1 /*
   2  * Copyright (c) 2015, 2019, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #include "precompiled.hpp"
  25 
  26 #include "classfile/classLoaderDataGraph.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "code/codeCache.hpp"
  30 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
  31 #include "gc/shenandoah/shenandoahRootProcessor.inline.hpp"
  32 #include "gc/shenandoah/shenandoahHeap.hpp"
  33 #include "gc/shenandoah/shenandoahHeuristics.hpp"
  34 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
  35 #include "gc/shenandoah/shenandoahStringDedup.hpp"
  36 #include "gc/shenandoah/shenandoahTimingTracker.hpp"
  37 #include "gc/shenandoah/shenandoahUtils.hpp"
  38 #include "gc/shenandoah/shenandoahVMOperations.hpp"
  39 #include "gc/shared/weakProcessor.inline.hpp"
  40 #include "memory/allocation.inline.hpp"
  41 #include "memory/iterator.hpp"
  42 #include "memory/resourceArea.hpp"
  43 #include "memory/universe.hpp"
  44 #include "runtime/thread.hpp"
  45 #include "services/management.hpp"
  46 
  47 ShenandoahSerialRoot::ShenandoahSerialRoot(ShenandoahSerialRoot::OopsDo oops_do, ShenandoahPhaseTimings::GCParPhases phase) :
  48   _claimed(false), _oops_do(oops_do), _phase(phase) {
  49 }
  50 
  51 void ShenandoahSerialRoot::oops_do(OopClosure* cl, uint worker_id) {
  52   if (!_claimed && Atomic::cmpxchg(true, &_claimed, false) == false) {
  53     ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
  54     ShenandoahWorkerTimingsTracker timer(worker_times, _phase, worker_id);
  55     _oops_do(cl);
  56   }
  57 }
  58 
  59 ShenandoahSerialRoots::ShenandoahSerialRoots() :
  60   _universe_root(&Universe::oops_do, ShenandoahPhaseTimings::UniverseRoots),
  61   _object_synchronizer_root(&ObjectSynchronizer::oops_do, ShenandoahPhaseTimings::ObjectSynchronizerRoots),
  62   _management_root(&Management::oops_do, ShenandoahPhaseTimings::ManagementRoots),
  63   _system_dictionary_root(&SystemDictionary::oops_do, ShenandoahPhaseTimings::SystemDictionaryRoots),
  64   _jvmti_root(&JvmtiExport::oops_do, ShenandoahPhaseTimings::JVMTIRoots),
  65   _jni_handle_root(&JNIHandles::oops_do, ShenandoahPhaseTimings::JNIRoots) {
  66 }
  67 
  68 void ShenandoahSerialRoots::oops_do(OopClosure* cl, uint worker_id) {
  69   _universe_root.oops_do(cl, worker_id);
  70   _object_synchronizer_root.oops_do(cl, worker_id);
  71   _management_root.oops_do(cl, worker_id);
  72   _system_dictionary_root.oops_do(cl, worker_id);
  73   _jvmti_root.oops_do(cl, worker_id);
  74   _jni_handle_root.oops_do(cl, worker_id);
  75 }
  76 
  77 ShenandoahThreadRoots::ShenandoahThreadRoots(bool is_par) : _is_par(is_par) {
  78   Threads::change_thread_claim_token();
  79 }
  80 
  81 void ShenandoahThreadRoots::oops_do(OopClosure* oops_cl, CodeBlobClosure* code_cl, uint worker_id) {
  82   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
  83   ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
  84   ResourceMark rm;
  85   Threads::possibly_parallel_oops_do(_is_par, oops_cl, code_cl);
  86 }
  87 
  88 void ShenandoahThreadRoots::threads_do(ThreadClosure* tc, uint worker_id) {
  89   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
  90   ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
  91   ResourceMark rm;
  92   Threads::possibly_parallel_threads_do(_is_par, tc);
  93 }
  94 
  95 ShenandoahThreadRoots::~ShenandoahThreadRoots() {
  96   Threads::assert_all_threads_claimed();
  97 }
  98 
  99 ShenandoahWeakRoots::ShenandoahWeakRoots(uint n_workers) :
 100   _process_timings(n_workers),
 101   _task(&_process_timings, n_workers) {
 102 }
 103 
 104 ShenandoahWeakRoots::~ShenandoahWeakRoots() {
 105   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
 106   ShenandoahTimingConverter::weak_processing_timing_to_shenandoah_timing(&_process_timings,
 107                                                                          worker_times);
 108 }
 109 
 110 ShenandoahStringDedupRoots::ShenandoahStringDedupRoots() {
 111   if (ShenandoahStringDedup::is_enabled()) {
 112     StringDedup::gc_prologue(false);
 113   }
 114 }
 115 
 116 ShenandoahStringDedupRoots::~ShenandoahStringDedupRoots() {
 117   if (ShenandoahStringDedup::is_enabled()) {
 118     StringDedup::gc_epilogue();
 119   }
 120 }
 121 
 122 void ShenandoahStringDedupRoots::oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {
 123   if (ShenandoahStringDedup::is_enabled()) {
 124     ShenandoahStringDedup::parallel_oops_do(is_alive, keep_alive, worker_id);
 125   }
 126 }
 127 
 128 ShenandoahClassLoaderDataRoots::ShenandoahClassLoaderDataRoots() {
 129   ClassLoaderDataGraph::clear_claimed_marks();
 130 }
 131 
 132 void ShenandoahClassLoaderDataRoots::clds_do(CLDClosure* strong_clds, CLDClosure* weak_clds, uint worker_id) {
 133   ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
 134   ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::CLDGRoots, worker_id);
 135   ClassLoaderDataGraph::roots_cld_do(strong_clds, weak_clds);
 136 }
 137 
 138 ShenandoahRootProcessor::ShenandoahRootProcessor(ShenandoahPhaseTimings::Phase phase) :
 139   _heap(ShenandoahHeap::heap()),
 140   _phase(phase) {
 141   assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
 142   _heap->phase_timings()->record_workers_start(_phase);
 143 }
 144 
 145 ShenandoahRootProcessor::~ShenandoahRootProcessor() {
 146   assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
 147   _heap->phase_timings()->record_workers_end(_phase);
 148 }
 149 
 150 ShenandoahRootEvacuator::ShenandoahRootEvacuator(uint n_workers, ShenandoahPhaseTimings::Phase phase) :
 151   ShenandoahRootProcessor(phase),
 152   _thread_roots(n_workers > 1),
 153   _weak_roots(n_workers) {
 154 }
 155 
 156 void ShenandoahRootEvacuator::roots_do(uint worker_id, OopClosure* oops) {
 157   MarkingCodeBlobClosure blobsCl(oops, CodeBlobToOopClosure::FixRelocations);
 158   CLDToOopClosure clds(oops, ClassLoaderData::_claim_strong);
 159   CLDToOopClosure* weak_clds = ShenandoahHeap::heap()->unload_classes() ? NULL : &clds;
 160 
 161   AlwaysTrueClosure always_true;
 162 
 163   _serial_roots.oops_do(oops, worker_id);
 164 
 165   _thread_roots.oops_do(oops, NULL, worker_id);
 166   _cld_roots.clds_do(&clds, &clds, worker_id);
 167   _code_roots.code_blobs_do(&blobsCl, worker_id);
 168 
 169   _weak_roots.oops_do<AlwaysTrueClosure, OopClosure>(&always_true, oops, worker_id);
 170   _dedup_roots.oops_do(&always_true, oops, worker_id);
 171 }
 172 
 173 ShenandoahRootUpdater::ShenandoahRootUpdater(uint n_workers, ShenandoahPhaseTimings::Phase phase, bool update_code_cache) :
 174   ShenandoahRootProcessor(phase),
 175   _thread_roots(n_workers > 1),
 176   _weak_roots(n_workers),
 177   _update_code_cache(update_code_cache) {
 178 }
 179 
 180 ShenandoahRootAdjuster::ShenandoahRootAdjuster(uint n_workers, ShenandoahPhaseTimings::Phase phase) :
 181   ShenandoahRootProcessor(phase),
 182   _thread_roots(n_workers > 1),
 183   _weak_roots(n_workers) {
 184   assert(ShenandoahHeap::heap()->is_full_gc_in_progress(), "Full GC only");
 185 }
 186 
 187 void ShenandoahRootAdjuster::roots_do(uint worker_id, OopClosure* oops) {
 188   CodeBlobToOopClosure adjust_code_closure(oops, CodeBlobToOopClosure::FixRelocations);
 189   CLDToOopClosure adjust_cld_closure(oops, ClassLoaderData::_claim_strong);
 190   AlwaysTrueClosure always_true;
 191 
 192   _serial_roots.oops_do(oops, worker_id);
 193 
 194   _thread_roots.oops_do(oops, NULL, worker_id);
 195   _cld_roots.clds_do(&adjust_cld_closure, NULL, worker_id);
 196   _code_roots.code_blobs_do(&adjust_code_closure, worker_id);
 197 
 198   _weak_roots.oops_do<AlwaysTrueClosure, OopClosure>(&always_true, oops, worker_id);
 199   _dedup_roots.oops_do(&always_true, oops, worker_id);
 200 }