1 /*
  2  * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "precompiled.hpp"
 26 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
 27 #include "gc/shenandoah/shenandoahBarrierSetClone.inline.hpp"
 28 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
 29 #include "gc/shenandoah/shenandoahBarrierSetNMethod.hpp"
 30 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
 31 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
 32 #include "gc/shenandoah/shenandoahStackWatermark.hpp"
 33 #ifdef COMPILER1
 34 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
 35 #endif
 36 #ifdef COMPILER2
 37 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
 38 #endif
 39 
 40 class ShenandoahBarrierSetC1;
 41 class ShenandoahBarrierSetC2;
 42 
 43 ShenandoahBarrierSet::ShenandoahBarrierSet(ShenandoahHeap* heap) :
 44   BarrierSet(make_barrier_set_assembler<ShenandoahBarrierSetAssembler>(),
 45              make_barrier_set_c1<ShenandoahBarrierSetC1>(),
 46              make_barrier_set_c2<ShenandoahBarrierSetC2>(),
 47              ShenandoahNMethodBarrier ? new ShenandoahBarrierSetNMethod(heap) : NULL,
 48              BarrierSet::FakeRtti(BarrierSet::ShenandoahBarrierSet)),
 49   _heap(heap),
 50   _satb_mark_queue_buffer_allocator("SATB Buffer Allocator", ShenandoahSATBBufferSize),
 51   _satb_mark_queue_set(&_satb_mark_queue_buffer_allocator)
 52 {
 53 }
 54 
 55 ShenandoahBarrierSetAssembler* ShenandoahBarrierSet::assembler() {
 56   BarrierSetAssembler* const bsa = BarrierSet::barrier_set()->barrier_set_assembler();
 57   return reinterpret_cast<ShenandoahBarrierSetAssembler*>(bsa);
 58 }
 59 
 60 void ShenandoahBarrierSet::print_on(outputStream* st) const {
 61   st->print("ShenandoahBarrierSet");
 62 }
 63 
 64 bool ShenandoahBarrierSet::need_load_reference_barrier(DecoratorSet decorators, BasicType type) {
 65   if (!ShenandoahLoadRefBarrier) return false;
 66   // Only needed for references
 67   return is_reference_type(type);
 68 }
 69 
 70 bool ShenandoahBarrierSet::need_keep_alive_barrier(DecoratorSet decorators, BasicType type) {
 71   if (!ShenandoahSATBBarrier) return false;
 72   // Only needed for references
 73   if (!is_reference_type(type)) return false;
 74 
 75   bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0;
 76   bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
 77   bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0;
 78   return (on_weak_ref || unknown) && keep_alive;
 79 }
 80 
 81 void ShenandoahBarrierSet::on_thread_create(Thread* thread) {
 82   // Create thread local data
 83   ShenandoahThreadLocalData::create(thread);
 84 }
 85 
 86 void ShenandoahBarrierSet::on_thread_destroy(Thread* thread) {
 87   // Destroy thread local data
 88   ShenandoahThreadLocalData::destroy(thread);
 89 }
 90 
 91 void ShenandoahBarrierSet::on_thread_attach(Thread *thread) {
 92   assert(!thread->is_Java_thread() || !SafepointSynchronize::is_at_safepoint(),
 93          "We should not be at a safepoint");
 94   SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
 95   assert(!queue.is_active(), "SATB queue should not be active");
 96   assert(queue.buffer() == nullptr, "SATB queue should not have a buffer");
 97   assert(queue.index() == 0, "SATB queue index should be zero");
 98   queue.set_active(_satb_mark_queue_set.is_active());
 99   if (thread->is_Java_thread()) {
100     ShenandoahThreadLocalData::set_gc_state(thread, _heap->gc_state());
101     ShenandoahThreadLocalData::initialize_gclab(thread);
102     ShenandoahThreadLocalData::set_disarmed_value(thread, ShenandoahCodeRoots::disarmed_value());
103 
104     if (ShenandoahStackWatermarkBarrier) {
105       JavaThread* const jt = JavaThread::cast(thread);
106       StackWatermark* const watermark = new ShenandoahStackWatermark(jt);
107       StackWatermarkSet::add_watermark(jt, watermark);
108     }
109   }
110 }
111 
112 void ShenandoahBarrierSet::on_thread_detach(Thread *thread) {
113   SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
114   _satb_mark_queue_set.flush_queue(queue);
115   if (thread->is_Java_thread()) {
116     PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
117     if (gclab != NULL) {
118       gclab->retire();
119     }
120 
121     // SATB protocol requires to keep alive reacheable oops from roots at the beginning of GC
122     if (ShenandoahStackWatermarkBarrier) {
123       if (_heap->is_concurrent_mark_in_progress()) {
124         ShenandoahKeepAliveClosure oops;
125         StackWatermarkSet::finish_processing(JavaThread::cast(thread), &oops, StackWatermarkKind::gc);
126       } else if (_heap->is_concurrent_weak_root_in_progress() && _heap->is_evacuation_in_progress()) {
127         ShenandoahContextEvacuateUpdateRootsClosure oops;
128         StackWatermarkSet::finish_processing(JavaThread::cast(thread), &oops, StackWatermarkKind::gc);
129       }
130     }
131   }
132 }
133 
134 void ShenandoahBarrierSet::clone_barrier_runtime(oop src) {
135   if (_heap->has_forwarded_objects() || (ShenandoahIUBarrier && _heap->is_concurrent_mark_in_progress())) {
136     clone_barrier(src);
137   }
138 }