask stolen_task; 154 while (task_queues->steal(_worker_id, stolen_task)) { 155 assert(verify_task(stolen_task), "sanity"); 156 dispatch_reference(stolen_task); 157 158 // We've just processed a reference and we might have made 159 // available new entries on the queues. So we have to make sure 160 // we drain the queues as necessary. 161 trim_queue(); 162 } 163 } 164 165 inline bool G1ParScanThreadState::needs_partial_trimming() const { 166 return !_refs->overflow_empty() || _refs->size() > _stack_trim_upper_threshold; 167 } 168 169 inline bool G1ParScanThreadState::is_partially_trimmed() const { 170 return _refs->overflow_empty() && _refs->size() <= _stack_trim_lower_threshold; 171 } 172 173 inline void G1ParScanThreadState::trim_queue_to_threshold(uint threshold) { 174 StarTask ref; 175 // Drain the overflow stack first, so other threads can potentially steal. 176 while (_refs->pop_overflow(ref)) { 177 if (!_refs->try_push_to_taskqueue(ref)) { 178 dispatch_reference(ref); 179 } 180 } 181 182 while (_refs->pop_local(ref, threshold)) { 183 dispatch_reference(ref); 184 } 185 } 186 187 inline void G1ParScanThreadState::trim_queue_partially() { 188 if (!needs_partial_trimming()) { 189 return; 190 } 191 192 const Ticks start = Ticks::now(); 193 do { 194 trim_queue_to_threshold(_stack_trim_lower_threshold); 195 } while (!is_partially_trimmed()); 196 _trim_ticks += Ticks::now() - start; 197 } 198 199 inline Tickspan G1ParScanThreadState::trim_ticks() const { 200 return _trim_ticks; 201 } 202 203 inline void G1ParScanThreadState::reset_trim_ticks() { 204 _trim_ticks = Tickspan(); 205 } 206 207 template <typename T> 208 inline void G1ParScanThreadState::remember_root_into_optional_region(T* p) { 209 oop o = RawAccess<IS_NOT_NULL>::oop_load(p); 210 uint index = _g1h->heap_region_containing(o)->index_in_opt_cset(); 211 assert(index < _num_optional_regions, 212 "Trying to access optional region idx %u beyond " SIZE_FORMAT, index, _num_optional_regions); 213 _oops_into_optional_regions[index].push_root(p); 214 } 215 216 template <typename T> 217 inline void G1ParScanThreadState::remember_reference_into_optional_region(T* p) { 218 oop o = RawAccess<IS_NOT_NULL>::oop_load(p); 219 uint index = _g1h->heap_region_containing(o)->index_in_opt_cset(); 220 assert(index < _num_optional_regions, 221 "Trying to access optional region idx %u beyond " SIZE_FORMAT, index, _num_optional_regions); 222 _oops_into_optional_regions[index].push_oop(p); 223 DEBUG_ONLY(verify_ref(p);) 224 } 225 226 G1OopStarChunkedList* G1ParScanThreadState::oops_into_optional_region(const HeapRegion* hr) { 227 assert(hr->index_in_opt_cset() < _num_optional_regions, 228 "Trying to access optional region idx %u beyond " SIZE_FORMAT " " HR_FORMAT, 229 hr->index_in_opt_cset(), _num_optional_regions, HR_FORMAT_PARAMS(hr)); 230 return &_oops_into_optional_regions[hr->index_in_opt_cset()]; 231 } 232 233 void G1ParScanThreadState::initialize_numa_stats() { 234 if (_numa->is_enabled()) { 235 LogTarget(Info, gc, heap, numa) lt; 236 237 if (lt.is_enabled()) { 238 uint num_nodes = _numa->num_active_nodes(); 239 // Record only if there are multiple active nodes. 240 _obj_alloc_stat = NEW_C_HEAP_ARRAY(size_t, num_nodes, mtGC); 241 memset(_obj_alloc_stat, 0, sizeof(size_t) * num_nodes); 242 } 243 } 244 } 245 246 void G1ParScanThreadState::flush_numa_stats() { 247 if (_obj_alloc_stat != NULL) { 248 uint node_index = _numa->index_of_current_thread(); 249 _numa->copy_statistics(G1NUMAStats::LocalObjProcessAtCopyToSurv, node_index, _obj_alloc_stat); 250 } 251 } 252 253 void G1ParScanThreadState::update_numa_stats(uint node_index) { 254 if (_obj_alloc_stat != NULL) { 255 _obj_alloc_stat[node_index]++; 256 } 257 } 258 259 #endif // SHARE_GC_G1_G1PARSCANTHREADSTATE_INLINE_HPP