| /* |
| * Copyright (c) 2017, 2021, Red Hat, Inc. All rights reserved. |
| * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved. |
| * Copyright (c) 2025, 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 "gc/shared/tlab_globals.hpp" |
| #include "gc/shenandoah/shenandoahAsserts.hpp" |
| #include "gc/shenandoah/shenandoahForwarding.inline.hpp" |
| #include "gc/shenandoah/shenandoahGeneration.hpp" |
| #include "gc/shenandoah/shenandoahHeap.inline.hpp" |
| #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp" |
| #include "gc/shenandoah/shenandoahOldGeneration.hpp" |
| #include "gc/shenandoah/shenandoahPhaseTimings.hpp" |
| #include "gc/shenandoah/shenandoahRootProcessor.hpp" |
| #include "gc/shenandoah/shenandoahScanRemembered.inline.hpp" |
| #include "gc/shenandoah/shenandoahTaskqueue.inline.hpp" |
| #include "gc/shenandoah/shenandoahUtils.hpp" |
| #include "gc/shenandoah/shenandoahVerifier.hpp" |
| #include "gc/shenandoah/shenandoahYoungGeneration.hpp" |
| #include "memory/allocation.hpp" |
| #include "memory/iterator.inline.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/compressedOops.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/orderAccess.hpp" |
| #include "runtime/threads.hpp" |
| #include "utilities/align.hpp" |
| |
| // Avoid name collision on verify_oop (defined in macroAssembler_arm.hpp) |
| #ifdef verify_oop |
| #undef verify_oop |
| #endif |
| |
| static bool is_instance_ref_klass(Klass* k) { |
| return k->is_instance_klass() && InstanceKlass::cast(k)->reference_type() != REF_NONE; |
| } |
| |
| class ShenandoahVerifyOopClosure : public BasicOopIterateClosure { |
| private: |
| const char* _phase; |
| ShenandoahVerifier::VerifyOptions _options; |
| ShenandoahVerifierStack* _stack; |
| ShenandoahHeap* _heap; |
| MarkBitMap* _map; |
| ShenandoahLivenessData* _ld; |
| void* _interior_loc; |
| oop _loc; |
| ReferenceIterationMode _ref_mode; |
| ShenandoahGeneration* _generation; |
| |
| public: |
| ShenandoahVerifyOopClosure(ShenandoahVerifierStack* stack, MarkBitMap* map, ShenandoahLivenessData* ld, |
| const char* phase, ShenandoahVerifier::VerifyOptions options) : |
| _phase(phase), |
| _options(options), |
| _stack(stack), |
| _heap(ShenandoahHeap::heap()), |
| _map(map), |
| _ld(ld), |
| _interior_loc(nullptr), |
| _loc(nullptr), |
| _generation(nullptr) { |
| if (options._verify_marked == ShenandoahVerifier::_verify_marked_complete_except_references || |
| options._verify_marked == ShenandoahVerifier::_verify_marked_complete_satb_empty || |
| options._verify_marked == ShenandoahVerifier::_verify_marked_disable) { |
| // Unknown status for Reference.referent field. Do not touch it, it might be dead. |
| // Normally, barriers would prevent us from seeing the dead referents, but verifier |
| // runs with barriers disabled. |
| _ref_mode = DO_FIELDS_EXCEPT_REFERENT; |
| } else { |
| // Otherwise do all fields. |
| _ref_mode = DO_FIELDS; |
| } |
| |
| if (_heap->mode()->is_generational()) { |
| _generation = _heap->gc_generation(); |
| assert(_generation != nullptr, "Expected active generation in this mode"); |
| shenandoah_assert_generations_reconciled(); |
| } |
| } |
| |
| ReferenceIterationMode reference_iteration_mode() override { |
| return _ref_mode; |
| } |
| |
| private: |
| void check(ShenandoahAsserts::SafeLevel level, oop obj, bool test, const char* label) { |
| if (!test) { |
| ShenandoahAsserts::print_failure(level, obj, _interior_loc, _loc, _phase, label, __FILE__, __LINE__); |
| } |
| } |
| |
| template <class T> |
| void do_oop_work(T* p) { |
| T o = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(o)) { |
| oop obj = CompressedOops::decode_not_null(o); |
| if (is_instance_ref_klass(ShenandoahForwarding::klass(obj))) { |
| obj = ShenandoahForwarding::get_forwardee(obj); |
| } |
| // Single threaded verification can use faster non-atomic stack and bitmap |
| // methods. |
| // |
| // For performance reasons, only fully verify non-marked field values. |
| // We are here when the host object for *p is already marked. |
| if (in_generation(obj) && _map->par_mark(obj)) { |
| verify_oop_at(p, obj); |
| _stack->push(ShenandoahVerifierTask(obj)); |
| } |
| } |
| } |
| |
| bool in_generation(oop obj) { |
| if (_generation == nullptr) { |
| return true; |
| } |
| |
| ShenandoahHeapRegion* region = _heap->heap_region_containing(obj); |
| return _generation->contains(region); |
| } |
| |
| void verify_oop(oop obj) { |
| // Perform consistency checks with gradually decreasing safety level. This guarantees |
| // that failure report would not try to touch something that was not yet verified to be |
| // safe to process. |
| |
| check(ShenandoahAsserts::_safe_unknown, obj, _heap->is_in_reserved(obj), |
| "oop must be in heap bounds"); |
| check(ShenandoahAsserts::_safe_unknown, obj, is_object_aligned(obj), |
| "oop must be aligned"); |
| |
| ShenandoahHeapRegion *obj_reg = _heap->heap_region_containing(obj); |
| Klass* obj_klass = ShenandoahForwarding::klass(obj); |
| |
| // Verify that obj is not in dead space: |
| { |
| // Do this before touching obj->size() |
| check(ShenandoahAsserts::_safe_unknown, obj, obj_klass != nullptr, |
| "Object klass pointer should not be null"); |
| check(ShenandoahAsserts::_safe_unknown, obj, Metaspace::contains(obj_klass), |
| "Object klass pointer must go to metaspace"); |
| |
| HeapWord *obj_addr = cast_from_oop<HeapWord*>(obj); |
| check(ShenandoahAsserts::_safe_unknown, obj, obj_addr < obj_reg->top(), |
| "Object start should be within the region"); |
| |
| if (!obj_reg->is_humongous()) { |
| check(ShenandoahAsserts::_safe_unknown, obj, (obj_addr + ShenandoahForwarding::size(obj)) <= obj_reg->top(), |
| "Object end should be within the region"); |
| } else { |
| size_t humongous_start = obj_reg->index(); |
| size_t humongous_end = humongous_start + (ShenandoahForwarding::size(obj) >> ShenandoahHeapRegion::region_size_words_shift()); |
| for (size_t idx = humongous_start + 1; idx < humongous_end; idx++) { |
| check(ShenandoahAsserts::_safe_unknown, obj, _heap->get_region(idx)->is_humongous_continuation(), |
| "Humongous object is in continuation that fits it"); |
| } |
| } |
| |
| // ------------ obj is safe at this point -------------- |
| |
| check(ShenandoahAsserts::_safe_oop, obj, obj_reg->is_active(), |
| "Object should be in active region"); |
| |
| switch (_options._verify_liveness) { |
| case ShenandoahVerifier::_verify_liveness_disable: |
| // skip |
| break; |
| case ShenandoahVerifier::_verify_liveness_complete: |
| Atomic::add(&_ld[obj_reg->index()], (uint) ShenandoahForwarding::size(obj), memory_order_relaxed); |
| // fallthrough for fast failure for un-live regions: |
| case ShenandoahVerifier::_verify_liveness_conservative: |
| check(ShenandoahAsserts::_safe_oop, obj, obj_reg->has_live() || |
| (obj_reg->is_old() && _heap->gc_generation()->is_young()), |
| "Object must belong to region with live data"); |
| shenandoah_assert_generations_reconciled(); |
| break; |
| default: |
| assert(false, "Unhandled liveness verification"); |
| } |
| } |
| |
| oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj); |
| |
| ShenandoahHeapRegion* fwd_reg = nullptr; |
| |
| if (obj != fwd) { |
| check(ShenandoahAsserts::_safe_oop, obj, _heap->is_in_reserved(fwd), |
| "Forwardee must be in heap bounds"); |
| check(ShenandoahAsserts::_safe_oop, obj, !CompressedOops::is_null(fwd), |
| "Forwardee is set"); |
| check(ShenandoahAsserts::_safe_oop, obj, is_object_aligned(fwd), |
| "Forwardee must be aligned"); |
| |
| // Do this before touching fwd->size() |
| Klass* fwd_klass = fwd->klass_or_null(); |
| check(ShenandoahAsserts::_safe_oop, obj, fwd_klass != nullptr, |
| "Forwardee klass pointer should not be null"); |
| check(ShenandoahAsserts::_safe_oop, obj, Metaspace::contains(fwd_klass), |
| "Forwardee klass pointer must go to metaspace"); |
| check(ShenandoahAsserts::_safe_oop, obj, obj_klass == fwd_klass, |
| "Forwardee klass pointer must go to metaspace"); |
| |
| fwd_reg = _heap->heap_region_containing(fwd); |
| |
| check(ShenandoahAsserts::_safe_oop, obj, fwd_reg->is_active(), |
| "Forwardee should be in active region"); |
| |
| // Verify that forwardee is not in the dead space: |
| check(ShenandoahAsserts::_safe_oop, obj, !fwd_reg->is_humongous(), |
| "Should have no humongous forwardees"); |
| |
| HeapWord *fwd_addr = cast_from_oop<HeapWord *>(fwd); |
| check(ShenandoahAsserts::_safe_oop, obj, fwd_addr < fwd_reg->top(), |
| "Forwardee start should be within the region"); |
| check(ShenandoahAsserts::_safe_oop, obj, (fwd_addr + ShenandoahForwarding::size(fwd)) <= fwd_reg->top(), |
| "Forwardee end should be within the region"); |
| |
| oop fwd2 = ShenandoahForwarding::get_forwardee_raw_unchecked(fwd); |
| check(ShenandoahAsserts::_safe_oop, obj, (fwd == fwd2), |
| "Double forwarding"); |
| } else { |
| fwd_reg = obj_reg; |
| } |
| |
| // Do additional checks for special objects: their fields can hold metadata as well. |
| // We want to check class loading/unloading did not corrupt them. |
| |
| if (obj_klass == vmClasses::Class_klass()) { |
| Metadata* klass = obj->metadata_field(java_lang_Class::klass_offset()); |
| check(ShenandoahAsserts::_safe_oop, obj, |
| klass == nullptr || Metaspace::contains(klass), |
| "Instance class mirror should point to Metaspace"); |
| |
| Metadata* array_klass = obj->metadata_field(java_lang_Class::array_klass_offset()); |
| check(ShenandoahAsserts::_safe_oop, obj, |
| array_klass == nullptr || Metaspace::contains(array_klass), |
| "Array class mirror should point to Metaspace"); |
| } |
| |
| // ------------ obj and fwd are safe at this point -------------- |
| switch (_options._verify_marked) { |
| case ShenandoahVerifier::_verify_marked_disable: |
| // skip |
| break; |
| case ShenandoahVerifier::_verify_marked_incomplete: |
| check(ShenandoahAsserts::_safe_all, obj, _heap->marking_context()->is_marked(obj), |
| "Must be marked in incomplete bitmap"); |
| break; |
| case ShenandoahVerifier::_verify_marked_complete: |
| check(ShenandoahAsserts::_safe_all, obj, _heap->gc_generation()->complete_marking_context()->is_marked(obj), |
| "Must be marked in complete bitmap"); |
| break; |
| case ShenandoahVerifier::_verify_marked_complete_except_references: |
| case ShenandoahVerifier::_verify_marked_complete_satb_empty: |
| check(ShenandoahAsserts::_safe_all, obj, _heap->gc_generation()->complete_marking_context()->is_marked(obj), |
| "Must be marked in complete bitmap, except j.l.r.Reference referents"); |
| break; |
| default: |
| assert(false, "Unhandled mark verification"); |
| } |
| |
| switch (_options._verify_forwarded) { |
| case ShenandoahVerifier::_verify_forwarded_disable: |
| // skip |
| break; |
| case ShenandoahVerifier::_verify_forwarded_none: { |
| check(ShenandoahAsserts::_safe_all, obj, (obj == fwd), |
| "Should not be forwarded"); |
| break; |
| } |
| case ShenandoahVerifier::_verify_forwarded_allow: { |
| if (obj != fwd) { |
| check(ShenandoahAsserts::_safe_all, obj, obj_reg != fwd_reg, |
| "Forwardee should be in another region"); |
| } |
| break; |
| } |
| default: |
| assert(false, "Unhandled forwarding verification"); |
| } |
| |
| switch (_options._verify_cset) { |
| case ShenandoahVerifier::_verify_cset_disable: |
| // skip |
| break; |
| case ShenandoahVerifier::_verify_cset_none: |
| check(ShenandoahAsserts::_safe_all, obj, !_heap->in_collection_set(obj), |
| "Should not have references to collection set"); |
| break; |
| case ShenandoahVerifier::_verify_cset_forwarded: |
| if (_heap->in_collection_set(obj)) { |
| check(ShenandoahAsserts::_safe_all, obj, (obj != fwd), |
| "Object in collection set, should have forwardee"); |
| } |
| break; |
| default: |
| assert(false, "Unhandled cset verification"); |
| } |
| |
| } |
| |
| public: |
| /** |
| * Verify object with known interior reference. |
| * @param p interior reference where the object is referenced from; can be off-heap |
| * @param obj verified object |
| */ |
| template <class T> |
| void verify_oop_at(T* p, oop obj) { |
| _interior_loc = p; |
| verify_oop(obj); |
| _interior_loc = nullptr; |
| } |
| |
| /** |
| * Verify object without known interior reference. |
| * Useful when picking up the object at known offset in heap, |
| * but without knowing what objects reference it. |
| * @param obj verified object |
| */ |
| void verify_oop_standalone(oop obj) { |
| _interior_loc = nullptr; |
| verify_oop(obj); |
| _interior_loc = nullptr; |
| } |
| |
| /** |
| * Verify oop fields from this object. |
| * @param obj host object for verified fields |
| */ |
| void verify_oops_from(oop obj) { |
| _loc = obj; |
| // oop_iterate() can not deal with forwarded objects, because |
| // it needs to load klass(), which may be overridden by the |
| // forwarding pointer. |
| oop fwd = ShenandoahForwarding::get_forwardee_raw(obj); |
| fwd->oop_iterate(this); |
| _loc = nullptr; |
| } |
| |
| void do_oop(oop* p) override { do_oop_work(p); } |
| void do_oop(narrowOop* p) override { do_oop_work(p); } |
| }; |
| |
| // This closure computes the amounts of used, committed, and garbage memory and the number of regions contained within |
| // a subset (e.g. the young generation or old generation) of the total heap. |
| class ShenandoahCalculateRegionStatsClosure : public ShenandoahHeapRegionClosure { |
| private: |
| size_t _used, _committed, _garbage, _regions, _humongous_waste, _trashed_regions; |
| public: |
| ShenandoahCalculateRegionStatsClosure() : |
| _used(0), _committed(0), _garbage(0), _regions(0), _humongous_waste(0), _trashed_regions(0) {}; |
| |
| void heap_region_do(ShenandoahHeapRegion* r) override { |
| _used += r->used(); |
| _garbage += r->garbage(); |
| _committed += r->is_committed() ? ShenandoahHeapRegion::region_size_bytes() : 0; |
| if (r->is_humongous()) { |
| _humongous_waste += r->free(); |
| } |
| if (r->is_trash()) { |
| _trashed_regions++; |
| } |
| _regions++; |
| log_debug(gc)("ShenandoahCalculateRegionStatsClosure: adding %zu for %s Region %zu, yielding: %zu", |
| r->used(), (r->is_humongous() ? "humongous" : "regular"), r->index(), _used); |
| } |
| |
| size_t used() const { return _used; } |
| size_t committed() const { return _committed; } |
| size_t garbage() const { return _garbage; } |
| size_t regions() const { return _regions; } |
| size_t waste() const { return _humongous_waste; } |
| |
| // span is the total memory affiliated with these stats (some of which is in use and other is available) |
| size_t span() const { return _regions * ShenandoahHeapRegion::region_size_bytes(); } |
| size_t non_trashed_span() const { return (_regions - _trashed_regions) * ShenandoahHeapRegion::region_size_bytes(); } |
| }; |
| |
| class ShenandoahGenerationStatsClosure : public ShenandoahHeapRegionClosure { |
| public: |
| ShenandoahCalculateRegionStatsClosure old; |
| ShenandoahCalculateRegionStatsClosure young; |
| ShenandoahCalculateRegionStatsClosure global; |
| |
| void heap_region_do(ShenandoahHeapRegion* r) override { |
| switch (r->affiliation()) { |
| case FREE: |
| return; |
| case YOUNG_GENERATION: |
| young.heap_region_do(r); |
| global.heap_region_do(r); |
| break; |
| case OLD_GENERATION: |
| old.heap_region_do(r); |
| global.heap_region_do(r); |
| break; |
| default: |
| ShouldNotReachHere(); |
| } |
| } |
| |
| static void log_usage(ShenandoahGeneration* generation, ShenandoahCalculateRegionStatsClosure& stats) { |
| log_debug(gc)("Safepoint verification: %s verified usage: %zu%s, recorded usage: %zu%s", |
| generation->name(), |
| byte_size_in_proper_unit(generation->used()), proper_unit_for_byte_size(generation->used()), |
| byte_size_in_proper_unit(stats.used()), proper_unit_for_byte_size(stats.used())); |
| } |
| |
| static void validate_usage(const bool adjust_for_padding, |
| const char* label, ShenandoahGeneration* generation, ShenandoahCalculateRegionStatsClosure& stats) { |
| ShenandoahHeap* heap = ShenandoahHeap::heap(); |
| size_t generation_used = generation->used(); |
| size_t generation_used_regions = generation->used_regions(); |
| if (adjust_for_padding && (generation->is_young() || generation->is_global())) { |
| size_t pad = heap->old_generation()->get_pad_for_promote_in_place(); |
| generation_used += pad; |
| } |
| |
| guarantee(stats.used() == generation_used, |
| "%s: generation (%s) used size must be consistent: generation-used: " PROPERFMT ", regions-used: " PROPERFMT, |
| label, generation->name(), PROPERFMTARGS(generation_used), PROPERFMTARGS(stats.used())); |
| |
| guarantee(stats.regions() == generation_used_regions, |
| "%s: generation (%s) used regions (%zu) must equal regions that are in use (%zu)", |
| label, generation->name(), generation->used_regions(), stats.regions()); |
| |
| size_t generation_capacity = generation->max_capacity(); |
| guarantee(stats.non_trashed_span() <= generation_capacity, |
| "%s: generation (%s) size spanned by regions (%zu) * region size (" PROPERFMT |
| ") must not exceed current capacity (" PROPERFMT ")", |
| label, generation->name(), stats.regions(), PROPERFMTARGS(ShenandoahHeapRegion::region_size_bytes()), |
| PROPERFMTARGS(generation_capacity)); |
| |
| size_t humongous_waste = generation->get_humongous_waste(); |
| guarantee(stats.waste() == humongous_waste, |
| "%s: generation (%s) humongous waste must be consistent: generation: " PROPERFMT ", regions: " PROPERFMT, |
| label, generation->name(), PROPERFMTARGS(humongous_waste), PROPERFMTARGS(stats.waste())); |
| } |
| }; |
| |
| class ShenandoahVerifyHeapRegionClosure : public ShenandoahHeapRegionClosure { |
| private: |
| ShenandoahHeap* _heap; |
| const char* _phase; |
| ShenandoahVerifier::VerifyRegions _regions; |
| public: |
| ShenandoahVerifyHeapRegionClosure(const char* phase, ShenandoahVerifier::VerifyRegions regions) : |
| _heap(ShenandoahHeap::heap()), |
| _phase(phase), |
| _regions(regions) {}; |
| |
| void print_failure(ShenandoahHeapRegion* r, const char* label) { |
| ResourceMark rm; |
| |
| ShenandoahMessageBuffer msg("Shenandoah verification failed; %s: %s\n\n", _phase, label); |
| |
| stringStream ss; |
| r->print_on(&ss); |
| msg.append("%s", ss.as_string()); |
| |
| report_vm_error(__FILE__, __LINE__, msg.buffer()); |
| } |
| |
| void verify(ShenandoahHeapRegion* r, bool test, const char* msg) { |
| if (!test) { |
| print_failure(r, msg); |
| } |
| } |
| |
| void heap_region_do(ShenandoahHeapRegion* r) override { |
| switch (_regions) { |
| case ShenandoahVerifier::_verify_regions_disable: |
| break; |
| case ShenandoahVerifier::_verify_regions_notrash: |
| verify(r, !r->is_trash(), |
| "Should not have trash regions"); |
| break; |
| case ShenandoahVerifier::_verify_regions_nocset: |
| verify(r, !r->is_cset(), |
| "Should not have cset regions"); |
| break; |
| case ShenandoahVerifier::_verify_regions_notrash_nocset: |
| verify(r, !r->is_trash(), |
| "Should not have trash regions"); |
| verify(r, !r->is_cset(), |
| "Should not have cset regions"); |
| break; |
| default: |
| ShouldNotReachHere(); |
| } |
| |
| verify(r, r->capacity() == ShenandoahHeapRegion::region_size_bytes(), |
| "Capacity should match region size"); |
| |
| verify(r, r->bottom() <= r->top(), |
| "Region top should not be less than bottom"); |
| |
| verify(r, r->bottom() <= _heap->marking_context()->top_at_mark_start(r), |
| "Region TAMS should not be less than bottom"); |
| |
| verify(r, _heap->marking_context()->top_at_mark_start(r) <= r->top(), |
| "Complete TAMS should not be larger than top"); |
| |
| verify(r, r->get_live_data_bytes() <= r->capacity(), |
| "Live data cannot be larger than capacity"); |
| |
| verify(r, r->garbage() <= r->capacity(), |
| "Garbage cannot be larger than capacity"); |
| |
| verify(r, r->used() <= r->capacity(), |
| "Used cannot be larger than capacity"); |
| |
| verify(r, r->get_shared_allocs() <= r->capacity(), |
| "Shared alloc count should not be larger than capacity"); |
| |
| verify(r, r->get_tlab_allocs() <= r->capacity(), |
| "TLAB alloc count should not be larger than capacity"); |
| |
| verify(r, r->get_gclab_allocs() <= r->capacity(), |
| "GCLAB alloc count should not be larger than capacity"); |
| |
| verify(r, r->get_plab_allocs() <= r->capacity(), |
| "PLAB alloc count should not be larger than capacity"); |
| |
| verify(r, r->get_shared_allocs() + r->get_tlab_allocs() + r->get_gclab_allocs() + r->get_plab_allocs() == r->used(), |
| "Accurate accounting: shared + TLAB + GCLAB + PLAB = used"); |
| |
| verify(r, !r->is_empty() || !r->has_live(), |
| "Empty regions should not have live data"); |
| |
| verify(r, r->is_cset() == _heap->collection_set()->is_in(r), |
| "Transitional: region flags and collection set agree"); |
| } |
| }; |
| |
| class ShenandoahVerifierReachableTask : public WorkerTask { |
| private: |
| const char* _label; |
| ShenandoahVerifier::VerifyOptions _options; |
| ShenandoahHeap* _heap; |
| ShenandoahLivenessData* _ld; |
| MarkBitMap* _bitmap; |
| volatile size_t _processed; |
| |
| public: |
| ShenandoahVerifierReachableTask(MarkBitMap* bitmap, |
| ShenandoahLivenessData* ld, |
| const char* label, |
| ShenandoahVerifier::VerifyOptions options) : |
| WorkerTask("Shenandoah Verifier Reachable Objects"), |
| _label(label), |
| _options(options), |
| _heap(ShenandoahHeap::heap()), |
| _ld(ld), |
| _bitmap(bitmap), |
| _processed(0) {}; |
| |
| size_t processed() const { |
| return _processed; |
| } |
| |
| void work(uint worker_id) override { |
| ResourceMark rm; |
| ShenandoahVerifierStack stack; |
| |
| // On level 2, we need to only check the roots once. |
| // On level 3, we want to check the roots, and seed the local stack. |
| // It is a lesser evil to accept multiple root scans at level 3, because |
| // extended parallelism would buy us out. |
| if (((ShenandoahVerifyLevel == 2) && (worker_id == 0)) |
| || (ShenandoahVerifyLevel >= 3)) { |
| ShenandoahVerifyOopClosure cl(&stack, _bitmap, _ld, |
| ShenandoahMessageBuffer("%s, Roots", _label), |
| _options); |
| if (_heap->unload_classes()) { |
| ShenandoahRootVerifier::strong_roots_do(&cl); |
| } else { |
| ShenandoahRootVerifier::roots_do(&cl); |
| } |
| } |
| |
| size_t processed = 0; |
| |
| if (ShenandoahVerifyLevel >= 3) { |
| ShenandoahVerifyOopClosure cl(&stack, _bitmap, _ld, |
| ShenandoahMessageBuffer("%s, Reachable", _label), |
| _options); |
| while (!stack.is_empty()) { |
| processed++; |
| ShenandoahVerifierTask task = stack.pop(); |
| cl.verify_oops_from(task.obj()); |
| } |
| } |
| |
| Atomic::add(&_processed, processed, memory_order_relaxed); |
| } |
| }; |
| |
| class ShenandoahVerifyNoIncompleteSatbBuffers : public ThreadClosure { |
| public: |
| void do_thread(Thread* thread) override { |
| SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread); |
| if (!queue.is_empty()) { |
| fatal("All SATB buffers should have been flushed during mark"); |
| } |
| } |
| }; |
| |
| class ShenandoahVerifierMarkedRegionTask : public WorkerTask { |
| private: |
| const char* _label; |
| ShenandoahVerifier::VerifyOptions _options; |
| ShenandoahHeap *_heap; |
| MarkBitMap* _bitmap; |
| ShenandoahLivenessData* _ld; |
| volatile size_t _claimed; |
| volatile size_t _processed; |
| ShenandoahGeneration* _generation; |
| |
| public: |
| ShenandoahVerifierMarkedRegionTask(MarkBitMap* bitmap, |
| ShenandoahLivenessData* ld, |
| const char* label, |
| ShenandoahVerifier::VerifyOptions options) : |
| WorkerTask("Shenandoah Verifier Marked Objects"), |
| _label(label), |
| _options(options), |
| _heap(ShenandoahHeap::heap()), |
| _bitmap(bitmap), |
| _ld(ld), |
| _claimed(0), |
| _processed(0), |
| _generation(nullptr) { |
| if (_heap->mode()->is_generational()) { |
| _generation = _heap->gc_generation(); |
| assert(_generation != nullptr, "Expected active generation in this mode."); |
| shenandoah_assert_generations_reconciled(); |
| } |
| }; |
| |
| size_t processed() { |
| return Atomic::load(&_processed); |
| } |
| |
| void work(uint worker_id) override { |
| if (_options._verify_marked == ShenandoahVerifier::_verify_marked_complete_satb_empty) { |
| ShenandoahVerifyNoIncompleteSatbBuffers verify_satb; |
| Threads::threads_do(&verify_satb); |
| } |
| |
| ShenandoahVerifierStack stack; |
| ShenandoahVerifyOopClosure cl(&stack, _bitmap, _ld, |
| ShenandoahMessageBuffer("%s, Marked", _label), |
| _options); |
| |
| while (true) { |
| size_t v = Atomic::fetch_then_add(&_claimed, 1u, memory_order_relaxed); |
| if (v < _heap->num_regions()) { |
| ShenandoahHeapRegion* r = _heap->get_region(v); |
| if (!in_generation(r)) { |
| continue; |
| } |
| |
| if (!r->is_humongous() && !r->is_trash()) { |
| work_regular(r, stack, cl); |
| } else if (r->is_humongous_start()) { |
| work_humongous(r, stack, cl); |
| } |
| } else { |
| break; |
| } |
| } |
| } |
| |
| bool in_generation(ShenandoahHeapRegion* r) { |
| return _generation == nullptr || _generation->contains(r); |
| } |
| |
| virtual void work_humongous(ShenandoahHeapRegion *r, ShenandoahVerifierStack& stack, ShenandoahVerifyOopClosure& cl) { |
| size_t processed = 0; |
| HeapWord* obj = r->bottom(); |
| if (_heap->gc_generation()->complete_marking_context()->is_marked(cast_to_oop(obj))) { |
| verify_and_follow(obj, stack, cl, &processed); |
| } |
| Atomic::add(&_processed, processed, memory_order_relaxed); |
| } |
| |
| virtual void work_regular(ShenandoahHeapRegion *r, ShenandoahVerifierStack &stack, ShenandoahVerifyOopClosure &cl) { |
| size_t processed = 0; |
| ShenandoahMarkingContext* ctx = _heap->gc_generation()->complete_marking_context(); |
| HeapWord* tams = ctx->top_at_mark_start(r); |
| |
| // Bitmaps, before TAMS |
| if (tams > r->bottom()) { |
| HeapWord* start = r->bottom(); |
| HeapWord* addr = ctx->get_next_marked_addr(start, tams); |
| |
| while (addr < tams) { |
| verify_and_follow(addr, stack, cl, &processed); |
| addr += 1; |
| if (addr < tams) { |
| addr = ctx->get_next_marked_addr(addr, tams); |
| } |
| } |
| } |
| |
| // Size-based, after TAMS |
| { |
| HeapWord* limit = r->top(); |
| HeapWord* addr = tams; |
| |
| while (addr < limit) { |
| verify_and_follow(addr, stack, cl, &processed); |
| addr += ShenandoahForwarding::size(cast_to_oop(addr)); |
| } |
| } |
| |
| Atomic::add(&_processed, processed, memory_order_relaxed); |
| } |
| |
| void verify_and_follow(HeapWord *addr, ShenandoahVerifierStack &stack, ShenandoahVerifyOopClosure &cl, size_t *processed) { |
| if (!_bitmap->par_mark(addr)) return; |
| |
| // Verify the object itself: |
| oop obj = cast_to_oop(addr); |
| cl.verify_oop_standalone(obj); |
| |
| // Verify everything reachable from that object too, hopefully realizing |
| // everything was already marked, and never touching further: |
| if (!is_instance_ref_klass(ShenandoahForwarding::klass(obj))) { |
| cl.verify_oops_from(obj); |
| (*processed)++; |
| } |
| while (!stack.is_empty()) { |
| ShenandoahVerifierTask task = stack.pop(); |
| cl.verify_oops_from(task.obj()); |
| (*processed)++; |
| } |
| } |
| }; |
| |
| class VerifyThreadGCState : public ThreadClosure { |
| private: |
| const char* const _label; |
| char const _expected; |
| |
| public: |
| VerifyThreadGCState(const char* label, char expected) : _label(label), _expected(expected) {} |
| void do_thread(Thread* t) override { |
| char actual = ShenandoahThreadLocalData::gc_state(t); |
| if (!verify_gc_state(actual, _expected)) { |
| fatal("%s: Thread %s: expected gc-state %d, actual %d", _label, t->name(), _expected, actual); |
| } |
| } |
| |
| static bool verify_gc_state(char actual, char expected) { |
| // Old generation marking is allowed in all states. |
| if (ShenandoahHeap::heap()->mode()->is_generational()) { |
| return ((actual & ~(ShenandoahHeap::OLD_MARKING | ShenandoahHeap::MARKING)) == expected); |
| } else { |
| assert((actual & ShenandoahHeap::OLD_MARKING) == 0, "Should not mark old in non-generational mode"); |
| return (actual == expected); |
| } |
| } |
| }; |
| |
| void ShenandoahVerifier::verify_at_safepoint(const char* label, |
| VerifyRememberedSet remembered, |
| VerifyForwarded forwarded, |
| VerifyMarked marked, |
| VerifyCollectionSet cset, |
| VerifyLiveness liveness, |
| VerifyRegions regions, |
| VerifySize sizeness, |
| VerifyGCState gcstate) { |
| guarantee(ShenandoahSafepoint::is_at_shenandoah_safepoint(), "only when nothing else happens"); |
| guarantee(ShenandoahVerify, "only when enabled, and bitmap is initialized in ShenandoahHeap::initialize"); |
| |
| ShenandoahHeap::heap()->propagate_gc_state_to_all_threads(); |
| |
| // Avoid side-effect of changing workers' active thread count, but bypass concurrent/parallel protocol check |
| ShenandoahPushWorkerScope verify_worker_scope(_heap->workers(), _heap->max_workers(), false /*bypass check*/); |
| |
| log_info(gc,start)("Verify %s, Level %zd", label, ShenandoahVerifyLevel); |
| |
| // GC state checks |
| { |
| char expected = -1; |
| bool enabled; |
| switch (gcstate) { |
| case _verify_gcstate_disable: |
| enabled = false; |
| break; |
| case _verify_gcstate_forwarded: |
| enabled = true; |
| expected = ShenandoahHeap::HAS_FORWARDED; |
| break; |
| case _verify_gcstate_updating: |
| enabled = true; |
| expected = ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::UPDATE_REFS; |
| break; |
| case _verify_gcstate_stable: |
| enabled = true; |
| expected = ShenandoahHeap::STABLE; |
| break; |
| case _verify_gcstate_stable_weakroots: |
| enabled = true; |
| expected = ShenandoahHeap::STABLE; |
| if (!_heap->is_stw_gc_in_progress()) { |
| // Only concurrent GC sets this. |
| expected |= ShenandoahHeap::WEAK_ROOTS; |
| } |
| break; |
| default: |
| enabled = false; |
| assert(false, "Unhandled gc-state verification"); |
| } |
| |
| if (enabled) { |
| char actual = _heap->gc_state(); |
| |
| bool is_marking = (actual & ShenandoahHeap::MARKING); |
| bool is_marking_young_or_old = (actual & (ShenandoahHeap::YOUNG_MARKING | ShenandoahHeap::OLD_MARKING)); |
| assert(is_marking == is_marking_young_or_old, "MARKING iff (YOUNG_MARKING or OLD_MARKING), gc_state is: %x", actual); |
| |
| // Old generation marking is allowed in all states. |
| if (!VerifyThreadGCState::verify_gc_state(actual, expected)) { |
| fatal("%s: Global gc-state: expected %d, actual %d", label, expected, actual); |
| } |
| |
| VerifyThreadGCState vtgcs(label, expected); |
| Threads::java_threads_do(&vtgcs); |
| } |
| } |
| |
| // Deactivate barriers temporarily: Verifier wants plain heap accesses |
| ShenandoahGCStateResetter resetter; |
| |
| // Heap size checks |
| { |
| ShenandoahHeapLocker lock(_heap->lock()); |
| |
| ShenandoahCalculateRegionStatsClosure cl; |
| _heap->heap_region_iterate(&cl); |
| size_t heap_used; |
| if (_heap->mode()->is_generational() && (sizeness == _verify_size_adjusted_for_padding)) { |
| // Prior to evacuation, regular regions that are to be evacuated in place are padded to prevent further allocations |
| heap_used = _heap->used() + _heap->old_generation()->get_pad_for_promote_in_place(); |
| } else if (sizeness != _verify_size_disable) { |
| heap_used = _heap->used(); |
| } |
| if (sizeness != _verify_size_disable) { |
| guarantee(cl.used() == heap_used, |
| "%s: heap used size must be consistent: heap-used = %zu%s, regions-used = %zu%s", |
| label, |
| byte_size_in_proper_unit(heap_used), proper_unit_for_byte_size(heap_used), |
| byte_size_in_proper_unit(cl.used()), proper_unit_for_byte_size(cl.used())); |
| } |
| size_t heap_committed = _heap->committed(); |
| guarantee(cl.committed() == heap_committed, |
| "%s: heap committed size must be consistent: heap-committed = %zu%s, regions-committed = %zu%s", |
| label, |
| byte_size_in_proper_unit(heap_committed), proper_unit_for_byte_size(heap_committed), |
| byte_size_in_proper_unit(cl.committed()), proper_unit_for_byte_size(cl.committed())); |
| } |
| |
| log_debug(gc)("Safepoint verification finished heap usage verification"); |
| |
| ShenandoahGeneration* generation; |
| if (_heap->mode()->is_generational()) { |
| generation = _heap->gc_generation(); |
| guarantee(generation != nullptr, "Need to know which generation to verify."); |
| shenandoah_assert_generations_reconciled(); |
| } else { |
| generation = nullptr; |
| } |
| |
| if (generation != nullptr) { |
| ShenandoahHeapLocker lock(_heap->lock()); |
| |
| switch (remembered) { |
| case _verify_remembered_disable: |
| break; |
| case _verify_remembered_before_marking: |
| log_debug(gc)("Safepoint verification of remembered set at mark"); |
| verify_rem_set_before_mark(); |
| break; |
| case _verify_remembered_before_updating_references: |
| log_debug(gc)("Safepoint verification of remembered set at update ref"); |
| verify_rem_set_before_update_ref(); |
| break; |
| case _verify_remembered_after_full_gc: |
| log_debug(gc)("Safepoint verification of remembered set after full gc"); |
| verify_rem_set_after_full_gc(); |
| break; |
| default: |
| fatal("Unhandled remembered set verification mode"); |
| } |
| |
| ShenandoahGenerationStatsClosure cl; |
| _heap->heap_region_iterate(&cl); |
| |
| if (LogTarget(Debug, gc)::is_enabled()) { |
| ShenandoahGenerationStatsClosure::log_usage(_heap->old_generation(), cl.old); |
| ShenandoahGenerationStatsClosure::log_usage(_heap->young_generation(), cl.young); |
| ShenandoahGenerationStatsClosure::log_usage(_heap->global_generation(), cl.global); |
| } |
| if (sizeness == _verify_size_adjusted_for_padding) { |
| ShenandoahGenerationStatsClosure::validate_usage(false, label, _heap->old_generation(), cl.old); |
| ShenandoahGenerationStatsClosure::validate_usage(true, label, _heap->young_generation(), cl.young); |
| ShenandoahGenerationStatsClosure::validate_usage(true, label, _heap->global_generation(), cl.global); |
| } else if (sizeness == _verify_size_exact) { |
| ShenandoahGenerationStatsClosure::validate_usage(false, label, _heap->old_generation(), cl.old); |
| ShenandoahGenerationStatsClosure::validate_usage(false, label, _heap->young_generation(), cl.young); |
| ShenandoahGenerationStatsClosure::validate_usage(false, label, _heap->global_generation(), cl.global); |
| } |
| // else: sizeness must equal _verify_size_disable |
| } |
| |
| log_debug(gc)("Safepoint verification finished remembered set verification"); |
| |
| // Internal heap region checks |
| if (ShenandoahVerifyLevel >= 1) { |
| ShenandoahVerifyHeapRegionClosure cl(label, regions); |
| if (generation != nullptr) { |
| generation->heap_region_iterate(&cl); |
| } else { |
| _heap->heap_region_iterate(&cl); |
| } |
| } |
| |
| log_debug(gc)("Safepoint verification finished heap region closure verification"); |
| |
| OrderAccess::fence(); |
| |
| if (UseTLAB) { |
| _heap->labs_make_parsable(); |
| } |
| |
| // Allocate temporary bitmap for storing marking wavefront: |
| _verification_bit_map->clear(); |
| |
| // Allocate temporary array for storing liveness data |
| ShenandoahLivenessData* ld = NEW_C_HEAP_ARRAY(ShenandoahLivenessData, _heap->num_regions(), mtGC); |
| Copy::fill_to_bytes((void*)ld, _heap->num_regions()*sizeof(ShenandoahLivenessData), 0); |
| |
| const VerifyOptions& options = ShenandoahVerifier::VerifyOptions(forwarded, marked, cset, liveness, regions, gcstate); |
| |
| // Steps 1-2. Scan root set to get initial reachable set. Finish walking the reachable heap. |
| // This verifies what application can see, since it only cares about reachable objects. |
| size_t count_reachable = 0; |
| if (ShenandoahVerifyLevel >= 2) { |
| ShenandoahVerifierReachableTask task(_verification_bit_map, ld, label, options); |
| _heap->workers()->run_task(&task); |
| count_reachable = task.processed(); |
| } |
| |
| log_debug(gc)("Safepoint verification finished getting initial reachable set"); |
| |
| // Step 3. Walk marked objects. Marked objects might be unreachable. This verifies what collector, |
| // not the application, can see during the region scans. There is no reason to process the objects |
| // that were already verified, e.g. those marked in verification bitmap. There is interaction with TAMS: |
| // before TAMS, we verify the bitmaps, if available; after TAMS, we walk until the top(). It mimics |
| // what marked_object_iterate is doing, without calling into that optimized (and possibly incorrect) |
| // version |
| |
| size_t count_marked = 0; |
| if (ShenandoahVerifyLevel >= 4 && |
| (marked == _verify_marked_complete || |
| marked == _verify_marked_complete_except_references || |
| marked == _verify_marked_complete_satb_empty)) { |
| guarantee(_heap->gc_generation()->is_mark_complete(), "Marking context should be complete"); |
| ShenandoahVerifierMarkedRegionTask task(_verification_bit_map, ld, label, options); |
| _heap->workers()->run_task(&task); |
| count_marked = task.processed(); |
| } else { |
| guarantee(ShenandoahVerifyLevel < 4 || marked == _verify_marked_incomplete || marked == _verify_marked_disable, "Should be"); |
| } |
| |
| log_debug(gc)("Safepoint verification finished walking marked objects"); |
| |
| // Step 4. Verify accumulated liveness data, if needed. Only reliable if verification level includes |
| // marked objects. |
| |
| if (ShenandoahVerifyLevel >= 4 && marked == _verify_marked_complete && liveness == _verify_liveness_complete) { |
| for (size_t i = 0; i < _heap->num_regions(); i++) { |
| ShenandoahHeapRegion* r = _heap->get_region(i); |
| if (generation != nullptr && !generation->contains(r)) { |
| continue; |
| } |
| |
| juint verf_live = 0; |
| if (r->is_humongous()) { |
| // For humongous objects, test if start region is marked live, and if so, |
| // all humongous regions in that chain have live data equal to their "used". |
| juint start_live = Atomic::load(&ld[r->humongous_start_region()->index()]); |
| if (start_live > 0) { |
| verf_live = (juint)(r->used() / HeapWordSize); |
| } |
| } else { |
| verf_live = Atomic::load(&ld[r->index()]); |
| } |
| |
| size_t reg_live = r->get_live_data_words(); |
| if (reg_live != verf_live) { |
| stringStream ss; |
| r->print_on(&ss); |
| fatal("%s: Live data should match: region-live = %zu, verifier-live = " UINT32_FORMAT "\n%s", |
| label, reg_live, verf_live, ss.freeze()); |
| } |
| } |
| } |
| |
| log_debug(gc)("Safepoint verification finished accumulation of liveness data"); |
| |
| |
| log_info(gc)("Verify %s, Level %zd (%zu reachable, %zu marked)", |
| label, ShenandoahVerifyLevel, count_reachable, count_marked); |
| |
| FREE_C_HEAP_ARRAY(ShenandoahLivenessData, ld); |
| } |
| |
| void ShenandoahVerifier::verify_generic(VerifyOption vo) { |
| verify_at_safepoint( |
| "Generic Verification", |
| _verify_remembered_disable, // do not verify remembered set |
| _verify_forwarded_allow, // conservatively allow forwarded |
| _verify_marked_disable, // do not verify marked: lots ot time wasted checking dead allocations |
| _verify_cset_disable, // cset may be inconsistent |
| _verify_liveness_disable, // no reliable liveness data |
| _verify_regions_disable, // no reliable region data |
| _verify_size_exact, // expect generation and heap sizes to match exactly |
| _verify_gcstate_disable // no data about gcstate |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_before_concmark() { |
| VerifyRememberedSet verify_remembered_set = _verify_remembered_before_marking; |
| if (_heap->mode()->is_generational() && |
| !_heap->old_generation()->is_mark_complete()) { |
| // Before marking in generational mode, remembered set can't be verified w/o complete old marking. |
| verify_remembered_set = _verify_remembered_disable; |
| } |
| verify_at_safepoint( |
| "Before Mark", |
| verify_remembered_set, |
| // verify read-only remembered set from bottom() to top() |
| _verify_forwarded_none, // UR should have fixed up |
| _verify_marked_disable, // do not verify marked: lots ot time wasted checking dead allocations |
| _verify_cset_none, // UR should have fixed this |
| _verify_liveness_disable, // no reliable liveness data |
| _verify_regions_notrash, // no trash regions |
| _verify_size_exact, // expect generation and heap sizes to match exactly |
| _verify_gcstate_stable // there are no forwarded objects |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_after_concmark() { |
| verify_at_safepoint( |
| "After Mark", |
| _verify_remembered_disable, // do not verify remembered set |
| _verify_forwarded_none, // no forwarded references |
| _verify_marked_complete_satb_empty, // bitmaps as precise as we can get, except dangling j.l.r.Refs |
| _verify_cset_none, // no references to cset anymore |
| _verify_liveness_complete, // liveness data must be complete here |
| _verify_regions_disable, // trash regions not yet recycled |
| _verify_size_exact, // expect generation and heap sizes to match exactly |
| _verify_gcstate_stable_weakroots // heap is still stable, weakroots are in progress |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_after_concmark_with_promotions() { |
| verify_at_safepoint( |
| "After Mark", |
| _verify_remembered_disable, // do not verify remembered set |
| _verify_forwarded_none, // no forwarded references |
| _verify_marked_complete_satb_empty, // bitmaps as precise as we can get, except dangling j.l.r.Refs |
| _verify_cset_none, // no references to cset anymore |
| _verify_liveness_complete, // liveness data must be complete here |
| _verify_regions_disable, // trash regions not yet recycled |
| _verify_size_adjusted_for_padding, // expect generation and heap sizes to match after adjustments |
| // for promote in place padding |
| _verify_gcstate_stable_weakroots // heap is still stable, weakroots are in progress |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_before_evacuation() { |
| verify_at_safepoint( |
| "Before Evacuation", |
| _verify_remembered_disable, // do not verify remembered set |
| _verify_forwarded_none, // no forwarded references |
| _verify_marked_complete_except_references, // walk over marked objects too |
| _verify_cset_disable, // non-forwarded references to cset expected |
| _verify_liveness_complete, // liveness data must be complete here |
| _verify_regions_disable, // trash regions not yet recycled |
| _verify_size_adjusted_for_padding, // expect generation and heap sizes to match after adjustments |
| // for promote in place padding |
| _verify_gcstate_stable_weakroots // heap is still stable, weakroots are in progress |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_before_update_refs() { |
| VerifyRememberedSet verify_remembered_set = _verify_remembered_before_updating_references; |
| if (_heap->mode()->is_generational() && |
| !_heap->old_generation()->is_mark_complete()) { |
| verify_remembered_set = _verify_remembered_disable; |
| } |
| verify_at_safepoint( |
| "Before Updating References", |
| verify_remembered_set, // verify read-write remembered set |
| _verify_forwarded_allow, // forwarded references allowed |
| _verify_marked_complete, // bitmaps might be stale, but alloc-after-mark should be well |
| _verify_cset_forwarded, // all cset refs are fully forwarded |
| _verify_liveness_disable, // no reliable liveness data anymore |
| _verify_regions_notrash, // trash regions have been recycled already |
| _verify_size_exact, // expect generation and heap sizes to match exactly |
| _verify_gcstate_updating // evacuation should have produced some forwarded objects |
| ); |
| } |
| |
| // We have not yet cleanup (reclaimed) the collection set |
| void ShenandoahVerifier::verify_after_update_refs() { |
| verify_at_safepoint( |
| "After Updating References", |
| _verify_remembered_disable, // do not verify remembered set |
| _verify_forwarded_none, // no forwarded references |
| _verify_marked_complete, // bitmaps might be stale, but alloc-after-mark should be well |
| _verify_cset_none, // no cset references, all updated |
| _verify_liveness_disable, // no reliable liveness data anymore |
| _verify_regions_nocset, // no cset regions, trash regions have appeared |
| _verify_size_exact, // expect generation and heap sizes to match exactly |
| _verify_gcstate_stable // update refs had cleaned up forwarded objects |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_after_degenerated() { |
| verify_at_safepoint( |
| "After Degenerated GC", |
| _verify_remembered_disable, // do not verify remembered set |
| _verify_forwarded_none, // all objects are non-forwarded |
| _verify_marked_complete, // all objects are marked in complete bitmap |
| _verify_cset_none, // no cset references |
| _verify_liveness_disable, // no reliable liveness data anymore |
| _verify_regions_notrash_nocset, // no trash, no cset |
| _verify_size_exact, // expect generation and heap sizes to match exactly |
| _verify_gcstate_stable // degenerated refs had cleaned up forwarded objects |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_before_fullgc() { |
| verify_at_safepoint( |
| "Before Full GC", |
| _verify_remembered_disable, // do not verify remembered set |
| _verify_forwarded_allow, // can have forwarded objects |
| _verify_marked_disable, // do not verify marked: lots ot time wasted checking dead allocations |
| _verify_cset_disable, // cset might be foobared |
| _verify_liveness_disable, // no reliable liveness data anymore |
| _verify_regions_disable, // no reliable region data here |
| _verify_size_disable, // if we degenerate during evacuation, usage not valid: padding and deferred accounting |
| _verify_gcstate_disable // no reliable gcstate data |
| ); |
| } |
| |
| void ShenandoahVerifier::verify_after_fullgc() { |
| verify_at_safepoint( |
| "After Full GC", |
| _verify_remembered_after_full_gc, // verify read-write remembered set |
| _verify_forwarded_none, // all objects are non-forwarded |
| _verify_marked_incomplete, // all objects are marked in incomplete bitmap |
| _verify_cset_none, // no cset references |
| _verify_liveness_disable, // no reliable liveness data anymore |
| _verify_regions_notrash_nocset, // no trash, no cset |
| _verify_size_exact, // expect generation and heap sizes to match exactly |
| _verify_gcstate_stable // full gc cleaned up everything |
| ); |
| } |
| |
| class ShenandoahVerifyNoForwarded : public BasicOopIterateClosure { |
| private: |
| template <class T> |
| void do_oop_work(T* p) { |
| T o = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(o)) { |
| oop obj = CompressedOops::decode_not_null(o); |
| oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj); |
| if (obj != fwd) { |
| ShenandoahAsserts::print_failure(ShenandoahAsserts::_safe_all, obj, p, nullptr, |
| "Verify Roots", "Should not be forwarded", __FILE__, __LINE__); |
| } |
| } |
| } |
| |
| public: |
| void do_oop(narrowOop* p) { do_oop_work(p); } |
| void do_oop(oop* p) { do_oop_work(p); } |
| }; |
| |
| class ShenandoahVerifyInToSpaceClosure : public BasicOopIterateClosure { |
| private: |
| template <class T> |
| void do_oop_work(T* p) { |
| T o = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(o)) { |
| oop obj = CompressedOops::decode_not_null(o); |
| ShenandoahHeap* heap = ShenandoahHeap::heap(); |
| |
| if (!heap->marking_context()->is_marked_or_old(obj)) { |
| ShenandoahAsserts::print_failure(ShenandoahAsserts::_safe_all, obj, p, nullptr, |
| "Verify Roots In To-Space", "Should be marked", __FILE__, __LINE__); |
| } |
| |
| if (heap->in_collection_set(obj)) { |
| ShenandoahAsserts::print_failure(ShenandoahAsserts::_safe_all, obj, p, nullptr, |
| "Verify Roots In To-Space", "Should not be in collection set", __FILE__, __LINE__); |
| } |
| |
| oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj); |
| if (obj != fwd) { |
| ShenandoahAsserts::print_failure(ShenandoahAsserts::_safe_all, obj, p, nullptr, |
| "Verify Roots In To-Space", "Should not be forwarded", __FILE__, __LINE__); |
| } |
| } |
| } |
| |
| public: |
| void do_oop(narrowOop* p) override { do_oop_work(p); } |
| void do_oop(oop* p) override { do_oop_work(p); } |
| }; |
| |
| void ShenandoahVerifier::verify_roots_in_to_space() { |
| ShenandoahVerifyInToSpaceClosure cl; |
| ShenandoahRootVerifier::roots_do(&cl); |
| } |
| |
| void ShenandoahVerifier::verify_roots_no_forwarded() { |
| ShenandoahVerifyNoForwarded cl; |
| ShenandoahRootVerifier::roots_do(&cl); |
| } |
| |
| template<typename Scanner> |
| class ShenandoahVerifyRemSetClosure : public BasicOopIterateClosure { |
| protected: |
| ShenandoahGenerationalHeap* const _heap; |
| Scanner* const _scanner; |
| const char* _message; |
| |
| public: |
| // Argument distinguishes between initial mark or start of update refs verification. |
| explicit ShenandoahVerifyRemSetClosure(Scanner* scanner, const char* message) : |
| _heap(ShenandoahGenerationalHeap::heap()), |
| _scanner(scanner), |
| _message(message) {} |
| |
| template<class T> |
| inline void work(T* p) { |
| T o = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(o)) { |
| oop obj = CompressedOops::decode_not_null(o); |
| if (_heap->is_in_young(obj) && !_scanner->is_card_dirty((HeapWord*) p)) { |
| ShenandoahAsserts::print_failure(ShenandoahAsserts::_safe_all, obj, p, nullptr, |
| _message, "clean card, it should be dirty.", __FILE__, __LINE__); |
| } |
| } |
| } |
| |
| void do_oop(narrowOop* p) override { work(p); } |
| void do_oop(oop* p) override { work(p); } |
| }; |
| |
| template<typename Scanner> |
| void ShenandoahVerifier::help_verify_region_rem_set(Scanner* scanner, ShenandoahHeapRegion* r, |
| HeapWord* registration_watermark, const char* message) { |
| shenandoah_assert_generations_reconciled(); |
| ShenandoahOldGeneration* old_gen = _heap->old_generation(); |
| assert(old_gen->is_mark_complete() || old_gen->is_parsable(), "Sanity"); |
| |
| ShenandoahMarkingContext* ctx = old_gen->is_mark_complete() ? old_gen->complete_marking_context() : nullptr; |
| ShenandoahVerifyRemSetClosure<Scanner> check_interesting_pointers(scanner, message); |
| HeapWord* from = r->bottom(); |
| HeapWord* obj_addr = from; |
| if (r->is_humongous_start()) { |
| oop obj = cast_to_oop(obj_addr); |
| if ((ctx == nullptr) || ctx->is_marked(obj)) { |
| // For humongous objects, the typical object is an array, so the following checks may be overkill |
| // For regular objects (not object arrays), if the card holding the start of the object is dirty, |
| // we do not need to verify that cards spanning interesting pointers within this object are dirty. |
| if (!scanner->is_card_dirty(obj_addr) || obj->is_objArray()) { |
| obj->oop_iterate(&check_interesting_pointers); |
| } |
| // else, object's start is marked dirty and obj is not an objArray, so any interesting pointers are covered |
| } |
| // else, this humongous object is not live so no need to verify its internal pointers |
| |
| if ((obj_addr < registration_watermark) && !scanner->verify_registration(obj_addr, ctx)) { |
| ShenandoahAsserts::print_failure(ShenandoahAsserts::_safe_all, obj, obj_addr, nullptr, message, |
| "object not properly registered", __FILE__, __LINE__); |
| } |
| } else if (!r->is_humongous()) { |
| HeapWord* top = r->top(); |
| while (obj_addr < top) { |
| oop obj = cast_to_oop(obj_addr); |
| // ctx->is_marked() returns true if mark bit set or if obj above TAMS. |
| if ((ctx == nullptr) || ctx->is_marked(obj)) { |
| // For regular objects (not object arrays), if the card holding the start of the object is dirty, |
| // we do not need to verify that cards spanning interesting pointers within this object are dirty. |
| if (!scanner->is_card_dirty(obj_addr) || obj->is_objArray()) { |
| obj->oop_iterate(&check_interesting_pointers); |
| } |
| // else, object's start is marked dirty and obj is not an objArray, so any interesting pointers are covered |
| |
| if ((obj_addr < registration_watermark) && !scanner->verify_registration(obj_addr, ctx)) { |
| ShenandoahAsserts::print_failure(ShenandoahAsserts::_safe_all, obj, obj_addr, nullptr, message, |
| "object not properly registered", __FILE__, __LINE__); |
| } |
| obj_addr += obj->size(); |
| } else { |
| // This object is not live so we don't verify dirty cards contained therein |
| HeapWord* tams = ctx->top_at_mark_start(r); |
| obj_addr = ctx->get_next_marked_addr(obj_addr, tams); |
| } |
| } |
| } |
| } |
| |
| class ShenandoahWriteTableScanner { |
| private: |
| ShenandoahScanRemembered* _scanner; |
| public: |
| explicit ShenandoahWriteTableScanner(ShenandoahScanRemembered* scanner) : _scanner(scanner) {} |
| |
| bool is_card_dirty(HeapWord* obj_addr) { |
| return _scanner->is_write_card_dirty(obj_addr); |
| } |
| |
| bool verify_registration(HeapWord* obj_addr, ShenandoahMarkingContext* ctx) { |
| return _scanner->verify_registration(obj_addr, ctx); |
| } |
| }; |
| |
| // Assure that the remember set has a dirty card everywhere there is an interesting pointer. |
| // This examines the read_card_table between bottom() and top() since all PLABS are retired |
| // before the safepoint for init_mark. Actually, we retire them before update-references and don't |
| // restore them until the start of evacuation. |
| void ShenandoahVerifier::verify_rem_set_before_mark() { |
| shenandoah_assert_safepoint(); |
| shenandoah_assert_generational(); |
| |
| ShenandoahOldGeneration* old_generation = _heap->old_generation(); |
| |
| log_debug(gc)("Verifying remembered set at %s mark", old_generation->is_doing_mixed_evacuations() ? "mixed" : "young"); |
| |
| ShenandoahScanRemembered* scanner = old_generation->card_scan(); |
| for (size_t i = 0, n = _heap->num_regions(); i < n; ++i) { |
| ShenandoahHeapRegion* r = _heap->get_region(i); |
| if (r->is_old() && r->is_active()) { |
| help_verify_region_rem_set(scanner, r, r->end(), "Verify init-mark remembered set violation"); |
| } |
| } |
| } |
| |
| void ShenandoahVerifier::verify_rem_set_after_full_gc() { |
| shenandoah_assert_safepoint(); |
| shenandoah_assert_generational(); |
| |
| ShenandoahWriteTableScanner scanner(ShenandoahGenerationalHeap::heap()->old_generation()->card_scan()); |
| for (size_t i = 0, n = _heap->num_regions(); i < n; ++i) { |
| ShenandoahHeapRegion* r = _heap->get_region(i); |
| if (r->is_old() && !r->is_cset()) { |
| help_verify_region_rem_set(&scanner, r, r->top(), "Remembered set violation at end of Full GC"); |
| } |
| } |
| } |
| |
| // Assure that the remember set has a dirty card everywhere there is an interesting pointer. Even though |
| // the update-references scan of remembered set only examines cards up to update_watermark, the remembered |
| // set should be valid through top. This examines the write_card_table between bottom() and top() because |
| // all PLABS are retired immediately before the start of update refs. |
| void ShenandoahVerifier::verify_rem_set_before_update_ref() { |
| shenandoah_assert_safepoint(); |
| shenandoah_assert_generational(); |
| |
| ShenandoahWriteTableScanner scanner(_heap->old_generation()->card_scan()); |
| for (size_t i = 0, n = _heap->num_regions(); i < n; ++i) { |
| ShenandoahHeapRegion* r = _heap->get_region(i); |
| if (r->is_old() && !r->is_cset()) { |
| help_verify_region_rem_set(&scanner, r, r->get_update_watermark(), "Remembered set violation at init-update-references"); |
| } |
| } |
| } |
| |
| void ShenandoahVerifier::verify_before_rebuilding_free_set() { |
| ShenandoahGenerationStatsClosure cl; |
| _heap->heap_region_iterate(&cl); |
| |
| ShenandoahGenerationStatsClosure::validate_usage(false, "Before free set rebuild", _heap->old_generation(), cl.old); |
| ShenandoahGenerationStatsClosure::validate_usage(false, "Before free set rebuild", _heap->young_generation(), cl.young); |
| ShenandoahGenerationStatsClosure::validate_usage(false, "Before free set rebuild", _heap->global_generation(), cl.global); |
| } |
