/*
 * Copyright (c) 2015, Red Hat, Inc. and/or its affiliates.
 *
 * 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/stringTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/codeCache.hpp"
#include "gc/shenandoah/shenandoahRootProcessor.hpp"
#include "gc/shenandoah/shenandoahHeap.hpp"
#include "gc/shenandoah/shenandoahBarrierSet.hpp"
#include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
#include "gc/shenandoah/shenandoahPhaseTimes.hpp"
#include "memory/allocation.inline.hpp"
#include "runtime/fprofiler.hpp"
#include "runtime/mutex.hpp"
#include "services/management.hpp"

ShenandoahRootProcessor::ShenandoahRootProcessor(ShenandoahHeap* heap, uint n_workers,
                                                 ShenandoahCollectorPolicy::TimingPhase phase) :
  _process_strong_tasks(new SubTasksDone(SHENANDOAH_RP_PS_NumElements)),
  _srs(n_workers),
  _phase(phase),
  _codecache_iterator(CodeCache::parallel_iterator()),
  _om_iterator(ObjectSynchronizer::parallel_iterator())
{
  heap->shenandoahPolicy()->record_workers_start(_phase);
}

ShenandoahRootProcessor::~ShenandoahRootProcessor() {
  delete _process_strong_tasks;
  ShenandoahHeap::heap()->shenandoahPolicy()->record_workers_end(_phase);
}

void ShenandoahRootProcessor::process_strong_roots(OopClosure* oops,
                                                   OopClosure* weak_oops,
                                                   CLDClosure* clds,
                                                   CodeBlobClosure* blobs,
                                                   uint worker_id) {

  process_java_roots(oops, clds, NULL, blobs, worker_id);
  process_vm_roots(oops, NULL, weak_oops, worker_id);

  _process_strong_tasks->all_tasks_completed(n_workers());
}

void ShenandoahRootProcessor::process_all_roots(OopClosure* oops,
                                                OopClosure* weak_oops,
                                                CLDClosure* clds,
                                                CodeBlobClosure* blobs,
                                                uint worker_id) {

  ShenandoahPhaseTimes* phase_times = ShenandoahHeap::heap()->shenandoahPolicy()->phase_times();
  process_java_roots(oops, clds, clds, NULL, worker_id);
  process_vm_roots(oops, oops, weak_oops, worker_id);

  if (blobs != NULL) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::CodeCacheRoots, worker_id);
    _codecache_iterator.parallel_blobs_do(blobs);
  }

  _process_strong_tasks->all_tasks_completed(n_workers());
}

void ShenandoahRootProcessor::process_java_roots(OopClosure* strong_roots,
                                                 CLDClosure* strong_clds,
                                                 CLDClosure* weak_clds,
                                                 CodeBlobClosure* strong_code,
                                                 uint worker_id)
{
  ShenandoahPhaseTimes* phase_times = ShenandoahHeap::heap()->shenandoahPolicy()->phase_times();
  // Iterating over the CLDG and the Threads are done early to allow us to
  // first process the strong CLDs and nmethods and then, after a barrier,
  // let the thread process the weak CLDs and nmethods.
  {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::CLDGRoots, worker_id);
    _cld_iterator.root_cld_do(strong_clds, weak_clds);
  }

  {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::ThreadRoots, worker_id);
    bool is_par = n_workers() > 1;
    ResourceMark rm;
    Threads::possibly_parallel_oops_do(is_par, strong_roots, strong_code);
  }
}

void ShenandoahRootProcessor::process_vm_roots(OopClosure* strong_roots,
                                               OopClosure* weak_roots,
                                               OopClosure* jni_weak_roots,
                                               uint worker_id)
{
  ShenandoahPhaseTimes* phase_times = ShenandoahHeap::heap()->shenandoahPolicy()->phase_times();
  if (!_process_strong_tasks->is_task_claimed(SHENANDOAH_RP_PS_Universe_oops_do)) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::UniverseRoots, worker_id);
    Universe::oops_do(strong_roots);
  }

  if (!_process_strong_tasks->is_task_claimed(SHENANDOAH_RP_PS_JNIHandles_oops_do)) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::JNIRoots, worker_id);
    JNIHandles::oops_do(strong_roots);
  }

  if (!_process_strong_tasks->is_task_claimed(SHENANDOAH_RP_PS_FlatProfiler_oops_do)) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::FlatProfilerRoots, worker_id);
    FlatProfiler::oops_do(strong_roots);
  }
  if (!_process_strong_tasks->is_task_claimed(SHENANDOAH_RP_PS_Management_oops_do)) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::ManagementRoots, worker_id);
    Management::oops_do(strong_roots);
  }
  if (!_process_strong_tasks->is_task_claimed(SHENANDOAH_RP_PS_jvmti_oops_do)) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::JVMTIRoots, worker_id);
    JvmtiExport::oops_do(strong_roots);
  }
  if (!_process_strong_tasks->is_task_claimed(SHENANDOAH_RP_PS_SystemDictionary_oops_do)) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::SystemDictionaryRoots, worker_id);
    SystemDictionary::roots_oops_do(strong_roots, weak_roots);
  }
  if (jni_weak_roots != NULL) {
    if (!_process_strong_tasks->is_task_claimed(SHENANDOAH_RP_PS_JNIHandles_weak_oops_do)) {
      ShenandoahAlwaysTrueClosure always_true;
      ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::JNIWeakRoots, worker_id);
      JNIHandles::weak_oops_do(&always_true, jni_weak_roots);
    }
  }

  {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::ObjectSynchronizerRoots, worker_id);
    while(_om_iterator.parallel_oops_do(strong_roots));
  }

  // All threads execute the following. A specific chunk of buckets
  // from the StringTable are the individual tasks.
  if (weak_roots != NULL) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::StringTableRoots, worker_id);
    StringTable::possibly_parallel_oops_do(weak_roots);
  }
}

uint ShenandoahRootProcessor::n_workers() const {
  return _srs.n_threads();
}

ShenandoahRootEvacuator::ShenandoahRootEvacuator(ShenandoahHeap* heap, uint n_workers, ShenandoahCollectorPolicy::TimingPhase phase) :
  _process_strong_tasks(new SubTasksDone(SHENANDOAH_RP_PS_NumElements)),
  _srs(n_workers),
  _phase(phase),
  _codecache_iterator(CodeCache::parallel_iterator())
{
  heap->shenandoahPolicy()->record_workers_start(_phase);
}

ShenandoahRootEvacuator::~ShenandoahRootEvacuator() {
  delete _process_strong_tasks;
  ShenandoahHeap::heap()->shenandoahPolicy()->record_workers_end(_phase);
}

void ShenandoahRootEvacuator::process_evacuate_roots(OopClosure* oops,
                                                     CodeBlobClosure* blobs,
                                                     uint worker_id) {

  ShenandoahPhaseTimes* phase_times = ShenandoahHeap::heap()->shenandoahPolicy()->phase_times();
  {
    bool is_par = n_workers() > 1;
    ResourceMark rm;
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::ThreadRoots, worker_id);
    Threads::possibly_parallel_oops_do(is_par, oops, NULL);
  }

  if (blobs != NULL) {
    ShenandoahParPhaseTimesTracker timer(phase_times, ShenandoahPhaseTimes::CodeCacheRoots, worker_id);
    _codecache_iterator.parallel_blobs_do(blobs);
  }

  _process_strong_tasks->all_tasks_completed(n_workers());
}

uint ShenandoahRootEvacuator::n_workers() const {
  return _srs.n_threads();
}

// Implemenation of ParallelCLDRootIterator
ParallelCLDRootIterator::ParallelCLDRootIterator() {
  assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
  ClassLoaderDataGraph::clear_claimed_marks();
}

void ParallelCLDRootIterator::root_cld_do(CLDClosure* strong, CLDClosure* weak) {
    ClassLoaderDataGraph::roots_cld_do(strong, weak);
}