1 /* 2 * Copyright (c) 2001, 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_G1_G1COLLECTEDHEAP_INLINE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP 27 28 #include "gc_implementation/g1/concurrentMark.hpp" 29 #include "gc_implementation/g1/g1CollectedHeap.hpp" 30 #include "gc_implementation/g1/g1AllocRegion.inline.hpp" 31 #include "gc_implementation/g1/g1CollectorPolicy.hpp" 32 #include "gc_implementation/g1/g1RemSet.inline.hpp" 33 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp" 34 #include "gc_implementation/g1/heapRegionSet.inline.hpp" 35 #include "gc_implementation/g1/heapRegionSeq.inline.hpp" 36 #include "runtime/orderAccess.inline.hpp" 37 #include "utilities/taskqueue.hpp" 38 39 // Inline functions for G1CollectedHeap 40 41 // Return the region with the given index. It assumes the index is valid. 42 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrs.at(index); } 43 44 template <class T> 45 inline HeapRegion* 46 G1CollectedHeap::heap_region_containing(const T addr) const { 47 HeapRegion* hr = _hrs.addr_to_region((HeapWord*) addr); 48 // hr can be null if addr in perm_gen 49 if (hr != NULL && hr->continuesHumongous()) { 50 hr = hr->humongous_start_region(); 51 } 52 return hr; 53 } 54 55 template <class T> 56 inline HeapRegion* 57 G1CollectedHeap::heap_region_containing_raw(const T addr) const { 58 assert(_g1_reserved.contains((const void*) addr), "invariant"); 59 HeapRegion* res = _hrs.addr_to_region_unsafe((HeapWord*) addr); 60 return res; 61 } 62 63 inline void G1CollectedHeap::reset_gc_time_stamp() { 64 _gc_time_stamp = 0; 65 OrderAccess::fence(); 66 // Clear the cached CSet starting regions and time stamps. 67 // Their validity is dependent on the GC timestamp. 68 clear_cset_start_regions(); 69 } 70 71 inline void G1CollectedHeap::increment_gc_time_stamp() { 72 ++_gc_time_stamp; 73 OrderAccess::fence(); 74 } 75 76 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) { 77 _old_set.remove(hr); 78 } 79 80 inline bool G1CollectedHeap::obj_in_cs(oop obj) { 81 HeapRegion* r = _hrs.addr_to_region((HeapWord*) obj); 82 return r != NULL && r->in_collection_set(); 83 } 84 85 inline HeapWord* 86 G1CollectedHeap::attempt_allocation(size_t word_size, 87 unsigned int* gc_count_before_ret, 88 int* gclocker_retry_count_ret) { 89 assert_heap_not_locked_and_not_at_safepoint(); 90 assert(!isHumongous(word_size), "attempt_allocation() should not " 91 "be called for humongous allocation requests"); 92 93 HeapWord* result = _mutator_alloc_region.attempt_allocation(word_size, 94 false /* bot_updates */); 95 if (result == NULL) { 96 result = attempt_allocation_slow(word_size, 97 gc_count_before_ret, 98 gclocker_retry_count_ret); 99 } 100 assert_heap_not_locked(); 101 if (result != NULL) { 102 dirty_young_block(result, word_size); 103 } 104 return result; 105 } 106 107 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t 108 word_size) { 109 assert(!isHumongous(word_size), 110 "we should not be seeing humongous-size allocations in this path"); 111 112 HeapWord* result = _survivor_gc_alloc_region.attempt_allocation(word_size, 113 false /* bot_updates */); 114 if (result == NULL) { 115 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag); 116 result = _survivor_gc_alloc_region.attempt_allocation_locked(word_size, 117 false /* bot_updates */); 118 } 119 if (result != NULL) { 120 dirty_young_block(result, word_size); 121 } 122 return result; 123 } 124 125 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size) { 126 assert(!isHumongous(word_size), 127 "we should not be seeing humongous-size allocations in this path"); 128 129 HeapWord* result = _old_gc_alloc_region.attempt_allocation(word_size, 130 true /* bot_updates */); 131 if (result == NULL) { 132 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag); 133 result = _old_gc_alloc_region.attempt_allocation_locked(word_size, 134 true /* bot_updates */); 135 } 136 return result; 137 } 138 139 // It dirties the cards that cover the block so that so that the post 140 // write barrier never queues anything when updating objects on this 141 // block. It is assumed (and in fact we assert) that the block 142 // belongs to a young region. 143 inline void 144 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) { 145 assert_heap_not_locked(); 146 147 // Assign the containing region to containing_hr so that we don't 148 // have to keep calling heap_region_containing_raw() in the 149 // asserts below. 150 DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);) 151 assert(containing_hr != NULL && start != NULL && word_size > 0, 152 "pre-condition"); 153 assert(containing_hr->is_in(start), "it should contain start"); 154 assert(containing_hr->is_young(), "it should be young"); 155 assert(!containing_hr->isHumongous(), "it should not be humongous"); 156 157 HeapWord* end = start + word_size; 158 assert(containing_hr->is_in(end - 1), "it should also contain end - 1"); 159 160 MemRegion mr(start, end); 161 g1_barrier_set()->g1_mark_as_young(mr); 162 } 163 164 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const { 165 return _task_queues->queue(i); 166 } 167 168 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const { 169 return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj); 170 } 171 172 inline bool G1CollectedHeap::isMarkedNext(oop obj) const { 173 return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj); 174 } 175 176 177 // This is a fast test on whether a reference points into the 178 // collection set or not. Assume that the reference 179 // points into the heap. 180 inline bool G1CollectedHeap::in_cset_fast_test(oop obj) { 181 bool ret = _in_cset_fast_test.get_by_address((HeapWord*)obj); 182 // let's make sure the result is consistent with what the slower 183 // test returns 184 assert( ret || !obj_in_cs(obj), "sanity"); 185 assert(!ret || obj_in_cs(obj), "sanity"); 186 return ret; 187 } 188 189 #ifndef PRODUCT 190 // Support for G1EvacuationFailureALot 191 192 inline bool 193 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young, 194 bool during_initial_mark, 195 bool during_marking) { 196 bool res = false; 197 if (during_marking) { 198 res |= G1EvacuationFailureALotDuringConcMark; 199 } 200 if (during_initial_mark) { 201 res |= G1EvacuationFailureALotDuringInitialMark; 202 } 203 if (gcs_are_young) { 204 res |= G1EvacuationFailureALotDuringYoungGC; 205 } else { 206 // GCs are mixed 207 res |= G1EvacuationFailureALotDuringMixedGC; 208 } 209 return res; 210 } 211 212 inline void 213 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() { 214 if (G1EvacuationFailureALot) { 215 // Note we can't assert that _evacuation_failure_alot_for_current_gc 216 // is clear here. It may have been set during a previous GC but that GC 217 // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to 218 // trigger an evacuation failure and clear the flags and and counts. 219 220 // Check if we have gone over the interval. 221 const size_t gc_num = total_collections(); 222 const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number; 223 224 _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval); 225 226 // Now check if G1EvacuationFailureALot is enabled for the current GC type. 227 const bool gcs_are_young = g1_policy()->gcs_are_young(); 228 const bool during_im = g1_policy()->during_initial_mark_pause(); 229 const bool during_marking = mark_in_progress(); 230 231 _evacuation_failure_alot_for_current_gc &= 232 evacuation_failure_alot_for_gc_type(gcs_are_young, 233 during_im, 234 during_marking); 235 } 236 } 237 238 inline bool 239 G1CollectedHeap::evacuation_should_fail() { 240 if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) { 241 return false; 242 } 243 // G1EvacuationFailureALot is in effect for current GC 244 // Access to _evacuation_failure_alot_count is not atomic; 245 // the value does not have to be exact. 246 if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) { 247 return false; 248 } 249 _evacuation_failure_alot_count = 0; 250 return true; 251 } 252 253 inline void G1CollectedHeap::reset_evacuation_should_fail() { 254 if (G1EvacuationFailureALot) { 255 _evacuation_failure_alot_gc_number = total_collections(); 256 _evacuation_failure_alot_count = 0; 257 _evacuation_failure_alot_for_current_gc = false; 258 } 259 } 260 #endif // #ifndef PRODUCT 261 262 inline bool G1CollectedHeap::is_in_young(const oop obj) { 263 HeapRegion* hr = heap_region_containing(obj); 264 return hr != NULL && hr->is_young(); 265 } 266 267 // We don't need barriers for initializing stores to objects 268 // in the young gen: for the SATB pre-barrier, there is no 269 // pre-value that needs to be remembered; for the remembered-set 270 // update logging post-barrier, we don't maintain remembered set 271 // information for young gen objects. 272 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) { 273 return is_in_young(new_obj); 274 } 275 276 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const { 277 const HeapRegion* hr = heap_region_containing(obj); 278 if (hr == NULL) { 279 if (obj == NULL) return false; 280 else return true; 281 } 282 else return is_obj_dead(obj, hr); 283 } 284 285 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const { 286 const HeapRegion* hr = heap_region_containing(obj); 287 if (hr == NULL) { 288 if (obj == NULL) return false; 289 else return true; 290 } 291 else return is_obj_ill(obj, hr); 292 } 293 294 template <class T> inline void G1ParScanThreadState::immediate_rs_update(HeapRegion* from, T* p, int tid) { 295 if (!from->is_survivor()) { 296 _g1_rem->par_write_ref(from, p, tid); 297 } 298 } 299 300 template <class T> void G1ParScanThreadState::update_rs(HeapRegion* from, T* p, int tid) { 301 if (G1DeferredRSUpdate) { 302 deferred_rs_update(from, p, tid); 303 } else { 304 immediate_rs_update(from, p, tid); 305 } 306 } 307 308 309 inline void G1ParScanThreadState::do_oop_partial_array(oop* p) { 310 assert(has_partial_array_mask(p), "invariant"); 311 oop from_obj = clear_partial_array_mask(p); 312 313 assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap."); 314 assert(from_obj->is_objArray(), "must be obj array"); 315 objArrayOop from_obj_array = objArrayOop(from_obj); 316 // The from-space object contains the real length. 317 int length = from_obj_array->length(); 318 319 assert(from_obj->is_forwarded(), "must be forwarded"); 320 oop to_obj = from_obj->forwardee(); 321 assert(from_obj != to_obj, "should not be chunking self-forwarded objects"); 322 objArrayOop to_obj_array = objArrayOop(to_obj); 323 // We keep track of the next start index in the length field of the 324 // to-space object. 325 int next_index = to_obj_array->length(); 326 assert(0 <= next_index && next_index < length, 327 err_msg("invariant, next index: %d, length: %d", next_index, length)); 328 329 int start = next_index; 330 int end = length; 331 int remainder = end - start; 332 // We'll try not to push a range that's smaller than ParGCArrayScanChunk. 333 if (remainder > 2 * ParGCArrayScanChunk) { 334 end = start + ParGCArrayScanChunk; 335 to_obj_array->set_length(end); 336 // Push the remainder before we process the range in case another 337 // worker has run out of things to do and can steal it. 338 oop* from_obj_p = set_partial_array_mask(from_obj); 339 push_on_queue(from_obj_p); 340 } else { 341 assert(length == end, "sanity"); 342 // We'll process the final range for this object. Restore the length 343 // so that the heap remains parsable in case of evacuation failure. 344 to_obj_array->set_length(end); 345 } 346 _scanner.set_region(_g1h->heap_region_containing_raw(to_obj)); 347 // Process indexes [start,end). It will also process the header 348 // along with the first chunk (i.e., the chunk with start == 0). 349 // Note that at this point the length field of to_obj_array is not 350 // correct given that we are using it to keep track of the next 351 // start index. oop_iterate_range() (thankfully!) ignores the length 352 // field and only relies on the start / end parameters. It does 353 // however return the size of the object which will be incorrect. So 354 // we have to ignore it even if we wanted to use it. 355 to_obj_array->oop_iterate_range(&_scanner, start, end); 356 } 357 358 template <class T> inline void G1ParScanThreadState::deal_with_reference(T* ref_to_scan) { 359 if (!has_partial_array_mask(ref_to_scan)) { 360 // Note: we can use "raw" versions of "region_containing" because 361 // "obj_to_scan" is definitely in the heap, and is not in a 362 // humongous region. 363 HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan); 364 do_oop_evac(ref_to_scan, r); 365 } else { 366 do_oop_partial_array((oop*)ref_to_scan); 367 } 368 } 369 370 inline void G1ParScanThreadState::deal_with_reference(StarTask ref) { 371 assert(verify_task(ref), "sanity"); 372 if (ref.is_narrow()) { 373 deal_with_reference((narrowOop*)ref); 374 } else { 375 deal_with_reference((oop*)ref); 376 } 377 } 378 379 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP