Mercurial > hg > graal-compiler
annotate src/share/vm/gc_implementation/g1/concurrentMark.hpp @ 1835:4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
Summary: Re-enable use of the lock-free versions of region stack push() and pop() by recording aborted regions in a thread-local structure, which are then processed when scanning of the region stack restarts. The previous locking versions of these routines are retained for diagnostic purposes.
Reviewed-by: tonyp, ysr
| author | johnc |
|---|---|
| date | Tue, 28 Sep 2010 09:51:37 -0700 |
| parents | c18cbe5936b8 |
| children | f95d63e2154a |
| rev | line source |
|---|---|
| 342 | 1 /* |
|
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1394
diff
changeset
|
2 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. |
| 342 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 18 * | |
|
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1394
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1394
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
|
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1394
diff
changeset
|
21 * questions. |
| 342 | 22 * |
| 23 */ | |
| 24 | |
| 25 class G1CollectedHeap; | |
| 26 class CMTask; | |
|
1311
2a1472c30599
4396719: Mark Sweep stack overflow on deeply nested Object arrays
jcoomes
parents:
1044
diff
changeset
|
27 typedef GenericTaskQueue<oop> CMTaskQueue; |
|
2a1472c30599
4396719: Mark Sweep stack overflow on deeply nested Object arrays
jcoomes
parents:
1044
diff
changeset
|
28 typedef GenericTaskQueueSet<CMTaskQueue> CMTaskQueueSet; |
| 342 | 29 |
| 30 // A generic CM bit map. This is essentially a wrapper around the BitMap | |
| 31 // class, with one bit per (1<<_shifter) HeapWords. | |
| 32 | |
|
549
fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
apetrusenko
parents:
342
diff
changeset
|
33 class CMBitMapRO VALUE_OBJ_CLASS_SPEC { |
| 342 | 34 protected: |
| 35 HeapWord* _bmStartWord; // base address of range covered by map | |
| 36 size_t _bmWordSize; // map size (in #HeapWords covered) | |
| 37 const int _shifter; // map to char or bit | |
| 38 VirtualSpace _virtual_space; // underlying the bit map | |
| 39 BitMap _bm; // the bit map itself | |
| 40 | |
| 41 public: | |
| 42 // constructor | |
| 43 CMBitMapRO(ReservedSpace rs, int shifter); | |
| 44 | |
| 45 enum { do_yield = true }; | |
| 46 | |
| 47 // inquiries | |
| 48 HeapWord* startWord() const { return _bmStartWord; } | |
| 49 size_t sizeInWords() const { return _bmWordSize; } | |
| 50 // the following is one past the last word in space | |
| 51 HeapWord* endWord() const { return _bmStartWord + _bmWordSize; } | |
| 52 | |
| 53 // read marks | |
| 54 | |
| 55 bool isMarked(HeapWord* addr) const { | |
| 56 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
| 57 "outside underlying space?"); | |
| 58 return _bm.at(heapWordToOffset(addr)); | |
| 59 } | |
| 60 | |
| 61 // iteration | |
| 62 bool iterate(BitMapClosure* cl) { return _bm.iterate(cl); } | |
| 63 bool iterate(BitMapClosure* cl, MemRegion mr); | |
| 64 | |
| 65 // Return the address corresponding to the next marked bit at or after | |
| 66 // "addr", and before "limit", if "limit" is non-NULL. If there is no | |
| 67 // such bit, returns "limit" if that is non-NULL, or else "endWord()". | |
| 68 HeapWord* getNextMarkedWordAddress(HeapWord* addr, | |
| 69 HeapWord* limit = NULL) const; | |
| 70 // Return the address corresponding to the next unmarked bit at or after | |
| 71 // "addr", and before "limit", if "limit" is non-NULL. If there is no | |
| 72 // such bit, returns "limit" if that is non-NULL, or else "endWord()". | |
| 73 HeapWord* getNextUnmarkedWordAddress(HeapWord* addr, | |
| 74 HeapWord* limit = NULL) const; | |
| 75 | |
| 76 // conversion utilities | |
| 77 // XXX Fix these so that offsets are size_t's... | |
| 78 HeapWord* offsetToHeapWord(size_t offset) const { | |
| 79 return _bmStartWord + (offset << _shifter); | |
| 80 } | |
| 81 size_t heapWordToOffset(HeapWord* addr) const { | |
| 82 return pointer_delta(addr, _bmStartWord) >> _shifter; | |
| 83 } | |
| 84 int heapWordDiffToOffsetDiff(size_t diff) const; | |
| 85 HeapWord* nextWord(HeapWord* addr) { | |
| 86 return offsetToHeapWord(heapWordToOffset(addr) + 1); | |
| 87 } | |
| 88 | |
| 89 void mostly_disjoint_range_union(BitMap* from_bitmap, | |
| 90 size_t from_start_index, | |
| 91 HeapWord* to_start_word, | |
| 92 size_t word_num); | |
| 93 | |
| 94 // debugging | |
| 95 NOT_PRODUCT(bool covers(ReservedSpace rs) const;) | |
| 96 }; | |
| 97 | |
| 98 class CMBitMap : public CMBitMapRO { | |
| 99 | |
| 100 public: | |
| 101 // constructor | |
| 102 CMBitMap(ReservedSpace rs, int shifter) : | |
| 103 CMBitMapRO(rs, shifter) {} | |
| 104 | |
| 105 // write marks | |
| 106 void mark(HeapWord* addr) { | |
| 107 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
| 108 "outside underlying space?"); | |
| 109 _bm.at_put(heapWordToOffset(addr), true); | |
| 110 } | |
| 111 void clear(HeapWord* addr) { | |
| 112 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
| 113 "outside underlying space?"); | |
| 114 _bm.at_put(heapWordToOffset(addr), false); | |
| 115 } | |
| 116 bool parMark(HeapWord* addr) { | |
| 117 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
| 118 "outside underlying space?"); | |
| 119 return _bm.par_at_put(heapWordToOffset(addr), true); | |
| 120 } | |
| 121 bool parClear(HeapWord* addr) { | |
| 122 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
| 123 "outside underlying space?"); | |
| 124 return _bm.par_at_put(heapWordToOffset(addr), false); | |
| 125 } | |
| 126 void markRange(MemRegion mr); | |
| 127 void clearAll(); | |
| 128 void clearRange(MemRegion mr); | |
| 129 | |
| 130 // Starting at the bit corresponding to "addr" (inclusive), find the next | |
| 131 // "1" bit, if any. This bit starts some run of consecutive "1"'s; find | |
| 132 // the end of this run (stopping at "end_addr"). Return the MemRegion | |
| 133 // covering from the start of the region corresponding to the first bit | |
| 134 // of the run to the end of the region corresponding to the last bit of | |
| 135 // the run. If there is no "1" bit at or after "addr", return an empty | |
| 136 // MemRegion. | |
| 137 MemRegion getAndClearMarkedRegion(HeapWord* addr, HeapWord* end_addr); | |
| 138 }; | |
| 139 | |
| 140 // Represents a marking stack used by the CM collector. | |
| 141 // Ideally this should be GrowableArray<> just like MSC's marking stack(s). | |
|
549
fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
apetrusenko
parents:
342
diff
changeset
|
142 class CMMarkStack VALUE_OBJ_CLASS_SPEC { |
| 342 | 143 ConcurrentMark* _cm; |
| 144 oop* _base; // bottom of stack | |
| 145 jint _index; // one more than last occupied index | |
| 146 jint _capacity; // max #elements | |
| 147 jint _oops_do_bound; // Number of elements to include in next iteration. | |
| 148 NOT_PRODUCT(jint _max_depth;) // max depth plumbed during run | |
| 149 | |
| 150 bool _overflow; | |
| 151 DEBUG_ONLY(bool _drain_in_progress;) | |
| 152 DEBUG_ONLY(bool _drain_in_progress_yields;) | |
| 153 | |
| 154 public: | |
| 155 CMMarkStack(ConcurrentMark* cm); | |
| 156 ~CMMarkStack(); | |
| 157 | |
| 158 void allocate(size_t size); | |
| 159 | |
| 160 oop pop() { | |
| 161 if (!isEmpty()) { | |
| 162 return _base[--_index] ; | |
| 163 } | |
| 164 return NULL; | |
| 165 } | |
| 166 | |
| 167 // If overflow happens, don't do the push, and record the overflow. | |
| 168 // *Requires* that "ptr" is already marked. | |
| 169 void push(oop ptr) { | |
| 170 if (isFull()) { | |
| 171 // Record overflow. | |
| 172 _overflow = true; | |
| 173 return; | |
| 174 } else { | |
| 175 _base[_index++] = ptr; | |
| 176 NOT_PRODUCT(_max_depth = MAX2(_max_depth, _index)); | |
| 177 } | |
| 178 } | |
| 179 // Non-block impl. Note: concurrency is allowed only with other | |
| 180 // "par_push" operations, not with "pop" or "drain". We would need | |
| 181 // parallel versions of them if such concurrency was desired. | |
| 182 void par_push(oop ptr); | |
| 183 | |
| 184 // Pushes the first "n" elements of "ptr_arr" on the stack. | |
| 185 // Non-block impl. Note: concurrency is allowed only with other | |
| 186 // "par_adjoin_arr" or "push" operations, not with "pop" or "drain". | |
| 187 void par_adjoin_arr(oop* ptr_arr, int n); | |
| 188 | |
| 189 // Pushes the first "n" elements of "ptr_arr" on the stack. | |
| 190 // Locking impl: concurrency is allowed only with | |
| 191 // "par_push_arr" and/or "par_pop_arr" operations, which use the same | |
| 192 // locking strategy. | |
| 193 void par_push_arr(oop* ptr_arr, int n); | |
| 194 | |
| 195 // If returns false, the array was empty. Otherwise, removes up to "max" | |
| 196 // elements from the stack, and transfers them to "ptr_arr" in an | |
| 197 // unspecified order. The actual number transferred is given in "n" ("n | |
| 198 // == 0" is deliberately redundant with the return value.) Locking impl: | |
| 199 // concurrency is allowed only with "par_push_arr" and/or "par_pop_arr" | |
| 200 // operations, which use the same locking strategy. | |
| 201 bool par_pop_arr(oop* ptr_arr, int max, int* n); | |
| 202 | |
| 203 // Drain the mark stack, applying the given closure to all fields of | |
| 204 // objects on the stack. (That is, continue until the stack is empty, | |
| 205 // even if closure applications add entries to the stack.) The "bm" | |
| 206 // argument, if non-null, may be used to verify that only marked objects | |
| 207 // are on the mark stack. If "yield_after" is "true", then the | |
| 208 // concurrent marker performing the drain offers to yield after | |
| 209 // processing each object. If a yield occurs, stops the drain operation | |
| 210 // and returns false. Otherwise, returns true. | |
| 211 template<class OopClosureClass> | |
| 212 bool drain(OopClosureClass* cl, CMBitMap* bm, bool yield_after = false); | |
| 213 | |
| 214 bool isEmpty() { return _index == 0; } | |
| 215 bool isFull() { return _index == _capacity; } | |
| 216 int maxElems() { return _capacity; } | |
| 217 | |
| 218 bool overflow() { return _overflow; } | |
| 219 void clear_overflow() { _overflow = false; } | |
| 220 | |
| 221 int size() { return _index; } | |
| 222 | |
| 223 void setEmpty() { _index = 0; clear_overflow(); } | |
| 224 | |
| 225 // Record the current size; a subsequent "oops_do" will iterate only over | |
| 226 // indices valid at the time of this call. | |
| 227 void set_oops_do_bound(jint bound = -1) { | |
| 228 if (bound == -1) { | |
| 229 _oops_do_bound = _index; | |
| 230 } else { | |
| 231 _oops_do_bound = bound; | |
| 232 } | |
| 233 } | |
| 234 jint oops_do_bound() { return _oops_do_bound; } | |
| 235 // iterate over the oops in the mark stack, up to the bound recorded via | |
| 236 // the call above. | |
| 237 void oops_do(OopClosure* f); | |
| 238 }; | |
| 239 | |
|
549
fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
apetrusenko
parents:
342
diff
changeset
|
240 class CMRegionStack VALUE_OBJ_CLASS_SPEC { |
| 342 | 241 MemRegion* _base; |
| 242 jint _capacity; | |
| 243 jint _index; | |
| 244 jint _oops_do_bound; | |
| 245 bool _overflow; | |
| 246 public: | |
| 247 CMRegionStack(); | |
| 248 ~CMRegionStack(); | |
| 249 void allocate(size_t size); | |
| 250 | |
| 251 // This is lock-free; assumes that it will only be called in parallel | |
| 252 // with other "push" operations (no pops). | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
253 void push_lock_free(MemRegion mr); |
|
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
254 |
| 342 | 255 // Lock-free; assumes that it will only be called in parallel |
| 256 // with other "pop" operations (no pushes). | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
257 MemRegion pop_lock_free(); |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
258 |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
259 #if 0 |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
260 // The routines that manipulate the region stack with a lock are |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
261 // not currently used. They should be retained, however, as a |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
262 // diagnostic aid. |
|
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
263 |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
264 // These two are the implementations that use a lock. They can be |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
265 // called concurrently with each other but they should not be called |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
266 // concurrently with the lock-free versions (push() / pop()). |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
267 void push_with_lock(MemRegion mr); |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
268 MemRegion pop_with_lock(); |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
269 #endif |
| 342 | 270 |
| 271 bool isEmpty() { return _index == 0; } | |
| 272 bool isFull() { return _index == _capacity; } | |
| 273 | |
| 274 bool overflow() { return _overflow; } | |
| 275 void clear_overflow() { _overflow = false; } | |
| 276 | |
| 277 int size() { return _index; } | |
| 278 | |
| 279 // It iterates over the entries in the region stack and it | |
| 280 // invalidates (i.e. assigns MemRegion()) the ones that point to | |
| 281 // regions in the collection set. | |
| 282 bool invalidate_entries_into_cset(); | |
| 283 | |
| 284 // This gives an upper bound up to which the iteration in | |
| 285 // invalidate_entries_into_cset() will reach. This prevents | |
| 286 // newly-added entries to be unnecessarily scanned. | |
| 287 void set_oops_do_bound() { | |
| 288 _oops_do_bound = _index; | |
| 289 } | |
| 290 | |
| 291 void setEmpty() { _index = 0; clear_overflow(); } | |
| 292 }; | |
| 293 | |
| 294 // this will enable a variety of different statistics per GC task | |
| 295 #define _MARKING_STATS_ 0 | |
| 296 // this will enable the higher verbose levels | |
| 297 #define _MARKING_VERBOSE_ 0 | |
| 298 | |
| 299 #if _MARKING_STATS_ | |
| 300 #define statsOnly(statement) \ | |
| 301 do { \ | |
| 302 statement ; \ | |
| 303 } while (0) | |
| 304 #else // _MARKING_STATS_ | |
| 305 #define statsOnly(statement) \ | |
| 306 do { \ | |
| 307 } while (0) | |
| 308 #endif // _MARKING_STATS_ | |
| 309 | |
| 310 typedef enum { | |
| 311 no_verbose = 0, // verbose turned off | |
| 312 stats_verbose, // only prints stats at the end of marking | |
| 313 low_verbose, // low verbose, mostly per region and per major event | |
| 314 medium_verbose, // a bit more detailed than low | |
| 315 high_verbose // per object verbose | |
| 316 } CMVerboseLevel; | |
| 317 | |
| 318 | |
| 319 class ConcurrentMarkThread; | |
| 320 | |
|
549
fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
apetrusenko
parents:
342
diff
changeset
|
321 class ConcurrentMark: public CHeapObj { |
| 342 | 322 friend class ConcurrentMarkThread; |
| 323 friend class CMTask; | |
| 324 friend class CMBitMapClosure; | |
| 325 friend class CSMarkOopClosure; | |
| 326 friend class CMGlobalObjectClosure; | |
| 327 friend class CMRemarkTask; | |
| 328 friend class CMConcurrentMarkingTask; | |
| 329 friend class G1ParNoteEndTask; | |
| 330 friend class CalcLiveObjectsClosure; | |
| 331 | |
| 332 protected: | |
| 333 ConcurrentMarkThread* _cmThread; // the thread doing the work | |
| 334 G1CollectedHeap* _g1h; // the heap. | |
| 335 size_t _parallel_marking_threads; // the number of marking | |
| 336 // threads we'll use | |
| 337 double _sleep_factor; // how much we have to sleep, with | |
| 338 // respect to the work we just did, to | |
| 339 // meet the marking overhead goal | |
| 340 double _marking_task_overhead; // marking target overhead for | |
| 341 // a single task | |
| 342 | |
| 343 // same as the two above, but for the cleanup task | |
| 344 double _cleanup_sleep_factor; | |
| 345 double _cleanup_task_overhead; | |
| 346 | |
| 347 // Stuff related to age cohort processing. | |
| 348 struct ParCleanupThreadState { | |
| 349 char _pre[64]; | |
| 350 UncleanRegionList list; | |
| 351 char _post[64]; | |
| 352 }; | |
| 353 ParCleanupThreadState** _par_cleanup_thread_state; | |
| 354 | |
| 355 // CMS marking support structures | |
| 356 CMBitMap _markBitMap1; | |
| 357 CMBitMap _markBitMap2; | |
| 358 CMBitMapRO* _prevMarkBitMap; // completed mark bitmap | |
| 359 CMBitMap* _nextMarkBitMap; // under-construction mark bitmap | |
| 360 bool _at_least_one_mark_complete; | |
| 361 | |
| 362 BitMap _region_bm; | |
| 363 BitMap _card_bm; | |
| 364 | |
| 365 // Heap bounds | |
| 366 HeapWord* _heap_start; | |
| 367 HeapWord* _heap_end; | |
| 368 | |
| 369 // For gray objects | |
| 370 CMMarkStack _markStack; // Grey objects behind global finger. | |
| 371 CMRegionStack _regionStack; // Grey regions behind global finger. | |
| 372 HeapWord* volatile _finger; // the global finger, region aligned, | |
| 373 // always points to the end of the | |
| 374 // last claimed region | |
| 375 | |
| 376 // marking tasks | |
| 377 size_t _max_task_num; // maximum task number | |
| 378 size_t _active_tasks; // task num currently active | |
| 379 CMTask** _tasks; // task queue array (max_task_num len) | |
| 380 CMTaskQueueSet* _task_queues; // task queue set | |
| 381 ParallelTaskTerminator _terminator; // for termination | |
| 382 | |
| 383 // Two sync barriers that are used to synchronise tasks when an | |
| 384 // overflow occurs. The algorithm is the following. All tasks enter | |
| 385 // the first one to ensure that they have all stopped manipulating | |
| 386 // the global data structures. After they exit it, they re-initialise | |
| 387 // their data structures and task 0 re-initialises the global data | |
| 388 // structures. Then, they enter the second sync barrier. This | |
| 389 // ensure, that no task starts doing work before all data | |
| 390 // structures (local and global) have been re-initialised. When they | |
| 391 // exit it, they are free to start working again. | |
| 392 WorkGangBarrierSync _first_overflow_barrier_sync; | |
| 393 WorkGangBarrierSync _second_overflow_barrier_sync; | |
| 394 | |
| 395 | |
| 396 // this is set by any task, when an overflow on the global data | |
| 397 // structures is detected. | |
| 398 volatile bool _has_overflown; | |
| 399 // true: marking is concurrent, false: we're in remark | |
| 400 volatile bool _concurrent; | |
| 401 // set at the end of a Full GC so that marking aborts | |
| 402 volatile bool _has_aborted; | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
403 |
| 342 | 404 // used when remark aborts due to an overflow to indicate that |
| 405 // another concurrent marking phase should start | |
| 406 volatile bool _restart_for_overflow; | |
| 407 | |
| 408 // This is true from the very start of concurrent marking until the | |
| 409 // point when all the tasks complete their work. It is really used | |
| 410 // to determine the points between the end of concurrent marking and | |
| 411 // time of remark. | |
| 412 volatile bool _concurrent_marking_in_progress; | |
| 413 | |
| 414 // verbose level | |
| 415 CMVerboseLevel _verbose_level; | |
| 416 | |
| 417 // These two fields are used to implement the optimisation that | |
| 418 // avoids pushing objects on the global/region stack if there are | |
| 419 // no collection set regions above the lowest finger. | |
| 420 | |
| 421 // This is the lowest finger (among the global and local fingers), | |
| 422 // which is calculated before a new collection set is chosen. | |
| 423 HeapWord* _min_finger; | |
| 424 // If this flag is true, objects/regions that are marked below the | |
| 425 // finger should be pushed on the stack(s). If this is flag is | |
| 426 // false, it is safe not to push them on the stack(s). | |
| 427 bool _should_gray_objects; | |
| 428 | |
| 429 // All of these times are in ms. | |
| 430 NumberSeq _init_times; | |
| 431 NumberSeq _remark_times; | |
| 432 NumberSeq _remark_mark_times; | |
| 433 NumberSeq _remark_weak_ref_times; | |
| 434 NumberSeq _cleanup_times; | |
| 435 double _total_counting_time; | |
| 436 double _total_rs_scrub_time; | |
| 437 | |
| 438 double* _accum_task_vtime; // accumulated task vtime | |
| 439 | |
| 440 WorkGang* _parallel_workers; | |
| 441 | |
| 442 void weakRefsWork(bool clear_all_soft_refs); | |
| 443 | |
| 444 void swapMarkBitMaps(); | |
| 445 | |
| 446 // It resets the global marking data structures, as well as the | |
| 447 // task local ones; should be called during initial mark. | |
| 448 void reset(); | |
| 449 // It resets all the marking data structures. | |
| 450 void clear_marking_state(); | |
| 451 | |
| 452 // It should be called to indicate which phase we're in (concurrent | |
| 453 // mark or remark) and how many threads are currently active. | |
| 454 void set_phase(size_t active_tasks, bool concurrent); | |
| 455 // We do this after we're done with marking so that the marking data | |
| 456 // structures are initialised to a sensible and predictable state. | |
| 457 void set_non_marking_state(); | |
| 458 | |
| 459 // prints all gathered CM-related statistics | |
| 460 void print_stats(); | |
| 461 | |
| 462 // accessor methods | |
| 463 size_t parallel_marking_threads() { return _parallel_marking_threads; } | |
| 464 double sleep_factor() { return _sleep_factor; } | |
| 465 double marking_task_overhead() { return _marking_task_overhead;} | |
| 466 double cleanup_sleep_factor() { return _cleanup_sleep_factor; } | |
| 467 double cleanup_task_overhead() { return _cleanup_task_overhead;} | |
| 468 | |
| 469 HeapWord* finger() { return _finger; } | |
| 470 bool concurrent() { return _concurrent; } | |
| 471 size_t active_tasks() { return _active_tasks; } | |
| 472 ParallelTaskTerminator* terminator() { return &_terminator; } | |
| 473 | |
| 474 // It claims the next available region to be scanned by a marking | |
| 475 // task. It might return NULL if the next region is empty or we have | |
| 476 // run out of regions. In the latter case, out_of_regions() | |
| 477 // determines whether we've really run out of regions or the task | |
| 478 // should call claim_region() again. This might seem a bit | |
| 479 // awkward. Originally, the code was written so that claim_region() | |
| 480 // either successfully returned with a non-empty region or there | |
| 481 // were no more regions to be claimed. The problem with this was | |
| 482 // that, in certain circumstances, it iterated over large chunks of | |
| 483 // the heap finding only empty regions and, while it was working, it | |
| 484 // was preventing the calling task to call its regular clock | |
| 485 // method. So, this way, each task will spend very little time in | |
| 486 // claim_region() and is allowed to call the regular clock method | |
| 487 // frequently. | |
| 488 HeapRegion* claim_region(int task); | |
| 489 | |
| 490 // It determines whether we've run out of regions to scan. | |
| 491 bool out_of_regions() { return _finger == _heap_end; } | |
| 492 | |
| 493 // Returns the task with the given id | |
| 494 CMTask* task(int id) { | |
|
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
495 assert(0 <= id && id < (int) _active_tasks, |
|
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
496 "task id not within active bounds"); |
| 342 | 497 return _tasks[id]; |
| 498 } | |
| 499 | |
| 500 // Returns the task queue with the given id | |
| 501 CMTaskQueue* task_queue(int id) { | |
|
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
502 assert(0 <= id && id < (int) _active_tasks, |
|
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
503 "task queue id not within active bounds"); |
| 342 | 504 return (CMTaskQueue*) _task_queues->queue(id); |
| 505 } | |
| 506 | |
| 507 // Returns the task queue set | |
| 508 CMTaskQueueSet* task_queues() { return _task_queues; } | |
| 509 | |
| 510 // Access / manipulation of the overflow flag which is set to | |
| 511 // indicate that the global stack or region stack has overflown | |
| 512 bool has_overflown() { return _has_overflown; } | |
| 513 void set_has_overflown() { _has_overflown = true; } | |
| 514 void clear_has_overflown() { _has_overflown = false; } | |
| 515 | |
| 516 bool has_aborted() { return _has_aborted; } | |
| 517 bool restart_for_overflow() { return _restart_for_overflow; } | |
| 518 | |
| 519 // Methods to enter the two overflow sync barriers | |
| 520 void enter_first_sync_barrier(int task_num); | |
| 521 void enter_second_sync_barrier(int task_num); | |
| 522 | |
| 523 public: | |
| 524 // Manipulation of the global mark stack. | |
| 525 // Notice that the first mark_stack_push is CAS-based, whereas the | |
| 526 // two below are Mutex-based. This is OK since the first one is only | |
| 527 // called during evacuation pauses and doesn't compete with the | |
| 528 // other two (which are called by the marking tasks during | |
| 529 // concurrent marking or remark). | |
| 530 bool mark_stack_push(oop p) { | |
| 531 _markStack.par_push(p); | |
| 532 if (_markStack.overflow()) { | |
| 533 set_has_overflown(); | |
| 534 return false; | |
| 535 } | |
| 536 return true; | |
| 537 } | |
| 538 bool mark_stack_push(oop* arr, int n) { | |
| 539 _markStack.par_push_arr(arr, n); | |
| 540 if (_markStack.overflow()) { | |
| 541 set_has_overflown(); | |
| 542 return false; | |
| 543 } | |
| 544 return true; | |
| 545 } | |
| 546 void mark_stack_pop(oop* arr, int max, int* n) { | |
| 547 _markStack.par_pop_arr(arr, max, n); | |
| 548 } | |
| 549 size_t mark_stack_size() { return _markStack.size(); } | |
| 550 size_t partial_mark_stack_size_target() { return _markStack.maxElems()/3; } | |
| 551 bool mark_stack_overflow() { return _markStack.overflow(); } | |
| 552 bool mark_stack_empty() { return _markStack.isEmpty(); } | |
| 553 | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
554 // (Lock-free) Manipulation of the region stack |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
555 bool region_stack_push_lock_free(MemRegion mr) { |
|
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
556 // Currently we only call the lock-free version during evacuation |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
557 // pauses. |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
558 assert(SafepointSynchronize::is_at_safepoint(), "world should be stopped"); |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
559 |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
560 _regionStack.push_lock_free(mr); |
| 342 | 561 if (_regionStack.overflow()) { |
| 562 set_has_overflown(); | |
| 563 return false; | |
| 564 } | |
| 565 return true; | |
| 566 } | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
567 |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
568 // Lock-free version of region-stack pop. Should only be |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
569 // called in tandem with other lock-free pops. |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
570 MemRegion region_stack_pop_lock_free() { |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
571 return _regionStack.pop_lock_free(); |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
572 } |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
573 |
|
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
574 #if 0 |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
575 // The routines that manipulate the region stack with a lock are |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
576 // not currently used. They should be retained, however, as a |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
577 // diagnostic aid. |
|
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
578 |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
579 bool region_stack_push_with_lock(MemRegion mr) { |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
580 // Currently we only call the lock-based version during either |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
581 // concurrent marking or remark. |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
582 assert(!SafepointSynchronize::is_at_safepoint() || !concurrent(), |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
583 "if we are at a safepoint it should be the remark safepoint"); |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
584 |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
585 _regionStack.push_with_lock(mr); |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
586 if (_regionStack.overflow()) { |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
587 set_has_overflown(); |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
588 return false; |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
589 } |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
590 return true; |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
591 } |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
592 |
|
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
593 MemRegion region_stack_pop_with_lock() { |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
594 // Currently we only call the lock-based version during either |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
595 // concurrent marking or remark. |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
596 assert(!SafepointSynchronize::is_at_safepoint() || !concurrent(), |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
597 "if we are at a safepoint it should be the remark safepoint"); |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
598 |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
599 return _regionStack.pop_with_lock(); |
|
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
600 } |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
601 #endif |
|
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
602 |
| 342 | 603 int region_stack_size() { return _regionStack.size(); } |
| 604 bool region_stack_overflow() { return _regionStack.overflow(); } | |
| 605 bool region_stack_empty() { return _regionStack.isEmpty(); } | |
| 606 | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
607 // Iterate over any regions that were aborted while draining the |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
608 // region stack (any such regions are saved in the corresponding |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
609 // CMTask) and invalidate (i.e. assign to the empty MemRegion()) |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
610 // any regions that point into the collection set. |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
611 bool invalidate_aborted_regions_in_cset(); |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
612 |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
613 // Returns true if there are any aborted memory regions. |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
614 bool has_aborted_regions(); |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
615 |
| 342 | 616 bool concurrent_marking_in_progress() { |
| 617 return _concurrent_marking_in_progress; | |
| 618 } | |
| 619 void set_concurrent_marking_in_progress() { | |
| 620 _concurrent_marking_in_progress = true; | |
| 621 } | |
| 622 void clear_concurrent_marking_in_progress() { | |
| 623 _concurrent_marking_in_progress = false; | |
| 624 } | |
| 625 | |
| 626 void update_accum_task_vtime(int i, double vtime) { | |
| 627 _accum_task_vtime[i] += vtime; | |
| 628 } | |
| 629 | |
| 630 double all_task_accum_vtime() { | |
| 631 double ret = 0.0; | |
| 632 for (int i = 0; i < (int)_max_task_num; ++i) | |
| 633 ret += _accum_task_vtime[i]; | |
| 634 return ret; | |
| 635 } | |
| 636 | |
| 637 // Attempts to steal an object from the task queues of other tasks | |
| 638 bool try_stealing(int task_num, int* hash_seed, oop& obj) { | |
| 639 return _task_queues->steal(task_num, hash_seed, obj); | |
| 640 } | |
| 641 | |
| 642 // It grays an object by first marking it. Then, if it's behind the | |
| 643 // global finger, it also pushes it on the global stack. | |
| 644 void deal_with_reference(oop obj); | |
| 645 | |
| 646 ConcurrentMark(ReservedSpace rs, int max_regions); | |
| 647 ~ConcurrentMark(); | |
| 648 ConcurrentMarkThread* cmThread() { return _cmThread; } | |
| 649 | |
| 650 CMBitMapRO* prevMarkBitMap() const { return _prevMarkBitMap; } | |
| 651 CMBitMap* nextMarkBitMap() const { return _nextMarkBitMap; } | |
| 652 | |
| 653 // The following three are interaction between CM and | |
| 654 // G1CollectedHeap | |
| 655 | |
| 656 // This notifies CM that a root during initial-mark needs to be | |
| 657 // grayed and it's MT-safe. Currently, we just mark it. But, in the | |
| 658 // future, we can experiment with pushing it on the stack and we can | |
| 659 // do this without changing G1CollectedHeap. | |
| 660 void grayRoot(oop p); | |
| 661 // It's used during evacuation pauses to gray a region, if | |
| 662 // necessary, and it's MT-safe. It assumes that the caller has | |
| 663 // marked any objects on that region. If _should_gray_objects is | |
| 664 // true and we're still doing concurrent marking, the region is | |
| 665 // pushed on the region stack, if it is located below the global | |
| 666 // finger, otherwise we do nothing. | |
| 667 void grayRegionIfNecessary(MemRegion mr); | |
| 668 // It's used during evacuation pauses to mark and, if necessary, | |
| 669 // gray a single object and it's MT-safe. It assumes the caller did | |
| 670 // not mark the object. If _should_gray_objects is true and we're | |
| 671 // still doing concurrent marking, the objects is pushed on the | |
| 672 // global stack, if it is located below the global finger, otherwise | |
| 673 // we do nothing. | |
| 674 void markAndGrayObjectIfNecessary(oop p); | |
| 675 | |
| 1388 | 676 // It iterates over the heap and for each object it comes across it |
| 677 // will dump the contents of its reference fields, as well as | |
| 678 // liveness information for the object and its referents. The dump | |
| 679 // will be written to a file with the following name: | |
| 680 // G1PrintReachableBaseFile + "." + str. use_prev_marking decides | |
| 681 // whether the prev (use_prev_marking == true) or next | |
| 682 // (use_prev_marking == false) marking information will be used to | |
| 683 // determine the liveness of each object / referent. If all is true, | |
| 684 // all objects in the heap will be dumped, otherwise only the live | |
| 685 // ones. In the dump the following symbols / abbreviations are used: | |
| 686 // M : an explicitly live object (its bitmap bit is set) | |
| 687 // > : an implicitly live object (over tams) | |
| 688 // O : an object outside the G1 heap (typically: in the perm gen) | |
| 689 // NOT : a reference field whose referent is not live | |
| 690 // AND MARKED : indicates that an object is both explicitly and | |
| 691 // implicitly live (it should be one or the other, not both) | |
| 692 void print_reachable(const char* str, | |
| 693 bool use_prev_marking, bool all) PRODUCT_RETURN; | |
| 342 | 694 |
| 695 // Clear the next marking bitmap (will be called concurrently). | |
| 696 void clearNextBitmap(); | |
| 697 | |
| 698 // main CMS steps and related support | |
| 699 void checkpointRootsInitial(); | |
| 700 | |
| 701 // These two do the work that needs to be done before and after the | |
| 702 // initial root checkpoint. Since this checkpoint can be done at two | |
| 703 // different points (i.e. an explicit pause or piggy-backed on a | |
| 704 // young collection), then it's nice to be able to easily share the | |
| 705 // pre/post code. It might be the case that we can put everything in | |
| 706 // the post method. TP | |
| 707 void checkpointRootsInitialPre(); | |
| 708 void checkpointRootsInitialPost(); | |
| 709 | |
| 710 // Do concurrent phase of marking, to a tentative transitive closure. | |
| 711 void markFromRoots(); | |
| 712 | |
| 713 // Process all unprocessed SATB buffers. It is called at the | |
| 714 // beginning of an evacuation pause. | |
| 715 void drainAllSATBBuffers(); | |
| 716 | |
| 717 void checkpointRootsFinal(bool clear_all_soft_refs); | |
| 718 void checkpointRootsFinalWork(); | |
| 719 void calcDesiredRegions(); | |
| 720 void cleanup(); | |
| 721 void completeCleanup(); | |
| 722 | |
| 723 // Mark in the previous bitmap. NB: this is usually read-only, so use | |
| 724 // this carefully! | |
| 725 void markPrev(oop p); | |
| 726 void clear(oop p); | |
| 727 // Clears marks for all objects in the given range, for both prev and | |
| 728 // next bitmaps. NB: the previous bitmap is usually read-only, so use | |
| 729 // this carefully! | |
| 730 void clearRangeBothMaps(MemRegion mr); | |
| 731 | |
| 732 // Record the current top of the mark and region stacks; a | |
| 733 // subsequent oops_do() on the mark stack and | |
| 734 // invalidate_entries_into_cset() on the region stack will iterate | |
| 735 // only over indices valid at the time of this call. | |
| 736 void set_oops_do_bound() { | |
| 737 _markStack.set_oops_do_bound(); | |
| 738 _regionStack.set_oops_do_bound(); | |
| 739 } | |
| 740 // Iterate over the oops in the mark stack and all local queues. It | |
| 741 // also calls invalidate_entries_into_cset() on the region stack. | |
| 742 void oops_do(OopClosure* f); | |
| 743 // It is called at the end of an evacuation pause during marking so | |
| 744 // that CM is notified of where the new end of the heap is. It | |
| 745 // doesn't do anything if concurrent_marking_in_progress() is false, | |
| 746 // unless the force parameter is true. | |
| 747 void update_g1_committed(bool force = false); | |
| 748 | |
| 749 void complete_marking_in_collection_set(); | |
| 750 | |
| 751 // It indicates that a new collection set is being chosen. | |
| 752 void newCSet(); | |
| 753 // It registers a collection set heap region with CM. This is used | |
| 754 // to determine whether any heap regions are located above the finger. | |
| 755 void registerCSetRegion(HeapRegion* hr); | |
| 756 | |
|
1394
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
757 // Registers the maximum region-end associated with a set of |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
758 // regions with CM. Again this is used to determine whether any |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
759 // heap regions are located above the finger. |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
760 void register_collection_set_finger(HeapWord* max_finger) { |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
761 // max_finger is the highest heap region end of the regions currently |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
762 // contained in the collection set. If this value is larger than |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
763 // _min_finger then we need to gray objects. |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
764 // This routine is like registerCSetRegion but for an entire |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
765 // collection of regions. |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
766 if (max_finger > _min_finger) |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
767 _should_gray_objects = true; |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
768 } |
|
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
769 |
| 342 | 770 // Returns "true" if at least one mark has been completed. |
| 771 bool at_least_one_mark_complete() { return _at_least_one_mark_complete; } | |
| 772 | |
| 773 bool isMarked(oop p) const { | |
| 774 assert(p != NULL && p->is_oop(), "expected an oop"); | |
| 775 HeapWord* addr = (HeapWord*)p; | |
| 776 assert(addr >= _nextMarkBitMap->startWord() || | |
| 777 addr < _nextMarkBitMap->endWord(), "in a region"); | |
| 778 | |
| 779 return _nextMarkBitMap->isMarked(addr); | |
| 780 } | |
| 781 | |
| 782 inline bool not_yet_marked(oop p) const; | |
| 783 | |
| 784 // XXX Debug code | |
| 785 bool containing_card_is_marked(void* p); | |
| 786 bool containing_cards_are_marked(void* start, void* last); | |
| 787 | |
| 788 bool isPrevMarked(oop p) const { | |
| 789 assert(p != NULL && p->is_oop(), "expected an oop"); | |
| 790 HeapWord* addr = (HeapWord*)p; | |
| 791 assert(addr >= _prevMarkBitMap->startWord() || | |
| 792 addr < _prevMarkBitMap->endWord(), "in a region"); | |
| 793 | |
| 794 return _prevMarkBitMap->isMarked(addr); | |
| 795 } | |
| 796 | |
| 797 inline bool do_yield_check(int worker_i = 0); | |
| 798 inline bool should_yield(); | |
| 799 | |
| 800 // Called to abort the marking cycle after a Full GC takes palce. | |
| 801 void abort(); | |
| 802 | |
| 803 // This prints the global/local fingers. It is used for debugging. | |
| 804 NOT_PRODUCT(void print_finger();) | |
| 805 | |
| 806 void print_summary_info(); | |
| 807 | |
| 1019 | 808 void print_worker_threads_on(outputStream* st) const; |
| 809 | |
| 342 | 810 // The following indicate whether a given verbose level has been |
| 811 // set. Notice that anything above stats is conditional to | |
| 812 // _MARKING_VERBOSE_ having been set to 1 | |
| 813 bool verbose_stats() | |
| 814 { return _verbose_level >= stats_verbose; } | |
| 815 bool verbose_low() | |
| 816 { return _MARKING_VERBOSE_ && _verbose_level >= low_verbose; } | |
| 817 bool verbose_medium() | |
| 818 { return _MARKING_VERBOSE_ && _verbose_level >= medium_verbose; } | |
| 819 bool verbose_high() | |
| 820 { return _MARKING_VERBOSE_ && _verbose_level >= high_verbose; } | |
| 821 }; | |
| 822 | |
| 823 // A class representing a marking task. | |
| 824 class CMTask : public TerminatorTerminator { | |
| 825 private: | |
| 826 enum PrivateConstants { | |
| 827 // the regular clock call is called once the scanned words reaches | |
| 828 // this limit | |
| 829 words_scanned_period = 12*1024, | |
| 830 // the regular clock call is called once the number of visited | |
| 831 // references reaches this limit | |
| 832 refs_reached_period = 384, | |
| 833 // initial value for the hash seed, used in the work stealing code | |
| 834 init_hash_seed = 17, | |
| 835 // how many entries will be transferred between global stack and | |
| 836 // local queues | |
| 837 global_stack_transfer_size = 16 | |
| 838 }; | |
| 839 | |
| 840 int _task_id; | |
| 841 G1CollectedHeap* _g1h; | |
| 842 ConcurrentMark* _cm; | |
| 843 CMBitMap* _nextMarkBitMap; | |
| 844 // the task queue of this task | |
| 845 CMTaskQueue* _task_queue; | |
|
845
df6caf649ff7
6700789: G1: Enable use of compressed oops with G1 heaps
ysr
parents:
579
diff
changeset
|
846 private: |
| 342 | 847 // the task queue set---needed for stealing |
| 848 CMTaskQueueSet* _task_queues; | |
| 849 // indicates whether the task has been claimed---this is only for | |
| 850 // debugging purposes | |
| 851 bool _claimed; | |
| 852 | |
| 853 // number of calls to this task | |
| 854 int _calls; | |
| 855 | |
| 856 // when the virtual timer reaches this time, the marking step should | |
| 857 // exit | |
| 858 double _time_target_ms; | |
| 859 // the start time of the current marking step | |
| 860 double _start_time_ms; | |
| 861 | |
| 862 // the oop closure used for iterations over oops | |
| 863 OopClosure* _oop_closure; | |
| 864 | |
| 865 // the region this task is scanning, NULL if we're not scanning any | |
| 866 HeapRegion* _curr_region; | |
| 867 // the local finger of this task, NULL if we're not scanning a region | |
| 868 HeapWord* _finger; | |
| 869 // limit of the region this task is scanning, NULL if we're not scanning one | |
| 870 HeapWord* _region_limit; | |
| 871 | |
| 872 // This is used only when we scan regions popped from the region | |
| 873 // stack. It records what the last object on such a region we | |
| 874 // scanned was. It is used to ensure that, if we abort region | |
| 875 // iteration, we do not rescan the first part of the region. This | |
| 876 // should be NULL when we're not scanning a region from the region | |
| 877 // stack. | |
| 878 HeapWord* _region_finger; | |
| 879 | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
880 // If we abort while scanning a region we record the remaining |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
881 // unscanned portion and check this field when marking restarts. |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
882 // This avoids having to push on the region stack while other |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
883 // marking threads may still be popping regions. |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
884 // If we were to push the unscanned portion directly to the |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
885 // region stack then we would need to using locking versions |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
886 // of the push and pop operations. |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
887 MemRegion _aborted_region; |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
888 |
| 342 | 889 // the number of words this task has scanned |
| 890 size_t _words_scanned; | |
| 891 // When _words_scanned reaches this limit, the regular clock is | |
| 892 // called. Notice that this might be decreased under certain | |
| 893 // circumstances (i.e. when we believe that we did an expensive | |
| 894 // operation). | |
| 895 size_t _words_scanned_limit; | |
| 896 // the initial value of _words_scanned_limit (i.e. what it was | |
| 897 // before it was decreased). | |
| 898 size_t _real_words_scanned_limit; | |
| 899 | |
| 900 // the number of references this task has visited | |
| 901 size_t _refs_reached; | |
| 902 // When _refs_reached reaches this limit, the regular clock is | |
| 903 // called. Notice this this might be decreased under certain | |
| 904 // circumstances (i.e. when we believe that we did an expensive | |
| 905 // operation). | |
| 906 size_t _refs_reached_limit; | |
| 907 // the initial value of _refs_reached_limit (i.e. what it was before | |
| 908 // it was decreased). | |
| 909 size_t _real_refs_reached_limit; | |
| 910 | |
| 911 // used by the work stealing stuff | |
| 912 int _hash_seed; | |
| 913 // if this is true, then the task has aborted for some reason | |
| 914 bool _has_aborted; | |
| 915 // set when the task aborts because it has met its time quota | |
| 916 bool _has_aborted_timed_out; | |
| 917 // true when we're draining SATB buffers; this avoids the task | |
| 918 // aborting due to SATB buffers being available (as we're already | |
| 919 // dealing with them) | |
| 920 bool _draining_satb_buffers; | |
| 921 | |
| 922 // number sequence of past step times | |
| 923 NumberSeq _step_times_ms; | |
| 924 // elapsed time of this task | |
| 925 double _elapsed_time_ms; | |
| 926 // termination time of this task | |
| 927 double _termination_time_ms; | |
| 928 // when this task got into the termination protocol | |
| 929 double _termination_start_time_ms; | |
| 930 | |
| 931 // true when the task is during a concurrent phase, false when it is | |
| 932 // in the remark phase (so, in the latter case, we do not have to | |
| 933 // check all the things that we have to check during the concurrent | |
| 934 // phase, i.e. SATB buffer availability...) | |
| 935 bool _concurrent; | |
| 936 | |
| 937 TruncatedSeq _marking_step_diffs_ms; | |
| 938 | |
| 939 // LOTS of statistics related with this task | |
| 940 #if _MARKING_STATS_ | |
| 941 NumberSeq _all_clock_intervals_ms; | |
| 942 double _interval_start_time_ms; | |
| 943 | |
| 944 int _aborted; | |
| 945 int _aborted_overflow; | |
| 946 int _aborted_cm_aborted; | |
| 947 int _aborted_yield; | |
| 948 int _aborted_timed_out; | |
| 949 int _aborted_satb; | |
| 950 int _aborted_termination; | |
| 951 | |
| 952 int _steal_attempts; | |
| 953 int _steals; | |
| 954 | |
| 955 int _clock_due_to_marking; | |
| 956 int _clock_due_to_scanning; | |
| 957 | |
| 958 int _local_pushes; | |
| 959 int _local_pops; | |
| 960 int _local_max_size; | |
| 961 int _objs_scanned; | |
| 962 | |
| 963 int _global_pushes; | |
| 964 int _global_pops; | |
| 965 int _global_max_size; | |
| 966 | |
| 967 int _global_transfers_to; | |
| 968 int _global_transfers_from; | |
| 969 | |
| 970 int _region_stack_pops; | |
| 971 | |
| 972 int _regions_claimed; | |
| 973 int _objs_found_on_bitmap; | |
| 974 | |
| 975 int _satb_buffers_processed; | |
| 976 #endif // _MARKING_STATS_ | |
| 977 | |
| 978 // it updates the local fields after this task has claimed | |
| 979 // a new region to scan | |
| 980 void setup_for_region(HeapRegion* hr); | |
| 981 // it brings up-to-date the limit of the region | |
| 982 void update_region_limit(); | |
| 983 // it resets the local fields after a task has finished scanning a | |
| 984 // region | |
| 985 void giveup_current_region(); | |
| 986 | |
| 987 // called when either the words scanned or the refs visited limit | |
| 988 // has been reached | |
| 989 void reached_limit(); | |
| 990 // recalculates the words scanned and refs visited limits | |
| 991 void recalculate_limits(); | |
| 992 // decreases the words scanned and refs visited limits when we reach | |
| 993 // an expensive operation | |
| 994 void decrease_limits(); | |
| 995 // it checks whether the words scanned or refs visited reached their | |
| 996 // respective limit and calls reached_limit() if they have | |
| 997 void check_limits() { | |
| 998 if (_words_scanned >= _words_scanned_limit || | |
| 999 _refs_reached >= _refs_reached_limit) | |
| 1000 reached_limit(); | |
| 1001 } | |
| 1002 // this is supposed to be called regularly during a marking step as | |
| 1003 // it checks a bunch of conditions that might cause the marking step | |
| 1004 // to abort | |
| 1005 void regular_clock_call(); | |
| 1006 bool concurrent() { return _concurrent; } | |
| 1007 | |
| 1008 public: | |
| 1009 // It resets the task; it should be called right at the beginning of | |
| 1010 // a marking phase. | |
| 1011 void reset(CMBitMap* _nextMarkBitMap); | |
| 1012 // it clears all the fields that correspond to a claimed region. | |
| 1013 void clear_region_fields(); | |
| 1014 | |
| 1015 void set_concurrent(bool concurrent) { _concurrent = concurrent; } | |
| 1016 | |
| 1017 // The main method of this class which performs a marking step | |
| 1018 // trying not to exceed the given duration. However, it might exit | |
| 1019 // prematurely, according to some conditions (i.e. SATB buffers are | |
| 1020 // available for processing). | |
| 1021 void do_marking_step(double target_ms); | |
| 1022 | |
| 1023 // These two calls start and stop the timer | |
| 1024 void record_start_time() { | |
| 1025 _elapsed_time_ms = os::elapsedTime() * 1000.0; | |
| 1026 } | |
| 1027 void record_end_time() { | |
| 1028 _elapsed_time_ms = os::elapsedTime() * 1000.0 - _elapsed_time_ms; | |
| 1029 } | |
| 1030 | |
| 1031 // returns the task ID | |
| 1032 int task_id() { return _task_id; } | |
| 1033 | |
| 1034 // From TerminatorTerminator. It determines whether this task should | |
| 1035 // exit the termination protocol after it's entered it. | |
| 1036 virtual bool should_exit_termination(); | |
| 1037 | |
| 1038 HeapWord* finger() { return _finger; } | |
| 1039 | |
| 1040 bool has_aborted() { return _has_aborted; } | |
| 1041 void set_has_aborted() { _has_aborted = true; } | |
| 1042 void clear_has_aborted() { _has_aborted = false; } | |
| 1043 bool claimed() { return _claimed; } | |
| 1044 | |
|
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1045 // Support routines for the partially scanned region that may be |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1046 // recorded as a result of aborting while draining the CMRegionStack |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1047 MemRegion aborted_region() { return _aborted_region; } |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1048 void set_aborted_region(MemRegion mr) |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1049 { _aborted_region = mr; } |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1050 |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1051 // Clears any recorded partially scanned region |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1052 void clear_aborted_region() { set_aborted_region(MemRegion()); } |
|
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1053 |
| 342 | 1054 void set_oop_closure(OopClosure* oop_closure) { |
| 1055 _oop_closure = oop_closure; | |
| 1056 } | |
| 1057 | |
| 1058 // It grays the object by marking it and, if necessary, pushing it | |
| 1059 // on the local queue | |
| 1060 void deal_with_reference(oop obj); | |
| 1061 | |
| 1062 // It scans an object and visits its children. | |
| 1063 void scan_object(oop obj) { | |
|
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
1064 assert(_nextMarkBitMap->isMarked((HeapWord*) obj), "invariant"); |
| 342 | 1065 |
| 1066 if (_cm->verbose_high()) | |
| 1067 gclog_or_tty->print_cr("[%d] we're scanning object "PTR_FORMAT, | |
| 1068 _task_id, (void*) obj); | |
| 1069 | |
| 1070 size_t obj_size = obj->size(); | |
| 1071 _words_scanned += obj_size; | |
| 1072 | |
| 1073 obj->oop_iterate(_oop_closure); | |
| 1074 statsOnly( ++_objs_scanned ); | |
| 1075 check_limits(); | |
| 1076 } | |
| 1077 | |
| 1078 // It pushes an object on the local queue. | |
| 1079 void push(oop obj); | |
| 1080 | |
| 1081 // These two move entries to/from the global stack. | |
| 1082 void move_entries_to_global_stack(); | |
| 1083 void get_entries_from_global_stack(); | |
| 1084 | |
| 1085 // It pops and scans objects from the local queue. If partially is | |
| 1086 // true, then it stops when the queue size is of a given limit. If | |
| 1087 // partially is false, then it stops when the queue is empty. | |
| 1088 void drain_local_queue(bool partially); | |
| 1089 // It moves entries from the global stack to the local queue and | |
| 1090 // drains the local queue. If partially is true, then it stops when | |
| 1091 // both the global stack and the local queue reach a given size. If | |
| 1092 // partially if false, it tries to empty them totally. | |
| 1093 void drain_global_stack(bool partially); | |
| 1094 // It keeps picking SATB buffers and processing them until no SATB | |
| 1095 // buffers are available. | |
| 1096 void drain_satb_buffers(); | |
| 1097 // It keeps popping regions from the region stack and processing | |
| 1098 // them until the region stack is empty. | |
| 1099 void drain_region_stack(BitMapClosure* closure); | |
| 1100 | |
| 1101 // moves the local finger to a new location | |
| 1102 inline void move_finger_to(HeapWord* new_finger) { | |
|
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
1103 assert(new_finger >= _finger && new_finger < _region_limit, "invariant"); |
| 342 | 1104 _finger = new_finger; |
| 1105 } | |
| 1106 | |
| 1107 // moves the region finger to a new location | |
| 1108 inline void move_region_finger_to(HeapWord* new_finger) { | |
|
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
1109 assert(new_finger < _cm->finger(), "invariant"); |
| 342 | 1110 _region_finger = new_finger; |
| 1111 } | |
| 1112 | |
| 1113 CMTask(int task_num, ConcurrentMark *cm, | |
| 1114 CMTaskQueue* task_queue, CMTaskQueueSet* task_queues); | |
| 1115 | |
| 1116 // it prints statistics associated with this task | |
| 1117 void print_stats(); | |
| 1118 | |
| 1119 #if _MARKING_STATS_ | |
| 1120 void increase_objs_found_on_bitmap() { ++_objs_found_on_bitmap; } | |
| 1121 #endif // _MARKING_STATS_ | |
| 1122 }; |