annotate src/share/vm/gc_implementation/g1/concurrentMark.hpp @ 1398:2a1472c30599

4396719: Mark Sweep stack overflow on deeply nested Object arrays Summary: Use an explicit stack for object arrays and process them in chunks. Reviewed-by: iveresov, apetrusenko
author jcoomes
date Wed, 03 Mar 2010 14:48:26 -0800
parents 6270f80a7331
children 72f725c5a7be
rev   line source
ysr@345 1 /*
xdono@615 2 * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
ysr@345 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@345 4 *
ysr@345 5 * This code is free software; you can redistribute it and/or modify it
ysr@345 6 * under the terms of the GNU General Public License version 2 only, as
ysr@345 7 * published by the Free Software Foundation.
ysr@345 8 *
ysr@345 9 * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@345 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@345 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
ysr@345 12 * version 2 for more details (a copy is included in the LICENSE file that
ysr@345 13 * accompanied this code).
ysr@345 14 *
ysr@345 15 * You should have received a copy of the GNU General Public License version
ysr@345 16 * 2 along with this work; if not, write to the Free Software Foundation,
ysr@345 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@345 18 *
ysr@345 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@345 20 * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@345 21 * have any questions.
ysr@345 22 *
ysr@345 23 */
ysr@345 24
ysr@345 25 class G1CollectedHeap;
ysr@345 26 class CMTask;
jcoomes@1398 27 typedef GenericTaskQueue<oop> CMTaskQueue;
jcoomes@1398 28 typedef GenericTaskQueueSet<CMTaskQueue> CMTaskQueueSet;
ysr@345 29
ysr@345 30 // A generic CM bit map. This is essentially a wrapper around the BitMap
ysr@345 31 // class, with one bit per (1<<_shifter) HeapWords.
ysr@345 32
apetrusenko@581 33 class CMBitMapRO VALUE_OBJ_CLASS_SPEC {
ysr@345 34 protected:
ysr@345 35 HeapWord* _bmStartWord; // base address of range covered by map
ysr@345 36 size_t _bmWordSize; // map size (in #HeapWords covered)
ysr@345 37 const int _shifter; // map to char or bit
ysr@345 38 VirtualSpace _virtual_space; // underlying the bit map
ysr@345 39 BitMap _bm; // the bit map itself
ysr@345 40
ysr@345 41 public:
ysr@345 42 // constructor
ysr@345 43 CMBitMapRO(ReservedSpace rs, int shifter);
ysr@345 44
ysr@345 45 enum { do_yield = true };
ysr@345 46
ysr@345 47 // inquiries
ysr@345 48 HeapWord* startWord() const { return _bmStartWord; }
ysr@345 49 size_t sizeInWords() const { return _bmWordSize; }
ysr@345 50 // the following is one past the last word in space
ysr@345 51 HeapWord* endWord() const { return _bmStartWord + _bmWordSize; }
ysr@345 52
ysr@345 53 // read marks
ysr@345 54
ysr@345 55 bool isMarked(HeapWord* addr) const {
ysr@345 56 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize),
ysr@345 57 "outside underlying space?");
ysr@345 58 return _bm.at(heapWordToOffset(addr));
ysr@345 59 }
ysr@345 60
ysr@345 61 // iteration
ysr@345 62 bool iterate(BitMapClosure* cl) { return _bm.iterate(cl); }
ysr@345 63 bool iterate(BitMapClosure* cl, MemRegion mr);
ysr@345 64
ysr@345 65 // Return the address corresponding to the next marked bit at or after
ysr@345 66 // "addr", and before "limit", if "limit" is non-NULL. If there is no
ysr@345 67 // such bit, returns "limit" if that is non-NULL, or else "endWord()".
ysr@345 68 HeapWord* getNextMarkedWordAddress(HeapWord* addr,
ysr@345 69 HeapWord* limit = NULL) const;
ysr@345 70 // Return the address corresponding to the next unmarked bit at or after
ysr@345 71 // "addr", and before "limit", if "limit" is non-NULL. If there is no
ysr@345 72 // such bit, returns "limit" if that is non-NULL, or else "endWord()".
ysr@345 73 HeapWord* getNextUnmarkedWordAddress(HeapWord* addr,
ysr@345 74 HeapWord* limit = NULL) const;
ysr@345 75
ysr@345 76 // conversion utilities
ysr@345 77 // XXX Fix these so that offsets are size_t's...
ysr@345 78 HeapWord* offsetToHeapWord(size_t offset) const {
ysr@345 79 return _bmStartWord + (offset << _shifter);
ysr@345 80 }
ysr@345 81 size_t heapWordToOffset(HeapWord* addr) const {
ysr@345 82 return pointer_delta(addr, _bmStartWord) >> _shifter;
ysr@345 83 }
ysr@345 84 int heapWordDiffToOffsetDiff(size_t diff) const;
ysr@345 85 HeapWord* nextWord(HeapWord* addr) {
ysr@345 86 return offsetToHeapWord(heapWordToOffset(addr) + 1);
ysr@345 87 }
ysr@345 88
ysr@345 89 void mostly_disjoint_range_union(BitMap* from_bitmap,
ysr@345 90 size_t from_start_index,
ysr@345 91 HeapWord* to_start_word,
ysr@345 92 size_t word_num);
ysr@345 93
ysr@345 94 // debugging
ysr@345 95 NOT_PRODUCT(bool covers(ReservedSpace rs) const;)
ysr@345 96 };
ysr@345 97
ysr@345 98 class CMBitMap : public CMBitMapRO {
ysr@345 99
ysr@345 100 public:
ysr@345 101 // constructor
ysr@345 102 CMBitMap(ReservedSpace rs, int shifter) :
ysr@345 103 CMBitMapRO(rs, shifter) {}
ysr@345 104
ysr@345 105 // write marks
ysr@345 106 void mark(HeapWord* addr) {
ysr@345 107 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize),
ysr@345 108 "outside underlying space?");
ysr@345 109 _bm.at_put(heapWordToOffset(addr), true);
ysr@345 110 }
ysr@345 111 void clear(HeapWord* addr) {
ysr@345 112 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize),
ysr@345 113 "outside underlying space?");
ysr@345 114 _bm.at_put(heapWordToOffset(addr), false);
ysr@345 115 }
ysr@345 116 bool parMark(HeapWord* addr) {
ysr@345 117 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize),
ysr@345 118 "outside underlying space?");
ysr@345 119 return _bm.par_at_put(heapWordToOffset(addr), true);
ysr@345 120 }
ysr@345 121 bool parClear(HeapWord* addr) {
ysr@345 122 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize),
ysr@345 123 "outside underlying space?");
ysr@345 124 return _bm.par_at_put(heapWordToOffset(addr), false);
ysr@345 125 }
ysr@345 126 void markRange(MemRegion mr);
ysr@345 127 void clearAll();
ysr@345 128 void clearRange(MemRegion mr);
ysr@345 129
ysr@345 130 // Starting at the bit corresponding to "addr" (inclusive), find the next
ysr@345 131 // "1" bit, if any. This bit starts some run of consecutive "1"'s; find
ysr@345 132 // the end of this run (stopping at "end_addr"). Return the MemRegion
ysr@345 133 // covering from the start of the region corresponding to the first bit
ysr@345 134 // of the run to the end of the region corresponding to the last bit of
ysr@345 135 // the run. If there is no "1" bit at or after "addr", return an empty
ysr@345 136 // MemRegion.
ysr@345 137 MemRegion getAndClearMarkedRegion(HeapWord* addr, HeapWord* end_addr);
ysr@345 138 };
ysr@345 139
ysr@345 140 // Represents a marking stack used by the CM collector.
ysr@345 141 // Ideally this should be GrowableArray<> just like MSC's marking stack(s).
apetrusenko@581 142 class CMMarkStack VALUE_OBJ_CLASS_SPEC {
ysr@345 143 ConcurrentMark* _cm;
ysr@345 144 oop* _base; // bottom of stack
ysr@345 145 jint _index; // one more than last occupied index
ysr@345 146 jint _capacity; // max #elements
ysr@345 147 jint _oops_do_bound; // Number of elements to include in next iteration.
ysr@345 148 NOT_PRODUCT(jint _max_depth;) // max depth plumbed during run
ysr@345 149
ysr@345 150 bool _overflow;
ysr@345 151 DEBUG_ONLY(bool _drain_in_progress;)
ysr@345 152 DEBUG_ONLY(bool _drain_in_progress_yields;)
ysr@345 153
ysr@345 154 public:
ysr@345 155 CMMarkStack(ConcurrentMark* cm);
ysr@345 156 ~CMMarkStack();
ysr@345 157
ysr@345 158 void allocate(size_t size);
ysr@345 159
ysr@345 160 oop pop() {
ysr@345 161 if (!isEmpty()) {
ysr@345 162 return _base[--_index] ;
ysr@345 163 }
ysr@345 164 return NULL;
ysr@345 165 }
ysr@345 166
ysr@345 167 // If overflow happens, don't do the push, and record the overflow.
ysr@345 168 // *Requires* that "ptr" is already marked.
ysr@345 169 void push(oop ptr) {
ysr@345 170 if (isFull()) {
ysr@345 171 // Record overflow.
ysr@345 172 _overflow = true;
ysr@345 173 return;
ysr@345 174 } else {
ysr@345 175 _base[_index++] = ptr;
ysr@345 176 NOT_PRODUCT(_max_depth = MAX2(_max_depth, _index));
ysr@345 177 }
ysr@345 178 }
ysr@345 179 // Non-block impl. Note: concurrency is allowed only with other
ysr@345 180 // "par_push" operations, not with "pop" or "drain". We would need
ysr@345 181 // parallel versions of them if such concurrency was desired.
ysr@345 182 void par_push(oop ptr);
ysr@345 183
ysr@345 184 // Pushes the first "n" elements of "ptr_arr" on the stack.
ysr@345 185 // Non-block impl. Note: concurrency is allowed only with other
ysr@345 186 // "par_adjoin_arr" or "push" operations, not with "pop" or "drain".
ysr@345 187 void par_adjoin_arr(oop* ptr_arr, int n);
ysr@345 188
ysr@345 189 // Pushes the first "n" elements of "ptr_arr" on the stack.
ysr@345 190 // Locking impl: concurrency is allowed only with
ysr@345 191 // "par_push_arr" and/or "par_pop_arr" operations, which use the same
ysr@345 192 // locking strategy.
ysr@345 193 void par_push_arr(oop* ptr_arr, int n);
ysr@345 194
ysr@345 195 // If returns false, the array was empty. Otherwise, removes up to "max"
ysr@345 196 // elements from the stack, and transfers them to "ptr_arr" in an
ysr@345 197 // unspecified order. The actual number transferred is given in "n" ("n
ysr@345 198 // == 0" is deliberately redundant with the return value.) Locking impl:
ysr@345 199 // concurrency is allowed only with "par_push_arr" and/or "par_pop_arr"
ysr@345 200 // operations, which use the same locking strategy.
ysr@345 201 bool par_pop_arr(oop* ptr_arr, int max, int* n);
ysr@345 202
ysr@345 203 // Drain the mark stack, applying the given closure to all fields of
ysr@345 204 // objects on the stack. (That is, continue until the stack is empty,
ysr@345 205 // even if closure applications add entries to the stack.) The "bm"
ysr@345 206 // argument, if non-null, may be used to verify that only marked objects
ysr@345 207 // are on the mark stack. If "yield_after" is "true", then the
ysr@345 208 // concurrent marker performing the drain offers to yield after
ysr@345 209 // processing each object. If a yield occurs, stops the drain operation
ysr@345 210 // and returns false. Otherwise, returns true.
ysr@345 211 template<class OopClosureClass>
ysr@345 212 bool drain(OopClosureClass* cl, CMBitMap* bm, bool yield_after = false);
ysr@345 213
ysr@345 214 bool isEmpty() { return _index == 0; }
ysr@345 215 bool isFull() { return _index == _capacity; }
ysr@345 216 int maxElems() { return _capacity; }
ysr@345 217
ysr@345 218 bool overflow() { return _overflow; }
ysr@345 219 void clear_overflow() { _overflow = false; }
ysr@345 220
ysr@345 221 int size() { return _index; }
ysr@345 222
ysr@345 223 void setEmpty() { _index = 0; clear_overflow(); }
ysr@345 224
ysr@345 225 // Record the current size; a subsequent "oops_do" will iterate only over
ysr@345 226 // indices valid at the time of this call.
ysr@345 227 void set_oops_do_bound(jint bound = -1) {
ysr@345 228 if (bound == -1) {
ysr@345 229 _oops_do_bound = _index;
ysr@345 230 } else {
ysr@345 231 _oops_do_bound = bound;
ysr@345 232 }
ysr@345 233 }
ysr@345 234 jint oops_do_bound() { return _oops_do_bound; }
ysr@345 235 // iterate over the oops in the mark stack, up to the bound recorded via
ysr@345 236 // the call above.
ysr@345 237 void oops_do(OopClosure* f);
ysr@345 238 };
ysr@345 239
apetrusenko@581 240 class CMRegionStack VALUE_OBJ_CLASS_SPEC {
ysr@345 241 MemRegion* _base;
ysr@345 242 jint _capacity;
ysr@345 243 jint _index;
ysr@345 244 jint _oops_do_bound;
ysr@345 245 bool _overflow;
ysr@345 246 public:
ysr@345 247 CMRegionStack();
ysr@345 248 ~CMRegionStack();
ysr@345 249 void allocate(size_t size);
ysr@345 250
ysr@345 251 // This is lock-free; assumes that it will only be called in parallel
ysr@345 252 // with other "push" operations (no pops).
ysr@345 253 void push(MemRegion mr);
ysr@345 254
ysr@345 255 // Lock-free; assumes that it will only be called in parallel
ysr@345 256 // with other "pop" operations (no pushes).
ysr@345 257 MemRegion pop();
ysr@345 258
ysr@345 259 bool isEmpty() { return _index == 0; }
ysr@345 260 bool isFull() { return _index == _capacity; }
ysr@345 261
ysr@345 262 bool overflow() { return _overflow; }
ysr@345 263 void clear_overflow() { _overflow = false; }
ysr@345 264
ysr@345 265 int size() { return _index; }
ysr@345 266
ysr@345 267 // It iterates over the entries in the region stack and it
ysr@345 268 // invalidates (i.e. assigns MemRegion()) the ones that point to
ysr@345 269 // regions in the collection set.
ysr@345 270 bool invalidate_entries_into_cset();
ysr@345 271
ysr@345 272 // This gives an upper bound up to which the iteration in
ysr@345 273 // invalidate_entries_into_cset() will reach. This prevents
ysr@345 274 // newly-added entries to be unnecessarily scanned.
ysr@345 275 void set_oops_do_bound() {
ysr@345 276 _oops_do_bound = _index;
ysr@345 277 }
ysr@345 278
ysr@345 279 void setEmpty() { _index = 0; clear_overflow(); }
ysr@345 280 };
ysr@345 281
ysr@345 282 // this will enable a variety of different statistics per GC task
ysr@345 283 #define _MARKING_STATS_ 0
ysr@345 284 // this will enable the higher verbose levels
ysr@345 285 #define _MARKING_VERBOSE_ 0
ysr@345 286
ysr@345 287 #if _MARKING_STATS_
ysr@345 288 #define statsOnly(statement) \
ysr@345 289 do { \
ysr@345 290 statement ; \
ysr@345 291 } while (0)
ysr@345 292 #else // _MARKING_STATS_
ysr@345 293 #define statsOnly(statement) \
ysr@345 294 do { \
ysr@345 295 } while (0)
ysr@345 296 #endif // _MARKING_STATS_
ysr@345 297
ysr@345 298 typedef enum {
ysr@345 299 no_verbose = 0, // verbose turned off
ysr@345 300 stats_verbose, // only prints stats at the end of marking
ysr@345 301 low_verbose, // low verbose, mostly per region and per major event
ysr@345 302 medium_verbose, // a bit more detailed than low
ysr@345 303 high_verbose // per object verbose
ysr@345 304 } CMVerboseLevel;
ysr@345 305
ysr@345 306
ysr@345 307 class ConcurrentMarkThread;
ysr@345 308
apetrusenko@581 309 class ConcurrentMark: public CHeapObj {
ysr@345 310 friend class ConcurrentMarkThread;
ysr@345 311 friend class CMTask;
ysr@345 312 friend class CMBitMapClosure;
ysr@345 313 friend class CSMarkOopClosure;
ysr@345 314 friend class CMGlobalObjectClosure;
ysr@345 315 friend class CMRemarkTask;
ysr@345 316 friend class CMConcurrentMarkingTask;
ysr@345 317 friend class G1ParNoteEndTask;
ysr@345 318 friend class CalcLiveObjectsClosure;
ysr@345 319
ysr@345 320 protected:
ysr@345 321 ConcurrentMarkThread* _cmThread; // the thread doing the work
ysr@345 322 G1CollectedHeap* _g1h; // the heap.
ysr@345 323 size_t _parallel_marking_threads; // the number of marking
ysr@345 324 // threads we'll use
ysr@345 325 double _sleep_factor; // how much we have to sleep, with
ysr@345 326 // respect to the work we just did, to
ysr@345 327 // meet the marking overhead goal
ysr@345 328 double _marking_task_overhead; // marking target overhead for
ysr@345 329 // a single task
ysr@345 330
ysr@345 331 // same as the two above, but for the cleanup task
ysr@345 332 double _cleanup_sleep_factor;
ysr@345 333 double _cleanup_task_overhead;
ysr@345 334
ysr@345 335 // Stuff related to age cohort processing.
ysr@345 336 struct ParCleanupThreadState {
ysr@345 337 char _pre[64];
ysr@345 338 UncleanRegionList list;
ysr@345 339 char _post[64];
ysr@345 340 };
ysr@345 341 ParCleanupThreadState** _par_cleanup_thread_state;
ysr@345 342
ysr@345 343 // CMS marking support structures
ysr@345 344 CMBitMap _markBitMap1;
ysr@345 345 CMBitMap _markBitMap2;
ysr@345 346 CMBitMapRO* _prevMarkBitMap; // completed mark bitmap
ysr@345 347 CMBitMap* _nextMarkBitMap; // under-construction mark bitmap
ysr@345 348 bool _at_least_one_mark_complete;
ysr@345 349
ysr@345 350 BitMap _region_bm;
ysr@345 351 BitMap _card_bm;
ysr@345 352
ysr@345 353 // Heap bounds
ysr@345 354 HeapWord* _heap_start;
ysr@345 355 HeapWord* _heap_end;
ysr@345 356
ysr@345 357 // For gray objects
ysr@345 358 CMMarkStack _markStack; // Grey objects behind global finger.
ysr@345 359 CMRegionStack _regionStack; // Grey regions behind global finger.
ysr@345 360 HeapWord* volatile _finger; // the global finger, region aligned,
ysr@345 361 // always points to the end of the
ysr@345 362 // last claimed region
ysr@345 363
ysr@345 364 // marking tasks
ysr@345 365 size_t _max_task_num; // maximum task number
ysr@345 366 size_t _active_tasks; // task num currently active
ysr@345 367 CMTask** _tasks; // task queue array (max_task_num len)
ysr@345 368 CMTaskQueueSet* _task_queues; // task queue set
ysr@345 369 ParallelTaskTerminator _terminator; // for termination
ysr@345 370
ysr@345 371 // Two sync barriers that are used to synchronise tasks when an
ysr@345 372 // overflow occurs. The algorithm is the following. All tasks enter
ysr@345 373 // the first one to ensure that they have all stopped manipulating
ysr@345 374 // the global data structures. After they exit it, they re-initialise
ysr@345 375 // their data structures and task 0 re-initialises the global data
ysr@345 376 // structures. Then, they enter the second sync barrier. This
ysr@345 377 // ensure, that no task starts doing work before all data
ysr@345 378 // structures (local and global) have been re-initialised. When they
ysr@345 379 // exit it, they are free to start working again.
ysr@345 380 WorkGangBarrierSync _first_overflow_barrier_sync;
ysr@345 381 WorkGangBarrierSync _second_overflow_barrier_sync;
ysr@345 382
ysr@345 383
ysr@345 384 // this is set by any task, when an overflow on the global data
ysr@345 385 // structures is detected.
ysr@345 386 volatile bool _has_overflown;
ysr@345 387 // true: marking is concurrent, false: we're in remark
ysr@345 388 volatile bool _concurrent;
ysr@345 389 // set at the end of a Full GC so that marking aborts
ysr@345 390 volatile bool _has_aborted;
ysr@345 391 // used when remark aborts due to an overflow to indicate that
ysr@345 392 // another concurrent marking phase should start
ysr@345 393 volatile bool _restart_for_overflow;
ysr@345 394
ysr@345 395 // This is true from the very start of concurrent marking until the
ysr@345 396 // point when all the tasks complete their work. It is really used
ysr@345 397 // to determine the points between the end of concurrent marking and
ysr@345 398 // time of remark.
ysr@345 399 volatile bool _concurrent_marking_in_progress;
ysr@345 400
ysr@345 401 // verbose level
ysr@345 402 CMVerboseLevel _verbose_level;
ysr@345 403
ysr@345 404 // These two fields are used to implement the optimisation that
ysr@345 405 // avoids pushing objects on the global/region stack if there are
ysr@345 406 // no collection set regions above the lowest finger.
ysr@345 407
ysr@345 408 // This is the lowest finger (among the global and local fingers),
ysr@345 409 // which is calculated before a new collection set is chosen.
ysr@345 410 HeapWord* _min_finger;
ysr@345 411 // If this flag is true, objects/regions that are marked below the
ysr@345 412 // finger should be pushed on the stack(s). If this is flag is
ysr@345 413 // false, it is safe not to push them on the stack(s).
ysr@345 414 bool _should_gray_objects;
ysr@345 415
ysr@345 416 // All of these times are in ms.
ysr@345 417 NumberSeq _init_times;
ysr@345 418 NumberSeq _remark_times;
ysr@345 419 NumberSeq _remark_mark_times;
ysr@345 420 NumberSeq _remark_weak_ref_times;
ysr@345 421 NumberSeq _cleanup_times;
ysr@345 422 double _total_counting_time;
ysr@345 423 double _total_rs_scrub_time;
ysr@345 424
ysr@345 425 double* _accum_task_vtime; // accumulated task vtime
ysr@345 426
ysr@345 427 WorkGang* _parallel_workers;
ysr@345 428
ysr@345 429 void weakRefsWork(bool clear_all_soft_refs);
ysr@345 430
ysr@345 431 void swapMarkBitMaps();
ysr@345 432
ysr@345 433 // It resets the global marking data structures, as well as the
ysr@345 434 // task local ones; should be called during initial mark.
ysr@345 435 void reset();
ysr@345 436 // It resets all the marking data structures.
ysr@345 437 void clear_marking_state();
ysr@345 438
ysr@345 439 // It should be called to indicate which phase we're in (concurrent
ysr@345 440 // mark or remark) and how many threads are currently active.
ysr@345 441 void set_phase(size_t active_tasks, bool concurrent);
ysr@345 442 // We do this after we're done with marking so that the marking data
ysr@345 443 // structures are initialised to a sensible and predictable state.
ysr@345 444 void set_non_marking_state();
ysr@345 445
ysr@345 446 // prints all gathered CM-related statistics
ysr@345 447 void print_stats();
ysr@345 448
ysr@345 449 // accessor methods
ysr@345 450 size_t parallel_marking_threads() { return _parallel_marking_threads; }
ysr@345 451 double sleep_factor() { return _sleep_factor; }
ysr@345 452 double marking_task_overhead() { return _marking_task_overhead;}
ysr@345 453 double cleanup_sleep_factor() { return _cleanup_sleep_factor; }
ysr@345 454 double cleanup_task_overhead() { return _cleanup_task_overhead;}
ysr@345 455
ysr@345 456 HeapWord* finger() { return _finger; }
ysr@345 457 bool concurrent() { return _concurrent; }
ysr@345 458 size_t active_tasks() { return _active_tasks; }
ysr@345 459 ParallelTaskTerminator* terminator() { return &_terminator; }
ysr@345 460
ysr@345 461 // It claims the next available region to be scanned by a marking
ysr@345 462 // task. It might return NULL if the next region is empty or we have
ysr@345 463 // run out of regions. In the latter case, out_of_regions()
ysr@345 464 // determines whether we've really run out of regions or the task
ysr@345 465 // should call claim_region() again. This might seem a bit
ysr@345 466 // awkward. Originally, the code was written so that claim_region()
ysr@345 467 // either successfully returned with a non-empty region or there
ysr@345 468 // were no more regions to be claimed. The problem with this was
ysr@345 469 // that, in certain circumstances, it iterated over large chunks of
ysr@345 470 // the heap finding only empty regions and, while it was working, it
ysr@345 471 // was preventing the calling task to call its regular clock
ysr@345 472 // method. So, this way, each task will spend very little time in
ysr@345 473 // claim_region() and is allowed to call the regular clock method
ysr@345 474 // frequently.
ysr@345 475 HeapRegion* claim_region(int task);
ysr@345 476
ysr@345 477 // It determines whether we've run out of regions to scan.
ysr@345 478 bool out_of_regions() { return _finger == _heap_end; }
ysr@345 479
ysr@345 480 // Returns the task with the given id
ysr@345 481 CMTask* task(int id) {
tonyp@1082 482 assert(0 <= id && id < (int) _active_tasks,
tonyp@1082 483 "task id not within active bounds");
ysr@345 484 return _tasks[id];
ysr@345 485 }
ysr@345 486
ysr@345 487 // Returns the task queue with the given id
ysr@345 488 CMTaskQueue* task_queue(int id) {
tonyp@1082 489 assert(0 <= id && id < (int) _active_tasks,
tonyp@1082 490 "task queue id not within active bounds");
ysr@345 491 return (CMTaskQueue*) _task_queues->queue(id);
ysr@345 492 }
ysr@345 493
ysr@345 494 // Returns the task queue set
ysr@345 495 CMTaskQueueSet* task_queues() { return _task_queues; }
ysr@345 496
ysr@345 497 // Access / manipulation of the overflow flag which is set to
ysr@345 498 // indicate that the global stack or region stack has overflown
ysr@345 499 bool has_overflown() { return _has_overflown; }
ysr@345 500 void set_has_overflown() { _has_overflown = true; }
ysr@345 501 void clear_has_overflown() { _has_overflown = false; }
ysr@345 502
ysr@345 503 bool has_aborted() { return _has_aborted; }
ysr@345 504 bool restart_for_overflow() { return _restart_for_overflow; }
ysr@345 505
ysr@345 506 // Methods to enter the two overflow sync barriers
ysr@345 507 void enter_first_sync_barrier(int task_num);
ysr@345 508 void enter_second_sync_barrier(int task_num);
ysr@345 509
ysr@345 510 public:
ysr@345 511 // Manipulation of the global mark stack.
ysr@345 512 // Notice that the first mark_stack_push is CAS-based, whereas the
ysr@345 513 // two below are Mutex-based. This is OK since the first one is only
ysr@345 514 // called during evacuation pauses and doesn't compete with the
ysr@345 515 // other two (which are called by the marking tasks during
ysr@345 516 // concurrent marking or remark).
ysr@345 517 bool mark_stack_push(oop p) {
ysr@345 518 _markStack.par_push(p);
ysr@345 519 if (_markStack.overflow()) {
ysr@345 520 set_has_overflown();
ysr@345 521 return false;
ysr@345 522 }
ysr@345 523 return true;
ysr@345 524 }
ysr@345 525 bool mark_stack_push(oop* arr, int n) {
ysr@345 526 _markStack.par_push_arr(arr, n);
ysr@345 527 if (_markStack.overflow()) {
ysr@345 528 set_has_overflown();
ysr@345 529 return false;
ysr@345 530 }
ysr@345 531 return true;
ysr@345 532 }
ysr@345 533 void mark_stack_pop(oop* arr, int max, int* n) {
ysr@345 534 _markStack.par_pop_arr(arr, max, n);
ysr@345 535 }
ysr@345 536 size_t mark_stack_size() { return _markStack.size(); }
ysr@345 537 size_t partial_mark_stack_size_target() { return _markStack.maxElems()/3; }
ysr@345 538 bool mark_stack_overflow() { return _markStack.overflow(); }
ysr@345 539 bool mark_stack_empty() { return _markStack.isEmpty(); }
ysr@345 540
ysr@345 541 // Manipulation of the region stack
ysr@345 542 bool region_stack_push(MemRegion mr) {
ysr@345 543 _regionStack.push(mr);
ysr@345 544 if (_regionStack.overflow()) {
ysr@345 545 set_has_overflown();
ysr@345 546 return false;
ysr@345 547 }
ysr@345 548 return true;
ysr@345 549 }
ysr@345 550 MemRegion region_stack_pop() { return _regionStack.pop(); }
ysr@345 551 int region_stack_size() { return _regionStack.size(); }
ysr@345 552 bool region_stack_overflow() { return _regionStack.overflow(); }
ysr@345 553 bool region_stack_empty() { return _regionStack.isEmpty(); }
ysr@345 554
ysr@345 555 bool concurrent_marking_in_progress() {
ysr@345 556 return _concurrent_marking_in_progress;
ysr@345 557 }
ysr@345 558 void set_concurrent_marking_in_progress() {
ysr@345 559 _concurrent_marking_in_progress = true;
ysr@345 560 }
ysr@345 561 void clear_concurrent_marking_in_progress() {
ysr@345 562 _concurrent_marking_in_progress = false;
ysr@345 563 }
ysr@345 564
ysr@345 565 void update_accum_task_vtime(int i, double vtime) {
ysr@345 566 _accum_task_vtime[i] += vtime;
ysr@345 567 }
ysr@345 568
ysr@345 569 double all_task_accum_vtime() {
ysr@345 570 double ret = 0.0;
ysr@345 571 for (int i = 0; i < (int)_max_task_num; ++i)
ysr@345 572 ret += _accum_task_vtime[i];
ysr@345 573 return ret;
ysr@345 574 }
ysr@345 575
ysr@345 576 // Attempts to steal an object from the task queues of other tasks
ysr@345 577 bool try_stealing(int task_num, int* hash_seed, oop& obj) {
ysr@345 578 return _task_queues->steal(task_num, hash_seed, obj);
ysr@345 579 }
ysr@345 580
ysr@345 581 // It grays an object by first marking it. Then, if it's behind the
ysr@345 582 // global finger, it also pushes it on the global stack.
ysr@345 583 void deal_with_reference(oop obj);
ysr@345 584
ysr@345 585 ConcurrentMark(ReservedSpace rs, int max_regions);
ysr@345 586 ~ConcurrentMark();
ysr@345 587 ConcurrentMarkThread* cmThread() { return _cmThread; }
ysr@345 588
ysr@345 589 CMBitMapRO* prevMarkBitMap() const { return _prevMarkBitMap; }
ysr@345 590 CMBitMap* nextMarkBitMap() const { return _nextMarkBitMap; }
ysr@345 591
ysr@345 592 // The following three are interaction between CM and
ysr@345 593 // G1CollectedHeap
ysr@345 594
ysr@345 595 // This notifies CM that a root during initial-mark needs to be
ysr@345 596 // grayed and it's MT-safe. Currently, we just mark it. But, in the
ysr@345 597 // future, we can experiment with pushing it on the stack and we can
ysr@345 598 // do this without changing G1CollectedHeap.
ysr@345 599 void grayRoot(oop p);
ysr@345 600 // It's used during evacuation pauses to gray a region, if
ysr@345 601 // necessary, and it's MT-safe. It assumes that the caller has
ysr@345 602 // marked any objects on that region. If _should_gray_objects is
ysr@345 603 // true and we're still doing concurrent marking, the region is
ysr@345 604 // pushed on the region stack, if it is located below the global
ysr@345 605 // finger, otherwise we do nothing.
ysr@345 606 void grayRegionIfNecessary(MemRegion mr);
ysr@345 607 // It's used during evacuation pauses to mark and, if necessary,
ysr@345 608 // gray a single object and it's MT-safe. It assumes the caller did
ysr@345 609 // not mark the object. If _should_gray_objects is true and we're
ysr@345 610 // still doing concurrent marking, the objects is pushed on the
ysr@345 611 // global stack, if it is located below the global finger, otherwise
ysr@345 612 // we do nothing.
ysr@345 613 void markAndGrayObjectIfNecessary(oop p);
ysr@345 614
tonyp@1106 615 // This iterates over the marking bitmap (either prev or next) and
tonyp@1106 616 // prints out all objects that are marked on the bitmap and indicates
tonyp@1106 617 // whether what they point to is also marked or not. It also iterates
tonyp@1106 618 // the objects over TAMS (either prev or next).
tonyp@1106 619 void print_reachable(bool use_prev_marking, const char* str);
ysr@345 620
ysr@345 621 // Clear the next marking bitmap (will be called concurrently).
ysr@345 622 void clearNextBitmap();
ysr@345 623
ysr@345 624 // main CMS steps and related support
ysr@345 625 void checkpointRootsInitial();
ysr@345 626
ysr@345 627 // These two do the work that needs to be done before and after the
ysr@345 628 // initial root checkpoint. Since this checkpoint can be done at two
ysr@345 629 // different points (i.e. an explicit pause or piggy-backed on a
ysr@345 630 // young collection), then it's nice to be able to easily share the
ysr@345 631 // pre/post code. It might be the case that we can put everything in
ysr@345 632 // the post method. TP
ysr@345 633 void checkpointRootsInitialPre();
ysr@345 634 void checkpointRootsInitialPost();
ysr@345 635
ysr@345 636 // Do concurrent phase of marking, to a tentative transitive closure.
ysr@345 637 void markFromRoots();
ysr@345 638
ysr@345 639 // Process all unprocessed SATB buffers. It is called at the
ysr@345 640 // beginning of an evacuation pause.
ysr@345 641 void drainAllSATBBuffers();
ysr@345 642
ysr@345 643 void checkpointRootsFinal(bool clear_all_soft_refs);
ysr@345 644 void checkpointRootsFinalWork();
ysr@345 645 void calcDesiredRegions();
ysr@345 646 void cleanup();
ysr@345 647 void completeCleanup();
ysr@345 648
ysr@345 649 // Mark in the previous bitmap. NB: this is usually read-only, so use
ysr@345 650 // this carefully!
ysr@345 651 void markPrev(oop p);
ysr@345 652 void clear(oop p);
ysr@345 653 // Clears marks for all objects in the given range, for both prev and
ysr@345 654 // next bitmaps. NB: the previous bitmap is usually read-only, so use
ysr@345 655 // this carefully!
ysr@345 656 void clearRangeBothMaps(MemRegion mr);
ysr@345 657
ysr@345 658 // Record the current top of the mark and region stacks; a
ysr@345 659 // subsequent oops_do() on the mark stack and
ysr@345 660 // invalidate_entries_into_cset() on the region stack will iterate
ysr@345 661 // only over indices valid at the time of this call.
ysr@345 662 void set_oops_do_bound() {
ysr@345 663 _markStack.set_oops_do_bound();
ysr@345 664 _regionStack.set_oops_do_bound();
ysr@345 665 }
ysr@345 666 // Iterate over the oops in the mark stack and all local queues. It
ysr@345 667 // also calls invalidate_entries_into_cset() on the region stack.
ysr@345 668 void oops_do(OopClosure* f);
ysr@345 669 // It is called at the end of an evacuation pause during marking so
ysr@345 670 // that CM is notified of where the new end of the heap is. It
ysr@345 671 // doesn't do anything if concurrent_marking_in_progress() is false,
ysr@345 672 // unless the force parameter is true.
ysr@345 673 void update_g1_committed(bool force = false);
ysr@345 674
ysr@345 675 void complete_marking_in_collection_set();
ysr@345 676
ysr@345 677 // It indicates that a new collection set is being chosen.
ysr@345 678 void newCSet();
ysr@345 679 // It registers a collection set heap region with CM. This is used
ysr@345 680 // to determine whether any heap regions are located above the finger.
ysr@345 681 void registerCSetRegion(HeapRegion* hr);
ysr@345 682
ysr@345 683 // Returns "true" if at least one mark has been completed.
ysr@345 684 bool at_least_one_mark_complete() { return _at_least_one_mark_complete; }
ysr@345 685
ysr@345 686 bool isMarked(oop p) const {
ysr@345 687 assert(p != NULL && p->is_oop(), "expected an oop");
ysr@345 688 HeapWord* addr = (HeapWord*)p;
ysr@345 689 assert(addr >= _nextMarkBitMap->startWord() ||
ysr@345 690 addr < _nextMarkBitMap->endWord(), "in a region");
ysr@345 691
ysr@345 692 return _nextMarkBitMap->isMarked(addr);
ysr@345 693 }
ysr@345 694
ysr@345 695 inline bool not_yet_marked(oop p) const;
ysr@345 696
ysr@345 697 // XXX Debug code
ysr@345 698 bool containing_card_is_marked(void* p);
ysr@345 699 bool containing_cards_are_marked(void* start, void* last);
ysr@345 700
ysr@345 701 bool isPrevMarked(oop p) const {
ysr@345 702 assert(p != NULL && p->is_oop(), "expected an oop");
ysr@345 703 HeapWord* addr = (HeapWord*)p;
ysr@345 704 assert(addr >= _prevMarkBitMap->startWord() ||
ysr@345 705 addr < _prevMarkBitMap->endWord(), "in a region");
ysr@345 706
ysr@345 707 return _prevMarkBitMap->isMarked(addr);
ysr@345 708 }
ysr@345 709
ysr@345 710 inline bool do_yield_check(int worker_i = 0);
ysr@345 711 inline bool should_yield();
ysr@345 712
ysr@345 713 // Called to abort the marking cycle after a Full GC takes palce.
ysr@345 714 void abort();
ysr@345 715
ysr@345 716 // This prints the global/local fingers. It is used for debugging.
ysr@345 717 NOT_PRODUCT(void print_finger();)
ysr@345 718
ysr@345 719 void print_summary_info();
ysr@345 720
tonyp@1078 721 void print_worker_threads_on(outputStream* st) const;
tonyp@1078 722
ysr@345 723 // The following indicate whether a given verbose level has been
ysr@345 724 // set. Notice that anything above stats is conditional to
ysr@345 725 // _MARKING_VERBOSE_ having been set to 1
ysr@345 726 bool verbose_stats()
ysr@345 727 { return _verbose_level >= stats_verbose; }
ysr@345 728 bool verbose_low()
ysr@345 729 { return _MARKING_VERBOSE_ && _verbose_level >= low_verbose; }
ysr@345 730 bool verbose_medium()
ysr@345 731 { return _MARKING_VERBOSE_ && _verbose_level >= medium_verbose; }
ysr@345 732 bool verbose_high()
ysr@345 733 { return _MARKING_VERBOSE_ && _verbose_level >= high_verbose; }
ysr@345 734 };
ysr@345 735
ysr@345 736 // A class representing a marking task.
ysr@345 737 class CMTask : public TerminatorTerminator {
ysr@345 738 private:
ysr@345 739 enum PrivateConstants {
ysr@345 740 // the regular clock call is called once the scanned words reaches
ysr@345 741 // this limit
ysr@345 742 words_scanned_period = 12*1024,
ysr@345 743 // the regular clock call is called once the number of visited
ysr@345 744 // references reaches this limit
ysr@345 745 refs_reached_period = 384,
ysr@345 746 // initial value for the hash seed, used in the work stealing code
ysr@345 747 init_hash_seed = 17,
ysr@345 748 // how many entries will be transferred between global stack and
ysr@345 749 // local queues
ysr@345 750 global_stack_transfer_size = 16
ysr@345 751 };
ysr@345 752
ysr@345 753 int _task_id;
ysr@345 754 G1CollectedHeap* _g1h;
ysr@345 755 ConcurrentMark* _cm;
ysr@345 756 CMBitMap* _nextMarkBitMap;
ysr@345 757 // the task queue of this task
ysr@345 758 CMTaskQueue* _task_queue;
ysr@896 759 private:
ysr@345 760 // the task queue set---needed for stealing
ysr@345 761 CMTaskQueueSet* _task_queues;
ysr@345 762 // indicates whether the task has been claimed---this is only for
ysr@345 763 // debugging purposes
ysr@345 764 bool _claimed;
ysr@345 765
ysr@345 766 // number of calls to this task
ysr@345 767 int _calls;
ysr@345 768
ysr@345 769 // when the virtual timer reaches this time, the marking step should
ysr@345 770 // exit
ysr@345 771 double _time_target_ms;
ysr@345 772 // the start time of the current marking step
ysr@345 773 double _start_time_ms;
ysr@345 774
ysr@345 775 // the oop closure used for iterations over oops
ysr@345 776 OopClosure* _oop_closure;
ysr@345 777
ysr@345 778 // the region this task is scanning, NULL if we're not scanning any
ysr@345 779 HeapRegion* _curr_region;
ysr@345 780 // the local finger of this task, NULL if we're not scanning a region
ysr@345 781 HeapWord* _finger;
ysr@345 782 // limit of the region this task is scanning, NULL if we're not scanning one
ysr@345 783 HeapWord* _region_limit;
ysr@345 784
ysr@345 785 // This is used only when we scan regions popped from the region
ysr@345 786 // stack. It records what the last object on such a region we
ysr@345 787 // scanned was. It is used to ensure that, if we abort region
ysr@345 788 // iteration, we do not rescan the first part of the region. This
ysr@345 789 // should be NULL when we're not scanning a region from the region
ysr@345 790 // stack.
ysr@345 791 HeapWord* _region_finger;
ysr@345 792
ysr@345 793 // the number of words this task has scanned
ysr@345 794 size_t _words_scanned;
ysr@345 795 // When _words_scanned reaches this limit, the regular clock is
ysr@345 796 // called. Notice that this might be decreased under certain
ysr@345 797 // circumstances (i.e. when we believe that we did an expensive
ysr@345 798 // operation).
ysr@345 799 size_t _words_scanned_limit;
ysr@345 800 // the initial value of _words_scanned_limit (i.e. what it was
ysr@345 801 // before it was decreased).
ysr@345 802 size_t _real_words_scanned_limit;
ysr@345 803
ysr@345 804 // the number of references this task has visited
ysr@345 805 size_t _refs_reached;
ysr@345 806 // When _refs_reached reaches this limit, the regular clock is
ysr@345 807 // called. Notice this this might be decreased under certain
ysr@345 808 // circumstances (i.e. when we believe that we did an expensive
ysr@345 809 // operation).
ysr@345 810 size_t _refs_reached_limit;
ysr@345 811 // the initial value of _refs_reached_limit (i.e. what it was before
ysr@345 812 // it was decreased).
ysr@345 813 size_t _real_refs_reached_limit;
ysr@345 814
ysr@345 815 // used by the work stealing stuff
ysr@345 816 int _hash_seed;
ysr@345 817 // if this is true, then the task has aborted for some reason
ysr@345 818 bool _has_aborted;
ysr@345 819 // set when the task aborts because it has met its time quota
ysr@345 820 bool _has_aborted_timed_out;
ysr@345 821 // true when we're draining SATB buffers; this avoids the task
ysr@345 822 // aborting due to SATB buffers being available (as we're already
ysr@345 823 // dealing with them)
ysr@345 824 bool _draining_satb_buffers;
ysr@345 825
ysr@345 826 // number sequence of past step times
ysr@345 827 NumberSeq _step_times_ms;
ysr@345 828 // elapsed time of this task
ysr@345 829 double _elapsed_time_ms;
ysr@345 830 // termination time of this task
ysr@345 831 double _termination_time_ms;
ysr@345 832 // when this task got into the termination protocol
ysr@345 833 double _termination_start_time_ms;
ysr@345 834
ysr@345 835 // true when the task is during a concurrent phase, false when it is
ysr@345 836 // in the remark phase (so, in the latter case, we do not have to
ysr@345 837 // check all the things that we have to check during the concurrent
ysr@345 838 // phase, i.e. SATB buffer availability...)
ysr@345 839 bool _concurrent;
ysr@345 840
ysr@345 841 TruncatedSeq _marking_step_diffs_ms;
ysr@345 842
ysr@345 843 // LOTS of statistics related with this task
ysr@345 844 #if _MARKING_STATS_
ysr@345 845 NumberSeq _all_clock_intervals_ms;
ysr@345 846 double _interval_start_time_ms;
ysr@345 847
ysr@345 848 int _aborted;
ysr@345 849 int _aborted_overflow;
ysr@345 850 int _aborted_cm_aborted;
ysr@345 851 int _aborted_yield;
ysr@345 852 int _aborted_timed_out;
ysr@345 853 int _aborted_satb;
ysr@345 854 int _aborted_termination;
ysr@345 855
ysr@345 856 int _steal_attempts;
ysr@345 857 int _steals;
ysr@345 858
ysr@345 859 int _clock_due_to_marking;
ysr@345 860 int _clock_due_to_scanning;
ysr@345 861
ysr@345 862 int _local_pushes;
ysr@345 863 int _local_pops;
ysr@345 864 int _local_max_size;
ysr@345 865 int _objs_scanned;
ysr@345 866
ysr@345 867 int _global_pushes;
ysr@345 868 int _global_pops;
ysr@345 869 int _global_max_size;
ysr@345 870
ysr@345 871 int _global_transfers_to;
ysr@345 872 int _global_transfers_from;
ysr@345 873
ysr@345 874 int _region_stack_pops;
ysr@345 875
ysr@345 876 int _regions_claimed;
ysr@345 877 int _objs_found_on_bitmap;
ysr@345 878
ysr@345 879 int _satb_buffers_processed;
ysr@345 880 #endif // _MARKING_STATS_
ysr@345 881
ysr@345 882 // it updates the local fields after this task has claimed
ysr@345 883 // a new region to scan
ysr@345 884 void setup_for_region(HeapRegion* hr);
ysr@345 885 // it brings up-to-date the limit of the region
ysr@345 886 void update_region_limit();
ysr@345 887 // it resets the local fields after a task has finished scanning a
ysr@345 888 // region
ysr@345 889 void giveup_current_region();
ysr@345 890
ysr@345 891 // called when either the words scanned or the refs visited limit
ysr@345 892 // has been reached
ysr@345 893 void reached_limit();
ysr@345 894 // recalculates the words scanned and refs visited limits
ysr@345 895 void recalculate_limits();
ysr@345 896 // decreases the words scanned and refs visited limits when we reach
ysr@345 897 // an expensive operation
ysr@345 898 void decrease_limits();
ysr@345 899 // it checks whether the words scanned or refs visited reached their
ysr@345 900 // respective limit and calls reached_limit() if they have
ysr@345 901 void check_limits() {
ysr@345 902 if (_words_scanned >= _words_scanned_limit ||
ysr@345 903 _refs_reached >= _refs_reached_limit)
ysr@345 904 reached_limit();
ysr@345 905 }
ysr@345 906 // this is supposed to be called regularly during a marking step as
ysr@345 907 // it checks a bunch of conditions that might cause the marking step
ysr@345 908 // to abort
ysr@345 909 void regular_clock_call();
ysr@345 910 bool concurrent() { return _concurrent; }
ysr@345 911
ysr@345 912 public:
ysr@345 913 // It resets the task; it should be called right at the beginning of
ysr@345 914 // a marking phase.
ysr@345 915 void reset(CMBitMap* _nextMarkBitMap);
ysr@345 916 // it clears all the fields that correspond to a claimed region.
ysr@345 917 void clear_region_fields();
ysr@345 918
ysr@345 919 void set_concurrent(bool concurrent) { _concurrent = concurrent; }
ysr@345 920
ysr@345 921 // The main method of this class which performs a marking step
ysr@345 922 // trying not to exceed the given duration. However, it might exit
ysr@345 923 // prematurely, according to some conditions (i.e. SATB buffers are
ysr@345 924 // available for processing).
ysr@345 925 void do_marking_step(double target_ms);
ysr@345 926
ysr@345 927 // These two calls start and stop the timer
ysr@345 928 void record_start_time() {
ysr@345 929 _elapsed_time_ms = os::elapsedTime() * 1000.0;
ysr@345 930 }
ysr@345 931 void record_end_time() {
ysr@345 932 _elapsed_time_ms = os::elapsedTime() * 1000.0 - _elapsed_time_ms;
ysr@345 933 }
ysr@345 934
ysr@345 935 // returns the task ID
ysr@345 936 int task_id() { return _task_id; }
ysr@345 937
ysr@345 938 // From TerminatorTerminator. It determines whether this task should
ysr@345 939 // exit the termination protocol after it's entered it.
ysr@345 940 virtual bool should_exit_termination();
ysr@345 941
ysr@345 942 HeapWord* finger() { return _finger; }
ysr@345 943
ysr@345 944 bool has_aborted() { return _has_aborted; }
ysr@345 945 void set_has_aborted() { _has_aborted = true; }
ysr@345 946 void clear_has_aborted() { _has_aborted = false; }
ysr@345 947 bool claimed() { return _claimed; }
ysr@345 948
ysr@345 949 void set_oop_closure(OopClosure* oop_closure) {
ysr@345 950 _oop_closure = oop_closure;
ysr@345 951 }
ysr@345 952
ysr@345 953 // It grays the object by marking it and, if necessary, pushing it
ysr@345 954 // on the local queue
ysr@345 955 void deal_with_reference(oop obj);
ysr@345 956
ysr@345 957 // It scans an object and visits its children.
ysr@345 958 void scan_object(oop obj) {
tonyp@1082 959 assert(_nextMarkBitMap->isMarked((HeapWord*) obj), "invariant");
ysr@345 960
ysr@345 961 if (_cm->verbose_high())
ysr@345 962 gclog_or_tty->print_cr("[%d] we're scanning object "PTR_FORMAT,
ysr@345 963 _task_id, (void*) obj);
ysr@345 964
ysr@345 965 size_t obj_size = obj->size();
ysr@345 966 _words_scanned += obj_size;
ysr@345 967
ysr@345 968 obj->oop_iterate(_oop_closure);
ysr@345 969 statsOnly( ++_objs_scanned );
ysr@345 970 check_limits();
ysr@345 971 }
ysr@345 972
ysr@345 973 // It pushes an object on the local queue.
ysr@345 974 void push(oop obj);
ysr@345 975
ysr@345 976 // These two move entries to/from the global stack.
ysr@345 977 void move_entries_to_global_stack();
ysr@345 978 void get_entries_from_global_stack();
ysr@345 979
ysr@345 980 // It pops and scans objects from the local queue. If partially is
ysr@345 981 // true, then it stops when the queue size is of a given limit. If
ysr@345 982 // partially is false, then it stops when the queue is empty.
ysr@345 983 void drain_local_queue(bool partially);
ysr@345 984 // It moves entries from the global stack to the local queue and
ysr@345 985 // drains the local queue. If partially is true, then it stops when
ysr@345 986 // both the global stack and the local queue reach a given size. If
ysr@345 987 // partially if false, it tries to empty them totally.
ysr@345 988 void drain_global_stack(bool partially);
ysr@345 989 // It keeps picking SATB buffers and processing them until no SATB
ysr@345 990 // buffers are available.
ysr@345 991 void drain_satb_buffers();
ysr@345 992 // It keeps popping regions from the region stack and processing
ysr@345 993 // them until the region stack is empty.
ysr@345 994 void drain_region_stack(BitMapClosure* closure);
ysr@345 995
ysr@345 996 // moves the local finger to a new location
ysr@345 997 inline void move_finger_to(HeapWord* new_finger) {
tonyp@1082 998 assert(new_finger >= _finger && new_finger < _region_limit, "invariant");
ysr@345 999 _finger = new_finger;
ysr@345 1000 }
ysr@345 1001
ysr@345 1002 // moves the region finger to a new location
ysr@345 1003 inline void move_region_finger_to(HeapWord* new_finger) {
tonyp@1082 1004 assert(new_finger < _cm->finger(), "invariant");
ysr@345 1005 _region_finger = new_finger;
ysr@345 1006 }
ysr@345 1007
ysr@345 1008 CMTask(int task_num, ConcurrentMark *cm,
ysr@345 1009 CMTaskQueue* task_queue, CMTaskQueueSet* task_queues);
ysr@345 1010
ysr@345 1011 // it prints statistics associated with this task
ysr@345 1012 void print_stats();
ysr@345 1013
ysr@345 1014 #if _MARKING_STATS_
ysr@345 1015 void increase_objs_found_on_bitmap() { ++_objs_found_on_bitmap; }
ysr@345 1016 #endif // _MARKING_STATS_
ysr@345 1017 };