src/share/vm/gc_implementation/g1/g1MarkSweep.cpp

Wed, 03 Jul 2013 17:26:59 -0400

author
jiangli
date
Wed, 03 Jul 2013 17:26:59 -0400
changeset 5369
71180a6e5080
parent 5237
f2110083203d
child 5811
d55c004e1d4d
permissions
-rw-r--r--

7133260: AllocationProfiler uses space in metadata and doesn't seem to do anything useful.
Summary: Remove -Xaprof and Klass::_alloc_count & ArrayKlass::_alloc_size.
Reviewed-by: stefank, coleenp

ysr@777 1 /*
sla@5237 2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
ysr@777 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777 4 *
ysr@777 5 * This code is free software; you can redistribute it and/or modify it
ysr@777 6 * under the terms of the GNU General Public License version 2 only, as
ysr@777 7 * published by the Free Software Foundation.
ysr@777 8 *
ysr@777 9 * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
ysr@777 12 * version 2 for more details (a copy is included in the LICENSE file that
ysr@777 13 * accompanied this code).
ysr@777 14 *
ysr@777 15 * You should have received a copy of the GNU General Public License version
ysr@777 16 * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777 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.
ysr@777 22 *
ysr@777 23 */
ysr@777 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "classfile/javaClasses.hpp"
stefank@2314 27 #include "classfile/symbolTable.hpp"
stefank@2314 28 #include "classfile/systemDictionary.hpp"
stefank@2314 29 #include "classfile/vmSymbols.hpp"
stefank@2314 30 #include "code/codeCache.hpp"
stefank@2314 31 #include "code/icBuffer.hpp"
brutisso@3710 32 #include "gc_implementation/g1/g1Log.hpp"
stefank@2314 33 #include "gc_implementation/g1/g1MarkSweep.hpp"
sla@5237 34 #include "gc_implementation/shared/gcHeapSummary.hpp"
sla@5237 35 #include "gc_implementation/shared/gcTimer.hpp"
sla@5237 36 #include "gc_implementation/shared/gcTrace.hpp"
sla@5237 37 #include "gc_implementation/shared/gcTraceTime.hpp"
stefank@2314 38 #include "memory/gcLocker.hpp"
stefank@2314 39 #include "memory/genCollectedHeap.hpp"
stefank@2314 40 #include "memory/modRefBarrierSet.hpp"
stefank@2314 41 #include "memory/referencePolicy.hpp"
stefank@2314 42 #include "memory/space.hpp"
stefank@2314 43 #include "oops/instanceRefKlass.hpp"
stefank@2314 44 #include "oops/oop.inline.hpp"
stefank@2314 45 #include "prims/jvmtiExport.hpp"
stefank@2314 46 #include "runtime/biasedLocking.hpp"
stefank@2314 47 #include "runtime/fprofiler.hpp"
stefank@2314 48 #include "runtime/synchronizer.hpp"
stefank@2314 49 #include "runtime/thread.hpp"
stefank@2314 50 #include "runtime/vmThread.hpp"
stefank@2314 51 #include "utilities/copy.hpp"
stefank@2314 52 #include "utilities/events.hpp"
ysr@777 53
ysr@777 54 class HeapRegion;
ysr@777 55
ysr@777 56 void G1MarkSweep::invoke_at_safepoint(ReferenceProcessor* rp,
ysr@777 57 bool clear_all_softrefs) {
ysr@777 58 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
ysr@777 59
jmasa@1822 60 SharedHeap* sh = SharedHeap::heap();
jmasa@1822 61 #ifdef ASSERT
jmasa@1822 62 if (sh->collector_policy()->should_clear_all_soft_refs()) {
jmasa@1822 63 assert(clear_all_softrefs, "Policy should have been checked earler");
jmasa@1822 64 }
jmasa@1822 65 #endif
ysr@777 66 // hook up weak ref data so it can be used during Mark-Sweep
ysr@777 67 assert(GenMarkSweep::ref_processor() == NULL, "no stomping");
ysr@888 68 assert(rp != NULL, "should be non-NULL");
johnc@3175 69 assert(rp == G1CollectedHeap::heap()->ref_processor_stw(), "Precondition");
johnc@3175 70
ysr@777 71 GenMarkSweep::_ref_processor = rp;
ysr@892 72 rp->setup_policy(clear_all_softrefs);
ysr@777 73
coleenp@4037 74 // When collecting the permanent generation Method*s may be moving,
ysr@777 75 // so we either have to flush all bcp data or convert it into bci.
ysr@777 76 CodeCache::gc_prologue();
ysr@777 77 Threads::gc_prologue();
ysr@777 78
ysr@777 79 bool marked_for_unloading = false;
ysr@777 80
ysr@777 81 allocate_stacks();
ysr@777 82
iveresov@793 83 // We should save the marks of the currently locked biased monitors.
iveresov@793 84 // The marking doesn't preserve the marks of biased objects.
iveresov@793 85 BiasedLocking::preserve_marks();
iveresov@793 86
ysr@777 87 mark_sweep_phase1(marked_for_unloading, clear_all_softrefs);
ysr@777 88
ysr@777 89 mark_sweep_phase2();
ysr@777 90
ysr@777 91 // Don't add any more derived pointers during phase3
ysr@777 92 COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
ysr@777 93
ysr@777 94 mark_sweep_phase3();
ysr@777 95
ysr@777 96 mark_sweep_phase4();
ysr@777 97
ysr@777 98 GenMarkSweep::restore_marks();
iveresov@793 99 BiasedLocking::restore_marks();
ysr@777 100 GenMarkSweep::deallocate_stacks();
ysr@777 101
ysr@777 102 // "free at last gc" is calculated from these.
ysr@777 103 // CHF: cheating for now!!!
ysr@777 104 // Universe::set_heap_capacity_at_last_gc(Universe::heap()->capacity());
ysr@777 105 // Universe::set_heap_used_at_last_gc(Universe::heap()->used());
ysr@777 106
ysr@777 107 Threads::gc_epilogue();
ysr@777 108 CodeCache::gc_epilogue();
kamg@2467 109 JvmtiExport::gc_epilogue();
ysr@777 110
ysr@777 111 // refs processing: clean slate
ysr@777 112 GenMarkSweep::_ref_processor = NULL;
ysr@777 113 }
ysr@777 114
ysr@777 115
ysr@777 116 void G1MarkSweep::allocate_stacks() {
ysr@777 117 GenMarkSweep::_preserved_count_max = 0;
ysr@777 118 GenMarkSweep::_preserved_marks = NULL;
ysr@777 119 GenMarkSweep::_preserved_count = 0;
ysr@777 120 }
ysr@777 121
ysr@777 122 void G1MarkSweep::mark_sweep_phase1(bool& marked_for_unloading,
ysr@777 123 bool clear_all_softrefs) {
ysr@777 124 // Recursively traverse all live objects and mark them
sla@5237 125 GCTraceTime tm("phase 1", G1Log::fine() && Verbose, true, gc_timer());
ysr@777 126 GenMarkSweep::trace(" 1");
ysr@777 127
ysr@777 128 SharedHeap* sh = SharedHeap::heap();
ysr@777 129
coleenp@4037 130 // Need cleared claim bits for the strong roots processing
coleenp@4037 131 ClassLoaderDataGraph::clear_claimed_marks();
coleenp@4037 132
coleenp@4037 133 sh->process_strong_roots(true, // activate StrongRootsScope
coleenp@4037 134 false, // not scavenging.
ysr@777 135 SharedHeap::SO_SystemClasses,
ysr@777 136 &GenMarkSweep::follow_root_closure,
jrose@1424 137 &GenMarkSweep::follow_code_root_closure,
coleenp@4037 138 &GenMarkSweep::follow_klass_closure);
ysr@777 139
ysr@777 140 // Process reference objects found during marking
ysr@888 141 ReferenceProcessor* rp = GenMarkSweep::ref_processor();
johnc@3175 142 assert(rp == G1CollectedHeap::heap()->ref_processor_stw(), "Sanity");
johnc@3175 143
ysr@892 144 rp->setup_policy(clear_all_softrefs);
sla@5237 145 const ReferenceProcessorStats& stats =
sla@5237 146 rp->process_discovered_references(&GenMarkSweep::is_alive,
sla@5237 147 &GenMarkSweep::keep_alive,
sla@5237 148 &GenMarkSweep::follow_stack_closure,
sla@5237 149 NULL,
sla@5237 150 gc_timer());
sla@5237 151 gc_tracer()->report_gc_reference_stats(stats);
ysr@777 152
stefank@5020 153
stefank@5020 154 // This is the point where the entire marking should have completed.
stefank@5020 155 assert(GenMarkSweep::_marking_stack.is_empty(), "Marking should have completed");
stefank@5020 156
stefank@5020 157 // Unload classes and purge the SystemDictionary.
ysr@777 158 bool purged_class = SystemDictionary::do_unloading(&GenMarkSweep::is_alive);
ysr@777 159
stefank@5020 160 // Unload nmethods.
brutisso@4098 161 CodeCache::do_unloading(&GenMarkSweep::is_alive, purged_class);
ysr@777 162
stefank@5020 163 // Prune dead klasses from subklass/sibling/implementor lists.
coleenp@4037 164 Klass::clean_weak_klass_links(&GenMarkSweep::is_alive);
ysr@777 165
stefank@5020 166 // Delete entries for dead interned strings.
ysr@777 167 StringTable::unlink(&GenMarkSweep::is_alive);
stefank@5020 168
coleenp@2497 169 // Clean up unreferenced symbols in symbol table.
coleenp@2497 170 SymbolTable::unlink();
ysr@777 171
johnc@2969 172 if (VerifyDuringGC) {
johnc@2969 173 HandleMark hm; // handle scope
johnc@2969 174 COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact);
johnc@2969 175 Universe::heap()->prepare_for_verify();
johnc@2969 176 // Note: we can verify only the heap here. When an object is
johnc@2969 177 // marked, the previous value of the mark word (including
johnc@2969 178 // identity hash values, ages, etc) is preserved, and the mark
johnc@2969 179 // word is set to markOop::marked_value - effectively removing
johnc@2969 180 // any hash values from the mark word. These hash values are
johnc@2969 181 // used when verifying the dictionaries and so removing them
johnc@2969 182 // from the mark word can make verification of the dictionaries
johnc@2969 183 // fail. At the end of the GC, the orginal mark word values
johnc@2969 184 // (including hash values) are restored to the appropriate
johnc@2969 185 // objects.
stefank@5018 186 if (!VerifySilently) {
stefank@5018 187 gclog_or_tty->print(" VerifyDuringGC:(full)[Verifying ");
stefank@5018 188 }
stefank@5018 189 Universe::heap()->verify(VerifySilently, VerifyOption_G1UseMarkWord);
stefank@5018 190 if (!VerifySilently) {
stefank@5018 191 gclog_or_tty->print_cr("]");
stefank@5018 192 }
johnc@2969 193 }
sla@5237 194
sla@5237 195 gc_tracer()->report_object_count_after_gc(&GenMarkSweep::is_alive);
ysr@777 196 }
ysr@777 197
ysr@777 198 class G1PrepareCompactClosure: public HeapRegionClosure {
tonyp@2472 199 G1CollectedHeap* _g1h;
ysr@777 200 ModRefBarrierSet* _mrbs;
ysr@777 201 CompactPoint _cp;
tonyp@2472 202 HumongousRegionSet _humongous_proxy_set;
ysr@777 203
ysr@777 204 void free_humongous_region(HeapRegion* hr) {
ysr@777 205 HeapWord* end = hr->end();
tonyp@2643 206 size_t dummy_pre_used;
tonyp@2643 207 FreeRegionList dummy_free_list("Dummy Free List for G1MarkSweep");
tonyp@2643 208
ysr@777 209 assert(hr->startsHumongous(),
ysr@777 210 "Only the start of a humongous region should be freed.");
tonyp@2643 211 _g1h->free_humongous_region(hr, &dummy_pre_used, &dummy_free_list,
tonyp@2472 212 &_humongous_proxy_set, false /* par */);
ysr@777 213 hr->prepare_for_compaction(&_cp);
ysr@777 214 // Also clear the part of the card table that will be unused after
ysr@777 215 // compaction.
tonyp@2472 216 _mrbs->clear(MemRegion(hr->compaction_top(), end));
tonyp@2643 217 dummy_free_list.remove_all();
ysr@777 218 }
ysr@777 219
ysr@777 220 public:
tonyp@2472 221 G1PrepareCompactClosure(CompactibleSpace* cs)
tonyp@2472 222 : _g1h(G1CollectedHeap::heap()),
tonyp@2472 223 _mrbs(G1CollectedHeap::heap()->mr_bs()),
ysr@777 224 _cp(NULL, cs, cs->initialize_threshold()),
tonyp@2472 225 _humongous_proxy_set("G1MarkSweep Humongous Proxy Set") { }
tonyp@2472 226
tonyp@2472 227 void update_sets() {
tonyp@2472 228 // We'll recalculate total used bytes and recreate the free list
tonyp@2472 229 // at the end of the GC, so no point in updating those values here.
tonyp@2472 230 _g1h->update_sets_after_freeing_regions(0, /* pre_used */
tonyp@2472 231 NULL, /* free_list */
tonyp@3268 232 NULL, /* old_proxy_set */
tonyp@2472 233 &_humongous_proxy_set,
tonyp@2472 234 false /* par */);
tonyp@2472 235 }
tonyp@2472 236
ysr@777 237 bool doHeapRegion(HeapRegion* hr) {
ysr@777 238 if (hr->isHumongous()) {
ysr@777 239 if (hr->startsHumongous()) {
ysr@777 240 oop obj = oop(hr->bottom());
ysr@777 241 if (obj->is_gc_marked()) {
ysr@777 242 obj->forward_to(obj);
ysr@777 243 } else {
ysr@777 244 free_humongous_region(hr);
ysr@777 245 }
ysr@777 246 } else {
ysr@777 247 assert(hr->continuesHumongous(), "Invalid humongous.");
ysr@777 248 }
ysr@777 249 } else {
ysr@777 250 hr->prepare_for_compaction(&_cp);
ysr@777 251 // Also clear the part of the card table that will be unused after
ysr@777 252 // compaction.
ysr@777 253 _mrbs->clear(MemRegion(hr->compaction_top(), hr->end()));
ysr@777 254 }
ysr@777 255 return false;
ysr@777 256 }
ysr@777 257 };
apetrusenko@1112 258
ysr@777 259 void G1MarkSweep::mark_sweep_phase2() {
ysr@777 260 // Now all live objects are marked, compute the new object addresses.
ysr@777 261
ysr@777 262 // It is not required that we traverse spaces in the same order in
ysr@777 263 // phase2, phase3 and phase4, but the ValidateMarkSweep live oops
ysr@777 264 // tracking expects us to do so. See comment under phase4.
ysr@777 265
ysr@777 266 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 267
sla@5237 268 GCTraceTime tm("phase 2", G1Log::fine() && Verbose, true, gc_timer());
ysr@777 269 GenMarkSweep::trace("2");
ysr@777 270
tonyp@3957 271 // find the first region
tonyp@3957 272 HeapRegion* r = g1h->region_at(0);
ysr@777 273 CompactibleSpace* sp = r;
ysr@777 274 if (r->isHumongous() && oop(r->bottom())->is_gc_marked()) {
ysr@777 275 sp = r->next_compaction_space();
ysr@777 276 }
ysr@777 277
apetrusenko@1112 278 G1PrepareCompactClosure blk(sp);
ysr@777 279 g1h->heap_region_iterate(&blk);
tonyp@2472 280 blk.update_sets();
ysr@777 281 }
ysr@777 282
ysr@777 283 class G1AdjustPointersClosure: public HeapRegionClosure {
ysr@777 284 public:
ysr@777 285 bool doHeapRegion(HeapRegion* r) {
ysr@777 286 if (r->isHumongous()) {
ysr@777 287 if (r->startsHumongous()) {
ysr@777 288 // We must adjust the pointers on the single H object.
ysr@777 289 oop obj = oop(r->bottom());
ysr@777 290 // point all the oops to the new location
ysr@777 291 obj->adjust_pointers();
ysr@777 292 }
ysr@777 293 } else {
ysr@777 294 // This really ought to be "as_CompactibleSpace"...
ysr@777 295 r->adjust_pointers();
ysr@777 296 }
ysr@777 297 return false;
ysr@777 298 }
ysr@777 299 };
ysr@777 300
ysr@777 301 void G1MarkSweep::mark_sweep_phase3() {
ysr@777 302 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 303
ysr@777 304 // Adjust the pointers to reflect the new locations
sla@5237 305 GCTraceTime tm("phase 3", G1Log::fine() && Verbose, true, gc_timer());
ysr@777 306 GenMarkSweep::trace("3");
ysr@777 307
ysr@777 308 SharedHeap* sh = SharedHeap::heap();
ysr@777 309
coleenp@4037 310 // Need cleared claim bits for the strong roots processing
coleenp@4037 311 ClassLoaderDataGraph::clear_claimed_marks();
coleenp@4037 312
jrose@1424 313 sh->process_strong_roots(true, // activate StrongRootsScope
coleenp@4037 314 false, // not scavenging.
ysr@777 315 SharedHeap::SO_AllClasses,
stefank@5011 316 &GenMarkSweep::adjust_pointer_closure,
jrose@1424 317 NULL, // do not touch code cache here
coleenp@4037 318 &GenMarkSweep::adjust_klass_closure);
ysr@777 319
johnc@3175 320 assert(GenMarkSweep::ref_processor() == g1h->ref_processor_stw(), "Sanity");
stefank@5011 321 g1h->ref_processor_stw()->weak_oops_do(&GenMarkSweep::adjust_pointer_closure);
ysr@777 322
ysr@777 323 // Now adjust pointers in remaining weak roots. (All of which should
ysr@777 324 // have been cleared if they pointed to non-surviving objects.)
stefank@5011 325 g1h->g1_process_weak_roots(&GenMarkSweep::adjust_pointer_closure);
ysr@777 326
ysr@777 327 GenMarkSweep::adjust_marks();
ysr@777 328
ysr@777 329 G1AdjustPointersClosure blk;
ysr@777 330 g1h->heap_region_iterate(&blk);
ysr@777 331 }
ysr@777 332
ysr@777 333 class G1SpaceCompactClosure: public HeapRegionClosure {
ysr@777 334 public:
ysr@777 335 G1SpaceCompactClosure() {}
ysr@777 336
ysr@777 337 bool doHeapRegion(HeapRegion* hr) {
ysr@777 338 if (hr->isHumongous()) {
ysr@777 339 if (hr->startsHumongous()) {
ysr@777 340 oop obj = oop(hr->bottom());
ysr@777 341 if (obj->is_gc_marked()) {
ysr@777 342 obj->init_mark();
ysr@777 343 } else {
ysr@777 344 assert(hr->is_empty(), "Should have been cleared in phase 2.");
ysr@777 345 }
ysr@777 346 hr->reset_during_compaction();
ysr@777 347 }
ysr@777 348 } else {
ysr@777 349 hr->compact();
ysr@777 350 }
ysr@777 351 return false;
ysr@777 352 }
ysr@777 353 };
ysr@777 354
ysr@777 355 void G1MarkSweep::mark_sweep_phase4() {
ysr@777 356 // All pointers are now adjusted, move objects accordingly
ysr@777 357
ysr@777 358 // The ValidateMarkSweep live oops tracking expects us to traverse spaces
ysr@777 359 // in the same order in phase2, phase3 and phase4. We don't quite do that
coleenp@4037 360 // here (code and comment not fixed for perm removal), so we tell the validate code
ysr@777 361 // to use a higher index (saved from phase2) when verifying perm_gen.
ysr@777 362 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 363
sla@5237 364 GCTraceTime tm("phase 4", G1Log::fine() && Verbose, true, gc_timer());
ysr@777 365 GenMarkSweep::trace("4");
ysr@777 366
ysr@777 367 G1SpaceCompactClosure blk;
ysr@777 368 g1h->heap_region_iterate(&blk);
ysr@777 369
ysr@777 370 }

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