Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp @ 374:a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
Reviewed-by: jmasa
| author | jcoomes |
|---|---|
| date | Tue, 30 Sep 2008 11:49:31 -0700 |
| parents | 12eea04c8b06 |
| children | eb28cf662f56 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. | |
| 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 * | |
| 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 #include "incls/_precompiled.incl" | |
| 26 #include "incls/_psMarkSweep.cpp.incl" | |
| 27 | |
| 28 elapsedTimer PSMarkSweep::_accumulated_time; | |
| 29 unsigned int PSMarkSweep::_total_invocations = 0; | |
| 30 jlong PSMarkSweep::_time_of_last_gc = 0; | |
| 31 CollectorCounters* PSMarkSweep::_counters = NULL; | |
| 32 | |
| 33 void PSMarkSweep::initialize() { | |
| 34 MemRegion mr = Universe::heap()->reserved_region(); | |
| 35 _ref_processor = new ReferenceProcessor(mr, | |
| 36 true, // atomic_discovery | |
| 37 false); // mt_discovery | |
|
374
a4b729f5b611
6716466: par compact - remove VerifyParallelOldWithMarkSweep code
jcoomes
parents:
263
diff
changeset
|
38 _counters = new CollectorCounters("PSMarkSweep", 1); |
| 0 | 39 } |
| 40 | |
| 41 // This method contains all heap specific policy for invoking mark sweep. | |
| 42 // PSMarkSweep::invoke_no_policy() will only attempt to mark-sweep-compact | |
| 43 // the heap. It will do nothing further. If we need to bail out for policy | |
| 44 // reasons, scavenge before full gc, or any other specialized behavior, it | |
| 45 // needs to be added here. | |
| 46 // | |
| 47 // Note that this method should only be called from the vm_thread while | |
| 48 // at a safepoint! | |
| 49 void PSMarkSweep::invoke(bool maximum_heap_compaction) { | |
| 50 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
| 51 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); | |
| 52 assert(!Universe::heap()->is_gc_active(), "not reentrant"); | |
| 53 | |
| 54 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 55 GCCause::Cause gc_cause = heap->gc_cause(); | |
| 56 PSAdaptiveSizePolicy* policy = heap->size_policy(); | |
| 57 | |
| 58 // Before each allocation/collection attempt, find out from the | |
| 59 // policy object if GCs are, on the whole, taking too long. If so, | |
| 60 // bail out without attempting a collection. The exceptions are | |
| 61 // for explicitly requested GC's. | |
| 62 if (!policy->gc_time_limit_exceeded() || | |
| 63 GCCause::is_user_requested_gc(gc_cause) || | |
| 64 GCCause::is_serviceability_requested_gc(gc_cause)) { | |
| 65 IsGCActiveMark mark; | |
| 66 | |
| 67 if (ScavengeBeforeFullGC) { | |
| 68 PSScavenge::invoke_no_policy(); | |
| 69 } | |
| 70 | |
| 71 int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount; | |
| 72 IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count); | |
| 73 PSMarkSweep::invoke_no_policy(maximum_heap_compaction); | |
| 74 } | |
| 75 } | |
| 76 | |
| 77 // This method contains no policy. You should probably | |
| 78 // be calling invoke() instead. | |
| 79 void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) { | |
| 80 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); | |
| 81 assert(ref_processor() != NULL, "Sanity"); | |
| 82 | |
| 83 if (GC_locker::check_active_before_gc()) { | |
| 84 return; | |
| 85 } | |
| 86 | |
| 87 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 88 GCCause::Cause gc_cause = heap->gc_cause(); | |
| 89 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 90 PSAdaptiveSizePolicy* size_policy = heap->size_policy(); | |
| 91 | |
| 92 PSYoungGen* young_gen = heap->young_gen(); | |
| 93 PSOldGen* old_gen = heap->old_gen(); | |
| 94 PSPermGen* perm_gen = heap->perm_gen(); | |
| 95 | |
| 96 // Increment the invocation count | |
| 97 heap->increment_total_collections(true /* full */); | |
| 98 | |
|
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
99 // Save information needed to minimize mangling |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
100 heap->record_gen_tops_before_GC(); |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
101 |
| 0 | 102 // We need to track unique mark sweep invocations as well. |
| 103 _total_invocations++; | |
| 104 | |
| 105 AdaptiveSizePolicyOutput(size_policy, heap->total_collections()); | |
| 106 | |
| 107 if (PrintHeapAtGC) { | |
| 108 Universe::print_heap_before_gc(); | |
| 109 } | |
| 110 | |
| 111 // Fill in TLABs | |
| 112 heap->accumulate_statistics_all_tlabs(); | |
| 113 heap->ensure_parsability(true); // retire TLABs | |
| 114 | |
| 115 if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) { | |
| 116 HandleMark hm; // Discard invalid handles created during verification | |
| 117 gclog_or_tty->print(" VerifyBeforeGC:"); | |
| 118 Universe::verify(true); | |
| 119 } | |
| 120 | |
| 121 // Verify object start arrays | |
| 122 if (VerifyObjectStartArray && | |
| 123 VerifyBeforeGC) { | |
| 124 old_gen->verify_object_start_array(); | |
| 125 perm_gen->verify_object_start_array(); | |
| 126 } | |
| 127 | |
| 128 // Filled in below to track the state of the young gen after the collection. | |
| 129 bool eden_empty; | |
| 130 bool survivors_empty; | |
| 131 bool young_gen_empty; | |
| 132 | |
| 133 { | |
| 134 HandleMark hm; | |
| 135 const bool is_system_gc = gc_cause == GCCause::_java_lang_system_gc; | |
| 136 // This is useful for debugging but don't change the output the | |
| 137 // the customer sees. | |
| 138 const char* gc_cause_str = "Full GC"; | |
| 139 if (is_system_gc && PrintGCDetails) { | |
| 140 gc_cause_str = "Full GC (System)"; | |
| 141 } | |
| 142 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); | |
| 143 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
| 144 TraceTime t1(gc_cause_str, PrintGC, !PrintGCDetails, gclog_or_tty); | |
| 145 TraceCollectorStats tcs(counters()); | |
| 146 TraceMemoryManagerStats tms(true /* Full GC */); | |
| 147 | |
| 148 if (TraceGen1Time) accumulated_time()->start(); | |
| 149 | |
| 150 // Let the size policy know we're starting | |
| 151 size_policy->major_collection_begin(); | |
| 152 | |
| 153 // When collecting the permanent generation methodOops may be moving, | |
| 154 // so we either have to flush all bcp data or convert it into bci. | |
| 155 CodeCache::gc_prologue(); | |
| 156 Threads::gc_prologue(); | |
| 157 BiasedLocking::preserve_marks(); | |
| 158 | |
| 159 // Capture heap size before collection for printing. | |
| 160 size_t prev_used = heap->used(); | |
| 161 | |
| 162 // Capture perm gen size before collection for sizing. | |
| 163 size_t perm_gen_prev_used = perm_gen->used_in_bytes(); | |
| 164 | |
| 165 // For PrintGCDetails | |
| 166 size_t old_gen_prev_used = old_gen->used_in_bytes(); | |
| 167 size_t young_gen_prev_used = young_gen->used_in_bytes(); | |
| 168 | |
| 169 allocate_stacks(); | |
| 170 | |
| 171 NOT_PRODUCT(ref_processor()->verify_no_references_recorded()); | |
| 172 COMPILER2_PRESENT(DerivedPointerTable::clear()); | |
| 173 | |
| 174 ref_processor()->enable_discovery(); | |
| 175 | |
| 176 mark_sweep_phase1(clear_all_softrefs); | |
| 177 | |
| 178 mark_sweep_phase2(); | |
| 179 | |
| 180 // Don't add any more derived pointers during phase3 | |
| 181 COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity")); | |
| 182 COMPILER2_PRESENT(DerivedPointerTable::set_active(false)); | |
| 183 | |
| 184 mark_sweep_phase3(); | |
| 185 | |
| 186 mark_sweep_phase4(); | |
| 187 | |
| 188 restore_marks(); | |
| 189 | |
| 190 deallocate_stacks(); | |
| 191 | |
|
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
192 if (ZapUnusedHeapArea) { |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
193 // Do a complete mangle (top to end) because the usage for |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
194 // scratch does not maintain a top pointer. |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
195 young_gen->to_space()->mangle_unused_area_complete(); |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
196 } |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
197 |
| 0 | 198 eden_empty = young_gen->eden_space()->is_empty(); |
| 199 if (!eden_empty) { | |
| 200 eden_empty = absorb_live_data_from_eden(size_policy, young_gen, old_gen); | |
| 201 } | |
| 202 | |
| 203 // Update heap occupancy information which is used as | |
| 204 // input to soft ref clearing policy at the next gc. | |
| 205 Universe::update_heap_info_at_gc(); | |
| 206 | |
| 207 survivors_empty = young_gen->from_space()->is_empty() && | |
|
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
208 young_gen->to_space()->is_empty(); |
| 0 | 209 young_gen_empty = eden_empty && survivors_empty; |
| 210 | |
| 211 BarrierSet* bs = heap->barrier_set(); | |
| 212 if (bs->is_a(BarrierSet::ModRef)) { | |
| 213 ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs; | |
| 214 MemRegion old_mr = heap->old_gen()->reserved(); | |
| 215 MemRegion perm_mr = heap->perm_gen()->reserved(); | |
| 216 assert(perm_mr.end() <= old_mr.start(), "Generations out of order"); | |
| 217 | |
| 218 if (young_gen_empty) { | |
| 219 modBS->clear(MemRegion(perm_mr.start(), old_mr.end())); | |
| 220 } else { | |
| 221 modBS->invalidate(MemRegion(perm_mr.start(), old_mr.end())); | |
| 222 } | |
| 223 } | |
| 224 | |
| 225 BiasedLocking::restore_marks(); | |
| 226 Threads::gc_epilogue(); | |
| 227 CodeCache::gc_epilogue(); | |
| 228 | |
| 229 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
| 230 | |
| 231 ref_processor()->enqueue_discovered_references(NULL); | |
| 232 | |
| 233 // Update time of last GC | |
| 234 reset_millis_since_last_gc(); | |
| 235 | |
| 236 // Let the size policy know we're done | |
| 237 size_policy->major_collection_end(old_gen->used_in_bytes(), gc_cause); | |
| 238 | |
| 239 if (UseAdaptiveSizePolicy) { | |
| 240 | |
| 241 if (PrintAdaptiveSizePolicy) { | |
| 242 gclog_or_tty->print("AdaptiveSizeStart: "); | |
| 243 gclog_or_tty->stamp(); | |
| 244 gclog_or_tty->print_cr(" collection: %d ", | |
| 245 heap->total_collections()); | |
| 246 if (Verbose) { | |
| 247 gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d" | |
| 248 " perm_gen_capacity: %d ", | |
| 249 old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(), | |
| 250 perm_gen->capacity_in_bytes()); | |
| 251 } | |
| 252 } | |
| 253 | |
| 254 // Don't check if the size_policy is ready here. Let | |
| 255 // the size_policy check that internally. | |
| 256 if (UseAdaptiveGenerationSizePolicyAtMajorCollection && | |
| 257 ((gc_cause != GCCause::_java_lang_system_gc) || | |
| 258 UseAdaptiveSizePolicyWithSystemGC)) { | |
| 259 // Calculate optimal free space amounts | |
| 260 assert(young_gen->max_size() > | |
| 261 young_gen->from_space()->capacity_in_bytes() + | |
| 262 young_gen->to_space()->capacity_in_bytes(), | |
| 263 "Sizes of space in young gen are out-of-bounds"); | |
| 264 size_t max_eden_size = young_gen->max_size() - | |
| 265 young_gen->from_space()->capacity_in_bytes() - | |
| 266 young_gen->to_space()->capacity_in_bytes(); | |
| 267 size_policy->compute_generation_free_space(young_gen->used_in_bytes(), | |
| 268 young_gen->eden_space()->used_in_bytes(), | |
| 269 old_gen->used_in_bytes(), | |
| 270 perm_gen->used_in_bytes(), | |
| 271 young_gen->eden_space()->capacity_in_bytes(), | |
| 272 old_gen->max_gen_size(), | |
| 273 max_eden_size, | |
| 274 true /* full gc*/, | |
| 275 gc_cause); | |
| 276 | |
| 277 heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes()); | |
| 278 | |
| 279 // Don't resize the young generation at an major collection. A | |
| 280 // desired young generation size may have been calculated but | |
| 281 // resizing the young generation complicates the code because the | |
| 282 // resizing of the old generation may have moved the boundary | |
| 283 // between the young generation and the old generation. Let the | |
| 284 // young generation resizing happen at the minor collections. | |
| 285 } | |
| 286 if (PrintAdaptiveSizePolicy) { | |
| 287 gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ", | |
| 288 heap->total_collections()); | |
| 289 } | |
| 290 } | |
| 291 | |
| 292 if (UsePerfData) { | |
| 293 heap->gc_policy_counters()->update_counters(); | |
| 294 heap->gc_policy_counters()->update_old_capacity( | |
| 295 old_gen->capacity_in_bytes()); | |
| 296 heap->gc_policy_counters()->update_young_capacity( | |
| 297 young_gen->capacity_in_bytes()); | |
| 298 } | |
| 299 | |
| 300 heap->resize_all_tlabs(); | |
| 301 | |
| 302 // We collected the perm gen, so we'll resize it here. | |
| 303 perm_gen->compute_new_size(perm_gen_prev_used); | |
| 304 | |
| 305 if (TraceGen1Time) accumulated_time()->stop(); | |
| 306 | |
| 307 if (PrintGC) { | |
| 308 if (PrintGCDetails) { | |
| 309 // Don't print a GC timestamp here. This is after the GC so | |
| 310 // would be confusing. | |
| 311 young_gen->print_used_change(young_gen_prev_used); | |
| 312 old_gen->print_used_change(old_gen_prev_used); | |
| 313 } | |
| 314 heap->print_heap_change(prev_used); | |
| 315 // Do perm gen after heap becase prev_used does | |
| 316 // not include the perm gen (done this way in the other | |
| 317 // collectors). | |
| 318 if (PrintGCDetails) { | |
| 319 perm_gen->print_used_change(perm_gen_prev_used); | |
| 320 } | |
| 321 } | |
| 322 | |
| 323 // Track memory usage and detect low memory | |
| 324 MemoryService::track_memory_usage(); | |
| 325 heap->update_counters(); | |
| 326 | |
| 327 if (PrintGCDetails) { | |
| 328 if (size_policy->print_gc_time_limit_would_be_exceeded()) { | |
| 329 if (size_policy->gc_time_limit_exceeded()) { | |
| 330 gclog_or_tty->print_cr(" GC time is exceeding GCTimeLimit " | |
| 331 "of %d%%", GCTimeLimit); | |
| 332 } else { | |
| 333 gclog_or_tty->print_cr(" GC time would exceed GCTimeLimit " | |
| 334 "of %d%%", GCTimeLimit); | |
| 335 } | |
| 336 } | |
| 337 size_policy->set_print_gc_time_limit_would_be_exceeded(false); | |
| 338 } | |
| 339 } | |
| 340 | |
| 341 if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) { | |
| 342 HandleMark hm; // Discard invalid handles created during verification | |
| 343 gclog_or_tty->print(" VerifyAfterGC:"); | |
| 344 Universe::verify(false); | |
| 345 } | |
| 346 | |
| 347 // Re-verify object start arrays | |
| 348 if (VerifyObjectStartArray && | |
| 349 VerifyAfterGC) { | |
| 350 old_gen->verify_object_start_array(); | |
| 351 perm_gen->verify_object_start_array(); | |
| 352 } | |
| 353 | |
|
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
354 if (ZapUnusedHeapArea) { |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
355 old_gen->object_space()->check_mangled_unused_area_complete(); |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
356 perm_gen->object_space()->check_mangled_unused_area_complete(); |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
357 } |
|
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
0
diff
changeset
|
358 |
| 0 | 359 NOT_PRODUCT(ref_processor()->verify_no_references_recorded()); |
| 360 | |
| 361 if (PrintHeapAtGC) { | |
| 362 Universe::print_heap_after_gc(); | |
| 363 } | |
| 364 } | |
| 365 | |
| 366 bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy, | |
| 367 PSYoungGen* young_gen, | |
| 368 PSOldGen* old_gen) { | |
| 369 MutableSpace* const eden_space = young_gen->eden_space(); | |
| 370 assert(!eden_space->is_empty(), "eden must be non-empty"); | |
| 371 assert(young_gen->virtual_space()->alignment() == | |
| 372 old_gen->virtual_space()->alignment(), "alignments do not match"); | |
| 373 | |
| 374 if (!(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary)) { | |
| 375 return false; | |
| 376 } | |
| 377 | |
| 378 // Both generations must be completely committed. | |
| 379 if (young_gen->virtual_space()->uncommitted_size() != 0) { | |
| 380 return false; | |
| 381 } | |
| 382 if (old_gen->virtual_space()->uncommitted_size() != 0) { | |
| 383 return false; | |
| 384 } | |
| 385 | |
| 386 // Figure out how much to take from eden. Include the average amount promoted | |
| 387 // in the total; otherwise the next young gen GC will simply bail out to a | |
| 388 // full GC. | |
| 389 const size_t alignment = old_gen->virtual_space()->alignment(); | |
| 390 const size_t eden_used = eden_space->used_in_bytes(); | |
| 391 const size_t promoted = (size_t)(size_policy->avg_promoted()->padded_average()); | |
| 392 const size_t absorb_size = align_size_up(eden_used + promoted, alignment); | |
| 393 const size_t eden_capacity = eden_space->capacity_in_bytes(); | |
| 394 | |
| 395 if (absorb_size >= eden_capacity) { | |
| 396 return false; // Must leave some space in eden. | |
| 397 } | |
| 398 | |
| 399 const size_t new_young_size = young_gen->capacity_in_bytes() - absorb_size; | |
| 400 if (new_young_size < young_gen->min_gen_size()) { | |
| 401 return false; // Respect young gen minimum size. | |
| 402 } | |
| 403 | |
| 404 if (TraceAdaptiveGCBoundary && Verbose) { | |
| 405 gclog_or_tty->print(" absorbing " SIZE_FORMAT "K: " | |
| 406 "eden " SIZE_FORMAT "K->" SIZE_FORMAT "K " | |
| 407 "from " SIZE_FORMAT "K, to " SIZE_FORMAT "K " | |
| 408 "young_gen " SIZE_FORMAT "K->" SIZE_FORMAT "K ", | |
| 409 absorb_size / K, | |
| 410 eden_capacity / K, (eden_capacity - absorb_size) / K, | |
| 411 young_gen->from_space()->used_in_bytes() / K, | |
| 412 young_gen->to_space()->used_in_bytes() / K, | |
| 413 young_gen->capacity_in_bytes() / K, new_young_size / K); | |
| 414 } | |
| 415 | |
| 416 // Fill the unused part of the old gen. | |
| 417 MutableSpace* const old_space = old_gen->object_space(); | |
| 418 MemRegion old_gen_unused(old_space->top(), old_space->end()); | |
| 419 | |
| 420 // If the unused part of the old gen cannot be filled, skip | |
| 421 // absorbing eden. | |
| 422 if (old_gen_unused.word_size() < SharedHeap::min_fill_size()) { | |
| 423 return false; | |
| 424 } | |
| 425 | |
| 426 if (!old_gen_unused.is_empty()) { | |
| 427 SharedHeap::fill_region_with_object(old_gen_unused); | |
| 428 } | |
| 429 | |
| 430 // Take the live data from eden and set both top and end in the old gen to | |
| 431 // eden top. (Need to set end because reset_after_change() mangles the region | |
| 432 // from end to virtual_space->high() in debug builds). | |
| 433 HeapWord* const new_top = eden_space->top(); | |
| 434 old_gen->virtual_space()->expand_into(young_gen->virtual_space(), | |
| 435 absorb_size); | |
| 436 young_gen->reset_after_change(); | |
| 437 old_space->set_top(new_top); | |
| 438 old_space->set_end(new_top); | |
| 439 old_gen->reset_after_change(); | |
| 440 | |
| 441 // Update the object start array for the filler object and the data from eden. | |
| 442 ObjectStartArray* const start_array = old_gen->start_array(); | |
| 443 HeapWord* const start = old_gen_unused.start(); | |
| 444 for (HeapWord* addr = start; addr < new_top; addr += oop(addr)->size()) { | |
| 445 start_array->allocate_block(addr); | |
| 446 } | |
| 447 | |
| 448 // Could update the promoted average here, but it is not typically updated at | |
| 449 // full GCs and the value to use is unclear. Something like | |
| 450 // | |
| 451 // cur_promoted_avg + absorb_size / number_of_scavenges_since_last_full_gc. | |
| 452 | |
| 453 size_policy->set_bytes_absorbed_from_eden(absorb_size); | |
| 454 return true; | |
| 455 } | |
| 456 | |
| 457 void PSMarkSweep::allocate_stacks() { | |
| 458 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 459 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 460 | |
| 461 PSYoungGen* young_gen = heap->young_gen(); | |
| 462 | |
| 463 MutableSpace* to_space = young_gen->to_space(); | |
| 464 _preserved_marks = (PreservedMark*)to_space->top(); | |
| 465 _preserved_count = 0; | |
| 466 | |
| 467 // We want to calculate the size in bytes first. | |
| 468 _preserved_count_max = pointer_delta(to_space->end(), to_space->top(), sizeof(jbyte)); | |
| 469 // Now divide by the size of a PreservedMark | |
| 470 _preserved_count_max /= sizeof(PreservedMark); | |
| 471 | |
| 472 _preserved_mark_stack = NULL; | |
| 473 _preserved_oop_stack = NULL; | |
| 474 | |
| 475 _marking_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(4000, true); | |
| 476 | |
| 477 int size = SystemDictionary::number_of_classes() * 2; | |
| 478 _revisit_klass_stack = new (ResourceObj::C_HEAP) GrowableArray<Klass*>(size, true); | |
| 479 } | |
| 480 | |
| 481 | |
| 482 void PSMarkSweep::deallocate_stacks() { | |
| 483 if (_preserved_oop_stack) { | |
| 484 delete _preserved_mark_stack; | |
| 485 _preserved_mark_stack = NULL; | |
| 486 delete _preserved_oop_stack; | |
| 487 _preserved_oop_stack = NULL; | |
| 488 } | |
| 489 | |
| 490 delete _marking_stack; | |
| 491 delete _revisit_klass_stack; | |
| 492 } | |
| 493 | |
| 494 void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) { | |
| 495 // Recursively traverse all live objects and mark them | |
| 496 EventMark m("1 mark object"); | |
| 497 TraceTime tm("phase 1", PrintGCDetails && Verbose, true, gclog_or_tty); | |
| 498 trace(" 1"); | |
| 499 | |
| 500 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 501 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 502 | |
| 503 // General strong roots. | |
| 504 Universe::oops_do(mark_and_push_closure()); | |
| 505 ReferenceProcessor::oops_do(mark_and_push_closure()); | |
| 506 JNIHandles::oops_do(mark_and_push_closure()); // Global (strong) JNI handles | |
| 507 Threads::oops_do(mark_and_push_closure()); | |
| 508 ObjectSynchronizer::oops_do(mark_and_push_closure()); | |
| 509 FlatProfiler::oops_do(mark_and_push_closure()); | |
| 510 Management::oops_do(mark_and_push_closure()); | |
| 511 JvmtiExport::oops_do(mark_and_push_closure()); | |
| 512 SystemDictionary::always_strong_oops_do(mark_and_push_closure()); | |
| 513 vmSymbols::oops_do(mark_and_push_closure()); | |
| 514 | |
| 515 // Flush marking stack. | |
| 516 follow_stack(); | |
| 517 | |
| 518 // Process reference objects found during marking | |
| 519 { | |
| 520 ReferencePolicy *soft_ref_policy; | |
| 521 if (clear_all_softrefs) { | |
| 522 soft_ref_policy = new AlwaysClearPolicy(); | |
| 523 } else { | |
| 524 #ifdef COMPILER2 | |
| 525 soft_ref_policy = new LRUMaxHeapPolicy(); | |
| 526 #else | |
| 527 soft_ref_policy = new LRUCurrentHeapPolicy(); | |
| 528 #endif // COMPILER2 | |
| 529 } | |
| 530 assert(soft_ref_policy != NULL,"No soft reference policy"); | |
| 531 ref_processor()->process_discovered_references( | |
| 532 soft_ref_policy, is_alive_closure(), mark_and_push_closure(), | |
| 533 follow_stack_closure(), NULL); | |
| 534 } | |
| 535 | |
| 536 // Follow system dictionary roots and unload classes | |
| 537 bool purged_class = SystemDictionary::do_unloading(is_alive_closure()); | |
| 538 | |
| 539 // Follow code cache roots | |
| 540 CodeCache::do_unloading(is_alive_closure(), mark_and_push_closure(), | |
| 541 purged_class); | |
| 542 follow_stack(); // Flush marking stack | |
| 543 | |
| 544 // Update subklass/sibling/implementor links of live klasses | |
| 545 follow_weak_klass_links(); | |
| 546 assert(_marking_stack->is_empty(), "just drained"); | |
| 547 | |
| 548 // Visit symbol and interned string tables and delete unmarked oops | |
| 549 SymbolTable::unlink(is_alive_closure()); | |
| 550 StringTable::unlink(is_alive_closure()); | |
| 551 | |
| 552 assert(_marking_stack->is_empty(), "stack should be empty by now"); | |
| 553 } | |
| 554 | |
| 555 | |
| 556 void PSMarkSweep::mark_sweep_phase2() { | |
| 557 EventMark m("2 compute new addresses"); | |
| 558 TraceTime tm("phase 2", PrintGCDetails && Verbose, true, gclog_or_tty); | |
| 559 trace("2"); | |
| 560 | |
| 561 // Now all live objects are marked, compute the new object addresses. | |
| 562 | |
| 563 // It is imperative that we traverse perm_gen LAST. If dead space is | |
| 564 // allowed a range of dead object may get overwritten by a dead int | |
| 565 // array. If perm_gen is not traversed last a klassOop may get | |
| 566 // overwritten. This is fine since it is dead, but if the class has dead | |
| 567 // instances we have to skip them, and in order to find their size we | |
| 568 // need the klassOop! | |
| 569 // | |
| 570 // It is not required that we traverse spaces in the same order in | |
| 571 // phase2, phase3 and phase4, but the ValidateMarkSweep live oops | |
| 572 // tracking expects us to do so. See comment under phase4. | |
| 573 | |
| 574 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 575 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 576 | |
| 577 PSOldGen* old_gen = heap->old_gen(); | |
| 578 PSPermGen* perm_gen = heap->perm_gen(); | |
| 579 | |
| 580 // Begin compacting into the old gen | |
| 581 PSMarkSweepDecorator::set_destination_decorator_tenured(); | |
| 582 | |
| 583 // This will also compact the young gen spaces. | |
| 584 old_gen->precompact(); | |
| 585 | |
| 586 // Compact the perm gen into the perm gen | |
| 587 PSMarkSweepDecorator::set_destination_decorator_perm_gen(); | |
| 588 | |
| 589 perm_gen->precompact(); | |
| 590 } | |
| 591 | |
| 592 // This should be moved to the shared markSweep code! | |
| 593 class PSAlwaysTrueClosure: public BoolObjectClosure { | |
| 594 public: | |
| 595 void do_object(oop p) { ShouldNotReachHere(); } | |
| 596 bool do_object_b(oop p) { return true; } | |
| 597 }; | |
| 598 static PSAlwaysTrueClosure always_true; | |
| 599 | |
| 600 void PSMarkSweep::mark_sweep_phase3() { | |
| 601 // Adjust the pointers to reflect the new locations | |
| 602 EventMark m("3 adjust pointers"); | |
| 603 TraceTime tm("phase 3", PrintGCDetails && Verbose, true, gclog_or_tty); | |
| 604 trace("3"); | |
| 605 | |
| 606 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 607 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 608 | |
| 609 PSYoungGen* young_gen = heap->young_gen(); | |
| 610 PSOldGen* old_gen = heap->old_gen(); | |
| 611 PSPermGen* perm_gen = heap->perm_gen(); | |
| 612 | |
| 613 // General strong roots. | |
| 614 Universe::oops_do(adjust_root_pointer_closure()); | |
| 615 ReferenceProcessor::oops_do(adjust_root_pointer_closure()); | |
| 616 JNIHandles::oops_do(adjust_root_pointer_closure()); // Global (strong) JNI handles | |
| 617 Threads::oops_do(adjust_root_pointer_closure()); | |
| 618 ObjectSynchronizer::oops_do(adjust_root_pointer_closure()); | |
| 619 FlatProfiler::oops_do(adjust_root_pointer_closure()); | |
| 620 Management::oops_do(adjust_root_pointer_closure()); | |
| 621 JvmtiExport::oops_do(adjust_root_pointer_closure()); | |
| 622 // SO_AllClasses | |
| 623 SystemDictionary::oops_do(adjust_root_pointer_closure()); | |
| 624 vmSymbols::oops_do(adjust_root_pointer_closure()); | |
| 625 | |
| 626 // Now adjust pointers in remaining weak roots. (All of which should | |
| 627 // have been cleared if they pointed to non-surviving objects.) | |
| 628 // Global (weak) JNI handles | |
| 629 JNIHandles::weak_oops_do(&always_true, adjust_root_pointer_closure()); | |
| 630 | |
| 631 CodeCache::oops_do(adjust_pointer_closure()); | |
| 632 SymbolTable::oops_do(adjust_root_pointer_closure()); | |
| 633 StringTable::oops_do(adjust_root_pointer_closure()); | |
| 634 ref_processor()->weak_oops_do(adjust_root_pointer_closure()); | |
| 635 PSScavenge::reference_processor()->weak_oops_do(adjust_root_pointer_closure()); | |
| 636 | |
| 637 adjust_marks(); | |
| 638 | |
| 639 young_gen->adjust_pointers(); | |
| 640 old_gen->adjust_pointers(); | |
| 641 perm_gen->adjust_pointers(); | |
| 642 } | |
| 643 | |
| 644 void PSMarkSweep::mark_sweep_phase4() { | |
| 645 EventMark m("4 compact heap"); | |
| 646 TraceTime tm("phase 4", PrintGCDetails && Verbose, true, gclog_or_tty); | |
| 647 trace("4"); | |
| 648 | |
| 649 // All pointers are now adjusted, move objects accordingly | |
| 650 | |
| 651 // It is imperative that we traverse perm_gen first in phase4. All | |
| 652 // classes must be allocated earlier than their instances, and traversing | |
| 653 // perm_gen first makes sure that all klassOops have moved to their new | |
| 654 // location before any instance does a dispatch through it's klass! | |
| 655 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 656 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 657 | |
| 658 PSYoungGen* young_gen = heap->young_gen(); | |
| 659 PSOldGen* old_gen = heap->old_gen(); | |
| 660 PSPermGen* perm_gen = heap->perm_gen(); | |
| 661 | |
| 662 perm_gen->compact(); | |
| 663 old_gen->compact(); | |
| 664 young_gen->compact(); | |
| 665 } | |
| 666 | |
| 667 jlong PSMarkSweep::millis_since_last_gc() { | |
| 668 jlong ret_val = os::javaTimeMillis() - _time_of_last_gc; | |
| 669 // XXX See note in genCollectedHeap::millis_since_last_gc(). | |
| 670 if (ret_val < 0) { | |
| 671 NOT_PRODUCT(warning("time warp: %d", ret_val);) | |
| 672 return 0; | |
| 673 } | |
| 674 return ret_val; | |
| 675 } | |
| 676 | |
| 677 void PSMarkSweep::reset_millis_since_last_gc() { | |
| 678 _time_of_last_gc = os::javaTimeMillis(); | |
| 679 } |