/* * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "code/nmethod.hpp" #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp" #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" #include "gc_implementation/g1/g1OopClosures.inline.hpp" #include "gc_implementation/g1/heapRegion.inline.hpp" #include "gc_implementation/g1/heapRegionBounds.inline.hpp" #include "gc_implementation/g1/heapRegionRemSet.hpp" #include "gc_implementation/g1/heapRegionManager.inline.hpp" #include "gc_implementation/shared/liveRange.hpp" #include "memory/genOopClosures.inline.hpp" #include "memory/iterator.hpp" #include "memory/space.inline.hpp" #include "oops/oop.inline.hpp" #include "runtime/orderAccess.inline.hpp" PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC int HeapRegion::LogOfHRGrainBytes = 0; int HeapRegion::LogOfHRGrainWords = 0; size_t HeapRegion::GrainBytes = 0; size_t HeapRegion::GrainWords = 0; size_t HeapRegion::CardsPerRegion = 0; HeapRegionDCTOC::HeapRegionDCTOC(G1CollectedHeap* g1, HeapRegion* hr, ExtendedOopClosure* cl, CardTableModRefBS::PrecisionStyle precision, FilterKind fk) : DirtyCardToOopClosure(hr, cl, precision, NULL), _hr(hr), _fk(fk), _g1(g1) { } FilterOutOfRegionClosure::FilterOutOfRegionClosure(HeapRegion* r, OopClosure* oc) : _r_bottom(r->bottom()), _r_end(r->end()), _oc(oc) { } template HeapWord* walk_mem_region_loop(ClosureType* cl, G1CollectedHeap* g1h, HeapRegion* hr, HeapWord* cur, HeapWord* top) { oop cur_oop = oop(cur); size_t oop_size = hr->block_size(cur); HeapWord* next_obj = cur + oop_size; while (next_obj < top) { // Keep filtering the remembered set. if (!g1h->is_obj_dead(cur_oop, hr)) { // Bottom lies entirely below top, so we can call the // non-memRegion version of oop_iterate below. cur_oop->oop_iterate(cl); } cur = next_obj; cur_oop = oop(cur); oop_size = hr->block_size(cur); next_obj = cur + oop_size; } return cur; } void HeapRegionDCTOC::walk_mem_region(MemRegion mr, HeapWord* bottom, HeapWord* top) { G1CollectedHeap* g1h = _g1; size_t oop_size; ExtendedOopClosure* cl2 = NULL; FilterIntoCSClosure intoCSFilt(this, g1h, _cl); FilterOutOfRegionClosure outOfRegionFilt(_hr, _cl); switch (_fk) { case NoFilterKind: cl2 = _cl; break; case IntoCSFilterKind: cl2 = &intoCSFilt; break; case OutOfRegionFilterKind: cl2 = &outOfRegionFilt; break; default: ShouldNotReachHere(); } // Start filtering what we add to the remembered set. If the object is // not considered dead, either because it is marked (in the mark bitmap) // or it was allocated after marking finished, then we add it. Otherwise // we can safely ignore the object. if (!g1h->is_obj_dead(oop(bottom), _hr)) { oop_size = oop(bottom)->oop_iterate(cl2, mr); } else { oop_size = _hr->block_size(bottom); } bottom += oop_size; if (bottom < top) { // We replicate the loop below for several kinds of possible filters. switch (_fk) { case NoFilterKind: bottom = walk_mem_region_loop(_cl, g1h, _hr, bottom, top); break; case IntoCSFilterKind: { FilterIntoCSClosure filt(this, g1h, _cl); bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top); break; } case OutOfRegionFilterKind: { FilterOutOfRegionClosure filt(_hr, _cl); bottom = walk_mem_region_loop(&filt, g1h, _hr, bottom, top); break; } default: ShouldNotReachHere(); } // Last object. Need to do dead-obj filtering here too. if (!g1h->is_obj_dead(oop(bottom), _hr)) { oop(bottom)->oop_iterate(cl2, mr); } } } size_t HeapRegion::max_region_size() { return HeapRegionBounds::max_size(); } void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) { uintx region_size = G1HeapRegionSize; if (FLAG_IS_DEFAULT(G1HeapRegionSize)) { size_t average_heap_size = (initial_heap_size + max_heap_size) / 2; region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(), (uintx) HeapRegionBounds::min_size()); } int region_size_log = log2_long((jlong) region_size); // Recalculate the region size to make sure it's a power of // 2. This means that region_size is the largest power of 2 that's // <= what we've calculated so far. region_size = ((uintx)1 << region_size_log); // Now make sure that we don't go over or under our limits. if (region_size < HeapRegionBounds::min_size()) { region_size = HeapRegionBounds::min_size(); } else if (region_size > HeapRegionBounds::max_size()) { region_size = HeapRegionBounds::max_size(); } // And recalculate the log. region_size_log = log2_long((jlong) region_size); // Now, set up the globals. guarantee(LogOfHRGrainBytes == 0, "we should only set it once"); LogOfHRGrainBytes = region_size_log; guarantee(LogOfHRGrainWords == 0, "we should only set it once"); LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize; guarantee(GrainBytes == 0, "we should only set it once"); // The cast to int is safe, given that we've bounded region_size by // MIN_REGION_SIZE and MAX_REGION_SIZE. GrainBytes = (size_t)region_size; guarantee(GrainWords == 0, "we should only set it once"); GrainWords = GrainBytes >> LogHeapWordSize; guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity"); guarantee(CardsPerRegion == 0, "we should only set it once"); CardsPerRegion = GrainBytes >> CardTableModRefBS::card_shift; } void HeapRegion::reset_after_compaction() { G1OffsetTableContigSpace::reset_after_compaction(); // After a compaction the mark bitmap is invalid, so we must // treat all objects as being inside the unmarked area. zero_marked_bytes(); init_top_at_mark_start(); } void HeapRegion::hr_clear(bool par, bool clear_space, bool locked) { assert(_humongous_start_region == NULL, "we should have already filtered out humongous regions"); assert(_end == _orig_end, "we should have already filtered out humongous regions"); _in_collection_set = false; set_allocation_context(AllocationContext::system()); set_young_index_in_cset(-1); uninstall_surv_rate_group(); set_free(); reset_pre_dummy_top(); if (!par) { // If this is parallel, this will be done later. HeapRegionRemSet* hrrs = rem_set(); if (locked) { hrrs->clear_locked(); } else { hrrs->clear(); } _claimed = InitialClaimValue; } zero_marked_bytes(); _offsets.resize(HeapRegion::GrainWords); init_top_at_mark_start(); if (clear_space) clear(SpaceDecorator::Mangle); } void HeapRegion::par_clear() { assert(used() == 0, "the region should have been already cleared"); assert(capacity() == HeapRegion::GrainBytes, "should be back to normal"); HeapRegionRemSet* hrrs = rem_set(); hrrs->clear(); CardTableModRefBS* ct_bs = (CardTableModRefBS*)G1CollectedHeap::heap()->barrier_set(); ct_bs->clear(MemRegion(bottom(), end())); } void HeapRegion::calc_gc_efficiency() { // GC efficiency is the ratio of how much space would be // reclaimed over how long we predict it would take to reclaim it. G1CollectedHeap* g1h = G1CollectedHeap::heap(); G1CollectorPolicy* g1p = g1h->g1_policy(); // Retrieve a prediction of the elapsed time for this region for // a mixed gc because the region will only be evacuated during a // mixed gc. double region_elapsed_time_ms = g1p->predict_region_elapsed_time_ms(this, false /* for_young_gc */); _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms; } void HeapRegion::set_startsHumongous(HeapWord* new_top, HeapWord* new_end) { assert(!isHumongous(), "sanity / pre-condition"); assert(end() == _orig_end, "Should be normal before the humongous object allocation"); assert(top() == bottom(), "should be empty"); assert(bottom() <= new_top && new_top <= new_end, "pre-condition"); _type.set_starts_humongous(); _humongous_start_region = this; set_end(new_end); _offsets.set_for_starts_humongous(new_top); } void HeapRegion::set_continuesHumongous(HeapRegion* first_hr) { assert(!isHumongous(), "sanity / pre-condition"); assert(end() == _orig_end, "Should be normal before the humongous object allocation"); assert(top() == bottom(), "should be empty"); assert(first_hr->startsHumongous(), "pre-condition"); _type.set_continues_humongous(); _humongous_start_region = first_hr; } void HeapRegion::clear_humongous() { assert(isHumongous(), "pre-condition"); if (startsHumongous()) { assert(top() <= end(), "pre-condition"); set_end(_orig_end); if (top() > end()) { // at least one "continues humongous" region after it set_top(end()); } } else { // continues humongous assert(end() == _orig_end, "sanity"); } assert(capacity() == HeapRegion::GrainBytes, "pre-condition"); _humongous_start_region = NULL; } bool HeapRegion::claimHeapRegion(jint claimValue) { jint current = _claimed; if (current != claimValue) { jint res = Atomic::cmpxchg(claimValue, &_claimed, current); if (res == current) { return true; } } return false; } HeapRegion::HeapRegion(uint hrm_index, G1BlockOffsetSharedArray* sharedOffsetArray, MemRegion mr) : G1OffsetTableContigSpace(sharedOffsetArray, mr), _hrm_index(hrm_index), _allocation_context(AllocationContext::system()), _humongous_start_region(NULL), _in_collection_set(false), _next_in_special_set(NULL), _orig_end(NULL), _claimed(InitialClaimValue), _evacuation_failed(false), _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0), _next_young_region(NULL), _next_dirty_cards_region(NULL), _next(NULL), _prev(NULL), #ifdef ASSERT _containing_set(NULL), #endif // ASSERT _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1), _rem_set(NULL), _recorded_rs_length(0), _predicted_elapsed_time_ms(0), _predicted_bytes_to_copy(0) { _rem_set = new HeapRegionRemSet(sharedOffsetArray, this); assert(HeapRegionRemSet::num_par_rem_sets() > 0, "Invariant."); initialize(mr); } void HeapRegion::initialize(MemRegion mr, bool clear_space, bool mangle_space) { assert(_rem_set->is_empty(), "Remembered set must be empty"); G1OffsetTableContigSpace::initialize(mr, clear_space, mangle_space); _orig_end = mr.end(); hr_clear(false /*par*/, false /*clear_space*/); set_top(bottom()); record_timestamp(); } CompactibleSpace* HeapRegion::next_compaction_space() const { return G1CollectedHeap::heap()->next_compaction_region(this); } void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark, bool during_conc_mark) { // We always recreate the prev marking info and we'll explicitly // mark all objects we find to be self-forwarded on the prev // bitmap. So all objects need to be below PTAMS. _prev_marked_bytes = 0; if (during_initial_mark) { // During initial-mark, we'll also explicitly mark all objects // we find to be self-forwarded on the next bitmap. So all // objects need to be below NTAMS. _next_top_at_mark_start = top(); _next_marked_bytes = 0; } else if (during_conc_mark) { // During concurrent mark, all objects in the CSet (including // the ones we find to be self-forwarded) are implicitly live. // So all objects need to be above NTAMS. _next_top_at_mark_start = bottom(); _next_marked_bytes = 0; } } void HeapRegion::note_self_forwarding_removal_end(bool during_initial_mark, bool during_conc_mark, size_t marked_bytes) { assert(0 <= marked_bytes && marked_bytes <= used(), err_msg("marked: "SIZE_FORMAT" used: "SIZE_FORMAT, marked_bytes, used())); _prev_top_at_mark_start = top(); _prev_marked_bytes = marked_bytes; } HeapWord* HeapRegion::object_iterate_mem_careful(MemRegion mr, ObjectClosure* cl) { G1CollectedHeap* g1h = G1CollectedHeap::heap(); // We used to use "block_start_careful" here. But we're actually happy // to update the BOT while we do this... HeapWord* cur = block_start(mr.start()); mr = mr.intersection(used_region()); if (mr.is_empty()) return NULL; // Otherwise, find the obj that extends onto mr.start(). assert(cur <= mr.start() && (oop(cur)->klass_or_null() == NULL || cur + oop(cur)->size() > mr.start()), "postcondition of block_start"); oop obj; while (cur < mr.end()) { obj = oop(cur); if (obj->klass_or_null() == NULL) { // Ran into an unparseable point. return cur; } else if (!g1h->is_obj_dead(obj)) { cl->do_object(obj); } if (cl->abort()) return cur; // The check above must occur before the operation below, since an // abort might invalidate the "size" operation. cur += block_size(cur); } return NULL; } HeapWord* HeapRegion:: oops_on_card_seq_iterate_careful(MemRegion mr, FilterOutOfRegionClosure* cl, bool filter_young, jbyte* card_ptr) { // Currently, we should only have to clean the card if filter_young // is true and vice versa. if (filter_young) { assert(card_ptr != NULL, "pre-condition"); } else { assert(card_ptr == NULL, "pre-condition"); } G1CollectedHeap* g1h = G1CollectedHeap::heap(); // If we're within a stop-world GC, then we might look at a card in a // GC alloc region that extends onto a GC LAB, which may not be // parseable. Stop such at the "scan_top" of the region. if (g1h->is_gc_active()) { mr = mr.intersection(MemRegion(bottom(), scan_top())); } else { mr = mr.intersection(used_region()); } if (mr.is_empty()) return NULL; // Otherwise, find the obj that extends onto mr.start(). // The intersection of the incoming mr (for the card) and the // allocated part of the region is non-empty. This implies that // we have actually allocated into this region. The code in // G1CollectedHeap.cpp that allocates a new region sets the // is_young tag on the region before allocating. Thus we // safely know if this region is young. if (is_young() && filter_young) { return NULL; } assert(!is_young(), "check value of filter_young"); // We can only clean the card here, after we make the decision that // the card is not young. And we only clean the card if we have been // asked to (i.e., card_ptr != NULL). if (card_ptr != NULL) { *card_ptr = CardTableModRefBS::clean_card_val(); // We must complete this write before we do any of the reads below. OrderAccess::storeload(); } // Cache the boundaries of the memory region in some const locals HeapWord* const start = mr.start(); HeapWord* const end = mr.end(); // We used to use "block_start_careful" here. But we're actually happy // to update the BOT while we do this... HeapWord* cur = block_start(start); assert(cur <= start, "Postcondition"); oop obj; HeapWord* next = cur; while (next <= start) { cur = next; obj = oop(cur); if (obj->klass_or_null() == NULL) { // Ran into an unparseable point. return cur; } // Otherwise... next = cur + block_size(cur); } // If we finish the above loop...We have a parseable object that // begins on or before the start of the memory region, and ends // inside or spans the entire region. assert(obj == oop(cur), "sanity"); assert(cur <= start, "Loop postcondition"); assert(obj->klass_or_null() != NULL, "Loop postcondition"); assert((cur + block_size(cur)) > start, "Loop postcondition"); if (!g1h->is_obj_dead(obj)) { obj->oop_iterate(cl, mr); } while (cur < end) { obj = oop(cur); if (obj->klass_or_null() == NULL) { // Ran into an unparseable point. return cur; }; // Otherwise: next = cur + block_size(cur); if (!g1h->is_obj_dead(obj)) { if (next < end || !obj->is_objArray()) { // This object either does not span the MemRegion // boundary, or if it does it's not an array. // Apply closure to whole object. obj->oop_iterate(cl); } else { // This obj is an array that spans the boundary. // Stop at the boundary. obj->oop_iterate(cl, mr); } } cur = next; } return NULL; } // Code roots support void HeapRegion::add_strong_code_root(nmethod* nm) { HeapRegionRemSet* hrrs = rem_set(); hrrs->add_strong_code_root(nm); } void HeapRegion::add_strong_code_root_locked(nmethod* nm) { assert_locked_or_safepoint(CodeCache_lock); HeapRegionRemSet* hrrs = rem_set(); hrrs->add_strong_code_root_locked(nm); } void HeapRegion::remove_strong_code_root(nmethod* nm) { HeapRegionRemSet* hrrs = rem_set(); hrrs->remove_strong_code_root(nm); } void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const { HeapRegionRemSet* hrrs = rem_set(); hrrs->strong_code_roots_do(blk); } class VerifyStrongCodeRootOopClosure: public OopClosure { const HeapRegion* _hr; nmethod* _nm; bool _failures; bool _has_oops_in_region; template void do_oop_work(T* p) { T heap_oop = oopDesc::load_heap_oop(p); if (!oopDesc::is_null(heap_oop)) { oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); // Note: not all the oops embedded in the nmethod are in the // current region. We only look at those which are. if (_hr->is_in(obj)) { // Object is in the region. Check that its less than top if (_hr->top() <= (HeapWord*)obj) { // Object is above top gclog_or_tty->print_cr("Object "PTR_FORMAT" in region " "["PTR_FORMAT", "PTR_FORMAT") is above " "top "PTR_FORMAT, (void *)obj, _hr->bottom(), _hr->end(), _hr->top()); _failures = true; return; } // Nmethod has at least one oop in the current region _has_oops_in_region = true; } } } public: VerifyStrongCodeRootOopClosure(const HeapRegion* hr, nmethod* nm): _hr(hr), _failures(false), _has_oops_in_region(false) {} void do_oop(narrowOop* p) { do_oop_work(p); } void do_oop(oop* p) { do_oop_work(p); } bool failures() { return _failures; } bool has_oops_in_region() { return _has_oops_in_region; } }; class VerifyStrongCodeRootCodeBlobClosure: public CodeBlobClosure { const HeapRegion* _hr; bool _failures; public: VerifyStrongCodeRootCodeBlobClosure(const HeapRegion* hr) : _hr(hr), _failures(false) {} void do_code_blob(CodeBlob* cb) { nmethod* nm = (cb == NULL) ? NULL : cb->as_nmethod_or_null(); if (nm != NULL) { // Verify that the nemthod is live if (!nm->is_alive()) { gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] has dead nmethod " PTR_FORMAT" in its strong code roots", _hr->bottom(), _hr->end(), nm); _failures = true; } else { VerifyStrongCodeRootOopClosure oop_cl(_hr, nm); nm->oops_do(&oop_cl); if (!oop_cl.has_oops_in_region()) { gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] has nmethod " PTR_FORMAT" in its strong code roots " "with no pointers into region", _hr->bottom(), _hr->end(), nm); _failures = true; } else if (oop_cl.failures()) { gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] has other " "failures for nmethod "PTR_FORMAT, _hr->bottom(), _hr->end(), nm); _failures = true; } } } } bool failures() { return _failures; } }; void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const { if (!G1VerifyHeapRegionCodeRoots) { // We're not verifying code roots. return; } if (vo == VerifyOption_G1UseMarkWord) { // Marking verification during a full GC is performed after class // unloading, code cache unloading, etc so the strong code roots // attached to each heap region are in an inconsistent state. They won't // be consistent until the strong code roots are rebuilt after the // actual GC. Skip verifying the strong code roots in this particular // time. assert(VerifyDuringGC, "only way to get here"); return; } HeapRegionRemSet* hrrs = rem_set(); size_t strong_code_roots_length = hrrs->strong_code_roots_list_length(); // if this region is empty then there should be no entries // on its strong code root list if (is_empty()) { if (strong_code_roots_length > 0) { gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] is empty " "but has "SIZE_FORMAT" code root entries", bottom(), end(), strong_code_roots_length); *failures = true; } return; } if (continuesHumongous()) { if (strong_code_roots_length > 0) { gclog_or_tty->print_cr("region "HR_FORMAT" is a continuation of a humongous " "region but has "SIZE_FORMAT" code root entries", HR_FORMAT_PARAMS(this), strong_code_roots_length); *failures = true; } return; } VerifyStrongCodeRootCodeBlobClosure cb_cl(this); strong_code_roots_do(&cb_cl); if (cb_cl.failures()) { *failures = true; } } void HeapRegion::print() const { print_on(gclog_or_tty); } void HeapRegion::print_on(outputStream* st) const { st->print("AC%4u", allocation_context()); st->print(" %2s", get_short_type_str()); if (in_collection_set()) st->print(" CS"); else st->print(" "); st->print(" TS %5d", _gc_time_stamp); st->print(" PTAMS "PTR_FORMAT" NTAMS "PTR_FORMAT, prev_top_at_mark_start(), next_top_at_mark_start()); G1OffsetTableContigSpace::print_on(st); } class VerifyLiveClosure: public OopClosure { private: G1CollectedHeap* _g1h; CardTableModRefBS* _bs; oop _containing_obj; bool _failures; int _n_failures; VerifyOption _vo; public: // _vo == UsePrevMarking -> use "prev" marking information, // _vo == UseNextMarking -> use "next" marking information, // _vo == UseMarkWord -> use mark word from object header. VerifyLiveClosure(G1CollectedHeap* g1h, VerifyOption vo) : _g1h(g1h), _bs(NULL), _containing_obj(NULL), _failures(false), _n_failures(0), _vo(vo) { BarrierSet* bs = _g1h->barrier_set(); if (bs->is_a(BarrierSet::CardTableModRef)) _bs = (CardTableModRefBS*)bs; } void set_containing_obj(oop obj) { _containing_obj = obj; } bool failures() { return _failures; } int n_failures() { return _n_failures; } virtual void do_oop(narrowOop* p) { do_oop_work(p); } virtual void do_oop( oop* p) { do_oop_work(p); } void print_object(outputStream* out, oop obj) { #ifdef PRODUCT Klass* k = obj->klass(); const char* class_name = InstanceKlass::cast(k)->external_name(); out->print_cr("class name %s", class_name); #else // PRODUCT obj->print_on(out); #endif // PRODUCT } template void do_oop_work(T* p) { assert(_containing_obj != NULL, "Precondition"); assert(!_g1h->is_obj_dead_cond(_containing_obj, _vo), "Precondition"); T heap_oop = oopDesc::load_heap_oop(p); if (!oopDesc::is_null(heap_oop)) { oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); bool failed = false; if (!_g1h->is_in_closed_subset(obj) || _g1h->is_obj_dead_cond(obj, _vo)) { MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); if (!_failures) { gclog_or_tty->cr(); gclog_or_tty->print_cr("----------"); } if (!_g1h->is_in_closed_subset(obj)) { HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); gclog_or_tty->print_cr("Field "PTR_FORMAT " of live obj "PTR_FORMAT" in region " "["PTR_FORMAT", "PTR_FORMAT")", p, (void*) _containing_obj, from->bottom(), from->end()); print_object(gclog_or_tty, _containing_obj); gclog_or_tty->print_cr("points to obj "PTR_FORMAT" not in the heap", (void*) obj); } else { HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); HeapRegion* to = _g1h->heap_region_containing((HeapWord*)obj); gclog_or_tty->print_cr("Field "PTR_FORMAT " of live obj "PTR_FORMAT" in region " "["PTR_FORMAT", "PTR_FORMAT")", p, (void*) _containing_obj, from->bottom(), from->end()); print_object(gclog_or_tty, _containing_obj); gclog_or_tty->print_cr("points to dead obj "PTR_FORMAT" in region " "["PTR_FORMAT", "PTR_FORMAT")", (void*) obj, to->bottom(), to->end()); print_object(gclog_or_tty, obj); } gclog_or_tty->print_cr("----------"); gclog_or_tty->flush(); _failures = true; failed = true; _n_failures++; } if (!_g1h->full_collection() || G1VerifyRSetsDuringFullGC) { HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p); HeapRegion* to = _g1h->heap_region_containing(obj); if (from != NULL && to != NULL && from != to && !to->isHumongous()) { jbyte cv_obj = *_bs->byte_for_const(_containing_obj); jbyte cv_field = *_bs->byte_for_const(p); const jbyte dirty = CardTableModRefBS::dirty_card_val(); bool is_bad = !(from->is_young() || to->rem_set()->contains_reference(p) || !G1HRRSFlushLogBuffersOnVerify && // buffers were not flushed (_containing_obj->is_objArray() ? cv_field == dirty : cv_obj == dirty || cv_field == dirty)); if (is_bad) { MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); if (!_failures) { gclog_or_tty->cr(); gclog_or_tty->print_cr("----------"); } gclog_or_tty->print_cr("Missing rem set entry:"); gclog_or_tty->print_cr("Field "PTR_FORMAT" " "of obj "PTR_FORMAT", " "in region "HR_FORMAT, p, (void*) _containing_obj, HR_FORMAT_PARAMS(from)); _containing_obj->print_on(gclog_or_tty); gclog_or_tty->print_cr("points to obj "PTR_FORMAT" " "in region "HR_FORMAT, (void*) obj, HR_FORMAT_PARAMS(to)); obj->print_on(gclog_or_tty); gclog_or_tty->print_cr("Obj head CTE = %d, field CTE = %d.", cv_obj, cv_field); gclog_or_tty->print_cr("----------"); gclog_or_tty->flush(); _failures = true; if (!failed) _n_failures++; } } } } } }; // This really ought to be commoned up into OffsetTableContigSpace somehow. // We would need a mechanism to make that code skip dead objects. void HeapRegion::verify(VerifyOption vo, bool* failures) const { G1CollectedHeap* g1 = G1CollectedHeap::heap(); *failures = false; HeapWord* p = bottom(); HeapWord* prev_p = NULL; VerifyLiveClosure vl_cl(g1, vo); bool is_humongous = isHumongous(); bool do_bot_verify = !is_young(); size_t object_num = 0; while (p < top()) { oop obj = oop(p); size_t obj_size = block_size(p); object_num += 1; if (is_humongous != g1->isHumongous(obj_size) && !g1->is_obj_dead(obj, this)) { // Dead objects may have bigger block_size since they span several objects. gclog_or_tty->print_cr("obj "PTR_FORMAT" is of %shumongous size (" SIZE_FORMAT" words) in a %shumongous region", p, g1->isHumongous(obj_size) ? "" : "non-", obj_size, is_humongous ? "" : "non-"); *failures = true; return; } // If it returns false, verify_for_object() will output the // appropriate message. if (do_bot_verify && !g1->is_obj_dead(obj, this) && !_offsets.verify_for_object(p, obj_size)) { *failures = true; return; } if (!g1->is_obj_dead_cond(obj, this, vo)) { if (obj->is_oop()) { Klass* klass = obj->klass(); bool is_metaspace_object = Metaspace::contains(klass) || (vo == VerifyOption_G1UsePrevMarking && ClassLoaderDataGraph::unload_list_contains(klass)); if (!is_metaspace_object) { gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" " "not metadata", klass, (void *)obj); *failures = true; return; } else if (!klass->is_klass()) { gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" " "not a klass", klass, (void *)obj); *failures = true; return; } else { vl_cl.set_containing_obj(obj); obj->oop_iterate_no_header(&vl_cl); if (vl_cl.failures()) { *failures = true; } if (G1MaxVerifyFailures >= 0 && vl_cl.n_failures() >= G1MaxVerifyFailures) { return; } } } else { gclog_or_tty->print_cr(PTR_FORMAT" no an oop", (void *)obj); *failures = true; return; } } prev_p = p; p += obj_size; } if (p != top()) { gclog_or_tty->print_cr("end of last object "PTR_FORMAT" " "does not match top "PTR_FORMAT, p, top()); *failures = true; return; } HeapWord* the_end = end(); assert(p == top(), "it should still hold"); // Do some extra BOT consistency checking for addresses in the // range [top, end). BOT look-ups in this range should yield // top. No point in doing that if top == end (there's nothing there). if (p < the_end) { // Look up top HeapWord* addr_1 = p; HeapWord* b_start_1 = _offsets.block_start_const(addr_1); if (b_start_1 != p) { gclog_or_tty->print_cr("BOT look up for top: "PTR_FORMAT" " " yielded "PTR_FORMAT", expecting "PTR_FORMAT, addr_1, b_start_1, p); *failures = true; return; } // Look up top + 1 HeapWord* addr_2 = p + 1; if (addr_2 < the_end) { HeapWord* b_start_2 = _offsets.block_start_const(addr_2); if (b_start_2 != p) { gclog_or_tty->print_cr("BOT look up for top + 1: "PTR_FORMAT" " " yielded "PTR_FORMAT", expecting "PTR_FORMAT, addr_2, b_start_2, p); *failures = true; return; } } // Look up an address between top and end size_t diff = pointer_delta(the_end, p) / 2; HeapWord* addr_3 = p + diff; if (addr_3 < the_end) { HeapWord* b_start_3 = _offsets.block_start_const(addr_3); if (b_start_3 != p) { gclog_or_tty->print_cr("BOT look up for top + diff: "PTR_FORMAT" " " yielded "PTR_FORMAT", expecting "PTR_FORMAT, addr_3, b_start_3, p); *failures = true; return; } } // Loook up end - 1 HeapWord* addr_4 = the_end - 1; HeapWord* b_start_4 = _offsets.block_start_const(addr_4); if (b_start_4 != p) { gclog_or_tty->print_cr("BOT look up for end - 1: "PTR_FORMAT" " " yielded "PTR_FORMAT", expecting "PTR_FORMAT, addr_4, b_start_4, p); *failures = true; return; } } if (is_humongous && object_num > 1) { gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] is humongous " "but has "SIZE_FORMAT", objects", bottom(), end(), object_num); *failures = true; return; } verify_strong_code_roots(vo, failures); } void HeapRegion::verify() const { bool dummy = false; verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy); } // G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go // away eventually. void G1OffsetTableContigSpace::clear(bool mangle_space) { set_top(bottom()); _scan_top = bottom(); CompactibleSpace::clear(mangle_space); reset_bot(); } void G1OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) { Space::set_bottom(new_bottom); _offsets.set_bottom(new_bottom); } void G1OffsetTableContigSpace::set_end(HeapWord* new_end) { Space::set_end(new_end); _offsets.resize(new_end - bottom()); } void G1OffsetTableContigSpace::print() const { print_short(); gclog_or_tty->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")", bottom(), top(), _offsets.threshold(), end()); } HeapWord* G1OffsetTableContigSpace::initialize_threshold() { return _offsets.initialize_threshold(); } HeapWord* G1OffsetTableContigSpace::cross_threshold(HeapWord* start, HeapWord* end) { _offsets.alloc_block(start, end); return _offsets.threshold(); } HeapWord* G1OffsetTableContigSpace::scan_top() const { G1CollectedHeap* g1h = G1CollectedHeap::heap(); HeapWord* local_top = top(); OrderAccess::loadload(); const unsigned local_time_stamp = _gc_time_stamp; assert(local_time_stamp <= g1h->get_gc_time_stamp(), "invariant"); if (local_time_stamp < g1h->get_gc_time_stamp()) { return local_top; } else { return _scan_top; } } void G1OffsetTableContigSpace::record_timestamp() { G1CollectedHeap* g1h = G1CollectedHeap::heap(); unsigned curr_gc_time_stamp = g1h->get_gc_time_stamp(); if (_gc_time_stamp < curr_gc_time_stamp) { // Setting the time stamp here tells concurrent readers to look at // scan_top to know the maximum allowed address to look at. // scan_top should be bottom for all regions except for the // retained old alloc region which should have scan_top == top HeapWord* st = _scan_top; guarantee(st == _bottom || st == _top, "invariant"); _gc_time_stamp = curr_gc_time_stamp; } } void G1OffsetTableContigSpace::record_retained_region() { // scan_top is the maximum address where it's safe for the next gc to // scan this region. _scan_top = top(); } void G1OffsetTableContigSpace::safe_object_iterate(ObjectClosure* blk) { object_iterate(blk); } void G1OffsetTableContigSpace::object_iterate(ObjectClosure* blk) { HeapWord* p = bottom(); while (p < top()) { if (block_is_obj(p)) { blk->do_object(oop(p)); } p += block_size(p); } } #define block_is_always_obj(q) true void G1OffsetTableContigSpace::prepare_for_compaction(CompactPoint* cp) { SCAN_AND_FORWARD(cp, top, block_is_always_obj, block_size); } #undef block_is_always_obj G1OffsetTableContigSpace:: G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray, MemRegion mr) : _offsets(sharedOffsetArray, mr), _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true), _gc_time_stamp(0) { _offsets.set_space(this); } void G1OffsetTableContigSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) { CompactibleSpace::initialize(mr, clear_space, mangle_space); _top = bottom(); _scan_top = bottom(); set_saved_mark_word(NULL); reset_bot(); }