/*

 * Copyright (c) 2015, 2019, 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 "classfile/classLoaderDataGraph.hpp"

#include "classfile/stringTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "code/codeCache.hpp"

#include "gc/shenandoah/shenandoahRootProcessor.inline.hpp"

#include "gc/shenandoah/shenandoahHeap.inline.hpp"

#include "gc/shenandoah/shenandoahPhaseTimings.hpp"

#include "gc/shenandoah/shenandoahStringDedup.hpp"

#include "gc/shenandoah/shenandoahTimingTracker.hpp"

#include "gc/shenandoah/shenandoahVMOperations.hpp"

#include "jfr/jfr.hpp"

#include "memory/iterator.hpp"

#include "memory/resourceArea.hpp"

#include "memory/universe.hpp"

#include "runtime/thread.hpp"

#include "services/management.hpp"

ShenandoahSerialRoot::ShenandoahSerialRoot(ShenandoahSerialRoot::OopsDo oops_do, ShenandoahPhaseTimings::GCParPhases phase) :

  _oops_do(oops_do), _phase(phase) {

}

void ShenandoahSerialRoot::oops_do(OopClosure* cl, uint worker_id) {

  if (_claimed.try_set()) {

    ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();

    ShenandoahWorkerTimingsTracker timer(worker_times, _phase, worker_id);

    _oops_do(cl);

  }

}

// Overwrite the second argument for SD::oops_do, don't include vm global oop storage.

static void system_dictionary_oops_do(OopClosure* cl) {

  SystemDictionary::oops_do(cl, false);

}

ShenandoahSerialRoots::ShenandoahSerialRoots() :

  _universe_root(&Universe::oops_do, ShenandoahPhaseTimings::UniverseRoots),

  _object_synchronizer_root(&ObjectSynchronizer::oops_do, ShenandoahPhaseTimings::ObjectSynchronizerRoots),

  _management_root(&Management::oops_do, ShenandoahPhaseTimings::ManagementRoots),

  _system_dictionary_root(&system_dictionary_oops_do, ShenandoahPhaseTimings::SystemDictionaryRoots),

  _jvmti_root(&JvmtiExport::oops_do, ShenandoahPhaseTimings::JVMTIRoots) {

}

void ShenandoahSerialRoots::oops_do(OopClosure* cl, uint worker_id) {

  _universe_root.oops_do(cl, worker_id);

  _object_synchronizer_root.oops_do(cl, worker_id);

  _management_root.oops_do(cl, worker_id);

  _system_dictionary_root.oops_do(cl, worker_id);

  _jvmti_root.oops_do(cl, worker_id);

}

ShenandoahWeakSerialRoot::ShenandoahWeakSerialRoot(ShenandoahWeakSerialRoot::WeakOopsDo weak_oops_do, ShenandoahPhaseTimings::GCParPhases phase) :

  _weak_oops_do(weak_oops_do), _phase(phase) {

}

void ShenandoahWeakSerialRoot::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {

  if (_claimed.try_set()) {

    ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();

    ShenandoahWorkerTimingsTracker timer(worker_times, _phase, worker_id);

    _weak_oops_do(is_alive, keep_alive);

  }

}

#if INCLUDE_JVMTI

ShenandoahJVMTIWeakRoot::ShenandoahJVMTIWeakRoot() :

  ShenandoahWeakSerialRoot(&JvmtiExport::weak_oops_do, ShenandoahPhaseTimings::JVMTIWeakRoots) {

}

#endif // INCLUDE_JVMTI

#if INCLUDE_JFR

ShenandoahJFRWeakRoot::ShenandoahJFRWeakRoot() :

  ShenandoahWeakSerialRoot(&Jfr::weak_oops_do, ShenandoahPhaseTimings::JFRWeakRoots) {

}

#endif // INCLUDE_JFR

void ShenandoahSerialWeakRoots::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {

  JVMTI_ONLY(_jvmti_weak_roots.weak_oops_do(is_alive, keep_alive, worker_id);)

  JFR_ONLY(_jfr_weak_roots.weak_oops_do(is_alive, keep_alive, worker_id);)

}

void ShenandoahSerialWeakRoots::weak_oops_do(OopClosure* cl, uint worker_id) {

  AlwaysTrueClosure always_true;

  weak_oops_do(&always_true, cl, worker_id);

}

ShenandoahThreadRoots::ShenandoahThreadRoots(bool is_par) : _is_par(is_par) {

  Threads::change_thread_claim_token();

}

void ShenandoahThreadRoots::oops_do(OopClosure* oops_cl, CodeBlobClosure* code_cl, uint worker_id) {

  ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();

  ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);

  ResourceMark rm;

  Threads::possibly_parallel_oops_do(_is_par, oops_cl, code_cl);

}

void ShenandoahThreadRoots::threads_do(ThreadClosure* tc, uint worker_id) {

  ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();

  ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);

  ResourceMark rm;

  Threads::possibly_parallel_threads_do(_is_par, tc);

}

ShenandoahThreadRoots::~ShenandoahThreadRoots() {

  Threads::assert_all_threads_claimed();

}

ShenandoahStringDedupRoots::ShenandoahStringDedupRoots() {

  if (ShenandoahStringDedup::is_enabled()) {

    StringDedup::gc_prologue(false);

  }

}

ShenandoahStringDedupRoots::~ShenandoahStringDedupRoots() {

  if (ShenandoahStringDedup::is_enabled()) {

    StringDedup::gc_epilogue();

  }

}

void ShenandoahStringDedupRoots::oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {

  if (ShenandoahStringDedup::is_enabled()) {

    ShenandoahStringDedup::parallel_oops_do(is_alive, keep_alive, worker_id);

  }

}

ShenandoahRootProcessor::ShenandoahRootProcessor(ShenandoahPhaseTimings::Phase phase) :

  _heap(ShenandoahHeap::heap()),

  _phase(phase) {

  assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");

  _heap->phase_timings()->record_workers_start(_phase);

}

ShenandoahRootProcessor::~ShenandoahRootProcessor() {

  assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");

  _heap->phase_timings()->record_workers_end(_phase);

}

ShenandoahRootEvacuator::ShenandoahRootEvacuator(uint n_workers, ShenandoahPhaseTimings::Phase phase, bool include_concurrent_roots) :

  ShenandoahRootProcessor(phase),

  _thread_roots(n_workers > 1),

  _include_concurrent_roots(include_concurrent_roots) {

}

void ShenandoahRootEvacuator::roots_do(uint worker_id, OopClosure* oops) {

  MarkingCodeBlobClosure blobsCl(oops, CodeBlobToOopClosure::FixRelocations);

  AlwaysTrueClosure always_true;

  _serial_roots.oops_do(oops, worker_id);

  _serial_weak_roots.weak_oops_do(oops, worker_id);

  if (_include_concurrent_roots) {

    CLDToOopClosure clds(oops, ClassLoaderData::_claim_strong);

    _vm_roots.oops_do<OopClosure>(oops, worker_id);

    _cld_roots.cld_do(&clds, worker_id);

    _weak_roots.oops_do<OopClosure>(oops, worker_id);

  }

  _thread_roots.oops_do(oops, NULL, worker_id);

  _code_roots.code_blobs_do(&blobsCl, worker_id);

  _dedup_roots.oops_do(&always_true, oops, worker_id);

}

ShenandoahRootUpdater::ShenandoahRootUpdater(uint n_workers, ShenandoahPhaseTimings::Phase phase) :

  ShenandoahRootProcessor(phase),

  _thread_roots(n_workers > 1) {

}

void ShenandoahRootUpdater::strong_roots_do(uint worker_id, OopClosure* oops_cl) {

  CodeBlobToOopClosure update_blobs(oops_cl, CodeBlobToOopClosure::FixRelocations);

  CLDToOopClosure clds(oops_cl, ClassLoaderData::_claim_strong);

  _serial_roots.oops_do(oops_cl, worker_id);

  _vm_roots.oops_do(oops_cl, worker_id);

  _thread_roots.oops_do(oops_cl, NULL, worker_id);

  _cld_roots.cld_do(&clds, worker_id);

  _code_roots.code_blobs_do(&update_blobs, worker_id);

}

ShenandoahRootAdjuster::ShenandoahRootAdjuster(uint n_workers, ShenandoahPhaseTimings::Phase phase) :

  ShenandoahRootProcessor(phase),

  _thread_roots(n_workers > 1) {

  assert(ShenandoahHeap::heap()->is_full_gc_in_progress(), "Full GC only");

}

void ShenandoahRootAdjuster::roots_do(uint worker_id, OopClosure* oops) {

  CodeBlobToOopClosure adjust_code_closure(oops, CodeBlobToOopClosure::FixRelocations);

  CLDToOopClosure adjust_cld_closure(oops, ClassLoaderData::_claim_strong);

  AlwaysTrueClosure always_true;

  _serial_roots.oops_do(oops, worker_id);

  _vm_roots.oops_do(oops, worker_id);

  _thread_roots.oops_do(oops, NULL, worker_id);

  _cld_roots.cld_do(&adjust_cld_closure, worker_id);

  _code_roots.code_blobs_do(&adjust_code_closure, worker_id);

  _serial_weak_roots.weak_oops_do(oops, worker_id);

  _weak_roots.oops_do<OopClosure>(oops, worker_id);

  _dedup_roots.oops_do(&always_true, oops, worker_id);

}

 ShenandoahHeapIterationRootScanner::ShenandoahHeapIterationRootScanner() :

   ShenandoahRootProcessor(ShenandoahPhaseTimings::_num_phases),

   _thread_roots(false /*is par*/) {

 }

 void ShenandoahHeapIterationRootScanner::roots_do(OopClosure* oops) {

   assert(Thread::current()->is_VM_thread(), "Only by VM thread");

   // Must use _claim_none to avoid interfering with concurrent CLDG iteration

   CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);

   MarkingCodeBlobClosure code(oops, !CodeBlobToOopClosure::FixRelocations);

   ShenandoahParallelOopsDoThreadClosure tc_cl(oops, &code, NULL);

   AlwaysTrueClosure always_true;

   ResourceMark rm;

   _serial_roots.oops_do(oops, 0);

   _vm_roots.oops_do(oops, 0);

   _cld_roots.cld_do(&clds, 0);

   _thread_roots.threads_do(&tc_cl, 0);

   _code_roots.code_blobs_do(&code, 0);

   _serial_weak_roots.weak_oops_do(oops, 0);

   _weak_roots.oops_do<OopClosure>(oops, 0);

   _dedup_roots.oops_do(&always_true, oops, 0);

 }

 void ShenandoahHeapIterationRootScanner::strong_roots_do(OopClosure* oops) {

   assert(Thread::current()->is_VM_thread(), "Only by VM thread");

   // Must use _claim_none to avoid interfering with concurrent CLDG iteration

   CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);

   MarkingCodeBlobClosure code(oops, !CodeBlobToOopClosure::FixRelocations);

   ShenandoahParallelOopsDoThreadClosure tc_cl(oops, &code, NULL);

   ResourceMark rm;

   _serial_roots.oops_do(oops, 0);

   _vm_roots.oops_do(oops, 0);

   _cld_roots.always_strong_cld_do(&clds, 0);

   _thread_roots.threads_do(&tc_cl, 0);

 }