/* * 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 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(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(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 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 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 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 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 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 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 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); }