Mercurial > hg > graal-jvmci-8
annotate src/share/vm/gc_implementation/g1/concurrentMark.hpp @ 2172:a672e43650cc
7013718: G1: small fixes for two assert/guarantee failures
Summary: Two small fixes to deal with a guarantee failure (the marking thread should join the SuspendibleThreadSet before calling a method that does pause prediction work so that said method is never called during a pause) and an assert failure (an assert is too strong).
Reviewed-by: iveresov, johnc
author | tonyp |
---|---|
date | Fri, 21 Jan 2011 11:30:22 -0500 |
parents | 0fa27f37d4d4 |
children | 234761c55641 |
rev | line source |
---|---|
342 | 1 /* |
2152 | 2 * Copyright (c) 2001, 2011, 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 | |
1972 | 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP |
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP | |
27 | |
2152 | 28 #include "gc_implementation/g1/heapRegionSets.hpp" |
1972 | 29 #include "utilities/taskqueue.hpp" |
30 | |
342 | 31 class G1CollectedHeap; |
32 class CMTask; | |
1311
2a1472c30599
4396719: Mark Sweep stack overflow on deeply nested Object arrays
jcoomes
parents:
1044
diff
changeset
|
33 typedef GenericTaskQueue<oop> CMTaskQueue; |
2a1472c30599
4396719: Mark Sweep stack overflow on deeply nested Object arrays
jcoomes
parents:
1044
diff
changeset
|
34 typedef GenericTaskQueueSet<CMTaskQueue> CMTaskQueueSet; |
342 | 35 |
2037
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
36 // Closure used by CM during concurrent reference discovery |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
37 // and reference processing (during remarking) to determine |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
38 // if a particular object is alive. It is primarily used |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
39 // to determine if referents of discovered reference objects |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
40 // are alive. An instance is also embedded into the |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
41 // reference processor as the _is_alive_non_header field |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
42 class G1CMIsAliveClosure: public BoolObjectClosure { |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
43 G1CollectedHeap* _g1; |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
44 public: |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
45 G1CMIsAliveClosure(G1CollectedHeap* g1) : |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
46 _g1(g1) |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
47 {} |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
48 |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
49 void do_object(oop obj) { |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
50 ShouldNotCallThis(); |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
51 } |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
52 bool do_object_b(oop obj); |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
53 }; |
b03260081e9b
7006113: G1: Initialize ReferenceProcessor::_is_alive_non_header field
johnc
parents:
1972
diff
changeset
|
54 |
342 | 55 // A generic CM bit map. This is essentially a wrapper around the BitMap |
56 // class, with one bit per (1<<_shifter) HeapWords. | |
57 | |
549
fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
apetrusenko
parents:
342
diff
changeset
|
58 class CMBitMapRO VALUE_OBJ_CLASS_SPEC { |
342 | 59 protected: |
60 HeapWord* _bmStartWord; // base address of range covered by map | |
61 size_t _bmWordSize; // map size (in #HeapWords covered) | |
62 const int _shifter; // map to char or bit | |
63 VirtualSpace _virtual_space; // underlying the bit map | |
64 BitMap _bm; // the bit map itself | |
65 | |
66 public: | |
67 // constructor | |
68 CMBitMapRO(ReservedSpace rs, int shifter); | |
69 | |
70 enum { do_yield = true }; | |
71 | |
72 // inquiries | |
73 HeapWord* startWord() const { return _bmStartWord; } | |
74 size_t sizeInWords() const { return _bmWordSize; } | |
75 // the following is one past the last word in space | |
76 HeapWord* endWord() const { return _bmStartWord + _bmWordSize; } | |
77 | |
78 // read marks | |
79 | |
80 bool isMarked(HeapWord* addr) const { | |
81 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
82 "outside underlying space?"); | |
83 return _bm.at(heapWordToOffset(addr)); | |
84 } | |
85 | |
86 // iteration | |
87 bool iterate(BitMapClosure* cl) { return _bm.iterate(cl); } | |
88 bool iterate(BitMapClosure* cl, MemRegion mr); | |
89 | |
90 // Return the address corresponding to the next marked bit at or after | |
91 // "addr", and before "limit", if "limit" is non-NULL. If there is no | |
92 // such bit, returns "limit" if that is non-NULL, or else "endWord()". | |
93 HeapWord* getNextMarkedWordAddress(HeapWord* addr, | |
94 HeapWord* limit = NULL) const; | |
95 // Return the address corresponding to the next unmarked bit at or after | |
96 // "addr", and before "limit", if "limit" is non-NULL. If there is no | |
97 // such bit, returns "limit" if that is non-NULL, or else "endWord()". | |
98 HeapWord* getNextUnmarkedWordAddress(HeapWord* addr, | |
99 HeapWord* limit = NULL) const; | |
100 | |
101 // conversion utilities | |
102 // XXX Fix these so that offsets are size_t's... | |
103 HeapWord* offsetToHeapWord(size_t offset) const { | |
104 return _bmStartWord + (offset << _shifter); | |
105 } | |
106 size_t heapWordToOffset(HeapWord* addr) const { | |
107 return pointer_delta(addr, _bmStartWord) >> _shifter; | |
108 } | |
109 int heapWordDiffToOffsetDiff(size_t diff) const; | |
110 HeapWord* nextWord(HeapWord* addr) { | |
111 return offsetToHeapWord(heapWordToOffset(addr) + 1); | |
112 } | |
113 | |
114 void mostly_disjoint_range_union(BitMap* from_bitmap, | |
115 size_t from_start_index, | |
116 HeapWord* to_start_word, | |
117 size_t word_num); | |
118 | |
119 // debugging | |
120 NOT_PRODUCT(bool covers(ReservedSpace rs) const;) | |
121 }; | |
122 | |
123 class CMBitMap : public CMBitMapRO { | |
124 | |
125 public: | |
126 // constructor | |
127 CMBitMap(ReservedSpace rs, int shifter) : | |
128 CMBitMapRO(rs, shifter) {} | |
129 | |
130 // write marks | |
131 void mark(HeapWord* addr) { | |
132 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
133 "outside underlying space?"); | |
134 _bm.at_put(heapWordToOffset(addr), true); | |
135 } | |
136 void clear(HeapWord* addr) { | |
137 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
138 "outside underlying space?"); | |
139 _bm.at_put(heapWordToOffset(addr), false); | |
140 } | |
141 bool parMark(HeapWord* addr) { | |
142 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
143 "outside underlying space?"); | |
144 return _bm.par_at_put(heapWordToOffset(addr), true); | |
145 } | |
146 bool parClear(HeapWord* addr) { | |
147 assert(_bmStartWord <= addr && addr < (_bmStartWord + _bmWordSize), | |
148 "outside underlying space?"); | |
149 return _bm.par_at_put(heapWordToOffset(addr), false); | |
150 } | |
151 void markRange(MemRegion mr); | |
152 void clearAll(); | |
153 void clearRange(MemRegion mr); | |
154 | |
155 // Starting at the bit corresponding to "addr" (inclusive), find the next | |
156 // "1" bit, if any. This bit starts some run of consecutive "1"'s; find | |
157 // the end of this run (stopping at "end_addr"). Return the MemRegion | |
158 // covering from the start of the region corresponding to the first bit | |
159 // of the run to the end of the region corresponding to the last bit of | |
160 // the run. If there is no "1" bit at or after "addr", return an empty | |
161 // MemRegion. | |
162 MemRegion getAndClearMarkedRegion(HeapWord* addr, HeapWord* end_addr); | |
163 }; | |
164 | |
165 // Represents a marking stack used by the CM collector. | |
166 // 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
|
167 class CMMarkStack VALUE_OBJ_CLASS_SPEC { |
342 | 168 ConcurrentMark* _cm; |
169 oop* _base; // bottom of stack | |
170 jint _index; // one more than last occupied index | |
171 jint _capacity; // max #elements | |
172 jint _oops_do_bound; // Number of elements to include in next iteration. | |
173 NOT_PRODUCT(jint _max_depth;) // max depth plumbed during run | |
174 | |
175 bool _overflow; | |
176 DEBUG_ONLY(bool _drain_in_progress;) | |
177 DEBUG_ONLY(bool _drain_in_progress_yields;) | |
178 | |
179 public: | |
180 CMMarkStack(ConcurrentMark* cm); | |
181 ~CMMarkStack(); | |
182 | |
183 void allocate(size_t size); | |
184 | |
185 oop pop() { | |
186 if (!isEmpty()) { | |
187 return _base[--_index] ; | |
188 } | |
189 return NULL; | |
190 } | |
191 | |
192 // If overflow happens, don't do the push, and record the overflow. | |
193 // *Requires* that "ptr" is already marked. | |
194 void push(oop ptr) { | |
195 if (isFull()) { | |
196 // Record overflow. | |
197 _overflow = true; | |
198 return; | |
199 } else { | |
200 _base[_index++] = ptr; | |
201 NOT_PRODUCT(_max_depth = MAX2(_max_depth, _index)); | |
202 } | |
203 } | |
204 // Non-block impl. Note: concurrency is allowed only with other | |
205 // "par_push" operations, not with "pop" or "drain". We would need | |
206 // parallel versions of them if such concurrency was desired. | |
207 void par_push(oop ptr); | |
208 | |
209 // Pushes the first "n" elements of "ptr_arr" on the stack. | |
210 // Non-block impl. Note: concurrency is allowed only with other | |
211 // "par_adjoin_arr" or "push" operations, not with "pop" or "drain". | |
212 void par_adjoin_arr(oop* ptr_arr, int n); | |
213 | |
214 // Pushes the first "n" elements of "ptr_arr" on the stack. | |
215 // Locking impl: concurrency is allowed only with | |
216 // "par_push_arr" and/or "par_pop_arr" operations, which use the same | |
217 // locking strategy. | |
218 void par_push_arr(oop* ptr_arr, int n); | |
219 | |
220 // If returns false, the array was empty. Otherwise, removes up to "max" | |
221 // elements from the stack, and transfers them to "ptr_arr" in an | |
222 // unspecified order. The actual number transferred is given in "n" ("n | |
223 // == 0" is deliberately redundant with the return value.) Locking impl: | |
224 // concurrency is allowed only with "par_push_arr" and/or "par_pop_arr" | |
225 // operations, which use the same locking strategy. | |
226 bool par_pop_arr(oop* ptr_arr, int max, int* n); | |
227 | |
228 // Drain the mark stack, applying the given closure to all fields of | |
229 // objects on the stack. (That is, continue until the stack is empty, | |
230 // even if closure applications add entries to the stack.) The "bm" | |
231 // argument, if non-null, may be used to verify that only marked objects | |
232 // are on the mark stack. If "yield_after" is "true", then the | |
233 // concurrent marker performing the drain offers to yield after | |
234 // processing each object. If a yield occurs, stops the drain operation | |
235 // and returns false. Otherwise, returns true. | |
236 template<class OopClosureClass> | |
237 bool drain(OopClosureClass* cl, CMBitMap* bm, bool yield_after = false); | |
238 | |
239 bool isEmpty() { return _index == 0; } | |
240 bool isFull() { return _index == _capacity; } | |
241 int maxElems() { return _capacity; } | |
242 | |
243 bool overflow() { return _overflow; } | |
244 void clear_overflow() { _overflow = false; } | |
245 | |
246 int size() { return _index; } | |
247 | |
248 void setEmpty() { _index = 0; clear_overflow(); } | |
249 | |
250 // Record the current size; a subsequent "oops_do" will iterate only over | |
251 // indices valid at the time of this call. | |
252 void set_oops_do_bound(jint bound = -1) { | |
253 if (bound == -1) { | |
254 _oops_do_bound = _index; | |
255 } else { | |
256 _oops_do_bound = bound; | |
257 } | |
258 } | |
259 jint oops_do_bound() { return _oops_do_bound; } | |
260 // iterate over the oops in the mark stack, up to the bound recorded via | |
261 // the call above. | |
262 void oops_do(OopClosure* f); | |
263 }; | |
264 | |
549
fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
apetrusenko
parents:
342
diff
changeset
|
265 class CMRegionStack VALUE_OBJ_CLASS_SPEC { |
342 | 266 MemRegion* _base; |
267 jint _capacity; | |
268 jint _index; | |
269 jint _oops_do_bound; | |
270 bool _overflow; | |
271 public: | |
272 CMRegionStack(); | |
273 ~CMRegionStack(); | |
274 void allocate(size_t size); | |
275 | |
276 // This is lock-free; assumes that it will only be called in parallel | |
277 // 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
|
278 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
|
279 |
342 | 280 // Lock-free; assumes that it will only be called in parallel |
281 // 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
|
282 MemRegion pop_lock_free(); |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
283 |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
284 #if 0 |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
285 // 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
|
286 // 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
|
287 // diagnostic aid. |
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
288 |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
289 // 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
|
290 // 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
|
291 // 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
|
292 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
|
293 MemRegion pop_with_lock(); |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
294 #endif |
342 | 295 |
296 bool isEmpty() { return _index == 0; } | |
297 bool isFull() { return _index == _capacity; } | |
298 | |
299 bool overflow() { return _overflow; } | |
300 void clear_overflow() { _overflow = false; } | |
301 | |
302 int size() { return _index; } | |
303 | |
304 // It iterates over the entries in the region stack and it | |
305 // invalidates (i.e. assigns MemRegion()) the ones that point to | |
306 // regions in the collection set. | |
307 bool invalidate_entries_into_cset(); | |
308 | |
309 // This gives an upper bound up to which the iteration in | |
310 // invalidate_entries_into_cset() will reach. This prevents | |
311 // newly-added entries to be unnecessarily scanned. | |
312 void set_oops_do_bound() { | |
313 _oops_do_bound = _index; | |
314 } | |
315 | |
316 void setEmpty() { _index = 0; clear_overflow(); } | |
317 }; | |
318 | |
319 // this will enable a variety of different statistics per GC task | |
320 #define _MARKING_STATS_ 0 | |
321 // this will enable the higher verbose levels | |
322 #define _MARKING_VERBOSE_ 0 | |
323 | |
324 #if _MARKING_STATS_ | |
325 #define statsOnly(statement) \ | |
326 do { \ | |
327 statement ; \ | |
328 } while (0) | |
329 #else // _MARKING_STATS_ | |
330 #define statsOnly(statement) \ | |
331 do { \ | |
332 } while (0) | |
333 #endif // _MARKING_STATS_ | |
334 | |
335 typedef enum { | |
336 no_verbose = 0, // verbose turned off | |
337 stats_verbose, // only prints stats at the end of marking | |
338 low_verbose, // low verbose, mostly per region and per major event | |
339 medium_verbose, // a bit more detailed than low | |
340 high_verbose // per object verbose | |
341 } CMVerboseLevel; | |
342 | |
343 | |
344 class ConcurrentMarkThread; | |
345 | |
549
fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
apetrusenko
parents:
342
diff
changeset
|
346 class ConcurrentMark: public CHeapObj { |
342 | 347 friend class ConcurrentMarkThread; |
348 friend class CMTask; | |
349 friend class CMBitMapClosure; | |
350 friend class CSMarkOopClosure; | |
351 friend class CMGlobalObjectClosure; | |
352 friend class CMRemarkTask; | |
353 friend class CMConcurrentMarkingTask; | |
354 friend class G1ParNoteEndTask; | |
355 friend class CalcLiveObjectsClosure; | |
356 | |
357 protected: | |
358 ConcurrentMarkThread* _cmThread; // the thread doing the work | |
359 G1CollectedHeap* _g1h; // the heap. | |
360 size_t _parallel_marking_threads; // the number of marking | |
361 // threads we'll use | |
362 double _sleep_factor; // how much we have to sleep, with | |
363 // respect to the work we just did, to | |
364 // meet the marking overhead goal | |
365 double _marking_task_overhead; // marking target overhead for | |
366 // a single task | |
367 | |
368 // same as the two above, but for the cleanup task | |
369 double _cleanup_sleep_factor; | |
370 double _cleanup_task_overhead; | |
371 | |
2152 | 372 FreeRegionList _cleanup_list; |
342 | 373 |
374 // CMS marking support structures | |
375 CMBitMap _markBitMap1; | |
376 CMBitMap _markBitMap2; | |
377 CMBitMapRO* _prevMarkBitMap; // completed mark bitmap | |
378 CMBitMap* _nextMarkBitMap; // under-construction mark bitmap | |
379 bool _at_least_one_mark_complete; | |
380 | |
381 BitMap _region_bm; | |
382 BitMap _card_bm; | |
383 | |
384 // Heap bounds | |
385 HeapWord* _heap_start; | |
386 HeapWord* _heap_end; | |
387 | |
388 // For gray objects | |
389 CMMarkStack _markStack; // Grey objects behind global finger. | |
390 CMRegionStack _regionStack; // Grey regions behind global finger. | |
391 HeapWord* volatile _finger; // the global finger, region aligned, | |
392 // always points to the end of the | |
393 // last claimed region | |
394 | |
395 // marking tasks | |
396 size_t _max_task_num; // maximum task number | |
397 size_t _active_tasks; // task num currently active | |
398 CMTask** _tasks; // task queue array (max_task_num len) | |
399 CMTaskQueueSet* _task_queues; // task queue set | |
400 ParallelTaskTerminator _terminator; // for termination | |
401 | |
402 // Two sync barriers that are used to synchronise tasks when an | |
403 // overflow occurs. The algorithm is the following. All tasks enter | |
404 // the first one to ensure that they have all stopped manipulating | |
405 // the global data structures. After they exit it, they re-initialise | |
406 // their data structures and task 0 re-initialises the global data | |
407 // structures. Then, they enter the second sync barrier. This | |
408 // ensure, that no task starts doing work before all data | |
409 // structures (local and global) have been re-initialised. When they | |
410 // exit it, they are free to start working again. | |
411 WorkGangBarrierSync _first_overflow_barrier_sync; | |
412 WorkGangBarrierSync _second_overflow_barrier_sync; | |
413 | |
414 | |
415 // this is set by any task, when an overflow on the global data | |
416 // structures is detected. | |
417 volatile bool _has_overflown; | |
418 // true: marking is concurrent, false: we're in remark | |
419 volatile bool _concurrent; | |
420 // set at the end of a Full GC so that marking aborts | |
421 volatile bool _has_aborted; | |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
422 |
342 | 423 // used when remark aborts due to an overflow to indicate that |
424 // another concurrent marking phase should start | |
425 volatile bool _restart_for_overflow; | |
426 | |
427 // This is true from the very start of concurrent marking until the | |
428 // point when all the tasks complete their work. It is really used | |
429 // to determine the points between the end of concurrent marking and | |
430 // time of remark. | |
431 volatile bool _concurrent_marking_in_progress; | |
432 | |
433 // verbose level | |
434 CMVerboseLevel _verbose_level; | |
435 | |
436 // These two fields are used to implement the optimisation that | |
437 // avoids pushing objects on the global/region stack if there are | |
438 // no collection set regions above the lowest finger. | |
439 | |
440 // This is the lowest finger (among the global and local fingers), | |
441 // which is calculated before a new collection set is chosen. | |
442 HeapWord* _min_finger; | |
443 // If this flag is true, objects/regions that are marked below the | |
444 // finger should be pushed on the stack(s). If this is flag is | |
445 // false, it is safe not to push them on the stack(s). | |
446 bool _should_gray_objects; | |
447 | |
448 // All of these times are in ms. | |
449 NumberSeq _init_times; | |
450 NumberSeq _remark_times; | |
451 NumberSeq _remark_mark_times; | |
452 NumberSeq _remark_weak_ref_times; | |
453 NumberSeq _cleanup_times; | |
454 double _total_counting_time; | |
455 double _total_rs_scrub_time; | |
456 | |
457 double* _accum_task_vtime; // accumulated task vtime | |
458 | |
459 WorkGang* _parallel_workers; | |
460 | |
461 void weakRefsWork(bool clear_all_soft_refs); | |
462 | |
463 void swapMarkBitMaps(); | |
464 | |
465 // It resets the global marking data structures, as well as the | |
466 // task local ones; should be called during initial mark. | |
467 void reset(); | |
468 // It resets all the marking data structures. | |
469 void clear_marking_state(); | |
470 | |
471 // It should be called to indicate which phase we're in (concurrent | |
472 // mark or remark) and how many threads are currently active. | |
473 void set_phase(size_t active_tasks, bool concurrent); | |
474 // We do this after we're done with marking so that the marking data | |
475 // structures are initialised to a sensible and predictable state. | |
476 void set_non_marking_state(); | |
477 | |
478 // prints all gathered CM-related statistics | |
479 void print_stats(); | |
480 | |
2152 | 481 bool cleanup_list_is_empty() { |
482 return _cleanup_list.is_empty(); | |
483 } | |
484 | |
342 | 485 // accessor methods |
486 size_t parallel_marking_threads() { return _parallel_marking_threads; } | |
487 double sleep_factor() { return _sleep_factor; } | |
488 double marking_task_overhead() { return _marking_task_overhead;} | |
489 double cleanup_sleep_factor() { return _cleanup_sleep_factor; } | |
490 double cleanup_task_overhead() { return _cleanup_task_overhead;} | |
491 | |
492 HeapWord* finger() { return _finger; } | |
493 bool concurrent() { return _concurrent; } | |
494 size_t active_tasks() { return _active_tasks; } | |
495 ParallelTaskTerminator* terminator() { return &_terminator; } | |
496 | |
497 // It claims the next available region to be scanned by a marking | |
498 // task. It might return NULL if the next region is empty or we have | |
499 // run out of regions. In the latter case, out_of_regions() | |
500 // determines whether we've really run out of regions or the task | |
501 // should call claim_region() again. This might seem a bit | |
502 // awkward. Originally, the code was written so that claim_region() | |
503 // either successfully returned with a non-empty region or there | |
504 // were no more regions to be claimed. The problem with this was | |
505 // that, in certain circumstances, it iterated over large chunks of | |
506 // the heap finding only empty regions and, while it was working, it | |
507 // was preventing the calling task to call its regular clock | |
508 // method. So, this way, each task will spend very little time in | |
509 // claim_region() and is allowed to call the regular clock method | |
510 // frequently. | |
511 HeapRegion* claim_region(int task); | |
512 | |
513 // It determines whether we've run out of regions to scan. | |
514 bool out_of_regions() { return _finger == _heap_end; } | |
515 | |
516 // Returns the task with the given id | |
517 CMTask* task(int id) { | |
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
518 assert(0 <= id && id < (int) _active_tasks, |
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
519 "task id not within active bounds"); |
342 | 520 return _tasks[id]; |
521 } | |
522 | |
523 // Returns the task queue with the given id | |
524 CMTaskQueue* task_queue(int id) { | |
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
525 assert(0 <= id && id < (int) _active_tasks, |
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
526 "task queue id not within active bounds"); |
342 | 527 return (CMTaskQueue*) _task_queues->queue(id); |
528 } | |
529 | |
530 // Returns the task queue set | |
531 CMTaskQueueSet* task_queues() { return _task_queues; } | |
532 | |
533 // Access / manipulation of the overflow flag which is set to | |
534 // indicate that the global stack or region stack has overflown | |
535 bool has_overflown() { return _has_overflown; } | |
536 void set_has_overflown() { _has_overflown = true; } | |
537 void clear_has_overflown() { _has_overflown = false; } | |
538 | |
539 bool has_aborted() { return _has_aborted; } | |
540 bool restart_for_overflow() { return _restart_for_overflow; } | |
541 | |
542 // Methods to enter the two overflow sync barriers | |
543 void enter_first_sync_barrier(int task_num); | |
544 void enter_second_sync_barrier(int task_num); | |
545 | |
546 public: | |
547 // Manipulation of the global mark stack. | |
548 // Notice that the first mark_stack_push is CAS-based, whereas the | |
549 // two below are Mutex-based. This is OK since the first one is only | |
550 // called during evacuation pauses and doesn't compete with the | |
551 // other two (which are called by the marking tasks during | |
552 // concurrent marking or remark). | |
553 bool mark_stack_push(oop p) { | |
554 _markStack.par_push(p); | |
555 if (_markStack.overflow()) { | |
556 set_has_overflown(); | |
557 return false; | |
558 } | |
559 return true; | |
560 } | |
561 bool mark_stack_push(oop* arr, int n) { | |
562 _markStack.par_push_arr(arr, n); | |
563 if (_markStack.overflow()) { | |
564 set_has_overflown(); | |
565 return false; | |
566 } | |
567 return true; | |
568 } | |
569 void mark_stack_pop(oop* arr, int max, int* n) { | |
570 _markStack.par_pop_arr(arr, max, n); | |
571 } | |
572 size_t mark_stack_size() { return _markStack.size(); } | |
573 size_t partial_mark_stack_size_target() { return _markStack.maxElems()/3; } | |
574 bool mark_stack_overflow() { return _markStack.overflow(); } | |
575 bool mark_stack_empty() { return _markStack.isEmpty(); } | |
576 | |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
577 // (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
|
578 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
|
579 // 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
|
580 // pauses. |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
581 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
|
582 |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
583 _regionStack.push_lock_free(mr); |
342 | 584 if (_regionStack.overflow()) { |
585 set_has_overflown(); | |
586 return false; | |
587 } | |
588 return true; | |
589 } | |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
590 |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
591 // 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
|
592 // 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
|
593 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
|
594 return _regionStack.pop_lock_free(); |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
595 } |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
596 |
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
597 #if 0 |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
598 // 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
|
599 // 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
|
600 // diagnostic aid. |
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
601 |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
602 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
|
603 // 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
|
604 // concurrent marking or remark. |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
605 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
|
606 "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
|
607 |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
608 _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
|
609 if (_regionStack.overflow()) { |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
610 set_has_overflown(); |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
611 return false; |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
612 } |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
613 return true; |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
614 } |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
615 |
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
616 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
|
617 // 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
|
618 // concurrent marking or remark. |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
619 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
|
620 "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
|
621 |
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
622 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
|
623 } |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
624 #endif |
1358
72f725c5a7be
6940310: G1: MT-unsafe calls to CM::region_stack_push() / CM::region_stack_pop()
tonyp
parents:
1311
diff
changeset
|
625 |
342 | 626 int region_stack_size() { return _regionStack.size(); } |
627 bool region_stack_overflow() { return _regionStack.overflow(); } | |
628 bool region_stack_empty() { return _regionStack.isEmpty(); } | |
629 | |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
630 // 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
|
631 // 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
|
632 // 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
|
633 // 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
|
634 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
|
635 |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
636 // 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
|
637 bool has_aborted_regions(); |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
638 |
342 | 639 bool concurrent_marking_in_progress() { |
640 return _concurrent_marking_in_progress; | |
641 } | |
642 void set_concurrent_marking_in_progress() { | |
643 _concurrent_marking_in_progress = true; | |
644 } | |
645 void clear_concurrent_marking_in_progress() { | |
646 _concurrent_marking_in_progress = false; | |
647 } | |
648 | |
649 void update_accum_task_vtime(int i, double vtime) { | |
650 _accum_task_vtime[i] += vtime; | |
651 } | |
652 | |
653 double all_task_accum_vtime() { | |
654 double ret = 0.0; | |
655 for (int i = 0; i < (int)_max_task_num; ++i) | |
656 ret += _accum_task_vtime[i]; | |
657 return ret; | |
658 } | |
659 | |
660 // Attempts to steal an object from the task queues of other tasks | |
661 bool try_stealing(int task_num, int* hash_seed, oop& obj) { | |
662 return _task_queues->steal(task_num, hash_seed, obj); | |
663 } | |
664 | |
665 // It grays an object by first marking it. Then, if it's behind the | |
666 // global finger, it also pushes it on the global stack. | |
667 void deal_with_reference(oop obj); | |
668 | |
669 ConcurrentMark(ReservedSpace rs, int max_regions); | |
670 ~ConcurrentMark(); | |
671 ConcurrentMarkThread* cmThread() { return _cmThread; } | |
672 | |
673 CMBitMapRO* prevMarkBitMap() const { return _prevMarkBitMap; } | |
674 CMBitMap* nextMarkBitMap() const { return _nextMarkBitMap; } | |
675 | |
676 // The following three are interaction between CM and | |
677 // G1CollectedHeap | |
678 | |
679 // This notifies CM that a root during initial-mark needs to be | |
680 // grayed and it's MT-safe. Currently, we just mark it. But, in the | |
681 // future, we can experiment with pushing it on the stack and we can | |
682 // do this without changing G1CollectedHeap. | |
683 void grayRoot(oop p); | |
684 // It's used during evacuation pauses to gray a region, if | |
685 // necessary, and it's MT-safe. It assumes that the caller has | |
686 // marked any objects on that region. If _should_gray_objects is | |
687 // true and we're still doing concurrent marking, the region is | |
688 // pushed on the region stack, if it is located below the global | |
689 // finger, otherwise we do nothing. | |
690 void grayRegionIfNecessary(MemRegion mr); | |
691 // It's used during evacuation pauses to mark and, if necessary, | |
692 // gray a single object and it's MT-safe. It assumes the caller did | |
693 // not mark the object. If _should_gray_objects is true and we're | |
694 // still doing concurrent marking, the objects is pushed on the | |
695 // global stack, if it is located below the global finger, otherwise | |
696 // we do nothing. | |
697 void markAndGrayObjectIfNecessary(oop p); | |
698 | |
1388 | 699 // It iterates over the heap and for each object it comes across it |
700 // will dump the contents of its reference fields, as well as | |
701 // liveness information for the object and its referents. The dump | |
702 // will be written to a file with the following name: | |
703 // G1PrintReachableBaseFile + "." + str. use_prev_marking decides | |
704 // whether the prev (use_prev_marking == true) or next | |
705 // (use_prev_marking == false) marking information will be used to | |
706 // determine the liveness of each object / referent. If all is true, | |
707 // all objects in the heap will be dumped, otherwise only the live | |
708 // ones. In the dump the following symbols / abbreviations are used: | |
709 // M : an explicitly live object (its bitmap bit is set) | |
710 // > : an implicitly live object (over tams) | |
711 // O : an object outside the G1 heap (typically: in the perm gen) | |
712 // NOT : a reference field whose referent is not live | |
713 // AND MARKED : indicates that an object is both explicitly and | |
714 // implicitly live (it should be one or the other, not both) | |
715 void print_reachable(const char* str, | |
716 bool use_prev_marking, bool all) PRODUCT_RETURN; | |
342 | 717 |
718 // Clear the next marking bitmap (will be called concurrently). | |
719 void clearNextBitmap(); | |
720 | |
721 // main CMS steps and related support | |
722 void checkpointRootsInitial(); | |
723 | |
724 // These two do the work that needs to be done before and after the | |
725 // initial root checkpoint. Since this checkpoint can be done at two | |
726 // different points (i.e. an explicit pause or piggy-backed on a | |
727 // young collection), then it's nice to be able to easily share the | |
728 // pre/post code. It might be the case that we can put everything in | |
729 // the post method. TP | |
730 void checkpointRootsInitialPre(); | |
731 void checkpointRootsInitialPost(); | |
732 | |
733 // Do concurrent phase of marking, to a tentative transitive closure. | |
734 void markFromRoots(); | |
735 | |
736 // Process all unprocessed SATB buffers. It is called at the | |
737 // beginning of an evacuation pause. | |
738 void drainAllSATBBuffers(); | |
739 | |
740 void checkpointRootsFinal(bool clear_all_soft_refs); | |
741 void checkpointRootsFinalWork(); | |
742 void calcDesiredRegions(); | |
743 void cleanup(); | |
744 void completeCleanup(); | |
745 | |
746 // Mark in the previous bitmap. NB: this is usually read-only, so use | |
747 // this carefully! | |
748 void markPrev(oop p); | |
749 void clear(oop p); | |
750 // Clears marks for all objects in the given range, for both prev and | |
751 // next bitmaps. NB: the previous bitmap is usually read-only, so use | |
752 // this carefully! | |
753 void clearRangeBothMaps(MemRegion mr); | |
754 | |
755 // Record the current top of the mark and region stacks; a | |
756 // subsequent oops_do() on the mark stack and | |
757 // invalidate_entries_into_cset() on the region stack will iterate | |
758 // only over indices valid at the time of this call. | |
759 void set_oops_do_bound() { | |
760 _markStack.set_oops_do_bound(); | |
761 _regionStack.set_oops_do_bound(); | |
762 } | |
763 // Iterate over the oops in the mark stack and all local queues. It | |
764 // also calls invalidate_entries_into_cset() on the region stack. | |
765 void oops_do(OopClosure* f); | |
766 // It is called at the end of an evacuation pause during marking so | |
767 // that CM is notified of where the new end of the heap is. It | |
768 // doesn't do anything if concurrent_marking_in_progress() is false, | |
769 // unless the force parameter is true. | |
770 void update_g1_committed(bool force = false); | |
771 | |
772 void complete_marking_in_collection_set(); | |
773 | |
774 // It indicates that a new collection set is being chosen. | |
775 void newCSet(); | |
776 // It registers a collection set heap region with CM. This is used | |
777 // to determine whether any heap regions are located above the finger. | |
778 void registerCSetRegion(HeapRegion* hr); | |
779 | |
1394
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
780 // 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
|
781 // 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
|
782 // 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
|
783 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
|
784 // 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
|
785 // 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
|
786 // _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
|
787 // 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
|
788 // collection of regions. |
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
789 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
|
790 _should_gray_objects = true; |
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
791 } |
1316cec51b4d
6819061: G1: eliminate serial Other times that are proportional to the collection set length
johnc
parents:
1388
diff
changeset
|
792 |
342 | 793 // Returns "true" if at least one mark has been completed. |
794 bool at_least_one_mark_complete() { return _at_least_one_mark_complete; } | |
795 | |
796 bool isMarked(oop p) const { | |
797 assert(p != NULL && p->is_oop(), "expected an oop"); | |
798 HeapWord* addr = (HeapWord*)p; | |
799 assert(addr >= _nextMarkBitMap->startWord() || | |
800 addr < _nextMarkBitMap->endWord(), "in a region"); | |
801 | |
802 return _nextMarkBitMap->isMarked(addr); | |
803 } | |
804 | |
805 inline bool not_yet_marked(oop p) const; | |
806 | |
807 // XXX Debug code | |
808 bool containing_card_is_marked(void* p); | |
809 bool containing_cards_are_marked(void* start, void* last); | |
810 | |
811 bool isPrevMarked(oop p) const { | |
812 assert(p != NULL && p->is_oop(), "expected an oop"); | |
813 HeapWord* addr = (HeapWord*)p; | |
814 assert(addr >= _prevMarkBitMap->startWord() || | |
815 addr < _prevMarkBitMap->endWord(), "in a region"); | |
816 | |
817 return _prevMarkBitMap->isMarked(addr); | |
818 } | |
819 | |
820 inline bool do_yield_check(int worker_i = 0); | |
821 inline bool should_yield(); | |
822 | |
823 // Called to abort the marking cycle after a Full GC takes palce. | |
824 void abort(); | |
825 | |
826 // This prints the global/local fingers. It is used for debugging. | |
827 NOT_PRODUCT(void print_finger();) | |
828 | |
829 void print_summary_info(); | |
830 | |
1019 | 831 void print_worker_threads_on(outputStream* st) const; |
832 | |
342 | 833 // The following indicate whether a given verbose level has been |
834 // set. Notice that anything above stats is conditional to | |
835 // _MARKING_VERBOSE_ having been set to 1 | |
836 bool verbose_stats() | |
837 { return _verbose_level >= stats_verbose; } | |
838 bool verbose_low() | |
839 { return _MARKING_VERBOSE_ && _verbose_level >= low_verbose; } | |
840 bool verbose_medium() | |
841 { return _MARKING_VERBOSE_ && _verbose_level >= medium_verbose; } | |
842 bool verbose_high() | |
843 { return _MARKING_VERBOSE_ && _verbose_level >= high_verbose; } | |
844 }; | |
845 | |
846 // A class representing a marking task. | |
847 class CMTask : public TerminatorTerminator { | |
848 private: | |
849 enum PrivateConstants { | |
850 // the regular clock call is called once the scanned words reaches | |
851 // this limit | |
852 words_scanned_period = 12*1024, | |
853 // the regular clock call is called once the number of visited | |
854 // references reaches this limit | |
855 refs_reached_period = 384, | |
856 // initial value for the hash seed, used in the work stealing code | |
857 init_hash_seed = 17, | |
858 // how many entries will be transferred between global stack and | |
859 // local queues | |
860 global_stack_transfer_size = 16 | |
861 }; | |
862 | |
863 int _task_id; | |
864 G1CollectedHeap* _g1h; | |
865 ConcurrentMark* _cm; | |
866 CMBitMap* _nextMarkBitMap; | |
867 // the task queue of this task | |
868 CMTaskQueue* _task_queue; | |
845
df6caf649ff7
6700789: G1: Enable use of compressed oops with G1 heaps
ysr
parents:
579
diff
changeset
|
869 private: |
342 | 870 // the task queue set---needed for stealing |
871 CMTaskQueueSet* _task_queues; | |
872 // indicates whether the task has been claimed---this is only for | |
873 // debugging purposes | |
874 bool _claimed; | |
875 | |
876 // number of calls to this task | |
877 int _calls; | |
878 | |
879 // when the virtual timer reaches this time, the marking step should | |
880 // exit | |
881 double _time_target_ms; | |
882 // the start time of the current marking step | |
883 double _start_time_ms; | |
884 | |
885 // the oop closure used for iterations over oops | |
886 OopClosure* _oop_closure; | |
887 | |
888 // the region this task is scanning, NULL if we're not scanning any | |
889 HeapRegion* _curr_region; | |
890 // the local finger of this task, NULL if we're not scanning a region | |
891 HeapWord* _finger; | |
892 // limit of the region this task is scanning, NULL if we're not scanning one | |
893 HeapWord* _region_limit; | |
894 | |
895 // This is used only when we scan regions popped from the region | |
896 // stack. It records what the last object on such a region we | |
897 // scanned was. It is used to ensure that, if we abort region | |
898 // iteration, we do not rescan the first part of the region. This | |
899 // should be NULL when we're not scanning a region from the region | |
900 // stack. | |
901 HeapWord* _region_finger; | |
902 | |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
903 // 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
|
904 // 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
|
905 // 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
|
906 // 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
|
907 // 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
|
908 // 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
|
909 // 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
|
910 MemRegion _aborted_region; |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
911 |
342 | 912 // the number of words this task has scanned |
913 size_t _words_scanned; | |
914 // When _words_scanned reaches this limit, the regular clock is | |
915 // called. Notice that this might be decreased under certain | |
916 // circumstances (i.e. when we believe that we did an expensive | |
917 // operation). | |
918 size_t _words_scanned_limit; | |
919 // the initial value of _words_scanned_limit (i.e. what it was | |
920 // before it was decreased). | |
921 size_t _real_words_scanned_limit; | |
922 | |
923 // the number of references this task has visited | |
924 size_t _refs_reached; | |
925 // When _refs_reached reaches this limit, the regular clock is | |
926 // called. Notice this this might be decreased under certain | |
927 // circumstances (i.e. when we believe that we did an expensive | |
928 // operation). | |
929 size_t _refs_reached_limit; | |
930 // the initial value of _refs_reached_limit (i.e. what it was before | |
931 // it was decreased). | |
932 size_t _real_refs_reached_limit; | |
933 | |
934 // used by the work stealing stuff | |
935 int _hash_seed; | |
936 // if this is true, then the task has aborted for some reason | |
937 bool _has_aborted; | |
938 // set when the task aborts because it has met its time quota | |
939 bool _has_aborted_timed_out; | |
940 // true when we're draining SATB buffers; this avoids the task | |
941 // aborting due to SATB buffers being available (as we're already | |
942 // dealing with them) | |
943 bool _draining_satb_buffers; | |
944 | |
945 // number sequence of past step times | |
946 NumberSeq _step_times_ms; | |
947 // elapsed time of this task | |
948 double _elapsed_time_ms; | |
949 // termination time of this task | |
950 double _termination_time_ms; | |
951 // when this task got into the termination protocol | |
952 double _termination_start_time_ms; | |
953 | |
954 // true when the task is during a concurrent phase, false when it is | |
955 // in the remark phase (so, in the latter case, we do not have to | |
956 // check all the things that we have to check during the concurrent | |
957 // phase, i.e. SATB buffer availability...) | |
958 bool _concurrent; | |
959 | |
960 TruncatedSeq _marking_step_diffs_ms; | |
961 | |
962 // LOTS of statistics related with this task | |
963 #if _MARKING_STATS_ | |
964 NumberSeq _all_clock_intervals_ms; | |
965 double _interval_start_time_ms; | |
966 | |
967 int _aborted; | |
968 int _aborted_overflow; | |
969 int _aborted_cm_aborted; | |
970 int _aborted_yield; | |
971 int _aborted_timed_out; | |
972 int _aborted_satb; | |
973 int _aborted_termination; | |
974 | |
975 int _steal_attempts; | |
976 int _steals; | |
977 | |
978 int _clock_due_to_marking; | |
979 int _clock_due_to_scanning; | |
980 | |
981 int _local_pushes; | |
982 int _local_pops; | |
983 int _local_max_size; | |
984 int _objs_scanned; | |
985 | |
986 int _global_pushes; | |
987 int _global_pops; | |
988 int _global_max_size; | |
989 | |
990 int _global_transfers_to; | |
991 int _global_transfers_from; | |
992 | |
993 int _region_stack_pops; | |
994 | |
995 int _regions_claimed; | |
996 int _objs_found_on_bitmap; | |
997 | |
998 int _satb_buffers_processed; | |
999 #endif // _MARKING_STATS_ | |
1000 | |
1001 // it updates the local fields after this task has claimed | |
1002 // a new region to scan | |
1003 void setup_for_region(HeapRegion* hr); | |
1004 // it brings up-to-date the limit of the region | |
1005 void update_region_limit(); | |
1006 // it resets the local fields after a task has finished scanning a | |
1007 // region | |
1008 void giveup_current_region(); | |
1009 | |
1010 // called when either the words scanned or the refs visited limit | |
1011 // has been reached | |
1012 void reached_limit(); | |
1013 // recalculates the words scanned and refs visited limits | |
1014 void recalculate_limits(); | |
1015 // decreases the words scanned and refs visited limits when we reach | |
1016 // an expensive operation | |
1017 void decrease_limits(); | |
1018 // it checks whether the words scanned or refs visited reached their | |
1019 // respective limit and calls reached_limit() if they have | |
1020 void check_limits() { | |
1021 if (_words_scanned >= _words_scanned_limit || | |
1022 _refs_reached >= _refs_reached_limit) | |
1023 reached_limit(); | |
1024 } | |
1025 // this is supposed to be called regularly during a marking step as | |
1026 // it checks a bunch of conditions that might cause the marking step | |
1027 // to abort | |
1028 void regular_clock_call(); | |
1029 bool concurrent() { return _concurrent; } | |
1030 | |
1031 public: | |
1032 // It resets the task; it should be called right at the beginning of | |
1033 // a marking phase. | |
1034 void reset(CMBitMap* _nextMarkBitMap); | |
1035 // it clears all the fields that correspond to a claimed region. | |
1036 void clear_region_fields(); | |
1037 | |
1038 void set_concurrent(bool concurrent) { _concurrent = concurrent; } | |
1039 | |
1040 // The main method of this class which performs a marking step | |
1041 // trying not to exceed the given duration. However, it might exit | |
1042 // prematurely, according to some conditions (i.e. SATB buffers are | |
1043 // available for processing). | |
1044 void do_marking_step(double target_ms); | |
1045 | |
1046 // These two calls start and stop the timer | |
1047 void record_start_time() { | |
1048 _elapsed_time_ms = os::elapsedTime() * 1000.0; | |
1049 } | |
1050 void record_end_time() { | |
1051 _elapsed_time_ms = os::elapsedTime() * 1000.0 - _elapsed_time_ms; | |
1052 } | |
1053 | |
1054 // returns the task ID | |
1055 int task_id() { return _task_id; } | |
1056 | |
1057 // From TerminatorTerminator. It determines whether this task should | |
1058 // exit the termination protocol after it's entered it. | |
1059 virtual bool should_exit_termination(); | |
1060 | |
1061 HeapWord* finger() { return _finger; } | |
1062 | |
1063 bool has_aborted() { return _has_aborted; } | |
1064 void set_has_aborted() { _has_aborted = true; } | |
1065 void clear_has_aborted() { _has_aborted = false; } | |
1066 bool claimed() { return _claimed; } | |
1067 | |
1835
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1068 // 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
|
1069 // 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
|
1070 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
|
1071 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
|
1072 { _aborted_region = mr; } |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1073 |
4805b9f4779e
6941395: G1: Use only lock-free versions of region stack push() and pop()
johnc
parents:
1552
diff
changeset
|
1074 // 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
|
1075 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
|
1076 |
342 | 1077 void set_oop_closure(OopClosure* oop_closure) { |
1078 _oop_closure = oop_closure; | |
1079 } | |
1080 | |
1081 // It grays the object by marking it and, if necessary, pushing it | |
1082 // on the local queue | |
1083 void deal_with_reference(oop obj); | |
1084 | |
1085 // It scans an object and visits its children. | |
1086 void scan_object(oop obj) { | |
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
1087 assert(_nextMarkBitMap->isMarked((HeapWord*) obj), "invariant"); |
342 | 1088 |
1089 if (_cm->verbose_high()) | |
1090 gclog_or_tty->print_cr("[%d] we're scanning object "PTR_FORMAT, | |
1091 _task_id, (void*) obj); | |
1092 | |
1093 size_t obj_size = obj->size(); | |
1094 _words_scanned += obj_size; | |
1095 | |
1096 obj->oop_iterate(_oop_closure); | |
1097 statsOnly( ++_objs_scanned ); | |
1098 check_limits(); | |
1099 } | |
1100 | |
1101 // It pushes an object on the local queue. | |
1102 void push(oop obj); | |
1103 | |
1104 // These two move entries to/from the global stack. | |
1105 void move_entries_to_global_stack(); | |
1106 void get_entries_from_global_stack(); | |
1107 | |
1108 // It pops and scans objects from the local queue. If partially is | |
1109 // true, then it stops when the queue size is of a given limit. If | |
1110 // partially is false, then it stops when the queue is empty. | |
1111 void drain_local_queue(bool partially); | |
1112 // It moves entries from the global stack to the local queue and | |
1113 // drains the local queue. If partially is true, then it stops when | |
1114 // both the global stack and the local queue reach a given size. If | |
1115 // partially if false, it tries to empty them totally. | |
1116 void drain_global_stack(bool partially); | |
1117 // It keeps picking SATB buffers and processing them until no SATB | |
1118 // buffers are available. | |
1119 void drain_satb_buffers(); | |
1120 // It keeps popping regions from the region stack and processing | |
1121 // them until the region stack is empty. | |
1122 void drain_region_stack(BitMapClosure* closure); | |
1123 | |
1124 // moves the local finger to a new location | |
1125 inline void move_finger_to(HeapWord* new_finger) { | |
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
1126 assert(new_finger >= _finger && new_finger < _region_limit, "invariant"); |
342 | 1127 _finger = new_finger; |
1128 } | |
1129 | |
1130 // moves the region finger to a new location | |
1131 inline void move_region_finger_to(HeapWord* new_finger) { | |
1023
11d4857fe5e1
6888619: G1: too many guarantees in concurrent marking
tonyp
parents:
1019
diff
changeset
|
1132 assert(new_finger < _cm->finger(), "invariant"); |
342 | 1133 _region_finger = new_finger; |
1134 } | |
1135 | |
1136 CMTask(int task_num, ConcurrentMark *cm, | |
1137 CMTaskQueue* task_queue, CMTaskQueueSet* task_queues); | |
1138 | |
1139 // it prints statistics associated with this task | |
1140 void print_stats(); | |
1141 | |
1142 #if _MARKING_STATS_ | |
1143 void increase_objs_found_on_bitmap() { ++_objs_found_on_bitmap; } | |
1144 #endif // _MARKING_STATS_ | |
1145 }; | |
1972 | 1146 |
1147 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP |