Mercurial > hg > graal-compiler
annotate src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp @ 4091:d06a2d7fcd5b
7110718: -XX:MarkSweepAlwaysCompactCount=0 crashes the JVM
Summary: Interpret MarkSweepAlwaysCompactCount < 1 as never do full compaction
Reviewed-by: ysr, tonyp, jmasa, johnc
| author | brutisso |
|---|---|
| date | Mon, 21 Nov 2011 07:47:34 +0100 |
| parents | f95d63e2154a |
| children | da91efe96a93 |
| rev | line source |
|---|---|
| 0 | 1 /* |
|
4091
d06a2d7fcd5b
7110718: -XX:MarkSweepAlwaysCompactCount=0 crashes the JVM
brutisso
parents:
1972
diff
changeset
|
2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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:
579
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
579
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:
579
diff
changeset
|
21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #include "precompiled.hpp" |
| 26 #include "classfile/systemDictionary.hpp" | |
| 27 #include "gc_implementation/parallelScavenge/objectStartArray.hpp" | |
| 28 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" | |
| 29 #include "gc_implementation/parallelScavenge/psMarkSweep.hpp" | |
| 30 #include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp" | |
| 31 #include "gc_implementation/shared/liveRange.hpp" | |
| 32 #include "gc_implementation/shared/markSweep.inline.hpp" | |
| 33 #include "gc_implementation/shared/spaceDecorator.hpp" | |
| 34 #include "oops/oop.inline.hpp" | |
| 0 | 35 |
| 36 PSMarkSweepDecorator* PSMarkSweepDecorator::_destination_decorator = NULL; | |
| 37 | |
| 38 | |
| 39 void PSMarkSweepDecorator::set_destination_decorator_tenured() { | |
| 40 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 41 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 42 | |
| 43 _destination_decorator = heap->old_gen()->object_mark_sweep(); | |
| 44 } | |
| 45 | |
| 46 void PSMarkSweepDecorator::set_destination_decorator_perm_gen() { | |
| 47 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 48 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 49 | |
| 50 _destination_decorator = heap->perm_gen()->object_mark_sweep(); | |
| 51 } | |
| 52 | |
| 53 void PSMarkSweepDecorator::advance_destination_decorator() { | |
| 54 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 55 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 56 | |
| 57 assert(_destination_decorator != NULL, "Sanity"); | |
| 58 guarantee(_destination_decorator != heap->perm_gen()->object_mark_sweep(), "Cannot advance perm gen decorator"); | |
| 59 | |
| 60 PSMarkSweepDecorator* first = heap->old_gen()->object_mark_sweep(); | |
| 61 PSMarkSweepDecorator* second = heap->young_gen()->eden_mark_sweep(); | |
| 62 PSMarkSweepDecorator* third = heap->young_gen()->from_mark_sweep(); | |
| 63 PSMarkSweepDecorator* fourth = heap->young_gen()->to_mark_sweep(); | |
| 64 | |
| 65 if ( _destination_decorator == first ) { | |
| 66 _destination_decorator = second; | |
| 67 } else if ( _destination_decorator == second ) { | |
| 68 _destination_decorator = third; | |
| 69 } else if ( _destination_decorator == third ) { | |
| 70 _destination_decorator = fourth; | |
| 71 } else { | |
| 72 fatal("PSMarkSweep attempting to advance past last compaction area"); | |
| 73 } | |
| 74 } | |
| 75 | |
| 76 PSMarkSweepDecorator* PSMarkSweepDecorator::destination_decorator() { | |
| 77 assert(_destination_decorator != NULL, "Sanity"); | |
| 78 | |
| 79 return _destination_decorator; | |
| 80 } | |
| 81 | |
| 82 // FIX ME FIX ME FIX ME FIX ME!!!!!!!!! | |
| 83 // The object forwarding code is duplicated. Factor this out!!!!! | |
| 84 // | |
| 85 // This method "precompacts" objects inside its space to dest. It places forwarding | |
| 86 // pointers into markOops for use by adjust_pointers. If "dest" should overflow, we | |
| 87 // finish by compacting into our own space. | |
| 88 | |
| 89 void PSMarkSweepDecorator::precompact() { | |
| 90 // Reset our own compact top. | |
| 91 set_compaction_top(space()->bottom()); | |
| 92 | |
| 93 /* We allow some amount of garbage towards the bottom of the space, so | |
| 94 * we don't start compacting before there is a significant gain to be made. | |
| 95 * Occasionally, we want to ensure a full compaction, which is determined | |
| 96 * by the MarkSweepAlwaysCompactCount parameter. This is a significant | |
| 97 * performance improvement! | |
| 98 */ | |
|
4091
d06a2d7fcd5b
7110718: -XX:MarkSweepAlwaysCompactCount=0 crashes the JVM
brutisso
parents:
1972
diff
changeset
|
99 bool skip_dead = (MarkSweepAlwaysCompactCount < 1) |
|
d06a2d7fcd5b
7110718: -XX:MarkSweepAlwaysCompactCount=0 crashes the JVM
brutisso
parents:
1972
diff
changeset
|
100 || ((PSMarkSweep::total_invocations() % MarkSweepAlwaysCompactCount) != 0); |
| 0 | 101 |
| 438 | 102 size_t allowed_deadspace = 0; |
| 0 | 103 if (skip_dead) { |
| 438 | 104 const size_t ratio = allowed_dead_ratio(); |
| 105 allowed_deadspace = space()->capacity_in_words() * ratio / 100; | |
| 0 | 106 } |
| 107 | |
| 108 // Fetch the current destination decorator | |
| 109 PSMarkSweepDecorator* dest = destination_decorator(); | |
| 110 ObjectStartArray* start_array = dest->start_array(); | |
| 111 | |
| 112 HeapWord* compact_top = dest->compaction_top(); | |
| 113 HeapWord* compact_end = dest->space()->end(); | |
| 114 | |
| 115 HeapWord* q = space()->bottom(); | |
| 116 HeapWord* t = space()->top(); | |
| 117 | |
| 118 HeapWord* end_of_live= q; /* One byte beyond the last byte of the last | |
| 119 live object. */ | |
| 120 HeapWord* first_dead = space()->end(); /* The first dead object. */ | |
| 121 LiveRange* liveRange = NULL; /* The current live range, recorded in the | |
| 122 first header of preceding free area. */ | |
| 123 _first_dead = first_dead; | |
| 124 | |
| 125 const intx interval = PrefetchScanIntervalInBytes; | |
| 126 | |
| 127 while (q < t) { | |
| 128 assert(oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() || | |
| 129 oop(q)->mark()->has_bias_pattern(), | |
| 130 "these are the only valid states during a mark sweep"); | |
| 131 if (oop(q)->is_gc_marked()) { | |
| 132 /* prefetch beyond q */ | |
| 133 Prefetch::write(q, interval); | |
| 134 size_t size = oop(q)->size(); | |
| 135 | |
| 136 size_t compaction_max_size = pointer_delta(compact_end, compact_top); | |
| 137 | |
| 138 // This should only happen if a space in the young gen overflows the | |
| 139 // old gen. If that should happen, we null out the start_array, because | |
| 140 // the young spaces are not covered by one. | |
| 141 while(size > compaction_max_size) { | |
| 142 // First record the last compact_top | |
| 143 dest->set_compaction_top(compact_top); | |
| 144 | |
| 145 // Advance to the next compaction decorator | |
| 146 advance_destination_decorator(); | |
| 147 dest = destination_decorator(); | |
| 148 | |
| 149 // Update compaction info | |
| 150 start_array = dest->start_array(); | |
| 151 compact_top = dest->compaction_top(); | |
| 152 compact_end = dest->space()->end(); | |
| 153 assert(compact_top == dest->space()->bottom(), "Advanced to space already in use"); | |
| 154 assert(compact_end > compact_top, "Must always be space remaining"); | |
| 155 compaction_max_size = | |
| 156 pointer_delta(compact_end, compact_top); | |
| 157 } | |
| 158 | |
| 159 // store the forwarding pointer into the mark word | |
| 160 if (q != compact_top) { | |
| 161 oop(q)->forward_to(oop(compact_top)); | |
| 162 assert(oop(q)->is_gc_marked(), "encoding the pointer should preserve the mark"); | |
| 163 } else { | |
|
374
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
164 // if the object isn't moving we can just set the mark to the default |
|
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
165 // mark and handle it specially later on. |
|
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
166 oop(q)->init_mark(); |
| 0 | 167 assert(oop(q)->forwardee() == NULL, "should be forwarded to NULL"); |
| 168 } | |
| 169 | |
| 170 // Update object start array | |
|
374
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
171 if (start_array) { |
|
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
172 start_array->allocate_block(compact_top); |
| 0 | 173 } |
| 174 | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
175 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(oop(q), size)); |
| 0 | 176 compact_top += size; |
| 177 assert(compact_top <= dest->space()->end(), | |
| 178 "Exceeding space in destination"); | |
| 179 | |
| 180 q += size; | |
| 181 end_of_live = q; | |
| 182 } else { | |
| 183 /* run over all the contiguous dead objects */ | |
| 184 HeapWord* end = q; | |
| 185 do { | |
| 186 /* prefetch beyond end */ | |
| 187 Prefetch::write(end, interval); | |
| 188 end += oop(end)->size(); | |
| 189 } while (end < t && (!oop(end)->is_gc_marked())); | |
| 190 | |
| 191 /* see if we might want to pretend this object is alive so that | |
| 192 * we don't have to compact quite as often. | |
| 193 */ | |
| 194 if (allowed_deadspace > 0 && q == compact_top) { | |
| 195 size_t sz = pointer_delta(end, q); | |
| 196 if (insert_deadspace(allowed_deadspace, q, sz)) { | |
| 197 size_t compaction_max_size = pointer_delta(compact_end, compact_top); | |
| 198 | |
| 199 // This should only happen if a space in the young gen overflows the | |
| 200 // old gen. If that should happen, we null out the start_array, because | |
| 201 // the young spaces are not covered by one. | |
| 202 while (sz > compaction_max_size) { | |
| 203 // First record the last compact_top | |
| 204 dest->set_compaction_top(compact_top); | |
| 205 | |
| 206 // Advance to the next compaction decorator | |
| 207 advance_destination_decorator(); | |
| 208 dest = destination_decorator(); | |
| 209 | |
| 210 // Update compaction info | |
| 211 start_array = dest->start_array(); | |
| 212 compact_top = dest->compaction_top(); | |
| 213 compact_end = dest->space()->end(); | |
| 214 assert(compact_top == dest->space()->bottom(), "Advanced to space already in use"); | |
| 215 assert(compact_end > compact_top, "Must always be space remaining"); | |
| 216 compaction_max_size = | |
| 217 pointer_delta(compact_end, compact_top); | |
| 218 } | |
| 219 | |
| 220 // store the forwarding pointer into the mark word | |
| 221 if (q != compact_top) { | |
| 222 oop(q)->forward_to(oop(compact_top)); | |
| 223 assert(oop(q)->is_gc_marked(), "encoding the pointer should preserve the mark"); | |
| 224 } else { | |
| 225 // if the object isn't moving we can just set the mark to the default | |
|
374
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
226 // mark and handle it specially later on. |
|
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
227 oop(q)->init_mark(); |
| 0 | 228 assert(oop(q)->forwardee() == NULL, "should be forwarded to NULL"); |
| 229 } | |
| 230 | |
|
374
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
231 // Update object start array |
|
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
232 if (start_array) { |
|
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
269
diff
changeset
|
233 start_array->allocate_block(compact_top); |
| 0 | 234 } |
| 235 | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
236 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(oop(q), sz)); |
| 0 | 237 compact_top += sz; |
| 238 assert(compact_top <= dest->space()->end(), | |
| 239 "Exceeding space in destination"); | |
| 240 | |
| 241 q = end; | |
| 242 end_of_live = end; | |
| 243 continue; | |
| 244 } | |
| 245 } | |
| 246 | |
| 247 /* for the previous LiveRange, record the end of the live objects. */ | |
| 248 if (liveRange) { | |
| 249 liveRange->set_end(q); | |
| 250 } | |
| 251 | |
| 252 /* record the current LiveRange object. | |
| 253 * liveRange->start() is overlaid on the mark word. | |
| 254 */ | |
| 255 liveRange = (LiveRange*)q; | |
| 256 liveRange->set_start(end); | |
| 257 liveRange->set_end(end); | |
| 258 | |
| 259 /* see if this is the first dead region. */ | |
| 260 if (q < first_dead) { | |
| 261 first_dead = q; | |
| 262 } | |
| 263 | |
| 264 /* move on to the next object */ | |
| 265 q = end; | |
| 266 } | |
| 267 } | |
| 268 | |
| 269 assert(q == t, "just checking"); | |
| 270 if (liveRange != NULL) { | |
| 271 liveRange->set_end(q); | |
| 272 } | |
| 273 _end_of_live = end_of_live; | |
| 274 if (end_of_live < first_dead) { | |
| 275 first_dead = end_of_live; | |
| 276 } | |
| 277 _first_dead = first_dead; | |
| 278 | |
| 279 // Update compaction top | |
| 280 dest->set_compaction_top(compact_top); | |
| 281 } | |
| 282 | |
| 438 | 283 bool PSMarkSweepDecorator::insert_deadspace(size_t& allowed_deadspace_words, |
| 284 HeapWord* q, size_t deadlength) { | |
| 285 if (allowed_deadspace_words >= deadlength) { | |
| 286 allowed_deadspace_words -= deadlength; | |
|
481
7d7a7c599c17
6578152: fill_region_with_object has usability and safety issues
jcoomes
parents:
438
diff
changeset
|
287 CollectedHeap::fill_with_object(q, deadlength); |
|
7d7a7c599c17
6578152: fill_region_with_object has usability and safety issues
jcoomes
parents:
438
diff
changeset
|
288 oop(q)->set_mark(oop(q)->mark()->set_marked()); |
|
7d7a7c599c17
6578152: fill_region_with_object has usability and safety issues
jcoomes
parents:
438
diff
changeset
|
289 assert((int) deadlength == oop(q)->size(), "bad filler object size"); |
| 0 | 290 // Recall that we required "q == compaction_top". |
| 291 return true; | |
| 292 } else { | |
| 293 allowed_deadspace_words = 0; | |
| 294 return false; | |
| 295 } | |
| 296 } | |
| 297 | |
| 298 void PSMarkSweepDecorator::adjust_pointers() { | |
| 299 // adjust all the interior pointers to point at the new locations of objects | |
| 300 // Used by MarkSweep::mark_sweep_phase3() | |
| 301 | |
| 302 HeapWord* q = space()->bottom(); | |
| 303 HeapWord* t = _end_of_live; // Established by "prepare_for_compaction". | |
| 304 | |
| 305 assert(_first_dead <= _end_of_live, "Stands to reason, no?"); | |
| 306 | |
| 307 if (q < t && _first_dead > q && | |
| 308 !oop(q)->is_gc_marked()) { | |
| 309 // we have a chunk of the space which hasn't moved and we've | |
| 310 // reinitialized the mark word during the previous pass, so we can't | |
| 311 // use is_gc_marked for the traversal. | |
| 312 HeapWord* end = _first_dead; | |
| 313 | |
| 314 while (q < end) { | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
315 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q))); |
| 0 | 316 // point all the oops to the new location |
| 317 size_t size = oop(q)->adjust_pointers(); | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
318 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers()); |
|
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
319 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size)); |
| 0 | 320 q += size; |
| 321 } | |
| 322 | |
| 323 if (_first_dead == t) { | |
| 324 q = t; | |
| 325 } else { | |
| 326 // $$$ This is funky. Using this to read the previously written | |
| 327 // LiveRange. See also use below. | |
| 328 q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); | |
| 329 } | |
| 330 } | |
| 331 const intx interval = PrefetchScanIntervalInBytes; | |
| 332 | |
| 333 debug_only(HeapWord* prev_q = NULL); | |
| 334 while (q < t) { | |
| 335 // prefetch beyond q | |
| 336 Prefetch::write(q, interval); | |
| 337 if (oop(q)->is_gc_marked()) { | |
| 338 // q is alive | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
339 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q))); |
| 0 | 340 // point all the oops to the new location |
| 341 size_t size = oop(q)->adjust_pointers(); | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
342 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers()); |
|
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
343 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size)); |
| 0 | 344 debug_only(prev_q = q); |
| 345 q += size; | |
| 346 } else { | |
| 347 // q is not a live object, so its mark should point at the next | |
| 348 // live object | |
| 349 debug_only(prev_q = q); | |
| 350 q = (HeapWord*) oop(q)->mark()->decode_pointer(); | |
| 351 assert(q > prev_q, "we should be moving forward through memory"); | |
| 352 } | |
| 353 } | |
| 354 | |
| 355 assert(q == t, "just checking"); | |
| 356 } | |
| 357 | |
| 358 void PSMarkSweepDecorator::compact(bool mangle_free_space ) { | |
| 359 // Copy all live objects to their new location | |
| 360 // Used by MarkSweep::mark_sweep_phase4() | |
| 361 | |
| 362 HeapWord* q = space()->bottom(); | |
| 363 HeapWord* const t = _end_of_live; | |
| 364 debug_only(HeapWord* prev_q = NULL); | |
| 365 | |
| 366 if (q < t && _first_dead > q && | |
| 367 !oop(q)->is_gc_marked()) { | |
| 368 #ifdef ASSERT | |
| 369 // we have a chunk of the space which hasn't moved and we've reinitialized the | |
| 370 // mark word during the previous pass, so we can't use is_gc_marked for the | |
| 371 // traversal. | |
| 372 HeapWord* const end = _first_dead; | |
| 373 | |
| 374 while (q < end) { | |
| 375 size_t size = oop(q)->size(); | |
| 376 assert(!oop(q)->is_gc_marked(), "should be unmarked (special dense prefix handling)"); | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
377 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size, q)); |
| 0 | 378 debug_only(prev_q = q); |
| 379 q += size; | |
| 380 } | |
| 381 #endif | |
| 382 | |
| 383 if (_first_dead == t) { | |
| 384 q = t; | |
| 385 } else { | |
| 386 // $$$ Funky | |
| 387 q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); | |
| 388 } | |
| 389 } | |
| 390 | |
| 391 const intx scan_interval = PrefetchScanIntervalInBytes; | |
| 392 const intx copy_interval = PrefetchCopyIntervalInBytes; | |
| 393 | |
| 394 while (q < t) { | |
| 395 if (!oop(q)->is_gc_marked()) { | |
| 396 // mark is pointer to next marked oop | |
| 397 debug_only(prev_q = q); | |
| 398 q = (HeapWord*) oop(q)->mark()->decode_pointer(); | |
| 399 assert(q > prev_q, "we should be moving forward through memory"); | |
| 400 } else { | |
| 401 // prefetch beyond q | |
| 402 Prefetch::read(q, scan_interval); | |
| 403 | |
| 404 // size and destination | |
| 405 size_t size = oop(q)->size(); | |
| 406 HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); | |
| 407 | |
| 408 // prefetch beyond compaction_top | |
| 409 Prefetch::write(compaction_top, copy_interval); | |
| 410 | |
| 411 // copy object and reinit its mark | |
|
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
412 VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size, compaction_top)); |
| 0 | 413 assert(q != compaction_top, "everything in this pass should be moving"); |
| 414 Copy::aligned_conjoint_words(q, compaction_top, size); | |
| 415 oop(compaction_top)->init_mark(); | |
| 416 assert(oop(compaction_top)->klass() != NULL, "should have a class"); | |
| 417 | |
| 418 debug_only(prev_q = q); | |
| 419 q += size; | |
| 420 } | |
| 421 } | |
| 422 | |
| 423 assert(compaction_top() >= space()->bottom() && compaction_top() <= space()->end(), | |
| 424 "should point inside space"); | |
| 425 space()->set_top(compaction_top()); | |
| 426 | |
|
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
427 if (mangle_free_space) { |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
428 space()->mangle_unused_area(); |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
429 } |
| 0 | 430 } |