annotate src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp @ 2749:246daf2c601d

7005808: G1: re-enable ReduceInitialCardMarks for G1 Summary: Remove the extra guard to allow G1 to use ReduceInitialCardMarks Reviewed-by: jmasa, tonyp, johnc, ysr
author brutisso
date Wed, 28 Sep 2011 08:21:30 +0200
parents 8229bd737950
children 8aae2050e83e
rev   line source
ysr@342 1 /*
tonyp@2018 2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
ysr@342 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@342 4 *
ysr@342 5 * This code is free software; you can redistribute it and/or modify it
ysr@342 6 * under the terms of the GNU General Public License version 2 only, as
ysr@342 7 * published by the Free Software Foundation.
ysr@342 8 *
ysr@342 9 * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@342 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@342 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
ysr@342 12 * version 2 for more details (a copy is included in the LICENSE file that
ysr@342 13 * accompanied this code).
ysr@342 14 *
ysr@342 15 * You should have received a copy of the GNU General Public License version
ysr@342 16 * 2 along with this work; if not, write to the Free Software Foundation,
ysr@342 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@342 18 *
trims@1472 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1472 20 * or visit www.oracle.com if you need additional information or have any
trims@1472 21 * questions.
ysr@342 22 *
ysr@342 23 */
ysr@342 24
stefank@1879 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP
stefank@1879 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP
stefank@1879 27
stefank@1879 28 #include "gc_implementation/g1/concurrentMark.hpp"
tonyp@2280 29 #include "gc_implementation/g1/g1AllocRegion.hpp"
tonyp@2540 30 #include "gc_implementation/g1/g1HRPrinter.hpp"
stefank@1879 31 #include "gc_implementation/g1/g1RemSet.hpp"
jmasa@2386 32 #include "gc_implementation/g1/g1MonitoringSupport.hpp"
tonyp@2528 33 #include "gc_implementation/g1/heapRegionSeq.hpp"
tonyp@2037 34 #include "gc_implementation/g1/heapRegionSets.hpp"
jmasa@2386 35 #include "gc_implementation/shared/hSpaceCounters.hpp"
stefank@1879 36 #include "gc_implementation/parNew/parGCAllocBuffer.hpp"
stefank@1879 37 #include "memory/barrierSet.hpp"
stefank@1879 38 #include "memory/memRegion.hpp"
stefank@1879 39 #include "memory/sharedHeap.hpp"
stefank@1879 40
ysr@342 41 // A "G1CollectedHeap" is an implementation of a java heap for HotSpot.
ysr@342 42 // It uses the "Garbage First" heap organization and algorithm, which
ysr@342 43 // may combine concurrent marking with parallel, incremental compaction of
ysr@342 44 // heap subsets that will yield large amounts of garbage.
ysr@342 45
ysr@342 46 class HeapRegion;
tonyp@2058 47 class HRRSCleanupTask;
ysr@342 48 class PermanentGenerationSpec;
ysr@342 49 class GenerationSpec;
ysr@342 50 class OopsInHeapRegionClosure;
ysr@342 51 class G1ScanHeapEvacClosure;
ysr@342 52 class ObjectClosure;
ysr@342 53 class SpaceClosure;
ysr@342 54 class CompactibleSpaceClosure;
ysr@342 55 class Space;
ysr@342 56 class G1CollectorPolicy;
ysr@342 57 class GenRemSet;
ysr@342 58 class G1RemSet;
ysr@342 59 class HeapRegionRemSetIterator;
ysr@342 60 class ConcurrentMark;
ysr@342 61 class ConcurrentMarkThread;
ysr@342 62 class ConcurrentG1Refine;
jmasa@2386 63 class GenerationCounters;
ysr@342 64
jcoomes@1629 65 typedef OverflowTaskQueue<StarTask> RefToScanQueue;
jcoomes@1311 66 typedef GenericTaskQueueSet<RefToScanQueue> RefToScanQueueSet;
ysr@342 67
johnc@807 68 typedef int RegionIdx_t; // needs to hold [ 0..max_regions() )
johnc@807 69 typedef int CardIdx_t; // needs to hold [ 0..CardsPerRegion )
johnc@807 70
ysr@342 71 enum GCAllocPurpose {
ysr@342 72 GCAllocForTenured,
ysr@342 73 GCAllocForSurvived,
ysr@342 74 GCAllocPurposeCount
ysr@342 75 };
ysr@342 76
ysr@342 77 class YoungList : public CHeapObj {
ysr@342 78 private:
ysr@342 79 G1CollectedHeap* _g1h;
ysr@342 80
ysr@342 81 HeapRegion* _head;
ysr@342 82
johnc@1394 83 HeapRegion* _survivor_head;
johnc@1394 84 HeapRegion* _survivor_tail;
johnc@1394 85
johnc@1394 86 HeapRegion* _curr;
johnc@1394 87
ysr@342 88 size_t _length;
johnc@1394 89 size_t _survivor_length;
ysr@342 90
ysr@342 91 size_t _last_sampled_rs_lengths;
ysr@342 92 size_t _sampled_rs_lengths;
ysr@342 93
johnc@1394 94 void empty_list(HeapRegion* list);
ysr@342 95
ysr@342 96 public:
ysr@342 97 YoungList(G1CollectedHeap* g1h);
ysr@342 98
johnc@1394 99 void push_region(HeapRegion* hr);
johnc@1394 100 void add_survivor_region(HeapRegion* hr);
johnc@1394 101
johnc@1394 102 void empty_list();
johnc@1394 103 bool is_empty() { return _length == 0; }
johnc@1394 104 size_t length() { return _length; }
johnc@1394 105 size_t survivor_length() { return _survivor_length; }
ysr@342 106
tonyp@2526 107 // Currently we do not keep track of the used byte sum for the
tonyp@2526 108 // young list and the survivors and it'd be quite a lot of work to
tonyp@2526 109 // do so. When we'll eventually replace the young list with
tonyp@2526 110 // instances of HeapRegionLinkedList we'll get that for free. So,
tonyp@2526 111 // we'll report the more accurate information then.
tonyp@2526 112 size_t eden_used_bytes() {
tonyp@2526 113 assert(length() >= survivor_length(), "invariant");
tonyp@2526 114 return (length() - survivor_length()) * HeapRegion::GrainBytes;
tonyp@2526 115 }
tonyp@2526 116 size_t survivor_used_bytes() {
tonyp@2526 117 return survivor_length() * HeapRegion::GrainBytes;
tonyp@2526 118 }
tonyp@2526 119
ysr@342 120 void rs_length_sampling_init();
ysr@342 121 bool rs_length_sampling_more();
ysr@342 122 void rs_length_sampling_next();
ysr@342 123
ysr@342 124 void reset_sampled_info() {
ysr@342 125 _last_sampled_rs_lengths = 0;
ysr@342 126 }
ysr@342 127 size_t sampled_rs_lengths() { return _last_sampled_rs_lengths; }
ysr@342 128
ysr@342 129 // for development purposes
ysr@342 130 void reset_auxilary_lists();
johnc@1394 131 void clear() { _head = NULL; _length = 0; }
johnc@1394 132
johnc@1394 133 void clear_survivors() {
johnc@1394 134 _survivor_head = NULL;
johnc@1394 135 _survivor_tail = NULL;
johnc@1394 136 _survivor_length = 0;
johnc@1394 137 }
johnc@1394 138
ysr@342 139 HeapRegion* first_region() { return _head; }
ysr@342 140 HeapRegion* first_survivor_region() { return _survivor_head; }
apetrusenko@545 141 HeapRegion* last_survivor_region() { return _survivor_tail; }
ysr@342 142
ysr@342 143 // debugging
ysr@342 144 bool check_list_well_formed();
johnc@1394 145 bool check_list_empty(bool check_sample = true);
ysr@342 146 void print();
ysr@342 147 };
ysr@342 148
tonyp@2280 149 class MutatorAllocRegion : public G1AllocRegion {
tonyp@2280 150 protected:
tonyp@2280 151 virtual HeapRegion* allocate_new_region(size_t word_size, bool force);
tonyp@2280 152 virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes);
tonyp@2280 153 public:
tonyp@2280 154 MutatorAllocRegion()
tonyp@2280 155 : G1AllocRegion("Mutator Alloc Region", false /* bot_updates */) { }
tonyp@2280 156 };
tonyp@2280 157
johnc@2740 158 // The G1 STW is alive closure.
johnc@2740 159 // An instance is embedded into the G1CH and used as the
johnc@2740 160 // (optional) _is_alive_non_header closure in the STW
johnc@2740 161 // reference processor. It is also extensively used during
johnc@2740 162 // refence processing during STW evacuation pauses.
johnc@2740 163 class G1STWIsAliveClosure: public BoolObjectClosure {
johnc@2740 164 G1CollectedHeap* _g1;
johnc@2740 165 public:
johnc@2740 166 G1STWIsAliveClosure(G1CollectedHeap* g1) : _g1(g1) {}
johnc@2740 167 void do_object(oop p) { assert(false, "Do not call."); }
johnc@2740 168 bool do_object_b(oop p);
johnc@2740 169 };
johnc@2740 170
tonyp@2593 171 class SurvivorGCAllocRegion : public G1AllocRegion {
tonyp@2593 172 protected:
tonyp@2593 173 virtual HeapRegion* allocate_new_region(size_t word_size, bool force);
tonyp@2593 174 virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes);
tonyp@2593 175 public:
tonyp@2593 176 SurvivorGCAllocRegion()
tonyp@2593 177 : G1AllocRegion("Survivor GC Alloc Region", false /* bot_updates */) { }
tonyp@2593 178 };
tonyp@2593 179
tonyp@2593 180 class OldGCAllocRegion : public G1AllocRegion {
tonyp@2593 181 protected:
tonyp@2593 182 virtual HeapRegion* allocate_new_region(size_t word_size, bool force);
tonyp@2593 183 virtual void retire_region(HeapRegion* alloc_region, size_t allocated_bytes);
tonyp@2593 184 public:
tonyp@2593 185 OldGCAllocRegion()
tonyp@2593 186 : G1AllocRegion("Old GC Alloc Region", true /* bot_updates */) { }
tonyp@2593 187 };
tonyp@2593 188
ysr@342 189 class RefineCardTableEntryClosure;
johnc@2740 190
ysr@342 191 class G1CollectedHeap : public SharedHeap {
ysr@342 192 friend class VM_G1CollectForAllocation;
ysr@342 193 friend class VM_GenCollectForPermanentAllocation;
ysr@342 194 friend class VM_G1CollectFull;
ysr@342 195 friend class VM_G1IncCollectionPause;
ysr@342 196 friend class VMStructs;
tonyp@2280 197 friend class MutatorAllocRegion;
tonyp@2593 198 friend class SurvivorGCAllocRegion;
tonyp@2593 199 friend class OldGCAllocRegion;
ysr@342 200
ysr@342 201 // Closures used in implementation.
ysr@342 202 friend class G1ParCopyHelper;
ysr@342 203 friend class G1IsAliveClosure;
ysr@342 204 friend class G1EvacuateFollowersClosure;
ysr@342 205 friend class G1ParScanThreadState;
ysr@342 206 friend class G1ParScanClosureSuper;
ysr@342 207 friend class G1ParEvacuateFollowersClosure;
ysr@342 208 friend class G1ParTask;
ysr@342 209 friend class G1FreeGarbageRegionClosure;
ysr@342 210 friend class RefineCardTableEntryClosure;
ysr@342 211 friend class G1PrepareCompactClosure;
ysr@342 212 friend class RegionSorter;
tonyp@2037 213 friend class RegionResetter;
ysr@342 214 friend class CountRCClosure;
ysr@342 215 friend class EvacPopObjClosure;
apetrusenko@796 216 friend class G1ParCleanupCTTask;
ysr@342 217
ysr@342 218 // Other related classes.
ysr@342 219 friend class G1MarkSweep;
ysr@342 220
ysr@342 221 private:
ysr@342 222 // The one and only G1CollectedHeap, so static functions can find it.
ysr@342 223 static G1CollectedHeap* _g1h;
ysr@342 224
tonyp@942 225 static size_t _humongous_object_threshold_in_words;
tonyp@942 226
ysr@342 227 // Storage for the G1 heap (excludes the permanent generation).
ysr@342 228 VirtualSpace _g1_storage;
ysr@342 229 MemRegion _g1_reserved;
ysr@342 230
ysr@342 231 // The part of _g1_storage that is currently committed.
ysr@342 232 MemRegion _g1_committed;
ysr@342 233
tonyp@2037 234 // The master free list. It will satisfy all new region allocations.
tonyp@2037 235 MasterFreeRegionList _free_list;
tonyp@2037 236
tonyp@2037 237 // The secondary free list which contains regions that have been
tonyp@2037 238 // freed up during the cleanup process. This will be appended to the
tonyp@2037 239 // master free list when appropriate.
tonyp@2037 240 SecondaryFreeRegionList _secondary_free_list;
tonyp@2037 241
tonyp@2037 242 // It keeps track of the humongous regions.
tonyp@2037 243 MasterHumongousRegionSet _humongous_set;
ysr@342 244
ysr@342 245 // The number of regions we could create by expansion.
ysr@342 246 size_t _expansion_regions;
ysr@342 247
ysr@342 248 // The block offset table for the G1 heap.
ysr@342 249 G1BlockOffsetSharedArray* _bot_shared;
ysr@342 250
ysr@342 251 // Move all of the regions off the free lists, then rebuild those free
ysr@342 252 // lists, before and after full GC.
ysr@342 253 void tear_down_region_lists();
ysr@342 254 void rebuild_region_lists();
ysr@342 255
ysr@342 256 // The sequence of all heap regions in the heap.
tonyp@2528 257 HeapRegionSeq _hrs;
ysr@342 258
tonyp@2280 259 // Alloc region used to satisfy mutator allocation requests.
tonyp@2280 260 MutatorAllocRegion _mutator_alloc_region;
ysr@342 261
tonyp@2593 262 // Alloc region used to satisfy allocation requests by the GC for
tonyp@2593 263 // survivor objects.
tonyp@2593 264 SurvivorGCAllocRegion _survivor_gc_alloc_region;
tonyp@2593 265
tonyp@2593 266 // Alloc region used to satisfy allocation requests by the GC for
tonyp@2593 267 // old objects.
tonyp@2593 268 OldGCAllocRegion _old_gc_alloc_region;
tonyp@2593 269
tonyp@2593 270 // The last old region we allocated to during the last GC.
tonyp@2593 271 // Typically, it is not full so we should re-use it during the next GC.
tonyp@2593 272 HeapRegion* _retained_old_gc_alloc_region;
tonyp@2593 273
tonyp@2280 274 // It resets the mutator alloc region before new allocations can take place.
tonyp@2280 275 void init_mutator_alloc_region();
tonyp@2280 276
tonyp@2280 277 // It releases the mutator alloc region.
tonyp@2280 278 void release_mutator_alloc_region();
tonyp@2280 279
tonyp@2593 280 // It initializes the GC alloc regions at the start of a GC.
tonyp@2593 281 void init_gc_alloc_regions();
tonyp@2593 282
tonyp@2593 283 // It releases the GC alloc regions at the end of a GC.
tonyp@2593 284 void release_gc_alloc_regions();
tonyp@2593 285
tonyp@2593 286 // It does any cleanup that needs to be done on the GC alloc regions
tonyp@2593 287 // before a Full GC.
tonyp@636 288 void abandon_gc_alloc_regions();
ysr@342 289
jmasa@2386 290 // Helper for monitoring and management support.
jmasa@2386 291 G1MonitoringSupport* _g1mm;
jmasa@2386 292
apetrusenko@1391 293 // Determines PLAB size for a particular allocation purpose.
apetrusenko@1391 294 static size_t desired_plab_sz(GCAllocPurpose purpose);
apetrusenko@1391 295
ysr@342 296 // Outside of GC pauses, the number of bytes used in all regions other
ysr@342 297 // than the current allocation region.
ysr@342 298 size_t _summary_bytes_used;
ysr@342 299
tonyp@526 300 // This is used for a quick test on whether a reference points into
tonyp@526 301 // the collection set or not. Basically, we have an array, with one
tonyp@526 302 // byte per region, and that byte denotes whether the corresponding
tonyp@526 303 // region is in the collection set or not. The entry corresponding
tonyp@526 304 // the bottom of the heap, i.e., region 0, is pointed to by
tonyp@526 305 // _in_cset_fast_test_base. The _in_cset_fast_test field has been
tonyp@526 306 // biased so that it actually points to address 0 of the address
tonyp@526 307 // space, to make the test as fast as possible (we can simply shift
tonyp@526 308 // the address to address into it, instead of having to subtract the
tonyp@526 309 // bottom of the heap from the address before shifting it; basically
tonyp@526 310 // it works in the same way the card table works).
tonyp@526 311 bool* _in_cset_fast_test;
tonyp@526 312
tonyp@526 313 // The allocated array used for the fast test on whether a reference
tonyp@526 314 // points into the collection set or not. This field is also used to
tonyp@526 315 // free the array.
tonyp@526 316 bool* _in_cset_fast_test_base;
tonyp@526 317
tonyp@526 318 // The length of the _in_cset_fast_test_base array.
tonyp@526 319 size_t _in_cset_fast_test_length;
tonyp@526 320
iveresov@353 321 volatile unsigned _gc_time_stamp;
ysr@342 322
ysr@342 323 size_t* _surviving_young_words;
ysr@342 324
tonyp@2540 325 G1HRPrinter _hr_printer;
tonyp@2540 326
ysr@342 327 void setup_surviving_young_words();
ysr@342 328 void update_surviving_young_words(size_t* surv_young_words);
ysr@342 329 void cleanup_surviving_young_words();
ysr@342 330
tonyp@1576 331 // It decides whether an explicit GC should start a concurrent cycle
tonyp@1576 332 // instead of doing a STW GC. Currently, a concurrent cycle is
tonyp@1576 333 // explicitly started if:
tonyp@1576 334 // (a) cause == _gc_locker and +GCLockerInvokesConcurrent, or
tonyp@1576 335 // (b) cause == _java_lang_system_gc and +ExplicitGCInvokesConcurrent.
tonyp@1576 336 bool should_do_concurrent_full_gc(GCCause::Cause cause);
tonyp@1576 337
tonyp@1576 338 // Keeps track of how many "full collections" (i.e., Full GCs or
tonyp@1576 339 // concurrent cycles) we have completed. The number of them we have
tonyp@1576 340 // started is maintained in _total_full_collections in CollectedHeap.
tonyp@1576 341 volatile unsigned int _full_collections_completed;
tonyp@1576 342
tonyp@2382 343 // This is a non-product method that is helpful for testing. It is
tonyp@2382 344 // called at the end of a GC and artificially expands the heap by
tonyp@2382 345 // allocating a number of dead regions. This way we can induce very
tonyp@2382 346 // frequent marking cycles and stress the cleanup / concurrent
tonyp@2382 347 // cleanup code more (as all the regions that will be allocated by
tonyp@2382 348 // this method will be found dead by the marking cycle).
tonyp@2382 349 void allocate_dummy_regions() PRODUCT_RETURN;
tonyp@2382 350
tonyp@1880 351 // These are macros so that, if the assert fires, we get the correct
tonyp@1880 352 // line number, file, etc.
tonyp@1880 353
tonyp@2208 354 #define heap_locking_asserts_err_msg(_extra_message_) \
tonyp@2037 355 err_msg("%s : Heap_lock locked: %s, at safepoint: %s, is VM thread: %s", \
tonyp@2208 356 (_extra_message_), \
tonyp@2037 357 BOOL_TO_STR(Heap_lock->owned_by_self()), \
tonyp@2037 358 BOOL_TO_STR(SafepointSynchronize::is_at_safepoint()), \
tonyp@2037 359 BOOL_TO_STR(Thread::current()->is_VM_thread()))
tonyp@1880 360
tonyp@1880 361 #define assert_heap_locked() \
tonyp@1880 362 do { \
tonyp@1880 363 assert(Heap_lock->owned_by_self(), \
tonyp@1880 364 heap_locking_asserts_err_msg("should be holding the Heap_lock")); \
tonyp@1880 365 } while (0)
tonyp@1880 366
tonyp@2208 367 #define assert_heap_locked_or_at_safepoint(_should_be_vm_thread_) \
tonyp@1880 368 do { \
tonyp@1880 369 assert(Heap_lock->owned_by_self() || \
tonyp@2037 370 (SafepointSynchronize::is_at_safepoint() && \
tonyp@2208 371 ((_should_be_vm_thread_) == Thread::current()->is_VM_thread())), \
tonyp@1880 372 heap_locking_asserts_err_msg("should be holding the Heap_lock or " \
tonyp@1880 373 "should be at a safepoint")); \
tonyp@1880 374 } while (0)
tonyp@1880 375
tonyp@1880 376 #define assert_heap_locked_and_not_at_safepoint() \
tonyp@1880 377 do { \
tonyp@1880 378 assert(Heap_lock->owned_by_self() && \
tonyp@1880 379 !SafepointSynchronize::is_at_safepoint(), \
tonyp@1880 380 heap_locking_asserts_err_msg("should be holding the Heap_lock and " \
tonyp@1880 381 "should not be at a safepoint")); \
tonyp@1880 382 } while (0)
tonyp@1880 383
tonyp@1880 384 #define assert_heap_not_locked() \
tonyp@1880 385 do { \
tonyp@1880 386 assert(!Heap_lock->owned_by_self(), \
tonyp@1880 387 heap_locking_asserts_err_msg("should not be holding the Heap_lock")); \
tonyp@1880 388 } while (0)
tonyp@1880 389
tonyp@1880 390 #define assert_heap_not_locked_and_not_at_safepoint() \
tonyp@1880 391 do { \
tonyp@1880 392 assert(!Heap_lock->owned_by_self() && \
tonyp@1880 393 !SafepointSynchronize::is_at_safepoint(), \
tonyp@1880 394 heap_locking_asserts_err_msg("should not be holding the Heap_lock and " \
tonyp@1880 395 "should not be at a safepoint")); \
tonyp@1880 396 } while (0)
tonyp@1880 397
tonyp@2208 398 #define assert_at_safepoint(_should_be_vm_thread_) \
tonyp@1880 399 do { \
tonyp@2037 400 assert(SafepointSynchronize::is_at_safepoint() && \
tonyp@2208 401 ((_should_be_vm_thread_) == Thread::current()->is_VM_thread()), \
tonyp@1880 402 heap_locking_asserts_err_msg("should be at a safepoint")); \
tonyp@1880 403 } while (0)
tonyp@1880 404
tonyp@1880 405 #define assert_not_at_safepoint() \
tonyp@1880 406 do { \
tonyp@1880 407 assert(!SafepointSynchronize::is_at_safepoint(), \
tonyp@1880 408 heap_locking_asserts_err_msg("should not be at a safepoint")); \
tonyp@1880 409 } while (0)
tonyp@1880 410
ysr@342 411 protected:
ysr@342 412
johnc@2586 413 // The young region list.
ysr@342 414 YoungList* _young_list;
ysr@342 415
ysr@342 416 // The current policy object for the collector.
ysr@342 417 G1CollectorPolicy* _g1_policy;
ysr@342 418
tonyp@2037 419 // This is the second level of trying to allocate a new region. If
tonyp@2280 420 // new_region() didn't find a region on the free_list, this call will
tonyp@2280 421 // check whether there's anything available on the
tonyp@2280 422 // secondary_free_list and/or wait for more regions to appear on
tonyp@2280 423 // that list, if _free_regions_coming is set.
tonyp@2208 424 HeapRegion* new_region_try_secondary_free_list();
ysr@342 425
tonyp@2208 426 // Try to allocate a single non-humongous HeapRegion sufficient for
tonyp@2208 427 // an allocation of the given word_size. If do_expand is true,
tonyp@2208 428 // attempt to expand the heap if necessary to satisfy the allocation
tonyp@2208 429 // request.
tonyp@2280 430 HeapRegion* new_region(size_t word_size, bool do_expand);
ysr@342 431
tonyp@2208 432 // Attempt to satisfy a humongous allocation request of the given
tonyp@2208 433 // size by finding a contiguous set of free regions of num_regions
tonyp@2208 434 // length and remove them from the master free list. Return the
tonyp@2528 435 // index of the first region or G1_NULL_HRS_INDEX if the search
tonyp@2528 436 // was unsuccessful.
tonyp@2528 437 size_t humongous_obj_allocate_find_first(size_t num_regions,
tonyp@2528 438 size_t word_size);
ysr@342 439
tonyp@2208 440 // Initialize a contiguous set of free regions of length num_regions
tonyp@2208 441 // and starting at index first so that they appear as a single
tonyp@2208 442 // humongous region.
tonyp@2528 443 HeapWord* humongous_obj_allocate_initialize_regions(size_t first,
tonyp@2208 444 size_t num_regions,
tonyp@2208 445 size_t word_size);
tonyp@2208 446
tonyp@2208 447 // Attempt to allocate a humongous object of the given size. Return
tonyp@2208 448 // NULL if unsuccessful.
tonyp@2037 449 HeapWord* humongous_obj_allocate(size_t word_size);
ysr@342 450
tonyp@1880 451 // The following two methods, allocate_new_tlab() and
tonyp@1880 452 // mem_allocate(), are the two main entry points from the runtime
tonyp@1880 453 // into the G1's allocation routines. They have the following
tonyp@1880 454 // assumptions:
tonyp@1880 455 //
tonyp@1880 456 // * They should both be called outside safepoints.
tonyp@1880 457 //
tonyp@1880 458 // * They should both be called without holding the Heap_lock.
tonyp@1880 459 //
tonyp@1880 460 // * All allocation requests for new TLABs should go to
tonyp@1880 461 // allocate_new_tlab().
tonyp@1880 462 //
tonyp@2536 463 // * All non-TLAB allocation requests should go to mem_allocate().
tonyp@1880 464 //
tonyp@1880 465 // * If either call cannot satisfy the allocation request using the
tonyp@1880 466 // current allocating region, they will try to get a new one. If
tonyp@1880 467 // this fails, they will attempt to do an evacuation pause and
tonyp@1880 468 // retry the allocation.
tonyp@1880 469 //
tonyp@1880 470 // * If all allocation attempts fail, even after trying to schedule
tonyp@1880 471 // an evacuation pause, allocate_new_tlab() will return NULL,
tonyp@1880 472 // whereas mem_allocate() will attempt a heap expansion and/or
tonyp@1880 473 // schedule a Full GC.
tonyp@1880 474 //
tonyp@1880 475 // * We do not allow humongous-sized TLABs. So, allocate_new_tlab
tonyp@1880 476 // should never be called with word_size being humongous. All
tonyp@1880 477 // humongous allocation requests should go to mem_allocate() which
tonyp@1880 478 // will satisfy them with a special path.
ysr@342 479
tonyp@1880 480 virtual HeapWord* allocate_new_tlab(size_t word_size);
tonyp@1880 481
tonyp@1880 482 virtual HeapWord* mem_allocate(size_t word_size,
tonyp@1880 483 bool* gc_overhead_limit_was_exceeded);
tonyp@1880 484
tonyp@2280 485 // The following three methods take a gc_count_before_ret
tonyp@2280 486 // parameter which is used to return the GC count if the method
tonyp@2280 487 // returns NULL. Given that we are required to read the GC count
tonyp@2280 488 // while holding the Heap_lock, and these paths will take the
tonyp@2280 489 // Heap_lock at some point, it's easier to get them to read the GC
tonyp@2280 490 // count while holding the Heap_lock before they return NULL instead
tonyp@2280 491 // of the caller (namely: mem_allocate()) having to also take the
tonyp@2280 492 // Heap_lock just to read the GC count.
tonyp@1880 493
tonyp@2280 494 // First-level mutator allocation attempt: try to allocate out of
tonyp@2280 495 // the mutator alloc region without taking the Heap_lock. This
tonyp@2280 496 // should only be used for non-humongous allocations.
tonyp@2280 497 inline HeapWord* attempt_allocation(size_t word_size,
tonyp@2280 498 unsigned int* gc_count_before_ret);
tonyp@1880 499
tonyp@2280 500 // Second-level mutator allocation attempt: take the Heap_lock and
tonyp@2280 501 // retry the allocation attempt, potentially scheduling a GC
tonyp@2280 502 // pause. This should only be used for non-humongous allocations.
tonyp@2280 503 HeapWord* attempt_allocation_slow(size_t word_size,
tonyp@2280 504 unsigned int* gc_count_before_ret);
tonyp@1880 505
tonyp@2280 506 // Takes the Heap_lock and attempts a humongous allocation. It can
tonyp@2280 507 // potentially schedule a GC pause.
tonyp@2280 508 HeapWord* attempt_allocation_humongous(size_t word_size,
tonyp@2280 509 unsigned int* gc_count_before_ret);
tonyp@2019 510
tonyp@2280 511 // Allocation attempt that should be called during safepoints (e.g.,
tonyp@2280 512 // at the end of a successful GC). expect_null_mutator_alloc_region
tonyp@2280 513 // specifies whether the mutator alloc region is expected to be NULL
tonyp@2280 514 // or not.
tonyp@1880 515 HeapWord* attempt_allocation_at_safepoint(size_t word_size,
tonyp@2280 516 bool expect_null_mutator_alloc_region);
tonyp@1880 517
tonyp@1880 518 // It dirties the cards that cover the block so that so that the post
tonyp@1880 519 // write barrier never queues anything when updating objects on this
tonyp@1880 520 // block. It is assumed (and in fact we assert) that the block
tonyp@1880 521 // belongs to a young region.
tonyp@1880 522 inline void dirty_young_block(HeapWord* start, size_t word_size);
ysr@342 523
ysr@342 524 // Allocate blocks during garbage collection. Will ensure an
ysr@342 525 // allocation region, either by picking one or expanding the
ysr@342 526 // heap, and then allocate a block of the given size. The block
ysr@342 527 // may not be a humongous - it must fit into a single heap region.
ysr@342 528 HeapWord* par_allocate_during_gc(GCAllocPurpose purpose, size_t word_size);
ysr@342 529
ysr@342 530 HeapWord* allocate_during_gc_slow(GCAllocPurpose purpose,
ysr@342 531 HeapRegion* alloc_region,
ysr@342 532 bool par,
ysr@342 533 size_t word_size);
ysr@342 534
ysr@342 535 // Ensure that no further allocations can happen in "r", bearing in mind
ysr@342 536 // that parallel threads might be attempting allocations.
ysr@342 537 void par_allocate_remaining_space(HeapRegion* r);
ysr@342 538
tonyp@2593 539 // Allocation attempt during GC for a survivor object / PLAB.
tonyp@2593 540 inline HeapWord* survivor_attempt_allocation(size_t word_size);
apetrusenko@545 541
tonyp@2593 542 // Allocation attempt during GC for an old object / PLAB.
tonyp@2593 543 inline HeapWord* old_attempt_allocation(size_t word_size);
tonyp@2280 544
tonyp@2593 545 // These methods are the "callbacks" from the G1AllocRegion class.
tonyp@2593 546
tonyp@2593 547 // For mutator alloc regions.
tonyp@2280 548 HeapRegion* new_mutator_alloc_region(size_t word_size, bool force);
tonyp@2280 549 void retire_mutator_alloc_region(HeapRegion* alloc_region,
tonyp@2280 550 size_t allocated_bytes);
tonyp@2280 551
tonyp@2593 552 // For GC alloc regions.
tonyp@2593 553 HeapRegion* new_gc_alloc_region(size_t word_size, size_t count,
tonyp@2593 554 GCAllocPurpose ap);
tonyp@2593 555 void retire_gc_alloc_region(HeapRegion* alloc_region,
tonyp@2593 556 size_t allocated_bytes, GCAllocPurpose ap);
tonyp@2593 557
tonyp@1576 558 // - if explicit_gc is true, the GC is for a System.gc() or a heap
tonyp@1880 559 // inspection request and should collect the entire heap
tonyp@1880 560 // - if clear_all_soft_refs is true, all soft references should be
tonyp@1880 561 // cleared during the GC
tonyp@1576 562 // - if explicit_gc is false, word_size describes the allocation that
tonyp@1880 563 // the GC should attempt (at least) to satisfy
tonyp@1880 564 // - it returns false if it is unable to do the collection due to the
tonyp@1880 565 // GC locker being active, true otherwise
tonyp@1880 566 bool do_collection(bool explicit_gc,
tonyp@1576 567 bool clear_all_soft_refs,
ysr@342 568 size_t word_size);
ysr@342 569
ysr@342 570 // Callback from VM_G1CollectFull operation.
ysr@342 571 // Perform a full collection.
ysr@342 572 void do_full_collection(bool clear_all_soft_refs);
ysr@342 573
ysr@342 574 // Resize the heap if necessary after a full collection. If this is
ysr@342 575 // after a collect-for allocation, "word_size" is the allocation size,
ysr@342 576 // and will be considered part of the used portion of the heap.
ysr@342 577 void resize_if_necessary_after_full_collection(size_t word_size);
ysr@342 578
ysr@342 579 // Callback from VM_G1CollectForAllocation operation.
ysr@342 580 // This function does everything necessary/possible to satisfy a
ysr@342 581 // failed allocation request (including collection, expansion, etc.)
tonyp@1880 582 HeapWord* satisfy_failed_allocation(size_t word_size, bool* succeeded);
ysr@342 583
ysr@342 584 // Attempting to expand the heap sufficiently
ysr@342 585 // to support an allocation of the given "word_size". If
ysr@342 586 // successful, perform the allocation and return the address of the
ysr@342 587 // allocated block, or else "NULL".
tonyp@1880 588 HeapWord* expand_and_allocate(size_t word_size);
ysr@342 589
johnc@2740 590 // Process any reference objects discovered during
johnc@2740 591 // an incremental evacuation pause.
johnc@2740 592 void process_discovered_references();
johnc@2740 593
johnc@2740 594 // Enqueue any remaining discovered references
johnc@2740 595 // after processing.
johnc@2740 596 void enqueue_discovered_references();
johnc@2740 597
ysr@342 598 public:
jmasa@2386 599
tonyp@2741 600 G1MonitoringSupport* g1mm() {
tonyp@2741 601 assert(_g1mm != NULL, "should have been initialized");
tonyp@2741 602 return _g1mm;
tonyp@2741 603 }
jmasa@2386 604
ysr@342 605 // Expand the garbage-first heap by at least the given size (in bytes!).
johnc@2069 606 // Returns true if the heap was expanded by the requested amount;
johnc@2069 607 // false otherwise.
ysr@342 608 // (Rounds up to a HeapRegion boundary.)
johnc@2069 609 bool expand(size_t expand_bytes);
ysr@342 610
ysr@342 611 // Do anything common to GC's.
ysr@342 612 virtual void gc_prologue(bool full);
ysr@342 613 virtual void gc_epilogue(bool full);
ysr@342 614
tonyp@526 615 // We register a region with the fast "in collection set" test. We
tonyp@526 616 // simply set to true the array slot corresponding to this region.
tonyp@526 617 void register_region_with_in_cset_fast_test(HeapRegion* r) {
tonyp@526 618 assert(_in_cset_fast_test_base != NULL, "sanity");
tonyp@526 619 assert(r->in_collection_set(), "invariant");
tonyp@2528 620 size_t index = r->hrs_index();
tonyp@2528 621 assert(index < _in_cset_fast_test_length, "invariant");
tonyp@526 622 assert(!_in_cset_fast_test_base[index], "invariant");
tonyp@526 623 _in_cset_fast_test_base[index] = true;
tonyp@526 624 }
tonyp@526 625
tonyp@526 626 // This is a fast test on whether a reference points into the
tonyp@526 627 // collection set or not. It does not assume that the reference
tonyp@526 628 // points into the heap; if it doesn't, it will return false.
tonyp@526 629 bool in_cset_fast_test(oop obj) {
tonyp@526 630 assert(_in_cset_fast_test != NULL, "sanity");
tonyp@526 631 if (_g1_committed.contains((HeapWord*) obj)) {
tonyp@526 632 // no need to subtract the bottom of the heap from obj,
tonyp@526 633 // _in_cset_fast_test is biased
tonyp@526 634 size_t index = ((size_t) obj) >> HeapRegion::LogOfHRGrainBytes;
tonyp@526 635 bool ret = _in_cset_fast_test[index];
tonyp@526 636 // let's make sure the result is consistent with what the slower
tonyp@526 637 // test returns
tonyp@526 638 assert( ret || !obj_in_cs(obj), "sanity");
tonyp@526 639 assert(!ret || obj_in_cs(obj), "sanity");
tonyp@526 640 return ret;
tonyp@526 641 } else {
tonyp@526 642 return false;
tonyp@526 643 }
tonyp@526 644 }
tonyp@526 645
johnc@1394 646 void clear_cset_fast_test() {
johnc@1394 647 assert(_in_cset_fast_test_base != NULL, "sanity");
johnc@1394 648 memset(_in_cset_fast_test_base, false,
johnc@1394 649 _in_cset_fast_test_length * sizeof(bool));
johnc@1394 650 }
johnc@1394 651
tonyp@1576 652 // This is called at the end of either a concurrent cycle or a Full
tonyp@1576 653 // GC to update the number of full collections completed. Those two
tonyp@1576 654 // can happen in a nested fashion, i.e., we start a concurrent
tonyp@1576 655 // cycle, a Full GC happens half-way through it which ends first,
tonyp@1576 656 // and then the cycle notices that a Full GC happened and ends
tonyp@1937 657 // too. The concurrent parameter is a boolean to help us do a bit
tonyp@1937 658 // tighter consistency checking in the method. If concurrent is
tonyp@1937 659 // false, the caller is the inner caller in the nesting (i.e., the
tonyp@1937 660 // Full GC). If concurrent is true, the caller is the outer caller
tonyp@1937 661 // in this nesting (i.e., the concurrent cycle). Further nesting is
tonyp@1937 662 // not currently supported. The end of the this call also notifies
tonyp@1937 663 // the FullGCCount_lock in case a Java thread is waiting for a full
tonyp@1937 664 // GC to happen (e.g., it called System.gc() with
tonyp@1576 665 // +ExplicitGCInvokesConcurrent).
tonyp@1937 666 void increment_full_collections_completed(bool concurrent);
tonyp@1576 667
tonyp@1576 668 unsigned int full_collections_completed() {
tonyp@1576 669 return _full_collections_completed;
tonyp@1576 670 }
tonyp@1576 671
tonyp@2540 672 G1HRPrinter* hr_printer() { return &_hr_printer; }
tonyp@2540 673
ysr@342 674 protected:
ysr@342 675
ysr@342 676 // Shrink the garbage-first heap by at most the given size (in bytes!).
ysr@342 677 // (Rounds down to a HeapRegion boundary.)
ysr@342 678 virtual void shrink(size_t expand_bytes);
ysr@342 679 void shrink_helper(size_t expand_bytes);
ysr@342 680
jcoomes@1629 681 #if TASKQUEUE_STATS
jcoomes@1629 682 static void print_taskqueue_stats_hdr(outputStream* const st = gclog_or_tty);
jcoomes@1629 683 void print_taskqueue_stats(outputStream* const st = gclog_or_tty) const;
jcoomes@1629 684 void reset_taskqueue_stats();
jcoomes@1629 685 #endif // TASKQUEUE_STATS
jcoomes@1629 686
tonyp@1880 687 // Schedule the VM operation that will do an evacuation pause to
tonyp@1880 688 // satisfy an allocation request of word_size. *succeeded will
tonyp@1880 689 // return whether the VM operation was successful (it did do an
tonyp@1880 690 // evacuation pause) or not (another thread beat us to it or the GC
tonyp@1880 691 // locker was active). Given that we should not be holding the
tonyp@1880 692 // Heap_lock when we enter this method, we will pass the
tonyp@1880 693 // gc_count_before (i.e., total_collections()) as a parameter since
tonyp@1880 694 // it has to be read while holding the Heap_lock. Currently, both
tonyp@1880 695 // methods that call do_collection_pause() release the Heap_lock
tonyp@1880 696 // before the call, so it's easy to read gc_count_before just before.
tonyp@1880 697 HeapWord* do_collection_pause(size_t word_size,
tonyp@1880 698 unsigned int gc_count_before,
tonyp@1880 699 bool* succeeded);
ysr@342 700
ysr@342 701 // The guts of the incremental collection pause, executed by the vm
tonyp@1880 702 // thread. It returns false if it is unable to do the collection due
tonyp@1880 703 // to the GC locker being active, true otherwise
tonyp@1880 704 bool do_collection_pause_at_safepoint(double target_pause_time_ms);
ysr@342 705
ysr@342 706 // Actually do the work of evacuating the collection set.
tonyp@1880 707 void evacuate_collection_set();
ysr@342 708
ysr@342 709 // The g1 remembered set of the heap.
ysr@342 710 G1RemSet* _g1_rem_set;
ysr@342 711 // And it's mod ref barrier set, used to track updates for the above.
ysr@342 712 ModRefBarrierSet* _mr_bs;
ysr@342 713
iveresov@616 714 // A set of cards that cover the objects for which the Rsets should be updated
iveresov@616 715 // concurrently after the collection.
iveresov@616 716 DirtyCardQueueSet _dirty_card_queue_set;
iveresov@616 717
ysr@342 718 // The Heap Region Rem Set Iterator.
ysr@342 719 HeapRegionRemSetIterator** _rem_set_iterator;
ysr@342 720
ysr@342 721 // The closure used to refine a single card.
ysr@342 722 RefineCardTableEntryClosure* _refine_cte_cl;
ysr@342 723
ysr@342 724 // A function to check the consistency of dirty card logs.
ysr@342 725 void check_ct_logs_at_safepoint();
ysr@342 726
johnc@1625 727 // A DirtyCardQueueSet that is used to hold cards that contain
johnc@1625 728 // references into the current collection set. This is used to
johnc@1625 729 // update the remembered sets of the regions in the collection
johnc@1625 730 // set in the event of an evacuation failure.
johnc@1625 731 DirtyCardQueueSet _into_cset_dirty_card_queue_set;
johnc@1625 732
ysr@342 733 // After a collection pause, make the regions in the CS into free
ysr@342 734 // regions.
ysr@342 735 void free_collection_set(HeapRegion* cs_head);
ysr@342 736
johnc@1394 737 // Abandon the current collection set without recording policy
johnc@1394 738 // statistics or updating free lists.
johnc@1394 739 void abandon_collection_set(HeapRegion* cs_head);
johnc@1394 740
ysr@342 741 // Applies "scan_non_heap_roots" to roots outside the heap,
ysr@342 742 // "scan_rs" to roots inside the heap (having done "set_region" to
ysr@342 743 // indicate the region in which the root resides), and does "scan_perm"
ysr@342 744 // (setting the generation to the perm generation.) If "scan_rs" is
ysr@342 745 // NULL, then this step is skipped. The "worker_i"
ysr@342 746 // param is for use with parallel roots processing, and should be
ysr@342 747 // the "i" of the calling parallel worker thread's work(i) function.
ysr@342 748 // In the sequential case this param will be ignored.
ysr@342 749 void g1_process_strong_roots(bool collecting_perm_gen,
ysr@342 750 SharedHeap::ScanningOption so,
ysr@342 751 OopClosure* scan_non_heap_roots,
ysr@342 752 OopsInHeapRegionClosure* scan_rs,
ysr@342 753 OopsInGenClosure* scan_perm,
ysr@342 754 int worker_i);
ysr@342 755
ysr@342 756 // Apply "blk" to all the weak roots of the system. These include
ysr@342 757 // JNI weak roots, the code cache, system dictionary, symbol table,
ysr@342 758 // string table, and referents of reachable weak refs.
ysr@342 759 void g1_process_weak_roots(OopClosure* root_closure,
ysr@342 760 OopClosure* non_root_closure);
ysr@342 761
tonyp@2208 762 // Frees a non-humongous region by initializing its contents and
tonyp@2037 763 // adding it to the free list that's passed as a parameter (this is
tonyp@2037 764 // usually a local list which will be appended to the master free
tonyp@2037 765 // list later). The used bytes of freed regions are accumulated in
tonyp@2037 766 // pre_used. If par is true, the region's RSet will not be freed
tonyp@2037 767 // up. The assumption is that this will be done later.
tonyp@2037 768 void free_region(HeapRegion* hr,
tonyp@2037 769 size_t* pre_used,
tonyp@2037 770 FreeRegionList* free_list,
tonyp@2037 771 bool par);
ysr@342 772
tonyp@2208 773 // Frees a humongous region by collapsing it into individual regions
tonyp@2208 774 // and calling free_region() for each of them. The freed regions
tonyp@2208 775 // will be added to the free list that's passed as a parameter (this
tonyp@2208 776 // is usually a local list which will be appended to the master free
tonyp@2208 777 // list later). The used bytes of freed regions are accumulated in
tonyp@2208 778 // pre_used. If par is true, the region's RSet will not be freed
tonyp@2208 779 // up. The assumption is that this will be done later.
tonyp@2037 780 void free_humongous_region(HeapRegion* hr,
tonyp@2037 781 size_t* pre_used,
tonyp@2037 782 FreeRegionList* free_list,
tonyp@2037 783 HumongousRegionSet* humongous_proxy_set,
tonyp@2037 784 bool par);
ysr@342 785
tonyp@2528 786 // Notifies all the necessary spaces that the committed space has
tonyp@2528 787 // been updated (either expanded or shrunk). It should be called
tonyp@2528 788 // after _g1_storage is updated.
tonyp@2528 789 void update_committed_space(HeapWord* old_end, HeapWord* new_end);
tonyp@2528 790
ysr@342 791 // The concurrent marker (and the thread it runs in.)
ysr@342 792 ConcurrentMark* _cm;
ysr@342 793 ConcurrentMarkThread* _cmThread;
ysr@342 794 bool _mark_in_progress;
ysr@342 795
ysr@342 796 // The concurrent refiner.
ysr@342 797 ConcurrentG1Refine* _cg1r;
ysr@342 798
ysr@342 799 // The parallel task queues
ysr@342 800 RefToScanQueueSet *_task_queues;
ysr@342 801
ysr@342 802 // True iff a evacuation has failed in the current collection.
ysr@342 803 bool _evacuation_failed;
ysr@342 804
ysr@342 805 // Set the attribute indicating whether evacuation has failed in the
ysr@342 806 // current collection.
ysr@342 807 void set_evacuation_failed(bool b) { _evacuation_failed = b; }
ysr@342 808
ysr@342 809 // Failed evacuations cause some logical from-space objects to have
ysr@342 810 // forwarding pointers to themselves. Reset them.
ysr@342 811 void remove_self_forwarding_pointers();
ysr@342 812
ysr@342 813 // When one is non-null, so is the other. Together, they each pair is
ysr@342 814 // an object with a preserved mark, and its mark value.
ysr@342 815 GrowableArray<oop>* _objs_with_preserved_marks;
ysr@342 816 GrowableArray<markOop>* _preserved_marks_of_objs;
ysr@342 817
ysr@342 818 // Preserve the mark of "obj", if necessary, in preparation for its mark
ysr@342 819 // word being overwritten with a self-forwarding-pointer.
ysr@342 820 void preserve_mark_if_necessary(oop obj, markOop m);
ysr@342 821
ysr@342 822 // The stack of evac-failure objects left to be scanned.
ysr@342 823 GrowableArray<oop>* _evac_failure_scan_stack;
ysr@342 824 // The closure to apply to evac-failure objects.
ysr@342 825
ysr@342 826 OopsInHeapRegionClosure* _evac_failure_closure;
ysr@342 827 // Set the field above.
ysr@342 828 void
ysr@342 829 set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_closure) {
ysr@342 830 _evac_failure_closure = evac_failure_closure;
ysr@342 831 }
ysr@342 832
ysr@342 833 // Push "obj" on the scan stack.
ysr@342 834 void push_on_evac_failure_scan_stack(oop obj);
ysr@342 835 // Process scan stack entries until the stack is empty.
ysr@342 836 void drain_evac_failure_scan_stack();
ysr@342 837 // True iff an invocation of "drain_scan_stack" is in progress; to
ysr@342 838 // prevent unnecessary recursion.
ysr@342 839 bool _drain_in_progress;
ysr@342 840
ysr@342 841 // Do any necessary initialization for evacuation-failure handling.
ysr@342 842 // "cl" is the closure that will be used to process evac-failure
ysr@342 843 // objects.
ysr@342 844 void init_for_evac_failure(OopsInHeapRegionClosure* cl);
ysr@342 845 // Do any necessary cleanup for evacuation-failure handling data
ysr@342 846 // structures.
ysr@342 847 void finalize_for_evac_failure();
ysr@342 848
ysr@342 849 // An attempt to evacuate "obj" has failed; take necessary steps.
johnc@2734 850 oop handle_evacuation_failure_par(OopsInHeapRegionClosure* cl, oop obj,
johnc@2734 851 bool should_mark_root);
ysr@342 852 void handle_evacuation_failure_common(oop obj, markOop m);
ysr@342 853
johnc@2740 854 // ("Weak") Reference processing support.
johnc@2740 855 //
johnc@2740 856 // G1 has 2 instances of the referece processor class. One
johnc@2740 857 // (_ref_processor_cm) handles reference object discovery
johnc@2740 858 // and subsequent processing during concurrent marking cycles.
johnc@2740 859 //
johnc@2740 860 // The other (_ref_processor_stw) handles reference object
johnc@2740 861 // discovery and processing during full GCs and incremental
johnc@2740 862 // evacuation pauses.
johnc@2740 863 //
johnc@2740 864 // During an incremental pause, reference discovery will be
johnc@2740 865 // temporarily disabled for _ref_processor_cm and will be
johnc@2740 866 // enabled for _ref_processor_stw. At the end of the evacuation
johnc@2740 867 // pause references discovered by _ref_processor_stw will be
johnc@2740 868 // processed and discovery will be disabled. The previous
johnc@2740 869 // setting for reference object discovery for _ref_processor_cm
johnc@2740 870 // will be re-instated.
johnc@2740 871 //
johnc@2740 872 // At the start of marking:
johnc@2740 873 // * Discovery by the CM ref processor is verified to be inactive
johnc@2740 874 // and it's discovered lists are empty.
johnc@2740 875 // * Discovery by the CM ref processor is then enabled.
johnc@2740 876 //
johnc@2740 877 // At the end of marking:
johnc@2740 878 // * Any references on the CM ref processor's discovered
johnc@2740 879 // lists are processed (possibly MT).
johnc@2740 880 //
johnc@2740 881 // At the start of full GC we:
johnc@2740 882 // * Disable discovery by the CM ref processor and
johnc@2740 883 // empty CM ref processor's discovered lists
johnc@2740 884 // (without processing any entries).
johnc@2740 885 // * Verify that the STW ref processor is inactive and it's
johnc@2740 886 // discovered lists are empty.
johnc@2740 887 // * Temporarily set STW ref processor discovery as single threaded.
johnc@2740 888 // * Temporarily clear the STW ref processor's _is_alive_non_header
johnc@2740 889 // field.
johnc@2740 890 // * Finally enable discovery by the STW ref processor.
johnc@2740 891 //
johnc@2740 892 // The STW ref processor is used to record any discovered
johnc@2740 893 // references during the full GC.
johnc@2740 894 //
johnc@2740 895 // At the end of a full GC we:
johnc@2740 896 // * Enqueue any reference objects discovered by the STW ref processor
johnc@2740 897 // that have non-live referents. This has the side-effect of
johnc@2740 898 // making the STW ref processor inactive by disabling discovery.
johnc@2740 899 // * Verify that the CM ref processor is still inactive
johnc@2740 900 // and no references have been placed on it's discovered
johnc@2740 901 // lists (also checked as a precondition during initial marking).
johnc@2740 902
johnc@2740 903 // The (stw) reference processor...
johnc@2740 904 ReferenceProcessor* _ref_processor_stw;
johnc@2740 905
johnc@2740 906 // During reference object discovery, the _is_alive_non_header
johnc@2740 907 // closure (if non-null) is applied to the referent object to
johnc@2740 908 // determine whether the referent is live. If so then the
johnc@2740 909 // reference object does not need to be 'discovered' and can
johnc@2740 910 // be treated as a regular oop. This has the benefit of reducing
johnc@2740 911 // the number of 'discovered' reference objects that need to
johnc@2740 912 // be processed.
johnc@2740 913 //
johnc@2740 914 // Instance of the is_alive closure for embedding into the
johnc@2740 915 // STW reference processor as the _is_alive_non_header field.
johnc@2740 916 // Supplying a value for the _is_alive_non_header field is
johnc@2740 917 // optional but doing so prevents unnecessary additions to
johnc@2740 918 // the discovered lists during reference discovery.
johnc@2740 919 G1STWIsAliveClosure _is_alive_closure_stw;
johnc@2740 920
johnc@2740 921 // The (concurrent marking) reference processor...
johnc@2740 922 ReferenceProcessor* _ref_processor_cm;
johnc@2740 923
johnc@1944 924 // Instance of the concurrent mark is_alive closure for embedding
johnc@2740 925 // into the Concurrent Marking reference processor as the
johnc@2740 926 // _is_alive_non_header field. Supplying a value for the
johnc@2740 927 // _is_alive_non_header field is optional but doing so prevents
johnc@2740 928 // unnecessary additions to the discovered lists during reference
johnc@2740 929 // discovery.
johnc@2740 930 G1CMIsAliveClosure _is_alive_closure_cm;
ysr@342 931
ysr@342 932 enum G1H_process_strong_roots_tasks {
ysr@342 933 G1H_PS_mark_stack_oops_do,
ysr@342 934 G1H_PS_refProcessor_oops_do,
ysr@342 935 // Leave this one last.
ysr@342 936 G1H_PS_NumElements
ysr@342 937 };
ysr@342 938
ysr@342 939 SubTasksDone* _process_strong_tasks;
ysr@342 940
tonyp@2037 941 volatile bool _free_regions_coming;
ysr@342 942
ysr@342 943 public:
jmasa@1753 944
jmasa@1753 945 SubTasksDone* process_strong_tasks() { return _process_strong_tasks; }
jmasa@1753 946
ysr@342 947 void set_refine_cte_cl_concurrency(bool concurrent);
ysr@342 948
jcoomes@1629 949 RefToScanQueue *task_queue(int i) const;
ysr@342 950
iveresov@616 951 // A set of cards where updates happened during the GC
iveresov@616 952 DirtyCardQueueSet& dirty_card_queue_set() { return _dirty_card_queue_set; }
iveresov@616 953
johnc@1625 954 // A DirtyCardQueueSet that is used to hold cards that contain
johnc@1625 955 // references into the current collection set. This is used to
johnc@1625 956 // update the remembered sets of the regions in the collection
johnc@1625 957 // set in the event of an evacuation failure.
johnc@1625 958 DirtyCardQueueSet& into_cset_dirty_card_queue_set()
johnc@1625 959 { return _into_cset_dirty_card_queue_set; }
johnc@1625 960
ysr@342 961 // Create a G1CollectedHeap with the specified policy.
ysr@342 962 // Must call the initialize method afterwards.
ysr@342 963 // May not return if something goes wrong.
ysr@342 964 G1CollectedHeap(G1CollectorPolicy* policy);
ysr@342 965
ysr@342 966 // Initialize the G1CollectedHeap to have the initial and
ysr@342 967 // maximum sizes, permanent generation, and remembered and barrier sets
ysr@342 968 // specified by the policy object.
ysr@342 969 jint initialize();
ysr@342 970
johnc@2740 971 // Initialize weak reference processing.
johnc@1944 972 virtual void ref_processing_init();
ysr@342 973
ysr@342 974 void set_par_threads(int t) {
ysr@342 975 SharedHeap::set_par_threads(t);
jmasa@1753 976 _process_strong_tasks->set_n_threads(t);
ysr@342 977 }
ysr@342 978
ysr@342 979 virtual CollectedHeap::Name kind() const {
ysr@342 980 return CollectedHeap::G1CollectedHeap;
ysr@342 981 }
ysr@342 982
ysr@342 983 // The current policy object for the collector.
ysr@342 984 G1CollectorPolicy* g1_policy() const { return _g1_policy; }
ysr@342 985
ysr@342 986 // Adaptive size policy. No such thing for g1.
ysr@342 987 virtual AdaptiveSizePolicy* size_policy() { return NULL; }
ysr@342 988
ysr@342 989 // The rem set and barrier set.
ysr@342 990 G1RemSet* g1_rem_set() const { return _g1_rem_set; }
ysr@342 991 ModRefBarrierSet* mr_bs() const { return _mr_bs; }
ysr@342 992
ysr@342 993 // The rem set iterator.
ysr@342 994 HeapRegionRemSetIterator* rem_set_iterator(int i) {
ysr@342 995 return _rem_set_iterator[i];
ysr@342 996 }
ysr@342 997
ysr@342 998 HeapRegionRemSetIterator* rem_set_iterator() {
ysr@342 999 return _rem_set_iterator[0];
ysr@342 1000 }
ysr@342 1001
ysr@342 1002 unsigned get_gc_time_stamp() {
ysr@342 1003 return _gc_time_stamp;
ysr@342 1004 }
ysr@342 1005
ysr@342 1006 void reset_gc_time_stamp() {
ysr@342 1007 _gc_time_stamp = 0;
iveresov@353 1008 OrderAccess::fence();
iveresov@353 1009 }
iveresov@353 1010
iveresov@353 1011 void increment_gc_time_stamp() {
iveresov@353 1012 ++_gc_time_stamp;
iveresov@353 1013 OrderAccess::fence();
ysr@342 1014 }
ysr@342 1015
johnc@1625 1016 void iterate_dirty_card_closure(CardTableEntryClosure* cl,
johnc@1625 1017 DirtyCardQueue* into_cset_dcq,
johnc@1625 1018 bool concurrent, int worker_i);
ysr@342 1019
ysr@342 1020 // The shared block offset table array.
ysr@342 1021 G1BlockOffsetSharedArray* bot_shared() const { return _bot_shared; }
ysr@342 1022
johnc@2740 1023 // Reference Processing accessors
johnc@2740 1024
johnc@2740 1025 // The STW reference processor....
johnc@2740 1026 ReferenceProcessor* ref_processor_stw() const { return _ref_processor_stw; }
johnc@2740 1027
johnc@2740 1028 // The Concurent Marking reference processor...
johnc@2740 1029 ReferenceProcessor* ref_processor_cm() const { return _ref_processor_cm; }
ysr@342 1030
ysr@342 1031 virtual size_t capacity() const;
ysr@342 1032 virtual size_t used() const;
tonyp@846 1033 // This should be called when we're not holding the heap lock. The
tonyp@846 1034 // result might be a bit inaccurate.
tonyp@846 1035 size_t used_unlocked() const;
ysr@342 1036 size_t recalculate_used() const;
ysr@342 1037
ysr@342 1038 // These virtual functions do the actual allocation.
ysr@342 1039 // Some heaps may offer a contiguous region for shared non-blocking
ysr@342 1040 // allocation, via inlined code (by exporting the address of the top and
ysr@342 1041 // end fields defining the extent of the contiguous allocation region.)
ysr@342 1042 // But G1CollectedHeap doesn't yet support this.
ysr@342 1043
ysr@342 1044 // Return an estimate of the maximum allocation that could be performed
ysr@342 1045 // without triggering any collection or expansion activity. In a
ysr@342 1046 // generational collector, for example, this is probably the largest
ysr@342 1047 // allocation that could be supported (without expansion) in the youngest
ysr@342 1048 // generation. It is "unsafe" because no locks are taken; the result
ysr@342 1049 // should be treated as an approximation, not a guarantee, for use in
ysr@342 1050 // heuristic resizing decisions.
ysr@342 1051 virtual size_t unsafe_max_alloc();
ysr@342 1052
ysr@342 1053 virtual bool is_maximal_no_gc() const {
ysr@342 1054 return _g1_storage.uncommitted_size() == 0;
ysr@342 1055 }
ysr@342 1056
ysr@342 1057 // The total number of regions in the heap.
tonyp@2528 1058 size_t n_regions() { return _hrs.length(); }
tonyp@2528 1059
tonyp@2528 1060 // The max number of regions in the heap.
tonyp@2528 1061 size_t max_regions() { return _hrs.max_length(); }
ysr@342 1062
ysr@342 1063 // The number of regions that are completely free.
tonyp@2528 1064 size_t free_regions() { return _free_list.length(); }
ysr@342 1065
ysr@342 1066 // The number of regions that are not completely free.
ysr@342 1067 size_t used_regions() { return n_regions() - free_regions(); }
ysr@342 1068
ysr@342 1069 // The number of regions available for "regular" expansion.
ysr@342 1070 size_t expansion_regions() { return _expansion_regions; }
ysr@342 1071
tonyp@2528 1072 // Factory method for HeapRegion instances. It will return NULL if
tonyp@2528 1073 // the allocation fails.
tonyp@2528 1074 HeapRegion* new_heap_region(size_t hrs_index, HeapWord* bottom);
tonyp@2528 1075
tonyp@2414 1076 void verify_not_dirty_region(HeapRegion* hr) PRODUCT_RETURN;
tonyp@2414 1077 void verify_dirty_region(HeapRegion* hr) PRODUCT_RETURN;
tonyp@2280 1078 void verify_dirty_young_list(HeapRegion* head) PRODUCT_RETURN;
tonyp@2280 1079 void verify_dirty_young_regions() PRODUCT_RETURN;
tonyp@2280 1080
tonyp@2037 1081 // verify_region_sets() performs verification over the region
tonyp@2037 1082 // lists. It will be compiled in the product code to be used when
tonyp@2037 1083 // necessary (i.e., during heap verification).
tonyp@2037 1084 void verify_region_sets();
ysr@342 1085
tonyp@2037 1086 // verify_region_sets_optional() is planted in the code for
tonyp@2037 1087 // list verification in non-product builds (and it can be enabled in
tonyp@2037 1088 // product builds by definning HEAP_REGION_SET_FORCE_VERIFY to be 1).
tonyp@2037 1089 #if HEAP_REGION_SET_FORCE_VERIFY
tonyp@2037 1090 void verify_region_sets_optional() {
tonyp@2037 1091 verify_region_sets();
tonyp@2037 1092 }
tonyp@2037 1093 #else // HEAP_REGION_SET_FORCE_VERIFY
tonyp@2037 1094 void verify_region_sets_optional() { }
tonyp@2037 1095 #endif // HEAP_REGION_SET_FORCE_VERIFY
ysr@342 1096
tonyp@2037 1097 #ifdef ASSERT
tonyp@2208 1098 bool is_on_master_free_list(HeapRegion* hr) {
tonyp@2037 1099 return hr->containing_set() == &_free_list;
tonyp@2037 1100 }
ysr@342 1101
tonyp@2208 1102 bool is_in_humongous_set(HeapRegion* hr) {
tonyp@2037 1103 return hr->containing_set() == &_humongous_set;
tonyp@2208 1104 }
tonyp@2037 1105 #endif // ASSERT
ysr@342 1106
tonyp@2037 1107 // Wrapper for the region list operations that can be called from
tonyp@2037 1108 // methods outside this class.
ysr@342 1109
tonyp@2037 1110 void secondary_free_list_add_as_tail(FreeRegionList* list) {
tonyp@2037 1111 _secondary_free_list.add_as_tail(list);
tonyp@2037 1112 }
ysr@342 1113
tonyp@2037 1114 void append_secondary_free_list() {
tonyp@2279 1115 _free_list.add_as_head(&_secondary_free_list);
tonyp@2037 1116 }
ysr@342 1117
tonyp@2208 1118 void append_secondary_free_list_if_not_empty_with_lock() {
tonyp@2208 1119 // If the secondary free list looks empty there's no reason to
tonyp@2208 1120 // take the lock and then try to append it.
tonyp@2037 1121 if (!_secondary_free_list.is_empty()) {
tonyp@2037 1122 MutexLockerEx x(SecondaryFreeList_lock, Mutex::_no_safepoint_check_flag);
tonyp@2037 1123 append_secondary_free_list();
tonyp@2037 1124 }
tonyp@2037 1125 }
ysr@342 1126
tonyp@2037 1127 void set_free_regions_coming();
tonyp@2037 1128 void reset_free_regions_coming();
tonyp@2037 1129 bool free_regions_coming() { return _free_regions_coming; }
tonyp@2037 1130 void wait_while_free_regions_coming();
ysr@342 1131
ysr@342 1132 // Perform a collection of the heap; intended for use in implementing
ysr@342 1133 // "System.gc". This probably implies as full a collection as the
ysr@342 1134 // "CollectedHeap" supports.
ysr@342 1135 virtual void collect(GCCause::Cause cause);
ysr@342 1136
ysr@342 1137 // The same as above but assume that the caller holds the Heap_lock.
ysr@342 1138 void collect_locked(GCCause::Cause cause);
ysr@342 1139
ysr@342 1140 // This interface assumes that it's being called by the
ysr@342 1141 // vm thread. It collects the heap assuming that the
ysr@342 1142 // heap lock is already held and that we are executing in
ysr@342 1143 // the context of the vm thread.
ysr@342 1144 virtual void collect_as_vm_thread(GCCause::Cause cause);
ysr@342 1145
ysr@342 1146 // True iff a evacuation has failed in the most-recent collection.
ysr@342 1147 bool evacuation_failed() { return _evacuation_failed; }
ysr@342 1148
tonyp@2037 1149 // It will free a region if it has allocated objects in it that are
tonyp@2037 1150 // all dead. It calls either free_region() or
tonyp@2037 1151 // free_humongous_region() depending on the type of the region that
tonyp@2037 1152 // is passed to it.
tonyp@2058 1153 void free_region_if_empty(HeapRegion* hr,
tonyp@2058 1154 size_t* pre_used,
tonyp@2058 1155 FreeRegionList* free_list,
tonyp@2058 1156 HumongousRegionSet* humongous_proxy_set,
tonyp@2058 1157 HRRSCleanupTask* hrrs_cleanup_task,
tonyp@2058 1158 bool par);
ysr@342 1159
tonyp@2037 1160 // It appends the free list to the master free list and updates the
tonyp@2037 1161 // master humongous list according to the contents of the proxy
tonyp@2037 1162 // list. It also adjusts the total used bytes according to pre_used
tonyp@2037 1163 // (if par is true, it will do so by taking the ParGCRareEvent_lock).
tonyp@2037 1164 void update_sets_after_freeing_regions(size_t pre_used,
tonyp@2037 1165 FreeRegionList* free_list,
tonyp@2037 1166 HumongousRegionSet* humongous_proxy_set,
tonyp@2037 1167 bool par);
ysr@342 1168
ysr@342 1169 // Returns "TRUE" iff "p" points into the allocated area of the heap.
ysr@342 1170 virtual bool is_in(const void* p) const;
ysr@342 1171
ysr@342 1172 // Return "TRUE" iff the given object address is within the collection
ysr@342 1173 // set.
ysr@342 1174 inline bool obj_in_cs(oop obj);
ysr@342 1175
ysr@342 1176 // Return "TRUE" iff the given object address is in the reserved
ysr@342 1177 // region of g1 (excluding the permanent generation).
ysr@342 1178 bool is_in_g1_reserved(const void* p) const {
ysr@342 1179 return _g1_reserved.contains(p);
ysr@342 1180 }
ysr@342 1181
tonyp@2282 1182 // Returns a MemRegion that corresponds to the space that has been
tonyp@2282 1183 // reserved for the heap
tonyp@2282 1184 MemRegion g1_reserved() {
tonyp@2282 1185 return _g1_reserved;
tonyp@2282 1186 }
tonyp@2282 1187
tonyp@2282 1188 // Returns a MemRegion that corresponds to the space that has been
ysr@342 1189 // committed in the heap
ysr@342 1190 MemRegion g1_committed() {
ysr@342 1191 return _g1_committed;
ysr@342 1192 }
ysr@342 1193
johnc@2158 1194 virtual bool is_in_closed_subset(const void* p) const;
ysr@342 1195
ysr@342 1196 // This resets the card table to all zeros. It is used after
ysr@342 1197 // a collection pause which used the card table to claim cards.
ysr@342 1198 void cleanUpCardTable();
ysr@342 1199
ysr@342 1200 // Iteration functions.
ysr@342 1201
ysr@342 1202 // Iterate over all the ref-containing fields of all objects, calling
ysr@342 1203 // "cl.do_oop" on each.
iveresov@678 1204 virtual void oop_iterate(OopClosure* cl) {
iveresov@678 1205 oop_iterate(cl, true);
iveresov@678 1206 }
iveresov@678 1207 void oop_iterate(OopClosure* cl, bool do_perm);
ysr@342 1208
ysr@342 1209 // Same as above, restricted to a memory region.
iveresov@678 1210 virtual void oop_iterate(MemRegion mr, OopClosure* cl) {
iveresov@678 1211 oop_iterate(mr, cl, true);
iveresov@678 1212 }
iveresov@678 1213 void oop_iterate(MemRegion mr, OopClosure* cl, bool do_perm);
ysr@342 1214
ysr@342 1215 // Iterate over all objects, calling "cl.do_object" on each.
iveresov@678 1216 virtual void object_iterate(ObjectClosure* cl) {
iveresov@678 1217 object_iterate(cl, true);
iveresov@678 1218 }
iveresov@678 1219 virtual void safe_object_iterate(ObjectClosure* cl) {
iveresov@678 1220 object_iterate(cl, true);
iveresov@678 1221 }
iveresov@678 1222 void object_iterate(ObjectClosure* cl, bool do_perm);
ysr@342 1223
ysr@342 1224 // Iterate over all objects allocated since the last collection, calling
ysr@342 1225 // "cl.do_object" on each. The heap must have been initialized properly
ysr@342 1226 // to support this function, or else this call will fail.
ysr@342 1227 virtual void object_iterate_since_last_GC(ObjectClosure* cl);
ysr@342 1228
ysr@342 1229 // Iterate over all spaces in use in the heap, in ascending address order.
ysr@342 1230 virtual void space_iterate(SpaceClosure* cl);
ysr@342 1231
ysr@342 1232 // Iterate over heap regions, in address order, terminating the
ysr@342 1233 // iteration early if the "doHeapRegion" method returns "true".
tonyp@2528 1234 void heap_region_iterate(HeapRegionClosure* blk) const;
ysr@342 1235
ysr@342 1236 // Iterate over heap regions starting with r (or the first region if "r"
ysr@342 1237 // is NULL), in address order, terminating early if the "doHeapRegion"
ysr@342 1238 // method returns "true".
tonyp@2528 1239 void heap_region_iterate_from(HeapRegion* r, HeapRegionClosure* blk) const;
ysr@342 1240
tonyp@2528 1241 // Return the region with the given index. It assumes the index is valid.
tonyp@2528 1242 HeapRegion* region_at(size_t index) const { return _hrs.at(index); }
ysr@342 1243
ysr@342 1244 // Divide the heap region sequence into "chunks" of some size (the number
ysr@342 1245 // of regions divided by the number of parallel threads times some
ysr@342 1246 // overpartition factor, currently 4). Assumes that this will be called
ysr@342 1247 // in parallel by ParallelGCThreads worker threads with discinct worker
ysr@342 1248 // ids in the range [0..max(ParallelGCThreads-1, 1)], that all parallel
ysr@342 1249 // calls will use the same "claim_value", and that that claim value is
ysr@342 1250 // different from the claim_value of any heap region before the start of
ysr@342 1251 // the iteration. Applies "blk->doHeapRegion" to each of the regions, by
ysr@342 1252 // attempting to claim the first region in each chunk, and, if
ysr@342 1253 // successful, applying the closure to each region in the chunk (and
ysr@342 1254 // setting the claim value of the second and subsequent regions of the
ysr@342 1255 // chunk.) For now requires that "doHeapRegion" always returns "false",
ysr@342 1256 // i.e., that a closure never attempt to abort a traversal.
ysr@342 1257 void heap_region_par_iterate_chunked(HeapRegionClosure* blk,
ysr@342 1258 int worker,
ysr@342 1259 jint claim_value);
ysr@342 1260
tonyp@390 1261 // It resets all the region claim values to the default.
tonyp@390 1262 void reset_heap_region_claim_values();
tonyp@390 1263
tonyp@355 1264 #ifdef ASSERT
tonyp@355 1265 bool check_heap_region_claim_values(jint claim_value);
tonyp@355 1266 #endif // ASSERT
tonyp@355 1267
ysr@342 1268 // Iterate over the regions (if any) in the current collection set.
ysr@342 1269 void collection_set_iterate(HeapRegionClosure* blk);
ysr@342 1270
ysr@342 1271 // As above but starting from region r
ysr@342 1272 void collection_set_iterate_from(HeapRegion* r, HeapRegionClosure *blk);
ysr@342 1273
ysr@342 1274 // Returns the first (lowest address) compactible space in the heap.
ysr@342 1275 virtual CompactibleSpace* first_compactible_space();
ysr@342 1276
ysr@342 1277 // A CollectedHeap will contain some number of spaces. This finds the
ysr@342 1278 // space containing a given address, or else returns NULL.
ysr@342 1279 virtual Space* space_containing(const void* addr) const;
ysr@342 1280
ysr@342 1281 // A G1CollectedHeap will contain some number of heap regions. This
ysr@342 1282 // finds the region containing a given address, or else returns NULL.
tonyp@2528 1283 template <class T>
tonyp@2528 1284 inline HeapRegion* heap_region_containing(const T addr) const;
ysr@342 1285
ysr@342 1286 // Like the above, but requires "addr" to be in the heap (to avoid a
ysr@342 1287 // null-check), and unlike the above, may return an continuing humongous
ysr@342 1288 // region.
tonyp@2528 1289 template <class T>
tonyp@2528 1290 inline HeapRegion* heap_region_containing_raw(const T addr) const;
ysr@342 1291
ysr@342 1292 // A CollectedHeap is divided into a dense sequence of "blocks"; that is,
ysr@342 1293 // each address in the (reserved) heap is a member of exactly
ysr@342 1294 // one block. The defining characteristic of a block is that it is
ysr@342 1295 // possible to find its size, and thus to progress forward to the next
ysr@342 1296 // block. (Blocks may be of different sizes.) Thus, blocks may
ysr@342 1297 // represent Java objects, or they might be free blocks in a
ysr@342 1298 // free-list-based heap (or subheap), as long as the two kinds are
ysr@342 1299 // distinguishable and the size of each is determinable.
ysr@342 1300
ysr@342 1301 // Returns the address of the start of the "block" that contains the
ysr@342 1302 // address "addr". We say "blocks" instead of "object" since some heaps
ysr@342 1303 // may not pack objects densely; a chunk may either be an object or a
ysr@342 1304 // non-object.
ysr@342 1305 virtual HeapWord* block_start(const void* addr) const;
ysr@342 1306
ysr@342 1307 // Requires "addr" to be the start of a chunk, and returns its size.
ysr@342 1308 // "addr + size" is required to be the start of a new chunk, or the end
ysr@342 1309 // of the active area of the heap.
ysr@342 1310 virtual size_t block_size(const HeapWord* addr) const;
ysr@342 1311
ysr@342 1312 // Requires "addr" to be the start of a block, and returns "TRUE" iff
ysr@342 1313 // the block is an object.
ysr@342 1314 virtual bool block_is_obj(const HeapWord* addr) const;
ysr@342 1315
ysr@342 1316 // Does this heap support heap inspection? (+PrintClassHistogram)
ysr@342 1317 virtual bool supports_heap_inspection() const { return true; }
ysr@342 1318
ysr@342 1319 // Section on thread-local allocation buffers (TLABs)
ysr@342 1320 // See CollectedHeap for semantics.
ysr@342 1321
ysr@342 1322 virtual bool supports_tlab_allocation() const;
ysr@342 1323 virtual size_t tlab_capacity(Thread* thr) const;
ysr@342 1324 virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
ysr@342 1325
ysr@342 1326 // Can a compiler initialize a new object without store barriers?
ysr@342 1327 // This permission only extends from the creation of a new object
ysr@1027 1328 // via a TLAB up to the first subsequent safepoint. If such permission
ysr@1027 1329 // is granted for this heap type, the compiler promises to call
ysr@1027 1330 // defer_store_barrier() below on any slow path allocation of
ysr@1027 1331 // a new object for which such initializing store barriers will
ysr@1027 1332 // have been elided. G1, like CMS, allows this, but should be
ysr@1027 1333 // ready to provide a compensating write barrier as necessary
ysr@1027 1334 // if that storage came out of a non-young region. The efficiency
ysr@1027 1335 // of this implementation depends crucially on being able to
ysr@1027 1336 // answer very efficiently in constant time whether a piece of
ysr@1027 1337 // storage in the heap comes from a young region or not.
ysr@1027 1338 // See ReduceInitialCardMarks.
ysr@342 1339 virtual bool can_elide_tlab_store_barriers() const {
brutisso@2749 1340 return true;
ysr@1027 1341 }
ysr@1027 1342
ysr@1166 1343 virtual bool card_mark_must_follow_store() const {
ysr@1166 1344 return true;
ysr@1166 1345 }
ysr@1166 1346
tonyp@2528 1347 bool is_in_young(const oop obj) {
ysr@1027 1348 HeapRegion* hr = heap_region_containing(obj);
ysr@1027 1349 return hr != NULL && hr->is_young();
ysr@1027 1350 }
ysr@1027 1351
jmasa@2474 1352 #ifdef ASSERT
jmasa@2474 1353 virtual bool is_in_partial_collection(const void* p);
jmasa@2474 1354 #endif
jmasa@2474 1355
jmasa@2474 1356 virtual bool is_scavengable(const void* addr);
jmasa@2474 1357
ysr@1027 1358 // We don't need barriers for initializing stores to objects
ysr@1027 1359 // in the young gen: for the SATB pre-barrier, there is no
ysr@1027 1360 // pre-value that needs to be remembered; for the remembered-set
ysr@1027 1361 // update logging post-barrier, we don't maintain remembered set
brutisso@2630 1362 // information for young gen objects.
ysr@1027 1363 virtual bool can_elide_initializing_store_barrier(oop new_obj) {
ysr@1027 1364 return is_in_young(new_obj);
ysr@342 1365 }
ysr@342 1366
ysr@342 1367 // Can a compiler elide a store barrier when it writes
ysr@342 1368 // a permanent oop into the heap? Applies when the compiler
ysr@342 1369 // is storing x to the heap, where x->is_perm() is true.
ysr@342 1370 virtual bool can_elide_permanent_oop_store_barriers() const {
ysr@342 1371 // At least until perm gen collection is also G1-ified, at
ysr@342 1372 // which point this should return false.
ysr@342 1373 return true;
ysr@342 1374 }
ysr@342 1375
ysr@342 1376 // Returns "true" iff the given word_size is "very large".
ysr@342 1377 static bool isHumongous(size_t word_size) {
johnc@1313 1378 // Note this has to be strictly greater-than as the TLABs
johnc@1313 1379 // are capped at the humongous thresold and we want to
johnc@1313 1380 // ensure that we don't try to allocate a TLAB as
johnc@1313 1381 // humongous and that we don't allocate a humongous
johnc@1313 1382 // object in a TLAB.
johnc@1313 1383 return word_size > _humongous_object_threshold_in_words;
ysr@342 1384 }
ysr@342 1385
ysr@342 1386 // Update mod union table with the set of dirty cards.
ysr@342 1387 void updateModUnion();
ysr@342 1388
ysr@342 1389 // Set the mod union bits corresponding to the given memRegion. Note
ysr@342 1390 // that this is always a safe operation, since it doesn't clear any
ysr@342 1391 // bits.
ysr@342 1392 void markModUnionRange(MemRegion mr);
ysr@342 1393
ysr@342 1394 // Records the fact that a marking phase is no longer in progress.
ysr@342 1395 void set_marking_complete() {
ysr@342 1396 _mark_in_progress = false;
ysr@342 1397 }
ysr@342 1398 void set_marking_started() {
ysr@342 1399 _mark_in_progress = true;
ysr@342 1400 }
ysr@342 1401 bool mark_in_progress() {
ysr@342 1402 return _mark_in_progress;
ysr@342 1403 }
ysr@342 1404
ysr@342 1405 // Print the maximum heap capacity.
ysr@342 1406 virtual size_t max_capacity() const;
ysr@342 1407
ysr@342 1408 virtual jlong millis_since_last_gc();
ysr@342 1409
ysr@342 1410 // Perform any cleanup actions necessary before allowing a verification.
ysr@342 1411 virtual void prepare_for_verify();
ysr@342 1412
ysr@342 1413 // Perform verification.
tonyp@811 1414
johnc@2534 1415 // vo == UsePrevMarking -> use "prev" marking information,
johnc@2534 1416 // vo == UseNextMarking -> use "next" marking information
johnc@2534 1417 // vo == UseMarkWord -> use the mark word in the object header
johnc@2534 1418 //
tonyp@811 1419 // NOTE: Only the "prev" marking information is guaranteed to be
tonyp@811 1420 // consistent most of the time, so most calls to this should use
johnc@2534 1421 // vo == UsePrevMarking.
johnc@2534 1422 // Currently, there is only one case where this is called with
johnc@2534 1423 // vo == UseNextMarking, which is to verify the "next" marking
johnc@2534 1424 // information at the end of remark.
johnc@2534 1425 // Currently there is only one place where this is called with
johnc@2534 1426 // vo == UseMarkWord, which is to verify the marking during a
johnc@2534 1427 // full GC.
johnc@2534 1428 void verify(bool allow_dirty, bool silent, VerifyOption vo);
tonyp@811 1429
tonyp@811 1430 // Override; it uses the "prev" marking information
ysr@342 1431 virtual void verify(bool allow_dirty, bool silent);
tonyp@838 1432 // Default behavior by calling print(tty);
ysr@342 1433 virtual void print() const;
tonyp@838 1434 // This calls print_on(st, PrintHeapAtGCExtended).
ysr@342 1435 virtual void print_on(outputStream* st) const;
tonyp@838 1436 // If extended is true, it will print out information for all
tonyp@838 1437 // regions in the heap by calling print_on_extended(st).
tonyp@838 1438 virtual void print_on(outputStream* st, bool extended) const;
tonyp@838 1439 virtual void print_on_extended(outputStream* st) const;
ysr@342 1440
ysr@342 1441 virtual void print_gc_threads_on(outputStream* st) const;
ysr@342 1442 virtual void gc_threads_do(ThreadClosure* tc) const;
ysr@342 1443
ysr@342 1444 // Override
ysr@342 1445 void print_tracing_info() const;
ysr@342 1446
tonyp@2539 1447 // The following two methods are helpful for debugging RSet issues.
tonyp@2539 1448 void print_cset_rsets() PRODUCT_RETURN;
tonyp@2539 1449 void print_all_rsets() PRODUCT_RETURN;
tonyp@2539 1450
ysr@342 1451 // Convenience function to be used in situations where the heap type can be
ysr@342 1452 // asserted to be this type.
ysr@342 1453 static G1CollectedHeap* heap();
ysr@342 1454
ysr@342 1455 void empty_young_list();
ysr@342 1456
ysr@342 1457 void set_region_short_lived_locked(HeapRegion* hr);
ysr@342 1458 // add appropriate methods for any other surv rate groups
ysr@342 1459
johnc@1394 1460 YoungList* young_list() { return _young_list; }
ysr@342 1461
ysr@342 1462 // debugging
ysr@342 1463 bool check_young_list_well_formed() {
ysr@342 1464 return _young_list->check_list_well_formed();
ysr@342 1465 }
johnc@1394 1466
johnc@1394 1467 bool check_young_list_empty(bool check_heap,
ysr@342 1468 bool check_sample = true);
ysr@342 1469
ysr@342 1470 // *** Stuff related to concurrent marking. It's not clear to me that so
ysr@342 1471 // many of these need to be public.
ysr@342 1472
ysr@342 1473 // The functions below are helper functions that a subclass of
ysr@342 1474 // "CollectedHeap" can use in the implementation of its virtual
ysr@342 1475 // functions.
ysr@342 1476 // This performs a concurrent marking of the live objects in a
ysr@342 1477 // bitmap off to the side.
ysr@342 1478 void doConcurrentMark();
ysr@342 1479
ysr@342 1480 bool isMarkedPrev(oop obj) const;
ysr@342 1481 bool isMarkedNext(oop obj) const;
ysr@342 1482
johnc@2534 1483 // vo == UsePrevMarking -> use "prev" marking information,
johnc@2534 1484 // vo == UseNextMarking -> use "next" marking information,
johnc@2534 1485 // vo == UseMarkWord -> use mark word from object header
tonyp@811 1486 bool is_obj_dead_cond(const oop obj,
tonyp@811 1487 const HeapRegion* hr,
johnc@2534 1488 const VerifyOption vo) const {
johnc@2534 1489
johnc@2534 1490 switch (vo) {
johnc@2534 1491 case VerifyOption_G1UsePrevMarking:
johnc@2534 1492 return is_obj_dead(obj, hr);
johnc@2534 1493 case VerifyOption_G1UseNextMarking:
johnc@2534 1494 return is_obj_ill(obj, hr);
johnc@2534 1495 default:
johnc@2534 1496 assert(vo == VerifyOption_G1UseMarkWord, "must be");
johnc@2534 1497 return !obj->is_gc_marked();
tonyp@811 1498 }
tonyp@811 1499 }
tonyp@811 1500
ysr@342 1501 // Determine if an object is dead, given the object and also
ysr@342 1502 // the region to which the object belongs. An object is dead
ysr@342 1503 // iff a) it was not allocated since the last mark and b) it
ysr@342 1504 // is not marked.
ysr@342 1505
ysr@342 1506 bool is_obj_dead(const oop obj, const HeapRegion* hr) const {
ysr@342 1507 return
ysr@342 1508 !hr->obj_allocated_since_prev_marking(obj) &&
ysr@342 1509 !isMarkedPrev(obj);
ysr@342 1510 }
ysr@342 1511
ysr@342 1512 // This is used when copying an object to survivor space.
ysr@342 1513 // If the object is marked live, then we mark the copy live.
ysr@342 1514 // If the object is allocated since the start of this mark
ysr@342 1515 // cycle, then we mark the copy live.
ysr@342 1516 // If the object has been around since the previous mark
ysr@342 1517 // phase, and hasn't been marked yet during this phase,
ysr@342 1518 // then we don't mark it, we just wait for the
ysr@342 1519 // current marking cycle to get to it.
ysr@342 1520
ysr@342 1521 // This function returns true when an object has been
ysr@342 1522 // around since the previous marking and hasn't yet
ysr@342 1523 // been marked during this marking.
ysr@342 1524
ysr@342 1525 bool is_obj_ill(const oop obj, const HeapRegion* hr) const {
ysr@342 1526 return
ysr@342 1527 !hr->obj_allocated_since_next_marking(obj) &&
ysr@342 1528 !isMarkedNext(obj);
ysr@342 1529 }
ysr@342 1530
ysr@342 1531 // Determine if an object is dead, given only the object itself.
ysr@342 1532 // This will find the region to which the object belongs and
ysr@342 1533 // then call the region version of the same function.
ysr@342 1534
ysr@342 1535 // Added if it is in permanent gen it isn't dead.
ysr@342 1536 // Added if it is NULL it isn't dead.
ysr@342 1537
johnc@2534 1538 // vo == UsePrevMarking -> use "prev" marking information,
johnc@2534 1539 // vo == UseNextMarking -> use "next" marking information,
johnc@2534 1540 // vo == UseMarkWord -> use mark word from object header
tonyp@811 1541 bool is_obj_dead_cond(const oop obj,
johnc@2534 1542 const VerifyOption vo) const {
johnc@2534 1543
johnc@2534 1544 switch (vo) {
johnc@2534 1545 case VerifyOption_G1UsePrevMarking:
johnc@2534 1546 return is_obj_dead(obj);
johnc@2534 1547 case VerifyOption_G1UseNextMarking:
johnc@2534 1548 return is_obj_ill(obj);
johnc@2534 1549 default:
johnc@2534 1550 assert(vo == VerifyOption_G1UseMarkWord, "must be");
johnc@2534 1551 return !obj->is_gc_marked();
tonyp@811 1552 }
tonyp@811 1553 }
tonyp@811 1554
johnc@2534 1555 bool is_obj_dead(const oop obj) const {
tonyp@811 1556 const HeapRegion* hr = heap_region_containing(obj);
ysr@342 1557 if (hr == NULL) {
ysr@342 1558 if (Universe::heap()->is_in_permanent(obj))
ysr@342 1559 return false;
ysr@342 1560 else if (obj == NULL) return false;
ysr@342 1561 else return true;
ysr@342 1562 }
ysr@342 1563 else return is_obj_dead(obj, hr);
ysr@342 1564 }
ysr@342 1565
johnc@2534 1566 bool is_obj_ill(const oop obj) const {
tonyp@811 1567 const HeapRegion* hr = heap_region_containing(obj);
ysr@342 1568 if (hr == NULL) {
ysr@342 1569 if (Universe::heap()->is_in_permanent(obj))
ysr@342 1570 return false;
ysr@342 1571 else if (obj == NULL) return false;
ysr@342 1572 else return true;
ysr@342 1573 }
ysr@342 1574 else return is_obj_ill(obj, hr);
ysr@342 1575 }
ysr@342 1576
ysr@342 1577 // The following is just to alert the verification code
ysr@342 1578 // that a full collection has occurred and that the
ysr@342 1579 // remembered sets are no longer up to date.
ysr@342 1580 bool _full_collection;
ysr@342 1581 void set_full_collection() { _full_collection = true;}
ysr@342 1582 void clear_full_collection() {_full_collection = false;}
ysr@342 1583 bool full_collection() {return _full_collection;}
ysr@342 1584
ysr@342 1585 ConcurrentMark* concurrent_mark() const { return _cm; }
ysr@342 1586 ConcurrentG1Refine* concurrent_g1_refine() const { return _cg1r; }
ysr@342 1587
apetrusenko@796 1588 // The dirty cards region list is used to record a subset of regions
apetrusenko@796 1589 // whose cards need clearing. The list if populated during the
apetrusenko@796 1590 // remembered set scanning and drained during the card table
apetrusenko@796 1591 // cleanup. Although the methods are reentrant, population/draining
apetrusenko@796 1592 // phases must not overlap. For synchronization purposes the last
apetrusenko@796 1593 // element on the list points to itself.
apetrusenko@796 1594 HeapRegion* _dirty_cards_region_list;
apetrusenko@796 1595 void push_dirty_cards_region(HeapRegion* hr);
apetrusenko@796 1596 HeapRegion* pop_dirty_cards_region();
apetrusenko@796 1597
ysr@342 1598 public:
ysr@342 1599 void stop_conc_gc_threads();
ysr@342 1600
ysr@342 1601 // <NEW PREDICTION>
ysr@342 1602
ysr@342 1603 double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
ysr@342 1604 void check_if_region_is_too_expensive(double predicted_time_ms);
ysr@342 1605 size_t pending_card_num();
ysr@342 1606 size_t max_pending_card_num();
ysr@342 1607 size_t cards_scanned();
ysr@342 1608
ysr@342 1609 // </NEW PREDICTION>
ysr@342 1610
ysr@342 1611 protected:
ysr@342 1612 size_t _max_heap_capacity;
ysr@342 1613 };
ysr@342 1614
ysr@845 1615 #define use_local_bitmaps 1
ysr@845 1616 #define verify_local_bitmaps 0
ysr@845 1617 #define oop_buffer_length 256
ysr@845 1618
ysr@845 1619 #ifndef PRODUCT
ysr@845 1620 class GCLabBitMap;
ysr@845 1621 class GCLabBitMapClosure: public BitMapClosure {
ysr@845 1622 private:
ysr@845 1623 ConcurrentMark* _cm;
ysr@845 1624 GCLabBitMap* _bitmap;
ysr@845 1625
ysr@845 1626 public:
ysr@845 1627 GCLabBitMapClosure(ConcurrentMark* cm,
ysr@845 1628 GCLabBitMap* bitmap) {
ysr@845 1629 _cm = cm;
ysr@845 1630 _bitmap = bitmap;
ysr@845 1631 }
ysr@845 1632
ysr@845 1633 virtual bool do_bit(size_t offset);
ysr@845 1634 };
ysr@845 1635 #endif // !PRODUCT
ysr@845 1636
ysr@845 1637 class GCLabBitMap: public BitMap {
ysr@845 1638 private:
ysr@845 1639 ConcurrentMark* _cm;
ysr@845 1640
ysr@845 1641 int _shifter;
ysr@845 1642 size_t _bitmap_word_covers_words;
ysr@845 1643
ysr@845 1644 // beginning of the heap
ysr@845 1645 HeapWord* _heap_start;
ysr@845 1646
ysr@845 1647 // this is the actual start of the GCLab
ysr@845 1648 HeapWord* _real_start_word;
ysr@845 1649
ysr@845 1650 // this is the actual end of the GCLab
ysr@845 1651 HeapWord* _real_end_word;
ysr@845 1652
ysr@845 1653 // this is the first word, possibly located before the actual start
ysr@845 1654 // of the GCLab, that corresponds to the first bit of the bitmap
ysr@845 1655 HeapWord* _start_word;
ysr@845 1656
ysr@845 1657 // size of a GCLab in words
ysr@845 1658 size_t _gclab_word_size;
ysr@845 1659
ysr@845 1660 static int shifter() {
ysr@845 1661 return MinObjAlignment - 1;
ysr@845 1662 }
ysr@845 1663
ysr@845 1664 // how many heap words does a single bitmap word corresponds to?
ysr@845 1665 static size_t bitmap_word_covers_words() {
ysr@845 1666 return BitsPerWord << shifter();
ysr@845 1667 }
ysr@845 1668
apetrusenko@1391 1669 size_t gclab_word_size() const {
apetrusenko@1391 1670 return _gclab_word_size;
ysr@845 1671 }
ysr@845 1672
apetrusenko@1391 1673 // Calculates actual GCLab size in words
apetrusenko@1391 1674 size_t gclab_real_word_size() const {
apetrusenko@1391 1675 return bitmap_size_in_bits(pointer_delta(_real_end_word, _start_word))
apetrusenko@1391 1676 / BitsPerWord;
apetrusenko@1391 1677 }
apetrusenko@1391 1678
apetrusenko@1391 1679 static size_t bitmap_size_in_bits(size_t gclab_word_size) {
apetrusenko@1391 1680 size_t bits_in_bitmap = gclab_word_size >> shifter();
ysr@845 1681 // We are going to ensure that the beginning of a word in this
ysr@845 1682 // bitmap also corresponds to the beginning of a word in the
ysr@845 1683 // global marking bitmap. To handle the case where a GCLab
ysr@845 1684 // starts from the middle of the bitmap, we need to add enough
ysr@845 1685 // space (i.e. up to a bitmap word) to ensure that we have
ysr@845 1686 // enough bits in the bitmap.
ysr@845 1687 return bits_in_bitmap + BitsPerWord - 1;
ysr@845 1688 }
ysr@845 1689 public:
apetrusenko@1391 1690 GCLabBitMap(HeapWord* heap_start, size_t gclab_word_size)
apetrusenko@1391 1691 : BitMap(bitmap_size_in_bits(gclab_word_size)),
ysr@845 1692 _cm(G1CollectedHeap::heap()->concurrent_mark()),
ysr@845 1693 _shifter(shifter()),
ysr@845 1694 _bitmap_word_covers_words(bitmap_word_covers_words()),
ysr@845 1695 _heap_start(heap_start),
apetrusenko@1391 1696 _gclab_word_size(gclab_word_size),
ysr@845 1697 _real_start_word(NULL),
ysr@845 1698 _real_end_word(NULL),
ysr@845 1699 _start_word(NULL)
ysr@845 1700 {
ysr@845 1701 guarantee( size_in_words() >= bitmap_size_in_words(),
ysr@845 1702 "just making sure");
ysr@845 1703 }
ysr@845 1704
ysr@845 1705 inline unsigned heapWordToOffset(HeapWord* addr) {
ysr@845 1706 unsigned offset = (unsigned) pointer_delta(addr, _start_word) >> _shifter;
ysr@845 1707 assert(offset < size(), "offset should be within bounds");
ysr@845 1708 return offset;
ysr@845 1709 }
ysr@845 1710
ysr@845 1711 inline HeapWord* offsetToHeapWord(size_t offset) {
ysr@845 1712 HeapWord* addr = _start_word + (offset << _shifter);
ysr@845 1713 assert(_real_start_word <= addr && addr < _real_end_word, "invariant");
ysr@845 1714 return addr;
ysr@845 1715 }
ysr@845 1716
ysr@845 1717 bool fields_well_formed() {
ysr@845 1718 bool ret1 = (_real_start_word == NULL) &&
ysr@845 1719 (_real_end_word == NULL) &&
ysr@845 1720 (_start_word == NULL);
ysr@845 1721 if (ret1)
ysr@845 1722 return true;
ysr@845 1723
ysr@845 1724 bool ret2 = _real_start_word >= _start_word &&
ysr@845 1725 _start_word < _real_end_word &&
ysr@845 1726 (_real_start_word + _gclab_word_size) == _real_end_word &&
ysr@845 1727 (_start_word + _gclab_word_size + _bitmap_word_covers_words)
ysr@845 1728 > _real_end_word;
ysr@845 1729 return ret2;
ysr@845 1730 }
ysr@845 1731
ysr@845 1732 inline bool mark(HeapWord* addr) {
ysr@845 1733 guarantee(use_local_bitmaps, "invariant");
ysr@845 1734 assert(fields_well_formed(), "invariant");
ysr@845 1735
ysr@845 1736 if (addr >= _real_start_word && addr < _real_end_word) {
ysr@845 1737 assert(!isMarked(addr), "should not have already been marked");
ysr@845 1738
ysr@845 1739 // first mark it on the bitmap
ysr@845 1740 at_put(heapWordToOffset(addr), true);
ysr@845 1741
ysr@845 1742 return true;
ysr@845 1743 } else {
ysr@845 1744 return false;
ysr@845 1745 }
ysr@845 1746 }
ysr@845 1747
ysr@845 1748 inline bool isMarked(HeapWord* addr) {
ysr@845 1749 guarantee(use_local_bitmaps, "invariant");
ysr@845 1750 assert(fields_well_formed(), "invariant");
ysr@845 1751
ysr@845 1752 return at(heapWordToOffset(addr));
ysr@845 1753 }
ysr@845 1754
ysr@845 1755 void set_buffer(HeapWord* start) {
ysr@845 1756 guarantee(use_local_bitmaps, "invariant");
ysr@845 1757 clear();
ysr@845 1758
ysr@845 1759 assert(start != NULL, "invariant");
ysr@845 1760 _real_start_word = start;
ysr@845 1761 _real_end_word = start + _gclab_word_size;
ysr@845 1762
ysr@845 1763 size_t diff =
ysr@845 1764 pointer_delta(start, _heap_start) % _bitmap_word_covers_words;
ysr@845 1765 _start_word = start - diff;
ysr@845 1766
ysr@845 1767 assert(fields_well_formed(), "invariant");
ysr@845 1768 }
ysr@845 1769
ysr@845 1770 #ifndef PRODUCT
ysr@845 1771 void verify() {
ysr@845 1772 // verify that the marks have been propagated
ysr@845 1773 GCLabBitMapClosure cl(_cm, this);
ysr@845 1774 iterate(&cl);
ysr@845 1775 }
ysr@845 1776 #endif // PRODUCT
ysr@845 1777
ysr@845 1778 void retire() {
ysr@845 1779 guarantee(use_local_bitmaps, "invariant");
ysr@845 1780 assert(fields_well_formed(), "invariant");
ysr@845 1781
ysr@845 1782 if (_start_word != NULL) {
ysr@845 1783 CMBitMap* mark_bitmap = _cm->nextMarkBitMap();
ysr@845 1784
ysr@845 1785 // this means that the bitmap was set up for the GCLab
ysr@845 1786 assert(_real_start_word != NULL && _real_end_word != NULL, "invariant");
ysr@845 1787
ysr@845 1788 mark_bitmap->mostly_disjoint_range_union(this,
ysr@845 1789 0, // always start from the start of the bitmap
ysr@845 1790 _start_word,
apetrusenko@1391 1791 gclab_real_word_size());
ysr@845 1792 _cm->grayRegionIfNecessary(MemRegion(_real_start_word, _real_end_word));
ysr@845 1793
ysr@845 1794 #ifndef PRODUCT
ysr@845 1795 if (use_local_bitmaps && verify_local_bitmaps)
ysr@845 1796 verify();
ysr@845 1797 #endif // PRODUCT
ysr@845 1798 } else {
ysr@845 1799 assert(_real_start_word == NULL && _real_end_word == NULL, "invariant");
ysr@845 1800 }
ysr@845 1801 }
ysr@845 1802
apetrusenko@1391 1803 size_t bitmap_size_in_words() const {
apetrusenko@1391 1804 return (bitmap_size_in_bits(gclab_word_size()) + BitsPerWord - 1) / BitsPerWord;
ysr@845 1805 }
apetrusenko@1391 1806
ysr@845 1807 };
ysr@845 1808
ysr@845 1809 class G1ParGCAllocBuffer: public ParGCAllocBuffer {
ysr@845 1810 private:
ysr@845 1811 bool _retired;
johnc@2651 1812 bool _should_mark_objects;
ysr@845 1813 GCLabBitMap _bitmap;
ysr@845 1814
ysr@845 1815 public:
johnc@2651 1816 G1ParGCAllocBuffer(size_t gclab_word_size);
ysr@845 1817
ysr@845 1818 inline bool mark(HeapWord* addr) {
ysr@845 1819 guarantee(use_local_bitmaps, "invariant");
johnc@2651 1820 assert(_should_mark_objects, "invariant");
ysr@845 1821 return _bitmap.mark(addr);
ysr@845 1822 }
ysr@845 1823
ysr@845 1824 inline void set_buf(HeapWord* buf) {
johnc@2651 1825 if (use_local_bitmaps && _should_mark_objects) {
ysr@845 1826 _bitmap.set_buffer(buf);
johnc@2651 1827 }
ysr@845 1828 ParGCAllocBuffer::set_buf(buf);
ysr@845 1829 _retired = false;
ysr@845 1830 }
ysr@845 1831
ysr@845 1832 inline void retire(bool end_of_gc, bool retain) {
ysr@845 1833 if (_retired)
ysr@845 1834 return;
johnc@2651 1835 if (use_local_bitmaps && _should_mark_objects) {
ysr@845 1836 _bitmap.retire();
ysr@845 1837 }
ysr@845 1838 ParGCAllocBuffer::retire(end_of_gc, retain);
ysr@845 1839 _retired = true;
ysr@845 1840 }
ysr@845 1841 };
ysr@845 1842
ysr@845 1843 class G1ParScanThreadState : public StackObj {
ysr@845 1844 protected:
ysr@845 1845 G1CollectedHeap* _g1h;
ysr@845 1846 RefToScanQueue* _refs;
ysr@845 1847 DirtyCardQueue _dcq;
ysr@845 1848 CardTableModRefBS* _ct_bs;
ysr@845 1849 G1RemSet* _g1_rem;
ysr@845 1850
apetrusenko@1391 1851 G1ParGCAllocBuffer _surviving_alloc_buffer;
apetrusenko@1391 1852 G1ParGCAllocBuffer _tenured_alloc_buffer;
apetrusenko@1391 1853 G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
apetrusenko@1391 1854 ageTable _age_table;
ysr@845 1855
ysr@845 1856 size_t _alloc_buffer_waste;
ysr@845 1857 size_t _undo_waste;
ysr@845 1858
ysr@845 1859 OopsInHeapRegionClosure* _evac_failure_cl;
ysr@845 1860 G1ParScanHeapEvacClosure* _evac_cl;
ysr@845 1861 G1ParScanPartialArrayClosure* _partial_scan_cl;
ysr@845 1862
ysr@845 1863 int _hash_seed;
ysr@845 1864 int _queue_num;
ysr@845 1865
tonyp@1531 1866 size_t _term_attempts;
ysr@845 1867
ysr@845 1868 double _start;
ysr@845 1869 double _start_strong_roots;
ysr@845 1870 double _strong_roots_time;
ysr@845 1871 double _start_term;
ysr@845 1872 double _term_time;
ysr@845 1873
ysr@845 1874 // Map from young-age-index (0 == not young, 1 is youngest) to
ysr@845 1875 // surviving words. base is what we get back from the malloc call
ysr@845 1876 size_t* _surviving_young_words_base;
ysr@845 1877 // this points into the array, as we use the first few entries for padding
ysr@845 1878 size_t* _surviving_young_words;
ysr@845 1879
jcoomes@1629 1880 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
ysr@845 1881
ysr@845 1882 void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
ysr@845 1883
ysr@845 1884 void add_to_undo_waste(size_t waste) { _undo_waste += waste; }
ysr@845 1885
ysr@845 1886 DirtyCardQueue& dirty_card_queue() { return _dcq; }
ysr@845 1887 CardTableModRefBS* ctbs() { return _ct_bs; }
ysr@845 1888
ysr@845 1889 template <class T> void immediate_rs_update(HeapRegion* from, T* p, int tid) {
ysr@845 1890 if (!from->is_survivor()) {
ysr@845 1891 _g1_rem->par_write_ref(from, p, tid);
ysr@845 1892 }
ysr@845 1893 }
ysr@845 1894
ysr@845 1895 template <class T> void deferred_rs_update(HeapRegion* from, T* p, int tid) {
ysr@845 1896 // If the new value of the field points to the same region or
ysr@845 1897 // is the to-space, we don't need to include it in the Rset updates.
ysr@845 1898 if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) {
ysr@845 1899 size_t card_index = ctbs()->index_for(p);
ysr@845 1900 // If the card hasn't been added to the buffer, do it.
ysr@845 1901 if (ctbs()->mark_card_deferred(card_index)) {
ysr@845 1902 dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
ysr@845 1903 }
ysr@845 1904 }
ysr@845 1905 }
ysr@845 1906
ysr@845 1907 public:
ysr@845 1908 G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num);
ysr@845 1909
ysr@845 1910 ~G1ParScanThreadState() {
ysr@845 1911 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base);
ysr@845 1912 }
ysr@845 1913
ysr@845 1914 RefToScanQueue* refs() { return _refs; }
ysr@845 1915 ageTable* age_table() { return &_age_table; }
ysr@845 1916
ysr@845 1917 G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
apetrusenko@1391 1918 return _alloc_buffers[purpose];
ysr@845 1919 }
ysr@845 1920
jcoomes@1629 1921 size_t alloc_buffer_waste() const { return _alloc_buffer_waste; }
jcoomes@1629 1922 size_t undo_waste() const { return _undo_waste; }
ysr@845 1923
jcoomes@1782 1924 #ifdef ASSERT
jcoomes@1782 1925 bool verify_ref(narrowOop* ref) const;
jcoomes@1782 1926 bool verify_ref(oop* ref) const;
jcoomes@1782 1927 bool verify_task(StarTask ref) const;
jcoomes@1782 1928 #endif // ASSERT
jcoomes@1782 1929
ysr@845 1930 template <class T> void push_on_queue(T* ref) {
jcoomes@1782 1931 assert(verify_ref(ref), "sanity");
jcoomes@1629 1932 refs()->push(ref);
ysr@845 1933 }
ysr@845 1934
ysr@845 1935 template <class T> void update_rs(HeapRegion* from, T* p, int tid) {
ysr@845 1936 if (G1DeferredRSUpdate) {
ysr@845 1937 deferred_rs_update(from, p, tid);
ysr@845 1938 } else {
ysr@845 1939 immediate_rs_update(from, p, tid);
ysr@845 1940 }
ysr@845 1941 }
ysr@845 1942
ysr@845 1943 HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
ysr@845 1944
ysr@845 1945 HeapWord* obj = NULL;
apetrusenko@1391 1946 size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
apetrusenko@1391 1947 if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
ysr@845 1948 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
apetrusenko@1391 1949 assert(gclab_word_size == alloc_buf->word_sz(),
apetrusenko@1391 1950 "dynamic resizing is not supported");
ysr@845 1951 add_to_alloc_buffer_waste(alloc_buf->words_remaining());
ysr@845 1952 alloc_buf->retire(false, false);
ysr@845 1953
apetrusenko@1391 1954 HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
ysr@845 1955 if (buf == NULL) return NULL; // Let caller handle allocation failure.
ysr@845 1956 // Otherwise.
ysr@845 1957 alloc_buf->set_buf(buf);
ysr@845 1958
ysr@845 1959 obj = alloc_buf->allocate(word_sz);
ysr@845 1960 assert(obj != NULL, "buffer was definitely big enough...");
ysr@845 1961 } else {
ysr@845 1962 obj = _g1h->par_allocate_during_gc(purpose, word_sz);
ysr@845 1963 }
ysr@845 1964 return obj;
ysr@845 1965 }
ysr@845 1966
ysr@845 1967 HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) {
ysr@845 1968 HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
ysr@845 1969 if (obj != NULL) return obj;
ysr@845 1970 return allocate_slow(purpose, word_sz);
ysr@845 1971 }
ysr@845 1972
ysr@845 1973 void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) {
ysr@845 1974 if (alloc_buffer(purpose)->contains(obj)) {
ysr@845 1975 assert(alloc_buffer(purpose)->contains(obj + word_sz - 1),
ysr@845 1976 "should contain whole object");
ysr@845 1977 alloc_buffer(purpose)->undo_allocation(obj, word_sz);
ysr@845 1978 } else {
ysr@845 1979 CollectedHeap::fill_with_object(obj, word_sz);
ysr@845 1980 add_to_undo_waste(word_sz);
ysr@845 1981 }
ysr@845 1982 }
ysr@845 1983
ysr@845 1984 void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) {
ysr@845 1985 _evac_failure_cl = evac_failure_cl;
ysr@845 1986 }
ysr@845 1987 OopsInHeapRegionClosure* evac_failure_closure() {
ysr@845 1988 return _evac_failure_cl;
ysr@845 1989 }
ysr@845 1990
ysr@845 1991 void set_evac_closure(G1ParScanHeapEvacClosure* evac_cl) {
ysr@845 1992 _evac_cl = evac_cl;
ysr@845 1993 }
ysr@845 1994
ysr@845 1995 void set_partial_scan_closure(G1ParScanPartialArrayClosure* partial_scan_cl) {
ysr@845 1996 _partial_scan_cl = partial_scan_cl;
ysr@845 1997 }
ysr@845 1998
ysr@845 1999 int* hash_seed() { return &_hash_seed; }
ysr@845 2000 int queue_num() { return _queue_num; }
ysr@845 2001
jcoomes@1629 2002 size_t term_attempts() const { return _term_attempts; }
tonyp@1531 2003 void note_term_attempt() { _term_attempts++; }
ysr@845 2004
ysr@845 2005 void start_strong_roots() {
ysr@845 2006 _start_strong_roots = os::elapsedTime();
ysr@845 2007 }
ysr@845 2008 void end_strong_roots() {
ysr@845 2009 _strong_roots_time += (os::elapsedTime() - _start_strong_roots);
ysr@845 2010 }
jcoomes@1629 2011 double strong_roots_time() const { return _strong_roots_time; }
ysr@845 2012
ysr@845 2013 void start_term_time() {
ysr@845 2014 note_term_attempt();
ysr@845 2015 _start_term = os::elapsedTime();
ysr@845 2016 }
ysr@845 2017 void end_term_time() {
ysr@845 2018 _term_time += (os::elapsedTime() - _start_term);
ysr@845 2019 }
jcoomes@1629 2020 double term_time() const { return _term_time; }
ysr@845 2021
jcoomes@1629 2022 double elapsed_time() const {
ysr@845 2023 return os::elapsedTime() - _start;
ysr@845 2024 }
ysr@845 2025
jcoomes@1629 2026 static void
jcoomes@1629 2027 print_termination_stats_hdr(outputStream* const st = gclog_or_tty);
jcoomes@1629 2028 void
jcoomes@1629 2029 print_termination_stats(int i, outputStream* const st = gclog_or_tty) const;
jcoomes@1629 2030
ysr@845 2031 size_t* surviving_young_words() {
ysr@845 2032 // We add on to hide entry 0 which accumulates surviving words for
ysr@845 2033 // age -1 regions (i.e. non-young ones)
ysr@845 2034 return _surviving_young_words;
ysr@845 2035 }
ysr@845 2036
ysr@845 2037 void retire_alloc_buffers() {
ysr@845 2038 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
apetrusenko@1391 2039 size_t waste = _alloc_buffers[ap]->words_remaining();
ysr@845 2040 add_to_alloc_buffer_waste(waste);
apetrusenko@1391 2041 _alloc_buffers[ap]->retire(true, false);
ysr@845 2042 }
ysr@845 2043 }
ysr@845 2044
ysr@845 2045 template <class T> void deal_with_reference(T* ref_to_scan) {
ysr@845 2046 if (has_partial_array_mask(ref_to_scan)) {
ysr@845 2047 _partial_scan_cl->do_oop_nv(ref_to_scan);
ysr@845 2048 } else {
ysr@845 2049 // Note: we can use "raw" versions of "region_containing" because
ysr@845 2050 // "obj_to_scan" is definitely in the heap, and is not in a
ysr@845 2051 // humongous region.
ysr@845 2052 HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
ysr@845 2053 _evac_cl->set_region(r);
ysr@845 2054 _evac_cl->do_oop_nv(ref_to_scan);
ysr@845 2055 }
ysr@845 2056 }
ysr@845 2057
jcoomes@1782 2058 void deal_with_reference(StarTask ref) {
jcoomes@1782 2059 assert(verify_task(ref), "sanity");
jcoomes@1782 2060 if (ref.is_narrow()) {
jcoomes@1782 2061 deal_with_reference((narrowOop*)ref);
jcoomes@1782 2062 } else {
jcoomes@1782 2063 deal_with_reference((oop*)ref);
ysr@845 2064 }
ysr@845 2065 }
jcoomes@1782 2066
jcoomes@1782 2067 public:
jcoomes@1782 2068 void trim_queue();
ysr@845 2069 };
stefank@1879 2070
stefank@1879 2071 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP