--- /dev/null 2020-01-17 11:46:19.065201212 +0100 +++ new/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp 2020-01-17 17:09:51.679131495 +0100 @@ -0,0 +1,224 @@ +/* + * Copyright (c) 2013, 2018, Red Hat, Inc. All rights reserved. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "gc/shenandoah/shenandoahAsserts.hpp" +#include "gc/shenandoah/shenandoahBarrierSet.hpp" +#include "gc/shenandoah/shenandoahBarrierSetClone.inline.hpp" +#include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp" +#include "gc/shenandoah/shenandoahCollectorPolicy.hpp" +#include "gc/shenandoah/shenandoahHeap.inline.hpp" +#include "gc/shenandoah/shenandoahHeuristics.hpp" +#include "gc/shenandoah/shenandoahTraversalGC.hpp" +#include "memory/iterator.inline.hpp" +#include "runtime/interfaceSupport.inline.hpp" +#ifdef COMPILER1 +#include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp" +#endif +#ifdef COMPILER2 +#include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp" +#endif + +class ShenandoahBarrierSetC1; +class ShenandoahBarrierSetC2; + +ShenandoahSATBMarkQueueSet ShenandoahBarrierSet::_satb_mark_queue_set; + +ShenandoahBarrierSet::ShenandoahBarrierSet(ShenandoahHeap* heap) : + BarrierSet(make_barrier_set_assembler(), + make_barrier_set_c1(), + make_barrier_set_c2(), + BarrierSet::FakeRtti(BarrierSet::ShenandoahBarrierSet)), + _heap(heap) +{ +} + +ShenandoahBarrierSetAssembler* ShenandoahBarrierSet::assembler() { + BarrierSetAssembler* const bsa = BarrierSet::barrier_set()->barrier_set_assembler(); + return reinterpret_cast(bsa); +} + +void ShenandoahBarrierSet::print_on(outputStream* st) const { + st->print("ShenandoahBarrierSet"); +} + +bool ShenandoahBarrierSet::is_a(BarrierSet::Name bsn) { + return bsn == BarrierSet::ShenandoahBarrierSet; +} + +bool ShenandoahBarrierSet::is_aligned(HeapWord* hw) { + return true; +} + +bool ShenandoahBarrierSet::need_load_reference_barrier(DecoratorSet decorators, BasicType type) { + if (!ShenandoahLoadRefBarrier) return false; + // Only needed for references + return is_reference_type(type); +} + +bool ShenandoahBarrierSet::need_keep_alive_barrier(DecoratorSet decorators,BasicType type) { + if (!ShenandoahKeepAliveBarrier) return false; + // Only needed for references + if (!is_reference_type(type)) return false; + + bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0; + bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0; + bool is_traversal_mode = ShenandoahHeap::heap()->is_traversal_mode(); + bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0; + return (on_weak_ref || unknown) && (keep_alive || is_traversal_mode); +} + +oop ShenandoahBarrierSet::load_reference_barrier_not_null(oop obj) { + if (ShenandoahLoadRefBarrier && _heap->has_forwarded_objects()) { + return load_reference_barrier_impl(obj); + } else { + return obj; + } +} + +oop ShenandoahBarrierSet::load_reference_barrier(oop obj) { + if (obj != NULL) { + return load_reference_barrier_not_null(obj); + } else { + return obj; + } +} + +oop ShenandoahBarrierSet::load_reference_barrier_mutator(oop obj, oop* load_addr) { + return load_reference_barrier_mutator_work(obj, load_addr); +} + +oop ShenandoahBarrierSet::load_reference_barrier_mutator(oop obj, narrowOop* load_addr) { + return load_reference_barrier_mutator_work(obj, load_addr); +} + +template +oop ShenandoahBarrierSet::load_reference_barrier_mutator_work(oop obj, T* load_addr) { + assert(ShenandoahLoadRefBarrier, "should be enabled"); + shenandoah_assert_in_cset(load_addr, obj); + + oop fwd = resolve_forwarded_not_null(obj); + if (obj == fwd) { + assert(_heap->is_gc_in_progress_mask(ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL), + "evac should be in progress"); + + ShenandoahEvacOOMScope oom_evac_scope; + + Thread* thread = Thread::current(); + oop res_oop = _heap->evacuate_object(obj, thread); + + // Since we are already here and paid the price of getting through runtime call adapters + // and acquiring oom-scope, it makes sense to try and evacuate more adjacent objects, + // thus amortizing the overhead. For sparsely live heaps, scan costs easily dominate + // total assist costs, and can introduce a lot of evacuation latency. This is why we + // only scan for _nearest_ N objects, regardless if they are eligible for evac or not. + // The scan itself should also avoid touching the non-marked objects below TAMS, because + // their metadata (notably, klasses) may be incorrect already. + + size_t max = ShenandoahEvacAssist; + if (max > 0) { + // Traversal is special: it uses incomplete marking context, because it coalesces evac with mark. + // Other code uses complete marking context, because evac happens after the mark. + ShenandoahMarkingContext* ctx = _heap->is_concurrent_traversal_in_progress() ? + _heap->marking_context() : _heap->complete_marking_context(); + + ShenandoahHeapRegion* r = _heap->heap_region_containing(obj); + assert(r->is_cset(), "sanity"); + + HeapWord* cur = (HeapWord*)obj + obj->size(); + + size_t count = 0; + while ((cur < r->top()) && ctx->is_marked(oop(cur)) && (count++ < max)) { + oop cur_oop = oop(cur); + if (cur_oop == resolve_forwarded_not_null(cur_oop)) { + _heap->evacuate_object(cur_oop, thread); + } + cur = cur + cur_oop->size(); + } + } + + fwd = res_oop; + } + + if (load_addr != NULL && fwd != obj) { + // Since we are here and we know the load address, update the reference. + ShenandoahHeap::cas_oop(fwd, load_addr, obj); + } + + return fwd; +} + +oop ShenandoahBarrierSet::load_reference_barrier_impl(oop obj) { + assert(ShenandoahLoadRefBarrier, "should be enabled"); + if (!CompressedOops::is_null(obj)) { + bool evac_in_progress = _heap->is_gc_in_progress_mask(ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL); + oop fwd = resolve_forwarded_not_null(obj); + if (evac_in_progress && + _heap->in_collection_set(obj) && + obj == fwd) { + Thread *t = Thread::current(); + ShenandoahEvacOOMScope oom_evac_scope; + return _heap->evacuate_object(obj, t); + } else { + return fwd; + } + } else { + return obj; + } +} + +void ShenandoahBarrierSet::on_thread_create(Thread* thread) { + // Create thread local data + ShenandoahThreadLocalData::create(thread); +} + +void ShenandoahBarrierSet::on_thread_destroy(Thread* thread) { + // Destroy thread local data + ShenandoahThreadLocalData::destroy(thread); +} + +void ShenandoahBarrierSet::on_thread_attach(JavaThread* thread) { + assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint"); + assert(!ShenandoahThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active"); + assert(ShenandoahThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty"); + if (ShenandoahBarrierSet::satb_mark_queue_set().is_active()) { + ShenandoahThreadLocalData::satb_mark_queue(thread).set_active(true); + } + ShenandoahThreadLocalData::set_gc_state(thread, _heap->gc_state()); + ShenandoahThreadLocalData::initialize_gclab(thread); +} + +void ShenandoahBarrierSet::on_thread_detach(JavaThread* thread) { + ShenandoahThreadLocalData::satb_mark_queue(thread).flush(); + PLAB* gclab = ShenandoahThreadLocalData::gclab(thread); + if (gclab != NULL) { + gclab->retire(); + } +} + +void ShenandoahBarrierSet::clone_barrier_runtime(oop src) { + if (_heap->has_forwarded_objects()) { + clone_barrier(src); + } +} +