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

Mon, 19 Aug 2019 10:11:31 +0200

author
neugens
date
Mon, 19 Aug 2019 10:11:31 +0200
changeset 9861
a248d0be1309
parent 9858
b985cbb00e68
child 9931
fd44df5e3bc3
permissions
-rw-r--r--

8229401: Fix JFR code cache test failures
8223689: Add JFR Thread Sampling Support
8223690: Add JFR BiasedLock Event Support
8223691: Add JFR G1 Region Type Change Event Support
8223692: Add JFR G1 Heap Summary Event Support
Summary: Backport JFR from JDK11, additional fixes
Reviewed-by: neugens, apetushkov
Contributed-by: denghui.ddh@alibaba-inc.com

ysr@777 1 /*
fmatte@9358 2 * Copyright (c) 2001, 2018, 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"
mgerdin@7659 34 #include "gc_implementation/g1/g1RootProcessor.hpp"
pliden@6413 35 #include "gc_implementation/g1/g1StringDedup.hpp"
sla@5237 36 #include "gc_implementation/shared/gcHeapSummary.hpp"
sla@5237 37 #include "gc_implementation/shared/gcTimer.hpp"
sla@5237 38 #include "gc_implementation/shared/gcTrace.hpp"
sla@5237 39 #include "gc_implementation/shared/gcTraceTime.hpp"
stefank@2314 40 #include "memory/gcLocker.hpp"
stefank@2314 41 #include "memory/genCollectedHeap.hpp"
stefank@2314 42 #include "memory/modRefBarrierSet.hpp"
stefank@2314 43 #include "memory/referencePolicy.hpp"
stefank@2314 44 #include "memory/space.hpp"
stefank@2314 45 #include "oops/instanceRefKlass.hpp"
stefank@2314 46 #include "oops/oop.inline.hpp"
stefank@2314 47 #include "prims/jvmtiExport.hpp"
stefank@2314 48 #include "runtime/biasedLocking.hpp"
stefank@2314 49 #include "runtime/fprofiler.hpp"
stefank@2314 50 #include "runtime/synchronizer.hpp"
stefank@2314 51 #include "runtime/thread.hpp"
stefank@2314 52 #include "runtime/vmThread.hpp"
stefank@2314 53 #include "utilities/copy.hpp"
stefank@2314 54 #include "utilities/events.hpp"
apetushkov@9858 55 #if INCLUDE_JFR
apetushkov@9858 56 #include "jfr/jfr.hpp"
apetushkov@9858 57 #endif // INCLUDE_JFR
ysr@777 58
ysr@777 59 class HeapRegion;
ysr@777 60
ysr@777 61 void G1MarkSweep::invoke_at_safepoint(ReferenceProcessor* rp,
ysr@777 62 bool clear_all_softrefs) {
ysr@777 63 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
ysr@777 64
jmasa@1822 65 SharedHeap* sh = SharedHeap::heap();
jmasa@1822 66 #ifdef ASSERT
jmasa@1822 67 if (sh->collector_policy()->should_clear_all_soft_refs()) {
jmasa@1822 68 assert(clear_all_softrefs, "Policy should have been checked earler");
jmasa@1822 69 }
jmasa@1822 70 #endif
ysr@777 71 // hook up weak ref data so it can be used during Mark-Sweep
ysr@777 72 assert(GenMarkSweep::ref_processor() == NULL, "no stomping");
ysr@888 73 assert(rp != NULL, "should be non-NULL");
johnc@3175 74 assert(rp == G1CollectedHeap::heap()->ref_processor_stw(), "Precondition");
johnc@3175 75
ysr@777 76 GenMarkSweep::_ref_processor = rp;
ysr@892 77 rp->setup_policy(clear_all_softrefs);
ysr@777 78
coleenp@4037 79 // When collecting the permanent generation Method*s may be moving,
ysr@777 80 // so we either have to flush all bcp data or convert it into bci.
ysr@777 81 CodeCache::gc_prologue();
ysr@777 82 Threads::gc_prologue();
ysr@777 83
ysr@777 84 bool marked_for_unloading = false;
ysr@777 85
ysr@777 86 allocate_stacks();
ysr@777 87
iveresov@793 88 // We should save the marks of the currently locked biased monitors.
iveresov@793 89 // The marking doesn't preserve the marks of biased objects.
iveresov@793 90 BiasedLocking::preserve_marks();
iveresov@793 91
ysr@777 92 mark_sweep_phase1(marked_for_unloading, clear_all_softrefs);
ysr@777 93
ysr@777 94 mark_sweep_phase2();
ysr@777 95
ysr@777 96 // Don't add any more derived pointers during phase3
ysr@777 97 COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
ysr@777 98
ysr@777 99 mark_sweep_phase3();
ysr@777 100
ysr@777 101 mark_sweep_phase4();
ysr@777 102
ysr@777 103 GenMarkSweep::restore_marks();
iveresov@793 104 BiasedLocking::restore_marks();
ysr@777 105 GenMarkSweep::deallocate_stacks();
ysr@777 106
ysr@777 107 // "free at last gc" is calculated from these.
ysr@777 108 // CHF: cheating for now!!!
ysr@777 109 // Universe::set_heap_capacity_at_last_gc(Universe::heap()->capacity());
ysr@777 110 // Universe::set_heap_used_at_last_gc(Universe::heap()->used());
ysr@777 111
ysr@777 112 Threads::gc_epilogue();
ysr@777 113 CodeCache::gc_epilogue();
kamg@2467 114 JvmtiExport::gc_epilogue();
ysr@777 115
ysr@777 116 // refs processing: clean slate
ysr@777 117 GenMarkSweep::_ref_processor = NULL;
ysr@777 118 }
ysr@777 119
ysr@777 120
ysr@777 121 void G1MarkSweep::allocate_stacks() {
ysr@777 122 GenMarkSweep::_preserved_count_max = 0;
ysr@777 123 GenMarkSweep::_preserved_marks = NULL;
ysr@777 124 GenMarkSweep::_preserved_count = 0;
ysr@777 125 }
ysr@777 126
ysr@777 127 void G1MarkSweep::mark_sweep_phase1(bool& marked_for_unloading,
ysr@777 128 bool clear_all_softrefs) {
ysr@777 129 // Recursively traverse all live objects and mark them
brutisso@6904 130 GCTraceTime tm("phase 1", G1Log::fine() && Verbose, true, gc_timer(), gc_tracer()->gc_id());
ysr@777 131 GenMarkSweep::trace(" 1");
ysr@777 132
mgerdin@7659 133 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 134
stefank@6992 135 // Need cleared claim bits for the roots processing
coleenp@4037 136 ClassLoaderDataGraph::clear_claimed_marks();
coleenp@4037 137
stefank@6992 138 MarkingCodeBlobClosure follow_code_closure(&GenMarkSweep::follow_root_closure, !CodeBlobToOopClosure::FixRelocations);
mgerdin@7659 139 {
mgerdin@7659 140 G1RootProcessor root_processor(g1h);
fmatte@9358 141 if (ClassUnloading) {
fmatte@9358 142 root_processor.process_strong_roots(&GenMarkSweep::follow_root_closure,
fmatte@9358 143 &GenMarkSweep::follow_cld_closure,
fmatte@9358 144 &follow_code_closure);
fmatte@9358 145 } else {
fmatte@9358 146 root_processor.process_all_roots_no_string_table(
fmatte@9358 147 &GenMarkSweep::follow_root_closure,
fmatte@9358 148 &GenMarkSweep::follow_cld_closure,
fmatte@9358 149 &follow_code_closure);
fmatte@9358 150 }
mgerdin@7659 151 }
ysr@777 152
ysr@777 153 // Process reference objects found during marking
ysr@888 154 ReferenceProcessor* rp = GenMarkSweep::ref_processor();
mgerdin@7659 155 assert(rp == g1h->ref_processor_stw(), "Sanity");
johnc@3175 156
ysr@892 157 rp->setup_policy(clear_all_softrefs);
sla@5237 158 const ReferenceProcessorStats& stats =
sla@5237 159 rp->process_discovered_references(&GenMarkSweep::is_alive,
sla@5237 160 &GenMarkSweep::keep_alive,
sla@5237 161 &GenMarkSweep::follow_stack_closure,
sla@5237 162 NULL,
brutisso@6904 163 gc_timer(),
brutisso@6904 164 gc_tracer()->gc_id());
sla@5237 165 gc_tracer()->report_gc_reference_stats(stats);
ysr@777 166
stefank@5020 167
stefank@5020 168 // This is the point where the entire marking should have completed.
stefank@5020 169 assert(GenMarkSweep::_marking_stack.is_empty(), "Marking should have completed");
stefank@5020 170
fmatte@9358 171 if (ClassUnloading) {
ysr@777 172
fmatte@9358 173 // Unload classes and purge the SystemDictionary.
fmatte@9358 174 bool purged_class = SystemDictionary::do_unloading(&GenMarkSweep::is_alive);
ysr@777 175
fmatte@9358 176 // Unload nmethods.
fmatte@9358 177 CodeCache::do_unloading(&GenMarkSweep::is_alive, purged_class);
ysr@777 178
fmatte@9358 179 // Prune dead klasses from subklass/sibling/implementor lists.
fmatte@9358 180 Klass::clean_weak_klass_links(&GenMarkSweep::is_alive);
fmatte@9358 181 }
tschatzl@6229 182 // Delete entries for dead interned string and clean up unreferenced symbols in symbol table.
tschatzl@6229 183 G1CollectedHeap::heap()->unlink_string_and_symbol_table(&GenMarkSweep::is_alive);
ysr@777 184
johnc@2969 185 if (VerifyDuringGC) {
johnc@2969 186 HandleMark hm; // handle scope
johnc@2969 187 COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact);
johnc@2969 188 Universe::heap()->prepare_for_verify();
johnc@2969 189 // Note: we can verify only the heap here. When an object is
johnc@2969 190 // marked, the previous value of the mark word (including
johnc@2969 191 // identity hash values, ages, etc) is preserved, and the mark
johnc@2969 192 // word is set to markOop::marked_value - effectively removing
johnc@2969 193 // any hash values from the mark word. These hash values are
johnc@2969 194 // used when verifying the dictionaries and so removing them
johnc@2969 195 // from the mark word can make verification of the dictionaries
johnc@2969 196 // fail. At the end of the GC, the orginal mark word values
johnc@2969 197 // (including hash values) are restored to the appropriate
johnc@2969 198 // objects.
stefank@5018 199 if (!VerifySilently) {
stefank@5018 200 gclog_or_tty->print(" VerifyDuringGC:(full)[Verifying ");
stefank@5018 201 }
stefank@5018 202 Universe::heap()->verify(VerifySilently, VerifyOption_G1UseMarkWord);
stefank@5018 203 if (!VerifySilently) {
stefank@5018 204 gclog_or_tty->print_cr("]");
stefank@5018 205 }
johnc@2969 206 }
sla@5237 207
sla@5237 208 gc_tracer()->report_object_count_after_gc(&GenMarkSweep::is_alive);
ysr@777 209 }
ysr@777 210
apetrusenko@1112 211
ysr@777 212 void G1MarkSweep::mark_sweep_phase2() {
ysr@777 213 // Now all live objects are marked, compute the new object addresses.
ysr@777 214
ysr@777 215 // It is not required that we traverse spaces in the same order in
ysr@777 216 // phase2, phase3 and phase4, but the ValidateMarkSweep live oops
ysr@777 217 // tracking expects us to do so. See comment under phase4.
ysr@777 218
brutisso@6904 219 GCTraceTime tm("phase 2", G1Log::fine() && Verbose, true, gc_timer(), gc_tracer()->gc_id());
ysr@777 220 GenMarkSweep::trace("2");
ysr@777 221
sjohanss@7131 222 prepare_compaction();
ysr@777 223 }
ysr@777 224
ysr@777 225 class G1AdjustPointersClosure: public HeapRegionClosure {
ysr@777 226 public:
ysr@777 227 bool doHeapRegion(HeapRegion* r) {
ysr@777 228 if (r->isHumongous()) {
ysr@777 229 if (r->startsHumongous()) {
ysr@777 230 // We must adjust the pointers on the single H object.
ysr@777 231 oop obj = oop(r->bottom());
ysr@777 232 // point all the oops to the new location
ysr@777 233 obj->adjust_pointers();
ysr@777 234 }
ysr@777 235 } else {
ysr@777 236 // This really ought to be "as_CompactibleSpace"...
ysr@777 237 r->adjust_pointers();
ysr@777 238 }
ysr@777 239 return false;
ysr@777 240 }
ysr@777 241 };
ysr@777 242
ysr@777 243 void G1MarkSweep::mark_sweep_phase3() {
ysr@777 244 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 245
ysr@777 246 // Adjust the pointers to reflect the new locations
brutisso@6904 247 GCTraceTime tm("phase 3", G1Log::fine() && Verbose, true, gc_timer(), gc_tracer()->gc_id());
ysr@777 248 GenMarkSweep::trace("3");
ysr@777 249
stefank@6992 250 // Need cleared claim bits for the roots processing
coleenp@4037 251 ClassLoaderDataGraph::clear_claimed_marks();
coleenp@4037 252
stefank@6992 253 CodeBlobToOopClosure adjust_code_closure(&GenMarkSweep::adjust_pointer_closure, CodeBlobToOopClosure::FixRelocations);
mgerdin@7659 254 {
mgerdin@7659 255 G1RootProcessor root_processor(g1h);
mgerdin@7659 256 root_processor.process_all_roots(&GenMarkSweep::adjust_pointer_closure,
mgerdin@7659 257 &GenMarkSweep::adjust_cld_closure,
mgerdin@7659 258 &adjust_code_closure);
mgerdin@7659 259 }
ysr@777 260
johnc@3175 261 assert(GenMarkSweep::ref_processor() == g1h->ref_processor_stw(), "Sanity");
stefank@5011 262 g1h->ref_processor_stw()->weak_oops_do(&GenMarkSweep::adjust_pointer_closure);
ysr@777 263
ysr@777 264 // Now adjust pointers in remaining weak roots. (All of which should
ysr@777 265 // have been cleared if they pointed to non-surviving objects.)
stefank@9665 266 JNIHandles::weak_oops_do(&GenMarkSweep::adjust_pointer_closure);
apetushkov@9858 267 JFR_ONLY(Jfr::weak_oops_do(&GenMarkSweep::adjust_pointer_closure));
ysr@777 268
pliden@6413 269 if (G1StringDedup::is_enabled()) {
pliden@6413 270 G1StringDedup::oops_do(&GenMarkSweep::adjust_pointer_closure);
pliden@6413 271 }
pliden@6413 272
ysr@777 273 GenMarkSweep::adjust_marks();
ysr@777 274
ysr@777 275 G1AdjustPointersClosure blk;
ysr@777 276 g1h->heap_region_iterate(&blk);
ysr@777 277 }
ysr@777 278
ysr@777 279 class G1SpaceCompactClosure: public HeapRegionClosure {
ysr@777 280 public:
ysr@777 281 G1SpaceCompactClosure() {}
ysr@777 282
ysr@777 283 bool doHeapRegion(HeapRegion* hr) {
ysr@777 284 if (hr->isHumongous()) {
ysr@777 285 if (hr->startsHumongous()) {
ysr@777 286 oop obj = oop(hr->bottom());
ysr@777 287 if (obj->is_gc_marked()) {
ysr@777 288 obj->init_mark();
ysr@777 289 } else {
ysr@777 290 assert(hr->is_empty(), "Should have been cleared in phase 2.");
ysr@777 291 }
ysr@777 292 hr->reset_during_compaction();
ysr@777 293 }
ysr@777 294 } else {
ysr@777 295 hr->compact();
ysr@777 296 }
ysr@777 297 return false;
ysr@777 298 }
ysr@777 299 };
ysr@777 300
ysr@777 301 void G1MarkSweep::mark_sweep_phase4() {
ysr@777 302 // All pointers are now adjusted, move objects accordingly
ysr@777 303
ysr@777 304 // The ValidateMarkSweep live oops tracking expects us to traverse spaces
ysr@777 305 // in the same order in phase2, phase3 and phase4. We don't quite do that
coleenp@4037 306 // here (code and comment not fixed for perm removal), so we tell the validate code
ysr@777 307 // to use a higher index (saved from phase2) when verifying perm_gen.
ysr@777 308 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 309
brutisso@6904 310 GCTraceTime tm("phase 4", G1Log::fine() && Verbose, true, gc_timer(), gc_tracer()->gc_id());
ysr@777 311 GenMarkSweep::trace("4");
ysr@777 312
ysr@777 313 G1SpaceCompactClosure blk;
ysr@777 314 g1h->heap_region_iterate(&blk);
ysr@777 315
ysr@777 316 }
sjohanss@7131 317
sjohanss@7131 318 void G1MarkSweep::prepare_compaction_work(G1PrepareCompactClosure* blk) {
sjohanss@7131 319 G1CollectedHeap* g1h = G1CollectedHeap::heap();
sjohanss@7131 320 g1h->heap_region_iterate(blk);
sjohanss@7131 321 blk->update_sets();
sjohanss@7131 322 }
sjohanss@7131 323
sjohanss@7131 324 void G1PrepareCompactClosure::free_humongous_region(HeapRegion* hr) {
sjohanss@7131 325 HeapWord* end = hr->end();
sjohanss@7131 326 FreeRegionList dummy_free_list("Dummy Free List for G1MarkSweep");
sjohanss@7131 327
sjohanss@7131 328 assert(hr->startsHumongous(),
sjohanss@7131 329 "Only the start of a humongous region should be freed.");
sjohanss@7131 330
sjohanss@7131 331 hr->set_containing_set(NULL);
sjohanss@7131 332 _humongous_regions_removed.increment(1u, hr->capacity());
sjohanss@7131 333
sjohanss@7131 334 _g1h->free_humongous_region(hr, &dummy_free_list, false /* par */);
sjohanss@7131 335 prepare_for_compaction(hr, end);
sjohanss@7131 336 dummy_free_list.remove_all();
sjohanss@7131 337 }
sjohanss@7131 338
sjohanss@7131 339 void G1PrepareCompactClosure::prepare_for_compaction(HeapRegion* hr, HeapWord* end) {
sjohanss@7131 340 // If this is the first live region that we came across which we can compact,
sjohanss@7131 341 // initialize the CompactPoint.
sjohanss@7131 342 if (!is_cp_initialized()) {
sjohanss@7131 343 _cp.space = hr;
sjohanss@7131 344 _cp.threshold = hr->initialize_threshold();
sjohanss@7131 345 }
sjohanss@7131 346 prepare_for_compaction_work(&_cp, hr, end);
sjohanss@7131 347 }
sjohanss@7131 348
sjohanss@7131 349 void G1PrepareCompactClosure::prepare_for_compaction_work(CompactPoint* cp,
sjohanss@7131 350 HeapRegion* hr,
sjohanss@7131 351 HeapWord* end) {
sjohanss@7131 352 hr->prepare_for_compaction(cp);
sjohanss@7131 353 // Also clear the part of the card table that will be unused after
sjohanss@7131 354 // compaction.
sjohanss@7131 355 _mrbs->clear(MemRegion(hr->compaction_top(), end));
sjohanss@7131 356 }
sjohanss@7131 357
sjohanss@7131 358 void G1PrepareCompactClosure::update_sets() {
sjohanss@7131 359 // We'll recalculate total used bytes and recreate the free list
sjohanss@7131 360 // at the end of the GC, so no point in updating those values here.
sjohanss@7131 361 HeapRegionSetCount empty_set;
sjohanss@7131 362 _g1h->remove_from_old_sets(empty_set, _humongous_regions_removed);
sjohanss@7131 363 }
sjohanss@7131 364
sjohanss@7131 365 bool G1PrepareCompactClosure::doHeapRegion(HeapRegion* hr) {
sjohanss@7131 366 if (hr->isHumongous()) {
sjohanss@7131 367 if (hr->startsHumongous()) {
sjohanss@7131 368 oop obj = oop(hr->bottom());
sjohanss@7131 369 if (obj->is_gc_marked()) {
sjohanss@7131 370 obj->forward_to(obj);
sjohanss@7131 371 } else {
sjohanss@7131 372 free_humongous_region(hr);
sjohanss@7131 373 }
sjohanss@7131 374 } else {
sjohanss@7131 375 assert(hr->continuesHumongous(), "Invalid humongous.");
sjohanss@7131 376 }
sjohanss@7131 377 } else {
sjohanss@7131 378 prepare_for_compaction(hr, hr->end());
sjohanss@7131 379 }
sjohanss@7131 380 return false;
sjohanss@7131 381 }

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