Mercurial > hg > graal-jvmci-8
view src/share/vm/memory/heapInspection.cpp @ 3992:d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
Summary: There is a race between one thread successfully forwarding and copying the klass mirror for the SoftReference class (including the static master clock) and another thread attempting to use the master clock while attempting to discover a soft reference object. Maintain a shadow copy of the soft reference master clock and use the shadow during reference discovery and reference processing.
Reviewed-by: tonyp, brutisso, ysr
author | johnc |
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date | Wed, 12 Oct 2011 10:25:51 -0700 |
parents | 1d1603768966 |
children | d2a62e0f25eb |
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/* * Copyright (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "gc_interface/collectedHeap.hpp" #include "memory/genCollectedHeap.hpp" #include "memory/heapInspection.hpp" #include "memory/resourceArea.hpp" #include "oops/klassOop.hpp" #include "runtime/os.hpp" #include "utilities/globalDefinitions.hpp" #ifndef SERIALGC #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" #endif // HeapInspection int KlassInfoEntry::compare(KlassInfoEntry* e1, KlassInfoEntry* e2) { if(e1->_instance_words > e2->_instance_words) { return -1; } else if(e1->_instance_words < e2->_instance_words) { return 1; } return 0; } void KlassInfoEntry::print_on(outputStream* st) const { ResourceMark rm; const char* name;; if (_klass->klass_part()->name() != NULL) { name = _klass->klass_part()->external_name(); } else { if (_klass == Universe::klassKlassObj()) name = "<klassKlass>"; else if (_klass == Universe::arrayKlassKlassObj()) name = "<arrayKlassKlass>"; else if (_klass == Universe::objArrayKlassKlassObj()) name = "<objArrayKlassKlass>"; else if (_klass == Universe::instanceKlassKlassObj()) name = "<instanceKlassKlass>"; else if (_klass == Universe::typeArrayKlassKlassObj()) name = "<typeArrayKlassKlass>"; else if (_klass == Universe::boolArrayKlassObj()) name = "<boolArrayKlass>"; else if (_klass == Universe::charArrayKlassObj()) name = "<charArrayKlass>"; else if (_klass == Universe::singleArrayKlassObj()) name = "<singleArrayKlass>"; else if (_klass == Universe::doubleArrayKlassObj()) name = "<doubleArrayKlass>"; else if (_klass == Universe::byteArrayKlassObj()) name = "<byteArrayKlass>"; else if (_klass == Universe::shortArrayKlassObj()) name = "<shortArrayKlass>"; else if (_klass == Universe::intArrayKlassObj()) name = "<intArrayKlass>"; else if (_klass == Universe::longArrayKlassObj()) name = "<longArrayKlass>"; else if (_klass == Universe::methodKlassObj()) name = "<methodKlass>"; else if (_klass == Universe::constMethodKlassObj()) name = "<constMethodKlass>"; else if (_klass == Universe::methodDataKlassObj()) name = "<methodDataKlass>"; else if (_klass == Universe::constantPoolKlassObj()) name = "<constantPoolKlass>"; else if (_klass == Universe::constantPoolCacheKlassObj()) name = "<constantPoolCacheKlass>"; else if (_klass == Universe::compiledICHolderKlassObj()) name = "<compiledICHolderKlass>"; else name = "<no name>"; } // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s", (jlong) _instance_count, (julong) _instance_words * HeapWordSize, name); } KlassInfoEntry* KlassInfoBucket::lookup(const klassOop k) { KlassInfoEntry* elt = _list; while (elt != NULL) { if (elt->is_equal(k)) { return elt; } elt = elt->next(); } elt = new KlassInfoEntry(k, list()); // We may be out of space to allocate the new entry. if (elt != NULL) { set_list(elt); } return elt; } void KlassInfoBucket::iterate(KlassInfoClosure* cic) { KlassInfoEntry* elt = _list; while (elt != NULL) { cic->do_cinfo(elt); elt = elt->next(); } } void KlassInfoBucket::empty() { KlassInfoEntry* elt = _list; _list = NULL; while (elt != NULL) { KlassInfoEntry* next = elt->next(); delete elt; elt = next; } } KlassInfoTable::KlassInfoTable(int size, HeapWord* ref) { _size = 0; _ref = ref; _buckets = NEW_C_HEAP_ARRAY(KlassInfoBucket, size); if (_buckets != NULL) { _size = size; for (int index = 0; index < _size; index++) { _buckets[index].initialize(); } } } KlassInfoTable::~KlassInfoTable() { if (_buckets != NULL) { for (int index = 0; index < _size; index++) { _buckets[index].empty(); } FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets); _size = 0; } } uint KlassInfoTable::hash(klassOop p) { assert(Universe::heap()->is_in_permanent((HeapWord*)p), "all klasses in permgen"); return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2); } KlassInfoEntry* KlassInfoTable::lookup(const klassOop k) { uint idx = hash(k) % _size; assert(_buckets != NULL, "Allocation failure should have been caught"); KlassInfoEntry* e = _buckets[idx].lookup(k); // Lookup may fail if this is a new klass for which we // could not allocate space for an new entry. assert(e == NULL || k == e->klass(), "must be equal"); return e; } // Return false if the entry could not be recorded on account // of running out of space required to create a new entry. bool KlassInfoTable::record_instance(const oop obj) { klassOop k = obj->klass(); KlassInfoEntry* elt = lookup(k); // elt may be NULL if it's a new klass for which we // could not allocate space for a new entry in the hashtable. if (elt != NULL) { elt->set_count(elt->count() + 1); elt->set_words(elt->words() + obj->size()); return true; } else { return false; } } void KlassInfoTable::iterate(KlassInfoClosure* cic) { assert(_size == 0 || _buckets != NULL, "Allocation failure should have been caught"); for (int index = 0; index < _size; index++) { _buckets[index].iterate(cic); } } int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) { return (*e1)->compare(*e1,*e2); } KlassInfoHisto::KlassInfoHisto(const char* title, int estimatedCount) : _title(title) { _elements = new (ResourceObj::C_HEAP) GrowableArray<KlassInfoEntry*>(estimatedCount,true); } KlassInfoHisto::~KlassInfoHisto() { delete _elements; } void KlassInfoHisto::add(KlassInfoEntry* cie) { elements()->append(cie); } void KlassInfoHisto::sort() { elements()->sort(KlassInfoHisto::sort_helper); } void KlassInfoHisto::print_elements(outputStream* st) const { // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit jlong total = 0; julong totalw = 0; for(int i=0; i < elements()->length(); i++) { st->print("%4d: ", i+1); elements()->at(i)->print_on(st); total += elements()->at(i)->count(); totalw += elements()->at(i)->words(); } st->print_cr("Total " INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13), total, totalw * HeapWordSize); } void KlassInfoHisto::print_on(outputStream* st) const { st->print_cr("%s",title()); print_elements(st); } class HistoClosure : public KlassInfoClosure { private: KlassInfoHisto* _cih; public: HistoClosure(KlassInfoHisto* cih) : _cih(cih) {} void do_cinfo(KlassInfoEntry* cie) { _cih->add(cie); } }; class RecordInstanceClosure : public ObjectClosure { private: KlassInfoTable* _cit; size_t _missed_count; public: RecordInstanceClosure(KlassInfoTable* cit) : _cit(cit), _missed_count(0) {} void do_object(oop obj) { if (!_cit->record_instance(obj)) { _missed_count++; } } size_t missed_count() { return _missed_count; } }; void HeapInspection::heap_inspection(outputStream* st, bool need_prologue) { ResourceMark rm; HeapWord* ref; CollectedHeap* heap = Universe::heap(); bool is_shared_heap = false; switch (heap->kind()) { case CollectedHeap::G1CollectedHeap: case CollectedHeap::GenCollectedHeap: { is_shared_heap = true; SharedHeap* sh = (SharedHeap*)heap; if (need_prologue) { sh->gc_prologue(false /* !full */); // get any necessary locks, etc. } ref = sh->perm_gen()->used_region().start(); break; } #ifndef SERIALGC case CollectedHeap::ParallelScavengeHeap: { ParallelScavengeHeap* psh = (ParallelScavengeHeap*)heap; ref = psh->perm_gen()->object_space()->used_region().start(); break; } #endif // SERIALGC default: ShouldNotReachHere(); // Unexpected heap kind for this op } // Collect klass instance info KlassInfoTable cit(KlassInfoTable::cit_size, ref); if (!cit.allocation_failed()) { // Iterate over objects in the heap RecordInstanceClosure ric(&cit); // If this operation encounters a bad object when using CMS, // consider using safe_object_iterate() which avoids perm gen // objects that may contain bad references. Universe::heap()->object_iterate(&ric); // Report if certain classes are not counted because of // running out of C-heap for the histogram. size_t missed_count = ric.missed_count(); if (missed_count != 0) { st->print_cr("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT " total instances in data below", missed_count); } // Sort and print klass instance info KlassInfoHisto histo("\n" " num #instances #bytes class name\n" "----------------------------------------------", KlassInfoHisto::histo_initial_size); HistoClosure hc(&histo); cit.iterate(&hc); histo.sort(); histo.print_on(st); } else { st->print_cr("WARNING: Ran out of C-heap; histogram not generated"); } st->flush(); if (need_prologue && is_shared_heap) { SharedHeap* sh = (SharedHeap*)heap; sh->gc_epilogue(false /* !full */); // release all acquired locks, etc. } } class FindInstanceClosure : public ObjectClosure { private: klassOop _klass; GrowableArray<oop>* _result; public: FindInstanceClosure(klassOop k, GrowableArray<oop>* result) : _klass(k), _result(result) {}; void do_object(oop obj) { if (obj->is_a(_klass)) { _result->append(obj); } } }; void HeapInspection::find_instances_at_safepoint(klassOop k, GrowableArray<oop>* result) { assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); assert(Heap_lock->is_locked(), "should have the Heap_lock"); // Ensure that the heap is parsable Universe::heap()->ensure_parsability(false); // no need to retire TALBs // Iterate over objects in the heap FindInstanceClosure fic(k, result); // If this operation encounters a bad object when using CMS, // consider using safe_object_iterate() which avoids perm gen // objects that may contain bad references. Universe::heap()->object_iterate(&fic); }