Tue, 07 Oct 2008 11:01:35 -0700
Merge
duke@435 | 1 | /* |
xdono@631 | 2 | * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | # include "incls/_precompiled.incl" |
duke@435 | 26 | # include "incls/_psMarkSweepDecorator.cpp.incl" |
duke@435 | 27 | |
duke@435 | 28 | PSMarkSweepDecorator* PSMarkSweepDecorator::_destination_decorator = NULL; |
duke@435 | 29 | |
duke@435 | 30 | |
duke@435 | 31 | void PSMarkSweepDecorator::set_destination_decorator_tenured() { |
duke@435 | 32 | ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
duke@435 | 33 | assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
duke@435 | 34 | |
duke@435 | 35 | _destination_decorator = heap->old_gen()->object_mark_sweep(); |
duke@435 | 36 | } |
duke@435 | 37 | |
duke@435 | 38 | void PSMarkSweepDecorator::set_destination_decorator_perm_gen() { |
duke@435 | 39 | ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
duke@435 | 40 | assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
duke@435 | 41 | |
duke@435 | 42 | _destination_decorator = heap->perm_gen()->object_mark_sweep(); |
duke@435 | 43 | } |
duke@435 | 44 | |
duke@435 | 45 | void PSMarkSweepDecorator::advance_destination_decorator() { |
duke@435 | 46 | ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
duke@435 | 47 | assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
duke@435 | 48 | |
duke@435 | 49 | assert(_destination_decorator != NULL, "Sanity"); |
duke@435 | 50 | guarantee(_destination_decorator != heap->perm_gen()->object_mark_sweep(), "Cannot advance perm gen decorator"); |
duke@435 | 51 | |
duke@435 | 52 | PSMarkSweepDecorator* first = heap->old_gen()->object_mark_sweep(); |
duke@435 | 53 | PSMarkSweepDecorator* second = heap->young_gen()->eden_mark_sweep(); |
duke@435 | 54 | PSMarkSweepDecorator* third = heap->young_gen()->from_mark_sweep(); |
duke@435 | 55 | PSMarkSweepDecorator* fourth = heap->young_gen()->to_mark_sweep(); |
duke@435 | 56 | |
duke@435 | 57 | if ( _destination_decorator == first ) { |
duke@435 | 58 | _destination_decorator = second; |
duke@435 | 59 | } else if ( _destination_decorator == second ) { |
duke@435 | 60 | _destination_decorator = third; |
duke@435 | 61 | } else if ( _destination_decorator == third ) { |
duke@435 | 62 | _destination_decorator = fourth; |
duke@435 | 63 | } else { |
duke@435 | 64 | fatal("PSMarkSweep attempting to advance past last compaction area"); |
duke@435 | 65 | } |
duke@435 | 66 | } |
duke@435 | 67 | |
duke@435 | 68 | PSMarkSweepDecorator* PSMarkSweepDecorator::destination_decorator() { |
duke@435 | 69 | assert(_destination_decorator != NULL, "Sanity"); |
duke@435 | 70 | |
duke@435 | 71 | return _destination_decorator; |
duke@435 | 72 | } |
duke@435 | 73 | |
duke@435 | 74 | // FIX ME FIX ME FIX ME FIX ME!!!!!!!!! |
duke@435 | 75 | // The object forwarding code is duplicated. Factor this out!!!!! |
duke@435 | 76 | // |
duke@435 | 77 | // This method "precompacts" objects inside its space to dest. It places forwarding |
duke@435 | 78 | // pointers into markOops for use by adjust_pointers. If "dest" should overflow, we |
duke@435 | 79 | // finish by compacting into our own space. |
duke@435 | 80 | |
duke@435 | 81 | void PSMarkSweepDecorator::precompact() { |
duke@435 | 82 | // Reset our own compact top. |
duke@435 | 83 | set_compaction_top(space()->bottom()); |
duke@435 | 84 | |
duke@435 | 85 | /* We allow some amount of garbage towards the bottom of the space, so |
duke@435 | 86 | * we don't start compacting before there is a significant gain to be made. |
duke@435 | 87 | * Occasionally, we want to ensure a full compaction, which is determined |
duke@435 | 88 | * by the MarkSweepAlwaysCompactCount parameter. This is a significant |
duke@435 | 89 | * performance improvement! |
duke@435 | 90 | */ |
duke@435 | 91 | bool skip_dead = ((PSMarkSweep::total_invocations() % MarkSweepAlwaysCompactCount) != 0); |
duke@435 | 92 | |
duke@435 | 93 | ssize_t allowed_deadspace = 0; |
duke@435 | 94 | if (skip_dead) { |
duke@435 | 95 | int ratio = allowed_dead_ratio(); |
duke@435 | 96 | allowed_deadspace = (space()->capacity_in_bytes() * ratio / 100) / HeapWordSize; |
duke@435 | 97 | } |
duke@435 | 98 | |
duke@435 | 99 | // Fetch the current destination decorator |
duke@435 | 100 | PSMarkSweepDecorator* dest = destination_decorator(); |
duke@435 | 101 | ObjectStartArray* start_array = dest->start_array(); |
duke@435 | 102 | |
duke@435 | 103 | HeapWord* compact_top = dest->compaction_top(); |
duke@435 | 104 | HeapWord* compact_end = dest->space()->end(); |
duke@435 | 105 | |
duke@435 | 106 | HeapWord* q = space()->bottom(); |
duke@435 | 107 | HeapWord* t = space()->top(); |
duke@435 | 108 | |
duke@435 | 109 | HeapWord* end_of_live= q; /* One byte beyond the last byte of the last |
duke@435 | 110 | live object. */ |
duke@435 | 111 | HeapWord* first_dead = space()->end(); /* The first dead object. */ |
duke@435 | 112 | LiveRange* liveRange = NULL; /* The current live range, recorded in the |
duke@435 | 113 | first header of preceding free area. */ |
duke@435 | 114 | _first_dead = first_dead; |
duke@435 | 115 | |
duke@435 | 116 | const intx interval = PrefetchScanIntervalInBytes; |
duke@435 | 117 | |
duke@435 | 118 | while (q < t) { |
duke@435 | 119 | assert(oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() || |
duke@435 | 120 | oop(q)->mark()->has_bias_pattern(), |
duke@435 | 121 | "these are the only valid states during a mark sweep"); |
duke@435 | 122 | if (oop(q)->is_gc_marked()) { |
duke@435 | 123 | /* prefetch beyond q */ |
duke@435 | 124 | Prefetch::write(q, interval); |
duke@435 | 125 | size_t size = oop(q)->size(); |
duke@435 | 126 | |
duke@435 | 127 | size_t compaction_max_size = pointer_delta(compact_end, compact_top); |
duke@435 | 128 | |
duke@435 | 129 | // This should only happen if a space in the young gen overflows the |
duke@435 | 130 | // old gen. If that should happen, we null out the start_array, because |
duke@435 | 131 | // the young spaces are not covered by one. |
duke@435 | 132 | while(size > compaction_max_size) { |
duke@435 | 133 | // First record the last compact_top |
duke@435 | 134 | dest->set_compaction_top(compact_top); |
duke@435 | 135 | |
duke@435 | 136 | // Advance to the next compaction decorator |
duke@435 | 137 | advance_destination_decorator(); |
duke@435 | 138 | dest = destination_decorator(); |
duke@435 | 139 | |
duke@435 | 140 | // Update compaction info |
duke@435 | 141 | start_array = dest->start_array(); |
duke@435 | 142 | compact_top = dest->compaction_top(); |
duke@435 | 143 | compact_end = dest->space()->end(); |
duke@435 | 144 | assert(compact_top == dest->space()->bottom(), "Advanced to space already in use"); |
duke@435 | 145 | assert(compact_end > compact_top, "Must always be space remaining"); |
duke@435 | 146 | compaction_max_size = |
duke@435 | 147 | pointer_delta(compact_end, compact_top); |
duke@435 | 148 | } |
duke@435 | 149 | |
duke@435 | 150 | // store the forwarding pointer into the mark word |
duke@435 | 151 | if (q != compact_top) { |
duke@435 | 152 | oop(q)->forward_to(oop(compact_top)); |
duke@435 | 153 | assert(oop(q)->is_gc_marked(), "encoding the pointer should preserve the mark"); |
duke@435 | 154 | } else { |
jcoomes@809 | 155 | // if the object isn't moving we can just set the mark to the default |
jcoomes@809 | 156 | // mark and handle it specially later on. |
jcoomes@809 | 157 | oop(q)->init_mark(); |
duke@435 | 158 | assert(oop(q)->forwardee() == NULL, "should be forwarded to NULL"); |
duke@435 | 159 | } |
duke@435 | 160 | |
duke@435 | 161 | // Update object start array |
jcoomes@809 | 162 | if (start_array) { |
jcoomes@809 | 163 | start_array->allocate_block(compact_top); |
duke@435 | 164 | } |
duke@435 | 165 | |
coleenp@548 | 166 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(oop(q), size)); |
duke@435 | 167 | compact_top += size; |
duke@435 | 168 | assert(compact_top <= dest->space()->end(), |
duke@435 | 169 | "Exceeding space in destination"); |
duke@435 | 170 | |
duke@435 | 171 | q += size; |
duke@435 | 172 | end_of_live = q; |
duke@435 | 173 | } else { |
duke@435 | 174 | /* run over all the contiguous dead objects */ |
duke@435 | 175 | HeapWord* end = q; |
duke@435 | 176 | do { |
duke@435 | 177 | /* prefetch beyond end */ |
duke@435 | 178 | Prefetch::write(end, interval); |
duke@435 | 179 | end += oop(end)->size(); |
duke@435 | 180 | } while (end < t && (!oop(end)->is_gc_marked())); |
duke@435 | 181 | |
duke@435 | 182 | /* see if we might want to pretend this object is alive so that |
duke@435 | 183 | * we don't have to compact quite as often. |
duke@435 | 184 | */ |
duke@435 | 185 | if (allowed_deadspace > 0 && q == compact_top) { |
duke@435 | 186 | size_t sz = pointer_delta(end, q); |
duke@435 | 187 | if (insert_deadspace(allowed_deadspace, q, sz)) { |
duke@435 | 188 | size_t compaction_max_size = pointer_delta(compact_end, compact_top); |
duke@435 | 189 | |
duke@435 | 190 | // This should only happen if a space in the young gen overflows the |
duke@435 | 191 | // old gen. If that should happen, we null out the start_array, because |
duke@435 | 192 | // the young spaces are not covered by one. |
duke@435 | 193 | while (sz > compaction_max_size) { |
duke@435 | 194 | // First record the last compact_top |
duke@435 | 195 | dest->set_compaction_top(compact_top); |
duke@435 | 196 | |
duke@435 | 197 | // Advance to the next compaction decorator |
duke@435 | 198 | advance_destination_decorator(); |
duke@435 | 199 | dest = destination_decorator(); |
duke@435 | 200 | |
duke@435 | 201 | // Update compaction info |
duke@435 | 202 | start_array = dest->start_array(); |
duke@435 | 203 | compact_top = dest->compaction_top(); |
duke@435 | 204 | compact_end = dest->space()->end(); |
duke@435 | 205 | assert(compact_top == dest->space()->bottom(), "Advanced to space already in use"); |
duke@435 | 206 | assert(compact_end > compact_top, "Must always be space remaining"); |
duke@435 | 207 | compaction_max_size = |
duke@435 | 208 | pointer_delta(compact_end, compact_top); |
duke@435 | 209 | } |
duke@435 | 210 | |
duke@435 | 211 | // store the forwarding pointer into the mark word |
duke@435 | 212 | if (q != compact_top) { |
duke@435 | 213 | oop(q)->forward_to(oop(compact_top)); |
duke@435 | 214 | assert(oop(q)->is_gc_marked(), "encoding the pointer should preserve the mark"); |
duke@435 | 215 | } else { |
duke@435 | 216 | // if the object isn't moving we can just set the mark to the default |
jcoomes@809 | 217 | // mark and handle it specially later on. |
jcoomes@809 | 218 | oop(q)->init_mark(); |
duke@435 | 219 | assert(oop(q)->forwardee() == NULL, "should be forwarded to NULL"); |
duke@435 | 220 | } |
duke@435 | 221 | |
jcoomes@809 | 222 | // Update object start array |
jcoomes@809 | 223 | if (start_array) { |
jcoomes@809 | 224 | start_array->allocate_block(compact_top); |
duke@435 | 225 | } |
duke@435 | 226 | |
coleenp@548 | 227 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(oop(q), sz)); |
duke@435 | 228 | compact_top += sz; |
duke@435 | 229 | assert(compact_top <= dest->space()->end(), |
duke@435 | 230 | "Exceeding space in destination"); |
duke@435 | 231 | |
duke@435 | 232 | q = end; |
duke@435 | 233 | end_of_live = end; |
duke@435 | 234 | continue; |
duke@435 | 235 | } |
duke@435 | 236 | } |
duke@435 | 237 | |
duke@435 | 238 | /* for the previous LiveRange, record the end of the live objects. */ |
duke@435 | 239 | if (liveRange) { |
duke@435 | 240 | liveRange->set_end(q); |
duke@435 | 241 | } |
duke@435 | 242 | |
duke@435 | 243 | /* record the current LiveRange object. |
duke@435 | 244 | * liveRange->start() is overlaid on the mark word. |
duke@435 | 245 | */ |
duke@435 | 246 | liveRange = (LiveRange*)q; |
duke@435 | 247 | liveRange->set_start(end); |
duke@435 | 248 | liveRange->set_end(end); |
duke@435 | 249 | |
duke@435 | 250 | /* see if this is the first dead region. */ |
duke@435 | 251 | if (q < first_dead) { |
duke@435 | 252 | first_dead = q; |
duke@435 | 253 | } |
duke@435 | 254 | |
duke@435 | 255 | /* move on to the next object */ |
duke@435 | 256 | q = end; |
duke@435 | 257 | } |
duke@435 | 258 | } |
duke@435 | 259 | |
duke@435 | 260 | assert(q == t, "just checking"); |
duke@435 | 261 | if (liveRange != NULL) { |
duke@435 | 262 | liveRange->set_end(q); |
duke@435 | 263 | } |
duke@435 | 264 | _end_of_live = end_of_live; |
duke@435 | 265 | if (end_of_live < first_dead) { |
duke@435 | 266 | first_dead = end_of_live; |
duke@435 | 267 | } |
duke@435 | 268 | _first_dead = first_dead; |
duke@435 | 269 | |
duke@435 | 270 | // Update compaction top |
duke@435 | 271 | dest->set_compaction_top(compact_top); |
duke@435 | 272 | } |
duke@435 | 273 | |
duke@435 | 274 | bool PSMarkSweepDecorator::insert_deadspace(ssize_t& allowed_deadspace_words, |
duke@435 | 275 | HeapWord* q, size_t deadlength) { |
duke@435 | 276 | allowed_deadspace_words -= deadlength; |
duke@435 | 277 | if (allowed_deadspace_words >= 0) { |
duke@435 | 278 | oop(q)->set_mark(markOopDesc::prototype()->set_marked()); |
duke@435 | 279 | const size_t aligned_min_int_array_size = |
duke@435 | 280 | align_object_size(typeArrayOopDesc::header_size(T_INT)); |
duke@435 | 281 | if (deadlength >= aligned_min_int_array_size) { |
duke@435 | 282 | oop(q)->set_klass(Universe::intArrayKlassObj()); |
duke@435 | 283 | assert(((deadlength - aligned_min_int_array_size) * (HeapWordSize/sizeof(jint))) < (size_t)max_jint, |
duke@435 | 284 | "deadspace too big for Arrayoop"); |
duke@435 | 285 | typeArrayOop(q)->set_length((int)((deadlength - aligned_min_int_array_size) |
duke@435 | 286 | * (HeapWordSize/sizeof(jint)))); |
duke@435 | 287 | } else { |
duke@435 | 288 | assert((int) deadlength == instanceOopDesc::header_size(), |
duke@435 | 289 | "size for smallest fake dead object doesn't match"); |
duke@435 | 290 | oop(q)->set_klass(SystemDictionary::object_klass()); |
duke@435 | 291 | } |
duke@435 | 292 | assert((int) deadlength == oop(q)->size(), |
duke@435 | 293 | "make sure size for fake dead object match"); |
duke@435 | 294 | // Recall that we required "q == compaction_top". |
duke@435 | 295 | return true; |
duke@435 | 296 | } else { |
duke@435 | 297 | allowed_deadspace_words = 0; |
duke@435 | 298 | return false; |
duke@435 | 299 | } |
duke@435 | 300 | } |
duke@435 | 301 | |
duke@435 | 302 | void PSMarkSweepDecorator::adjust_pointers() { |
duke@435 | 303 | // adjust all the interior pointers to point at the new locations of objects |
duke@435 | 304 | // Used by MarkSweep::mark_sweep_phase3() |
duke@435 | 305 | |
duke@435 | 306 | HeapWord* q = space()->bottom(); |
duke@435 | 307 | HeapWord* t = _end_of_live; // Established by "prepare_for_compaction". |
duke@435 | 308 | |
duke@435 | 309 | assert(_first_dead <= _end_of_live, "Stands to reason, no?"); |
duke@435 | 310 | |
duke@435 | 311 | if (q < t && _first_dead > q && |
duke@435 | 312 | !oop(q)->is_gc_marked()) { |
duke@435 | 313 | // we have a chunk of the space which hasn't moved and we've |
duke@435 | 314 | // reinitialized the mark word during the previous pass, so we can't |
duke@435 | 315 | // use is_gc_marked for the traversal. |
duke@435 | 316 | HeapWord* end = _first_dead; |
duke@435 | 317 | |
duke@435 | 318 | while (q < end) { |
coleenp@548 | 319 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q))); |
duke@435 | 320 | // point all the oops to the new location |
duke@435 | 321 | size_t size = oop(q)->adjust_pointers(); |
coleenp@548 | 322 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers()); |
coleenp@548 | 323 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size)); |
duke@435 | 324 | q += size; |
duke@435 | 325 | } |
duke@435 | 326 | |
duke@435 | 327 | if (_first_dead == t) { |
duke@435 | 328 | q = t; |
duke@435 | 329 | } else { |
duke@435 | 330 | // $$$ This is funky. Using this to read the previously written |
duke@435 | 331 | // LiveRange. See also use below. |
duke@435 | 332 | q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); |
duke@435 | 333 | } |
duke@435 | 334 | } |
duke@435 | 335 | const intx interval = PrefetchScanIntervalInBytes; |
duke@435 | 336 | |
duke@435 | 337 | debug_only(HeapWord* prev_q = NULL); |
duke@435 | 338 | while (q < t) { |
duke@435 | 339 | // prefetch beyond q |
duke@435 | 340 | Prefetch::write(q, interval); |
duke@435 | 341 | if (oop(q)->is_gc_marked()) { |
duke@435 | 342 | // q is alive |
coleenp@548 | 343 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::track_interior_pointers(oop(q))); |
duke@435 | 344 | // point all the oops to the new location |
duke@435 | 345 | size_t size = oop(q)->adjust_pointers(); |
coleenp@548 | 346 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::check_interior_pointers()); |
coleenp@548 | 347 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::validate_live_oop(oop(q), size)); |
duke@435 | 348 | debug_only(prev_q = q); |
duke@435 | 349 | q += size; |
duke@435 | 350 | } else { |
duke@435 | 351 | // q is not a live object, so its mark should point at the next |
duke@435 | 352 | // live object |
duke@435 | 353 | debug_only(prev_q = q); |
duke@435 | 354 | q = (HeapWord*) oop(q)->mark()->decode_pointer(); |
duke@435 | 355 | assert(q > prev_q, "we should be moving forward through memory"); |
duke@435 | 356 | } |
duke@435 | 357 | } |
duke@435 | 358 | |
duke@435 | 359 | assert(q == t, "just checking"); |
duke@435 | 360 | } |
duke@435 | 361 | |
duke@435 | 362 | void PSMarkSweepDecorator::compact(bool mangle_free_space ) { |
duke@435 | 363 | // Copy all live objects to their new location |
duke@435 | 364 | // Used by MarkSweep::mark_sweep_phase4() |
duke@435 | 365 | |
duke@435 | 366 | HeapWord* q = space()->bottom(); |
duke@435 | 367 | HeapWord* const t = _end_of_live; |
duke@435 | 368 | debug_only(HeapWord* prev_q = NULL); |
duke@435 | 369 | |
duke@435 | 370 | if (q < t && _first_dead > q && |
duke@435 | 371 | !oop(q)->is_gc_marked()) { |
duke@435 | 372 | #ifdef ASSERT |
duke@435 | 373 | // we have a chunk of the space which hasn't moved and we've reinitialized the |
duke@435 | 374 | // mark word during the previous pass, so we can't use is_gc_marked for the |
duke@435 | 375 | // traversal. |
duke@435 | 376 | HeapWord* const end = _first_dead; |
duke@435 | 377 | |
duke@435 | 378 | while (q < end) { |
duke@435 | 379 | size_t size = oop(q)->size(); |
duke@435 | 380 | assert(!oop(q)->is_gc_marked(), "should be unmarked (special dense prefix handling)"); |
coleenp@548 | 381 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size, q)); |
duke@435 | 382 | debug_only(prev_q = q); |
duke@435 | 383 | q += size; |
duke@435 | 384 | } |
duke@435 | 385 | #endif |
duke@435 | 386 | |
duke@435 | 387 | if (_first_dead == t) { |
duke@435 | 388 | q = t; |
duke@435 | 389 | } else { |
duke@435 | 390 | // $$$ Funky |
duke@435 | 391 | q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); |
duke@435 | 392 | } |
duke@435 | 393 | } |
duke@435 | 394 | |
duke@435 | 395 | const intx scan_interval = PrefetchScanIntervalInBytes; |
duke@435 | 396 | const intx copy_interval = PrefetchCopyIntervalInBytes; |
duke@435 | 397 | |
duke@435 | 398 | while (q < t) { |
duke@435 | 399 | if (!oop(q)->is_gc_marked()) { |
duke@435 | 400 | // mark is pointer to next marked oop |
duke@435 | 401 | debug_only(prev_q = q); |
duke@435 | 402 | q = (HeapWord*) oop(q)->mark()->decode_pointer(); |
duke@435 | 403 | assert(q > prev_q, "we should be moving forward through memory"); |
duke@435 | 404 | } else { |
duke@435 | 405 | // prefetch beyond q |
duke@435 | 406 | Prefetch::read(q, scan_interval); |
duke@435 | 407 | |
duke@435 | 408 | // size and destination |
duke@435 | 409 | size_t size = oop(q)->size(); |
duke@435 | 410 | HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); |
duke@435 | 411 | |
duke@435 | 412 | // prefetch beyond compaction_top |
duke@435 | 413 | Prefetch::write(compaction_top, copy_interval); |
duke@435 | 414 | |
duke@435 | 415 | // copy object and reinit its mark |
coleenp@548 | 416 | VALIDATE_MARK_SWEEP_ONLY(MarkSweep::live_oop_moved_to(q, size, compaction_top)); |
duke@435 | 417 | assert(q != compaction_top, "everything in this pass should be moving"); |
duke@435 | 418 | Copy::aligned_conjoint_words(q, compaction_top, size); |
duke@435 | 419 | oop(compaction_top)->init_mark(); |
duke@435 | 420 | assert(oop(compaction_top)->klass() != NULL, "should have a class"); |
duke@435 | 421 | |
duke@435 | 422 | debug_only(prev_q = q); |
duke@435 | 423 | q += size; |
duke@435 | 424 | } |
duke@435 | 425 | } |
duke@435 | 426 | |
duke@435 | 427 | assert(compaction_top() >= space()->bottom() && compaction_top() <= space()->end(), |
duke@435 | 428 | "should point inside space"); |
duke@435 | 429 | space()->set_top(compaction_top()); |
duke@435 | 430 | |
jmasa@698 | 431 | if (mangle_free_space) { |
jmasa@698 | 432 | space()->mangle_unused_area(); |
jmasa@698 | 433 | } |
duke@435 | 434 | } |