src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp

Wed, 22 May 2013 11:11:47 -0700

author
tamao
date
Wed, 22 May 2013 11:11:47 -0700
changeset 5192
14d3f71f831d
parent 5159
001ec9515f84
child 5237
f2110083203d
permissions
-rw-r--r--

8007762: Rename a bunch of methods in size policy across collectors
Summary: Rename: compute_generations_free_space() = compute_eden_space_size() + compute_old_gen_free_space(); update related logging messages
Reviewed-by: jmasa, johnc, tschatzl, brutisso
Contributed-by: tamao <tao.mao@oracle.com>

duke@435 1 /*
tamao@5120 2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. 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 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "classfile/symbolTable.hpp"
stefank@2314 27 #include "classfile/systemDictionary.hpp"
stefank@2314 28 #include "code/codeCache.hpp"
stefank@2314 29 #include "gc_implementation/parallelScavenge/generationSizer.hpp"
stefank@2314 30 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
stefank@2314 31 #include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp"
stefank@2314 32 #include "gc_implementation/parallelScavenge/psMarkSweep.hpp"
stefank@2314 33 #include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp"
stefank@2314 34 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
stefank@2314 35 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
stefank@2314 36 #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
stefank@2314 37 #include "gc_implementation/shared/isGCActiveMark.hpp"
coleenp@4037 38 #include "gc_implementation/shared/markSweep.hpp"
stefank@2314 39 #include "gc_implementation/shared/spaceDecorator.hpp"
stefank@2314 40 #include "gc_interface/gcCause.hpp"
stefank@2314 41 #include "memory/gcLocker.inline.hpp"
stefank@2314 42 #include "memory/referencePolicy.hpp"
stefank@2314 43 #include "memory/referenceProcessor.hpp"
stefank@2314 44 #include "oops/oop.inline.hpp"
stefank@2314 45 #include "runtime/biasedLocking.hpp"
stefank@2314 46 #include "runtime/fprofiler.hpp"
stefank@2314 47 #include "runtime/safepoint.hpp"
stefank@2314 48 #include "runtime/vmThread.hpp"
stefank@2314 49 #include "services/management.hpp"
stefank@2314 50 #include "services/memoryService.hpp"
stefank@2314 51 #include "utilities/events.hpp"
stefank@2314 52 #include "utilities/stack.inline.hpp"
duke@435 53
duke@435 54 elapsedTimer PSMarkSweep::_accumulated_time;
duke@435 55 jlong PSMarkSweep::_time_of_last_gc = 0;
duke@435 56 CollectorCounters* PSMarkSweep::_counters = NULL;
duke@435 57
duke@435 58 void PSMarkSweep::initialize() {
duke@435 59 MemRegion mr = Universe::heap()->reserved_region();
ysr@2651 60 _ref_processor = new ReferenceProcessor(mr); // a vanilla ref proc
jcoomes@809 61 _counters = new CollectorCounters("PSMarkSweep", 1);
duke@435 62 }
duke@435 63
duke@435 64 // This method contains all heap specific policy for invoking mark sweep.
duke@435 65 // PSMarkSweep::invoke_no_policy() will only attempt to mark-sweep-compact
duke@435 66 // the heap. It will do nothing further. If we need to bail out for policy
duke@435 67 // reasons, scavenge before full gc, or any other specialized behavior, it
duke@435 68 // needs to be added here.
duke@435 69 //
duke@435 70 // Note that this method should only be called from the vm_thread while
duke@435 71 // at a safepoint!
jmasa@1822 72 //
jmasa@1822 73 // Note that the all_soft_refs_clear flag in the collector policy
jmasa@1822 74 // may be true because this method can be called without intervening
jmasa@1822 75 // activity. For example when the heap space is tight and full measure
jmasa@1822 76 // are being taken to free space.
jmasa@1822 77
duke@435 78 void PSMarkSweep::invoke(bool maximum_heap_compaction) {
duke@435 79 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
duke@435 80 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
duke@435 81 assert(!Universe::heap()->is_gc_active(), "not reentrant");
duke@435 82
duke@435 83 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435 84 GCCause::Cause gc_cause = heap->gc_cause();
duke@435 85 PSAdaptiveSizePolicy* policy = heap->size_policy();
jmasa@1822 86 IsGCActiveMark mark;
duke@435 87
jmasa@1822 88 if (ScavengeBeforeFullGC) {
jmasa@1822 89 PSScavenge::invoke_no_policy();
jmasa@1822 90 }
duke@435 91
jmasa@1822 92 const bool clear_all_soft_refs =
jmasa@1822 93 heap->collector_policy()->should_clear_all_soft_refs();
duke@435 94
tschatzl@5119 95 uint count = maximum_heap_compaction ? 1 : MarkSweepAlwaysCompactCount;
tschatzl@5119 96 UIntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
jmasa@1822 97 PSMarkSweep::invoke_no_policy(clear_all_soft_refs || maximum_heap_compaction);
duke@435 98 }
duke@435 99
duke@435 100 // This method contains no policy. You should probably
duke@435 101 // be calling invoke() instead.
jcoomes@3540 102 bool PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
duke@435 103 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
duke@435 104 assert(ref_processor() != NULL, "Sanity");
duke@435 105
duke@435 106 if (GC_locker::check_active_before_gc()) {
jcoomes@3540 107 return false;
duke@435 108 }
duke@435 109
duke@435 110 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435 111 GCCause::Cause gc_cause = heap->gc_cause();
duke@435 112 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435 113 PSAdaptiveSizePolicy* size_policy = heap->size_policy();
duke@435 114
jmasa@1822 115 // The scope of casr should end after code that can change
jmasa@1822 116 // CollectorPolicy::_should_clear_all_soft_refs.
jmasa@1822 117 ClearedAllSoftRefs casr(clear_all_softrefs, heap->collector_policy());
jmasa@1822 118
duke@435 119 PSYoungGen* young_gen = heap->young_gen();
duke@435 120 PSOldGen* old_gen = heap->old_gen();
duke@435 121
duke@435 122 // Increment the invocation count
duke@435 123 heap->increment_total_collections(true /* full */);
duke@435 124
jmasa@698 125 // Save information needed to minimize mangling
jmasa@698 126 heap->record_gen_tops_before_GC();
jmasa@698 127
duke@435 128 // We need to track unique mark sweep invocations as well.
duke@435 129 _total_invocations++;
duke@435 130
duke@435 131 AdaptiveSizePolicyOutput(size_policy, heap->total_collections());
duke@435 132
never@3499 133 heap->print_heap_before_gc();
duke@435 134
duke@435 135 // Fill in TLABs
duke@435 136 heap->accumulate_statistics_all_tlabs();
duke@435 137 heap->ensure_parsability(true); // retire TLABs
duke@435 138
duke@435 139 if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
duke@435 140 HandleMark hm; // Discard invalid handles created during verification
stefank@5018 141 Universe::verify(" VerifyBeforeGC:");
duke@435 142 }
duke@435 143
duke@435 144 // Verify object start arrays
duke@435 145 if (VerifyObjectStartArray &&
duke@435 146 VerifyBeforeGC) {
duke@435 147 old_gen->verify_object_start_array();
duke@435 148 }
duke@435 149
ysr@1050 150 heap->pre_full_gc_dump();
ysr@1050 151
duke@435 152 // Filled in below to track the state of the young gen after the collection.
duke@435 153 bool eden_empty;
duke@435 154 bool survivors_empty;
duke@435 155 bool young_gen_empty;
duke@435 156
duke@435 157 {
duke@435 158 HandleMark hm;
brutisso@3767 159
duke@435 160 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
duke@435 161 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
brutisso@3767 162 TraceTime t1(GCCauseString("Full GC", gc_cause), PrintGC, !PrintGCDetails, gclog_or_tty);
duke@435 163 TraceCollectorStats tcs(counters());
fparain@2888 164 TraceMemoryManagerStats tms(true /* Full GC */,gc_cause);
duke@435 165
duke@435 166 if (TraceGen1Time) accumulated_time()->start();
duke@435 167
duke@435 168 // Let the size policy know we're starting
duke@435 169 size_policy->major_collection_begin();
duke@435 170
duke@435 171 CodeCache::gc_prologue();
duke@435 172 Threads::gc_prologue();
duke@435 173 BiasedLocking::preserve_marks();
duke@435 174
duke@435 175 // Capture heap size before collection for printing.
duke@435 176 size_t prev_used = heap->used();
duke@435 177
coleenp@4037 178 // Capture metadata size before collection for sizing.
jmasa@5015 179 size_t metadata_prev_used = MetaspaceAux::allocated_used_bytes();
duke@435 180
duke@435 181 // For PrintGCDetails
duke@435 182 size_t old_gen_prev_used = old_gen->used_in_bytes();
duke@435 183 size_t young_gen_prev_used = young_gen->used_in_bytes();
duke@435 184
duke@435 185 allocate_stacks();
duke@435 186
duke@435 187 COMPILER2_PRESENT(DerivedPointerTable::clear());
duke@435 188
johnc@3175 189 ref_processor()->enable_discovery(true /*verify_disabled*/, true /*verify_no_refs*/);
ysr@892 190 ref_processor()->setup_policy(clear_all_softrefs);
duke@435 191
duke@435 192 mark_sweep_phase1(clear_all_softrefs);
duke@435 193
duke@435 194 mark_sweep_phase2();
duke@435 195
duke@435 196 // Don't add any more derived pointers during phase3
duke@435 197 COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity"));
duke@435 198 COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
duke@435 199
duke@435 200 mark_sweep_phase3();
duke@435 201
duke@435 202 mark_sweep_phase4();
duke@435 203
duke@435 204 restore_marks();
duke@435 205
duke@435 206 deallocate_stacks();
duke@435 207
jmasa@698 208 if (ZapUnusedHeapArea) {
jmasa@698 209 // Do a complete mangle (top to end) because the usage for
jmasa@698 210 // scratch does not maintain a top pointer.
jmasa@698 211 young_gen->to_space()->mangle_unused_area_complete();
jmasa@698 212 }
jmasa@698 213
duke@435 214 eden_empty = young_gen->eden_space()->is_empty();
duke@435 215 if (!eden_empty) {
duke@435 216 eden_empty = absorb_live_data_from_eden(size_policy, young_gen, old_gen);
duke@435 217 }
duke@435 218
duke@435 219 // Update heap occupancy information which is used as
duke@435 220 // input to soft ref clearing policy at the next gc.
duke@435 221 Universe::update_heap_info_at_gc();
duke@435 222
duke@435 223 survivors_empty = young_gen->from_space()->is_empty() &&
jmasa@698 224 young_gen->to_space()->is_empty();
duke@435 225 young_gen_empty = eden_empty && survivors_empty;
duke@435 226
duke@435 227 BarrierSet* bs = heap->barrier_set();
duke@435 228 if (bs->is_a(BarrierSet::ModRef)) {
duke@435 229 ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs;
duke@435 230 MemRegion old_mr = heap->old_gen()->reserved();
duke@435 231 if (young_gen_empty) {
coleenp@4037 232 modBS->clear(MemRegion(old_mr.start(), old_mr.end()));
duke@435 233 } else {
coleenp@4037 234 modBS->invalidate(MemRegion(old_mr.start(), old_mr.end()));
duke@435 235 }
duke@435 236 }
duke@435 237
coleenp@4037 238 // Delete metaspaces for unloaded class loaders and clean up loader_data graph
coleenp@4037 239 ClassLoaderDataGraph::purge();
jmasa@5015 240 MetaspaceAux::verify_metrics();
coleenp@4037 241
duke@435 242 BiasedLocking::restore_marks();
duke@435 243 Threads::gc_epilogue();
duke@435 244 CodeCache::gc_epilogue();
kamg@2467 245 JvmtiExport::gc_epilogue();
duke@435 246
duke@435 247 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
duke@435 248
duke@435 249 ref_processor()->enqueue_discovered_references(NULL);
duke@435 250
duke@435 251 // Update time of last GC
duke@435 252 reset_millis_since_last_gc();
duke@435 253
duke@435 254 // Let the size policy know we're done
duke@435 255 size_policy->major_collection_end(old_gen->used_in_bytes(), gc_cause);
duke@435 256
duke@435 257 if (UseAdaptiveSizePolicy) {
duke@435 258
duke@435 259 if (PrintAdaptiveSizePolicy) {
duke@435 260 gclog_or_tty->print("AdaptiveSizeStart: ");
duke@435 261 gclog_or_tty->stamp();
duke@435 262 gclog_or_tty->print_cr(" collection: %d ",
duke@435 263 heap->total_collections());
duke@435 264 if (Verbose) {
coleenp@4037 265 gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d",
coleenp@4037 266 old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes());
duke@435 267 }
duke@435 268 }
duke@435 269
duke@435 270 // Don't check if the size_policy is ready here. Let
duke@435 271 // the size_policy check that internally.
duke@435 272 if (UseAdaptiveGenerationSizePolicyAtMajorCollection &&
duke@435 273 ((gc_cause != GCCause::_java_lang_system_gc) ||
duke@435 274 UseAdaptiveSizePolicyWithSystemGC)) {
duke@435 275 // Calculate optimal free space amounts
duke@435 276 assert(young_gen->max_size() >
duke@435 277 young_gen->from_space()->capacity_in_bytes() +
duke@435 278 young_gen->to_space()->capacity_in_bytes(),
duke@435 279 "Sizes of space in young gen are out-of-bounds");
tamao@5120 280
tamao@5120 281 size_t young_live = young_gen->used_in_bytes();
tamao@5120 282 size_t eden_live = young_gen->eden_space()->used_in_bytes();
tamao@5120 283 size_t old_live = old_gen->used_in_bytes();
tamao@5120 284 size_t cur_eden = young_gen->eden_space()->capacity_in_bytes();
tamao@5120 285 size_t max_old_gen_size = old_gen->max_gen_size();
duke@435 286 size_t max_eden_size = young_gen->max_size() -
duke@435 287 young_gen->from_space()->capacity_in_bytes() -
duke@435 288 young_gen->to_space()->capacity_in_bytes();
tamao@5120 289
tamao@5120 290 // Used for diagnostics
tamao@5120 291 size_policy->clear_generation_free_space_flags();
tamao@5120 292
tamao@5192 293 size_policy->compute_generations_free_space(young_live,
tamao@5192 294 eden_live,
tamao@5192 295 old_live,
tamao@5192 296 cur_eden,
tamao@5192 297 max_old_gen_size,
tamao@5192 298 max_eden_size,
tamao@5192 299 true /* full gc*/);
tamao@5120 300
tamao@5120 301 size_policy->check_gc_overhead_limit(young_live,
tamao@5120 302 eden_live,
tamao@5120 303 max_old_gen_size,
tamao@5120 304 max_eden_size,
tamao@5120 305 true /* full gc*/,
tamao@5120 306 gc_cause,
tamao@5120 307 heap->collector_policy());
tamao@5120 308
tamao@5120 309 size_policy->decay_supplemental_growth(true /* full gc*/);
duke@435 310
duke@435 311 heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
duke@435 312
duke@435 313 // Don't resize the young generation at an major collection. A
duke@435 314 // desired young generation size may have been calculated but
duke@435 315 // resizing the young generation complicates the code because the
duke@435 316 // resizing of the old generation may have moved the boundary
duke@435 317 // between the young generation and the old generation. Let the
duke@435 318 // young generation resizing happen at the minor collections.
duke@435 319 }
duke@435 320 if (PrintAdaptiveSizePolicy) {
duke@435 321 gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
duke@435 322 heap->total_collections());
duke@435 323 }
duke@435 324 }
duke@435 325
duke@435 326 if (UsePerfData) {
duke@435 327 heap->gc_policy_counters()->update_counters();
duke@435 328 heap->gc_policy_counters()->update_old_capacity(
duke@435 329 old_gen->capacity_in_bytes());
duke@435 330 heap->gc_policy_counters()->update_young_capacity(
duke@435 331 young_gen->capacity_in_bytes());
duke@435 332 }
duke@435 333
duke@435 334 heap->resize_all_tlabs();
duke@435 335
coleenp@4037 336 // We collected the heap, recalculate the metaspace capacity
coleenp@4037 337 MetaspaceGC::compute_new_size();
duke@435 338
duke@435 339 if (TraceGen1Time) accumulated_time()->stop();
duke@435 340
duke@435 341 if (PrintGC) {
duke@435 342 if (PrintGCDetails) {
duke@435 343 // Don't print a GC timestamp here. This is after the GC so
duke@435 344 // would be confusing.
duke@435 345 young_gen->print_used_change(young_gen_prev_used);
duke@435 346 old_gen->print_used_change(old_gen_prev_used);
duke@435 347 }
duke@435 348 heap->print_heap_change(prev_used);
duke@435 349 if (PrintGCDetails) {
coleenp@4037 350 MetaspaceAux::print_metaspace_change(metadata_prev_used);
duke@435 351 }
duke@435 352 }
duke@435 353
duke@435 354 // Track memory usage and detect low memory
duke@435 355 MemoryService::track_memory_usage();
duke@435 356 heap->update_counters();
duke@435 357 }
duke@435 358
duke@435 359 if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
duke@435 360 HandleMark hm; // Discard invalid handles created during verification
stefank@5018 361 Universe::verify(" VerifyAfterGC:");
duke@435 362 }
duke@435 363
duke@435 364 // Re-verify object start arrays
duke@435 365 if (VerifyObjectStartArray &&
duke@435 366 VerifyAfterGC) {
duke@435 367 old_gen->verify_object_start_array();
duke@435 368 }
duke@435 369
jmasa@698 370 if (ZapUnusedHeapArea) {
jmasa@698 371 old_gen->object_space()->check_mangled_unused_area_complete();
jmasa@698 372 }
jmasa@698 373
duke@435 374 NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
duke@435 375
never@3499 376 heap->print_heap_after_gc();
jmasa@981 377
ysr@1050 378 heap->post_full_gc_dump();
ysr@1050 379
jmasa@981 380 #ifdef TRACESPINNING
jmasa@981 381 ParallelTaskTerminator::print_termination_counts();
jmasa@981 382 #endif
jcoomes@3540 383
jcoomes@3540 384 return true;
duke@435 385 }
duke@435 386
duke@435 387 bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
duke@435 388 PSYoungGen* young_gen,
duke@435 389 PSOldGen* old_gen) {
duke@435 390 MutableSpace* const eden_space = young_gen->eden_space();
duke@435 391 assert(!eden_space->is_empty(), "eden must be non-empty");
duke@435 392 assert(young_gen->virtual_space()->alignment() ==
duke@435 393 old_gen->virtual_space()->alignment(), "alignments do not match");
duke@435 394
duke@435 395 if (!(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary)) {
duke@435 396 return false;
duke@435 397 }
duke@435 398
duke@435 399 // Both generations must be completely committed.
duke@435 400 if (young_gen->virtual_space()->uncommitted_size() != 0) {
duke@435 401 return false;
duke@435 402 }
duke@435 403 if (old_gen->virtual_space()->uncommitted_size() != 0) {
duke@435 404 return false;
duke@435 405 }
duke@435 406
duke@435 407 // Figure out how much to take from eden. Include the average amount promoted
duke@435 408 // in the total; otherwise the next young gen GC will simply bail out to a
duke@435 409 // full GC.
duke@435 410 const size_t alignment = old_gen->virtual_space()->alignment();
duke@435 411 const size_t eden_used = eden_space->used_in_bytes();
jcoomes@916 412 const size_t promoted = (size_t)size_policy->avg_promoted()->padded_average();
duke@435 413 const size_t absorb_size = align_size_up(eden_used + promoted, alignment);
duke@435 414 const size_t eden_capacity = eden_space->capacity_in_bytes();
duke@435 415
duke@435 416 if (absorb_size >= eden_capacity) {
duke@435 417 return false; // Must leave some space in eden.
duke@435 418 }
duke@435 419
duke@435 420 const size_t new_young_size = young_gen->capacity_in_bytes() - absorb_size;
duke@435 421 if (new_young_size < young_gen->min_gen_size()) {
duke@435 422 return false; // Respect young gen minimum size.
duke@435 423 }
duke@435 424
duke@435 425 if (TraceAdaptiveGCBoundary && Verbose) {
duke@435 426 gclog_or_tty->print(" absorbing " SIZE_FORMAT "K: "
duke@435 427 "eden " SIZE_FORMAT "K->" SIZE_FORMAT "K "
duke@435 428 "from " SIZE_FORMAT "K, to " SIZE_FORMAT "K "
duke@435 429 "young_gen " SIZE_FORMAT "K->" SIZE_FORMAT "K ",
duke@435 430 absorb_size / K,
duke@435 431 eden_capacity / K, (eden_capacity - absorb_size) / K,
duke@435 432 young_gen->from_space()->used_in_bytes() / K,
duke@435 433 young_gen->to_space()->used_in_bytes() / K,
duke@435 434 young_gen->capacity_in_bytes() / K, new_young_size / K);
duke@435 435 }
duke@435 436
duke@435 437 // Fill the unused part of the old gen.
duke@435 438 MutableSpace* const old_space = old_gen->object_space();
jcoomes@916 439 HeapWord* const unused_start = old_space->top();
jcoomes@916 440 size_t const unused_words = pointer_delta(old_space->end(), unused_start);
duke@435 441
jcoomes@916 442 if (unused_words > 0) {
jcoomes@916 443 if (unused_words < CollectedHeap::min_fill_size()) {
jcoomes@916 444 return false; // If the old gen cannot be filled, must give up.
jcoomes@916 445 }
jcoomes@916 446 CollectedHeap::fill_with_objects(unused_start, unused_words);
duke@435 447 }
duke@435 448
duke@435 449 // Take the live data from eden and set both top and end in the old gen to
duke@435 450 // eden top. (Need to set end because reset_after_change() mangles the region
duke@435 451 // from end to virtual_space->high() in debug builds).
duke@435 452 HeapWord* const new_top = eden_space->top();
duke@435 453 old_gen->virtual_space()->expand_into(young_gen->virtual_space(),
duke@435 454 absorb_size);
duke@435 455 young_gen->reset_after_change();
duke@435 456 old_space->set_top(new_top);
duke@435 457 old_space->set_end(new_top);
duke@435 458 old_gen->reset_after_change();
duke@435 459
duke@435 460 // Update the object start array for the filler object and the data from eden.
duke@435 461 ObjectStartArray* const start_array = old_gen->start_array();
jcoomes@916 462 for (HeapWord* p = unused_start; p < new_top; p += oop(p)->size()) {
jcoomes@916 463 start_array->allocate_block(p);
duke@435 464 }
duke@435 465
duke@435 466 // Could update the promoted average here, but it is not typically updated at
duke@435 467 // full GCs and the value to use is unclear. Something like
duke@435 468 //
duke@435 469 // cur_promoted_avg + absorb_size / number_of_scavenges_since_last_full_gc.
duke@435 470
duke@435 471 size_policy->set_bytes_absorbed_from_eden(absorb_size);
duke@435 472 return true;
duke@435 473 }
duke@435 474
duke@435 475 void PSMarkSweep::allocate_stacks() {
duke@435 476 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435 477 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435 478
duke@435 479 PSYoungGen* young_gen = heap->young_gen();
duke@435 480
duke@435 481 MutableSpace* to_space = young_gen->to_space();
duke@435 482 _preserved_marks = (PreservedMark*)to_space->top();
duke@435 483 _preserved_count = 0;
duke@435 484
duke@435 485 // We want to calculate the size in bytes first.
duke@435 486 _preserved_count_max = pointer_delta(to_space->end(), to_space->top(), sizeof(jbyte));
duke@435 487 // Now divide by the size of a PreservedMark
duke@435 488 _preserved_count_max /= sizeof(PreservedMark);
duke@435 489 }
duke@435 490
duke@435 491
duke@435 492 void PSMarkSweep::deallocate_stacks() {
jcoomes@2191 493 _preserved_mark_stack.clear(true);
jcoomes@2191 494 _preserved_oop_stack.clear(true);
jcoomes@2191 495 _marking_stack.clear();
jcoomes@2191 496 _objarray_stack.clear(true);
duke@435 497 }
duke@435 498
duke@435 499 void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) {
duke@435 500 // Recursively traverse all live objects and mark them
duke@435 501 TraceTime tm("phase 1", PrintGCDetails && Verbose, true, gclog_or_tty);
duke@435 502 trace(" 1");
duke@435 503
duke@435 504 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435 505 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435 506
coleenp@4037 507 // Need to clear claim bits before the tracing starts.
coleenp@4037 508 ClassLoaderDataGraph::clear_claimed_marks();
coleenp@4037 509
duke@435 510 // General strong roots.
jrose@1424 511 {
jrose@1424 512 ParallelScavengeHeap::ParStrongRootsScope psrs;
jrose@1424 513 Universe::oops_do(mark_and_push_closure());
jrose@1424 514 JNIHandles::oops_do(mark_and_push_closure()); // Global (strong) JNI handles
stefank@4298 515 CLDToOopClosure mark_and_push_from_cld(mark_and_push_closure());
jrose@1424 516 CodeBlobToOopClosure each_active_code_blob(mark_and_push_closure(), /*do_marking=*/ true);
stefank@4298 517 Threads::oops_do(mark_and_push_closure(), &mark_and_push_from_cld, &each_active_code_blob);
jrose@1424 518 ObjectSynchronizer::oops_do(mark_and_push_closure());
jrose@1424 519 FlatProfiler::oops_do(mark_and_push_closure());
jrose@1424 520 Management::oops_do(mark_and_push_closure());
jrose@1424 521 JvmtiExport::oops_do(mark_and_push_closure());
jrose@1424 522 SystemDictionary::always_strong_oops_do(mark_and_push_closure());
coleenp@4037 523 ClassLoaderDataGraph::always_strong_oops_do(mark_and_push_closure(), follow_klass_closure(), true);
jrose@1424 524 // Do not treat nmethods as strong roots for mark/sweep, since we can unload them.
jrose@1424 525 //CodeCache::scavenge_root_nmethods_do(CodeBlobToOopClosure(mark_and_push_closure()));
jrose@1424 526 }
duke@435 527
duke@435 528 // Flush marking stack.
duke@435 529 follow_stack();
duke@435 530
duke@435 531 // Process reference objects found during marking
duke@435 532 {
ysr@892 533 ref_processor()->setup_policy(clear_all_softrefs);
duke@435 534 ref_processor()->process_discovered_references(
ysr@888 535 is_alive_closure(), mark_and_push_closure(), follow_stack_closure(), NULL);
duke@435 536 }
duke@435 537
stefank@5020 538 // This is the point where the entire marking should have completed.
stefank@5020 539 assert(_marking_stack.is_empty(), "Marking should have completed");
stefank@5020 540
stefank@5020 541 // Unload classes and purge the SystemDictionary.
duke@435 542 bool purged_class = SystemDictionary::do_unloading(is_alive_closure());
duke@435 543
stefank@5020 544 // Unload nmethods.
brutisso@4098 545 CodeCache::do_unloading(is_alive_closure(), purged_class);
duke@435 546
stefank@5020 547 // Prune dead klasses from subklass/sibling/implementor lists.
stefank@5020 548 Klass::clean_weak_klass_links(is_alive_closure());
ysr@1376 549
stefank@5020 550 // Delete entries for dead interned strings.
duke@435 551 StringTable::unlink(is_alive_closure());
stefank@5020 552
coleenp@2497 553 // Clean up unreferenced symbols in symbol table.
coleenp@2497 554 SymbolTable::unlink();
duke@435 555 }
duke@435 556
duke@435 557
duke@435 558 void PSMarkSweep::mark_sweep_phase2() {
duke@435 559 TraceTime tm("phase 2", PrintGCDetails && Verbose, true, gclog_or_tty);
duke@435 560 trace("2");
duke@435 561
duke@435 562 // Now all live objects are marked, compute the new object addresses.
duke@435 563
duke@435 564 // It is not required that we traverse spaces in the same order in
duke@435 565 // phase2, phase3 and phase4, but the ValidateMarkSweep live oops
duke@435 566 // tracking expects us to do so. See comment under phase4.
duke@435 567
duke@435 568 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435 569 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435 570
duke@435 571 PSOldGen* old_gen = heap->old_gen();
duke@435 572
duke@435 573 // Begin compacting into the old gen
duke@435 574 PSMarkSweepDecorator::set_destination_decorator_tenured();
duke@435 575
duke@435 576 // This will also compact the young gen spaces.
duke@435 577 old_gen->precompact();
duke@435 578 }
duke@435 579
duke@435 580 // This should be moved to the shared markSweep code!
duke@435 581 class PSAlwaysTrueClosure: public BoolObjectClosure {
duke@435 582 public:
duke@435 583 bool do_object_b(oop p) { return true; }
duke@435 584 };
duke@435 585 static PSAlwaysTrueClosure always_true;
duke@435 586
duke@435 587 void PSMarkSweep::mark_sweep_phase3() {
duke@435 588 // Adjust the pointers to reflect the new locations
duke@435 589 TraceTime tm("phase 3", PrintGCDetails && Verbose, true, gclog_or_tty);
duke@435 590 trace("3");
duke@435 591
duke@435 592 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435 593 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435 594
duke@435 595 PSYoungGen* young_gen = heap->young_gen();
duke@435 596 PSOldGen* old_gen = heap->old_gen();
coleenp@4037 597
coleenp@4037 598 // Need to clear claim bits before the tracing starts.
coleenp@4037 599 ClassLoaderDataGraph::clear_claimed_marks();
duke@435 600
duke@435 601 // General strong roots.
stefank@5011 602 Universe::oops_do(adjust_pointer_closure());
stefank@5011 603 JNIHandles::oops_do(adjust_pointer_closure()); // Global (strong) JNI handles
stefank@5011 604 CLDToOopClosure adjust_from_cld(adjust_pointer_closure());
stefank@5011 605 Threads::oops_do(adjust_pointer_closure(), &adjust_from_cld, NULL);
stefank@5011 606 ObjectSynchronizer::oops_do(adjust_pointer_closure());
stefank@5011 607 FlatProfiler::oops_do(adjust_pointer_closure());
stefank@5011 608 Management::oops_do(adjust_pointer_closure());
stefank@5011 609 JvmtiExport::oops_do(adjust_pointer_closure());
duke@435 610 // SO_AllClasses
stefank@5011 611 SystemDictionary::oops_do(adjust_pointer_closure());
stefank@5011 612 ClassLoaderDataGraph::oops_do(adjust_pointer_closure(), adjust_klass_closure(), true);
duke@435 613
duke@435 614 // Now adjust pointers in remaining weak roots. (All of which should
duke@435 615 // have been cleared if they pointed to non-surviving objects.)
duke@435 616 // Global (weak) JNI handles
stefank@5011 617 JNIHandles::weak_oops_do(&always_true, adjust_pointer_closure());
duke@435 618
duke@435 619 CodeCache::oops_do(adjust_pointer_closure());
stefank@5011 620 StringTable::oops_do(adjust_pointer_closure());
stefank@5011 621 ref_processor()->weak_oops_do(adjust_pointer_closure());
stefank@5011 622 PSScavenge::reference_processor()->weak_oops_do(adjust_pointer_closure());
duke@435 623
duke@435 624 adjust_marks();
duke@435 625
duke@435 626 young_gen->adjust_pointers();
duke@435 627 old_gen->adjust_pointers();
duke@435 628 }
duke@435 629
duke@435 630 void PSMarkSweep::mark_sweep_phase4() {
duke@435 631 EventMark m("4 compact heap");
duke@435 632 TraceTime tm("phase 4", PrintGCDetails && Verbose, true, gclog_or_tty);
duke@435 633 trace("4");
duke@435 634
duke@435 635 // All pointers are now adjusted, move objects accordingly
duke@435 636
duke@435 637 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435 638 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435 639
duke@435 640 PSYoungGen* young_gen = heap->young_gen();
duke@435 641 PSOldGen* old_gen = heap->old_gen();
duke@435 642
duke@435 643 old_gen->compact();
duke@435 644 young_gen->compact();
duke@435 645 }
duke@435 646
duke@435 647 jlong PSMarkSweep::millis_since_last_gc() {
johnc@3339 648 // We need a monotonically non-deccreasing time in ms but
johnc@3339 649 // os::javaTimeMillis() does not guarantee monotonicity.
johnc@3339 650 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
johnc@3339 651 jlong ret_val = now - _time_of_last_gc;
duke@435 652 // XXX See note in genCollectedHeap::millis_since_last_gc().
duke@435 653 if (ret_val < 0) {
johnc@3339 654 NOT_PRODUCT(warning("time warp: "INT64_FORMAT, ret_val);)
duke@435 655 return 0;
duke@435 656 }
duke@435 657 return ret_val;
duke@435 658 }
duke@435 659
duke@435 660 void PSMarkSweep::reset_millis_since_last_gc() {
johnc@3339 661 // We need a monotonically non-deccreasing time in ms but
johnc@3339 662 // os::javaTimeMillis() does not guarantee monotonicity.
johnc@3339 663 _time_of_last_gc = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
duke@435 664 }

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