/*

 * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * 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/systemDictionary.hpp"

#include "code/codeCache.hpp"

#include "gc/parallel/parallelScavengeHeap.hpp"

#include "gc/parallel/pcTasks.hpp"

#include "gc/parallel/psCompactionManager.inline.hpp"

#include "gc/parallel/psParallelCompact.hpp"

#include "gc/shared/collectedHeap.hpp"

#include "gc/shared/gcTimer.hpp"

#include "gc/shared/gcTraceTime.hpp"

#include "memory/universe.hpp"

#include "oops/objArrayKlass.inline.hpp"

#include "oops/oop.inline.hpp"

#include "prims/jvmtiExport.hpp"

#include "runtime/fprofiler.hpp"

#include "runtime/jniHandles.hpp"

#include "runtime/thread.hpp"

#include "runtime/vmThread.hpp"

#include "services/management.hpp"

#include "utilities/stack.inline.hpp"

//

// ThreadRootsMarkingTask

//

void ThreadRootsMarkingTask::do_it(GCTaskManager* manager, uint which) {

  assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

  ResourceMark rm;

  NOT_PRODUCT(GCTraceTime tm("ThreadRootsMarkingTask",

    PrintGCDetails && TraceParallelOldGCTasks, true, NULL, PSParallelCompact::gc_tracer()->gc_id()));

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);

  CLDToOopClosure mark_and_push_from_clds(&mark_and_push_closure, true);

  MarkingCodeBlobClosure mark_and_push_in_blobs(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);

  if (_java_thread != NULL)

    _java_thread->oops_do(

        &mark_and_push_closure,

        &mark_and_push_from_clds,

        &mark_and_push_in_blobs);

  if (_vm_thread != NULL)

    _vm_thread->oops_do(

        &mark_and_push_closure,

        &mark_and_push_from_clds,

        &mark_and_push_in_blobs);

  // Do the real work

  cm->follow_marking_stacks();

}

void MarkFromRootsTask::do_it(GCTaskManager* manager, uint which) {

  assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

  NOT_PRODUCT(GCTraceTime tm("MarkFromRootsTask",

    PrintGCDetails && TraceParallelOldGCTasks, true, NULL, PSParallelCompact::gc_tracer()->gc_id()));

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);

  ParCompactionManager::FollowKlassClosure follow_klass_closure(&mark_and_push_closure);

  switch (_root_type) {

    case universe:

      Universe::oops_do(&mark_and_push_closure);

      break;

    case jni_handles:

      JNIHandles::oops_do(&mark_and_push_closure);

      break;

    case threads:

    {

      ResourceMark rm;

      MarkingCodeBlobClosure each_active_code_blob(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);

      CLDToOopClosure mark_and_push_from_cld(&mark_and_push_closure);

      Threads::oops_do(&mark_and_push_closure, &mark_and_push_from_cld, &each_active_code_blob);

    }

    break;

    case object_synchronizer:

      ObjectSynchronizer::oops_do(&mark_and_push_closure);

      break;

    case flat_profiler:

      FlatProfiler::oops_do(&mark_and_push_closure);

      break;

    case management:

      Management::oops_do(&mark_and_push_closure);

      break;

    case jvmti:

      JvmtiExport::oops_do(&mark_and_push_closure);

      break;

    case system_dictionary:

      SystemDictionary::always_strong_oops_do(&mark_and_push_closure);

      break;

    case class_loader_data:

      ClassLoaderDataGraph::always_strong_oops_do(&mark_and_push_closure, &follow_klass_closure, true);

      break;

    case code_cache:

      // Do not treat nmethods as strong roots for mark/sweep, since we can unload them.

      //CodeCache::scavenge_root_nmethods_do(CodeBlobToOopClosure(&mark_and_push_closure));

      break;

    default:

      fatal("Unknown root type");

  }

  // Do the real work

  cm->follow_marking_stacks();

}

//

// RefProcTaskProxy

//

void RefProcTaskProxy::do_it(GCTaskManager* manager, uint which)

{

  assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

  NOT_PRODUCT(GCTraceTime tm("RefProcTask",

    PrintGCDetails && TraceParallelOldGCTasks, true, NULL, PSParallelCompact::gc_tracer()->gc_id()));

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);

  ParCompactionManager::FollowStackClosure follow_stack_closure(cm);

  _rp_task.work(_work_id, *PSParallelCompact::is_alive_closure(),

                mark_and_push_closure, follow_stack_closure);

}

//

// RefProcTaskExecutor

//

void RefProcTaskExecutor::execute(ProcessTask& task)

{

  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  uint parallel_gc_threads = heap->gc_task_manager()->workers();

  uint active_gc_threads = heap->gc_task_manager()->active_workers();

  RegionTaskQueueSet* qset = ParCompactionManager::region_array();

  ParallelTaskTerminator terminator(active_gc_threads, qset);

  GCTaskQueue* q = GCTaskQueue::create();

  for(uint i=0; i<parallel_gc_threads; i++) {

    q->enqueue(new RefProcTaskProxy(task, i));

  }

  if (task.marks_oops_alive()) {

    if (parallel_gc_threads>1) {

      for (uint j=0; j<active_gc_threads; j++) {

        q->enqueue(new StealMarkingTask(&terminator));

      }

    }

  }

  PSParallelCompact::gc_task_manager()->execute_and_wait(q);

}

void RefProcTaskExecutor::execute(EnqueueTask& task)

{

  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  uint parallel_gc_threads = heap->gc_task_manager()->workers();

  GCTaskQueue* q = GCTaskQueue::create();

  for(uint i=0; i<parallel_gc_threads; i++) {

    q->enqueue(new RefEnqueueTaskProxy(task, i));

  }

  PSParallelCompact::gc_task_manager()->execute_and_wait(q);

}

//

// StealMarkingTask

//

StealMarkingTask::StealMarkingTask(ParallelTaskTerminator* t) :

  _terminator(t) {}

void StealMarkingTask::do_it(GCTaskManager* manager, uint which) {

  assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

  NOT_PRODUCT(GCTraceTime tm("StealMarkingTask",

    PrintGCDetails && TraceParallelOldGCTasks, true, NULL, PSParallelCompact::gc_tracer()->gc_id()));

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);

  oop obj = NULL;

  ObjArrayTask task;

  int random_seed = 17;

  do {

    while (ParCompactionManager::steal_objarray(which, &random_seed, task)) {

      cm->follow_contents((objArrayOop)task.obj(), task.index());

      cm->follow_marking_stacks();

    }

    while (ParCompactionManager::steal(which, &random_seed, obj)) {

      cm->follow_contents(obj);

      cm->follow_marking_stacks();

    }

  } while (!terminator()->offer_termination());

}

//

// StealRegionCompactionTask

//

StealRegionCompactionTask::StealRegionCompactionTask(ParallelTaskTerminator* t):

  _terminator(t) {}

void StealRegionCompactionTask::do_it(GCTaskManager* manager, uint which) {

  assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

  NOT_PRODUCT(GCTraceTime tm("StealRegionCompactionTask",

    PrintGCDetails && TraceParallelOldGCTasks, true, NULL, PSParallelCompact::gc_tracer()->gc_id()));

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  // If not all threads are active, get a draining stack

  // from the list.  Else, just use this threads draining stack.

  uint which_stack_index;

  bool use_all_workers = manager->all_workers_active();

  if (use_all_workers) {

    which_stack_index = which;

    assert(manager->active_workers() == ParallelGCThreads,

  } else {

    which_stack_index = ParCompactionManager::pop_recycled_stack_index();

  }

  cm->set_region_stack_index(which_stack_index);

  cm->set_region_stack(ParCompactionManager::region_list(which_stack_index));

  if (TraceDynamicGCThreads) {

    gclog_or_tty->print_cr("StealRegionCompactionTask::do_it "

                           "region_stack_index %d region_stack = " PTR_FORMAT " "

                           " empty (%d) use all workers %d",

    which_stack_index, p2i(ParCompactionManager::region_list(which_stack_index)),

    cm->region_stack()->is_empty(),

    use_all_workers);

  }

  // Has to drain stacks first because there may be regions on

  // preloaded onto the stack and this thread may never have

  // done a draining task.  Are the draining tasks needed?

  cm->drain_region_stacks();

  size_t region_index = 0;

  int random_seed = 17;

  // If we're the termination task, try 10 rounds of stealing before

  // setting the termination flag

  while(true) {

    if (ParCompactionManager::steal(which, &random_seed, region_index)) {

      PSParallelCompact::fill_and_update_region(cm, region_index);

      cm->drain_region_stacks();

    } else {

      if (terminator()->offer_termination()) {

        break;

      }

      // Go around again.

    }

  }

  return;

}

UpdateDensePrefixTask::UpdateDensePrefixTask(

                                   PSParallelCompact::SpaceId space_id,

                                   size_t region_index_start,

                                   size_t region_index_end) :

  _space_id(space_id), _region_index_start(region_index_start),

  _region_index_end(region_index_end) {}

void UpdateDensePrefixTask::do_it(GCTaskManager* manager, uint which) {

  NOT_PRODUCT(GCTraceTime tm("UpdateDensePrefixTask",

    PrintGCDetails && TraceParallelOldGCTasks, true, NULL, PSParallelCompact::gc_tracer()->gc_id()));

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  PSParallelCompact::update_and_deadwood_in_dense_prefix(cm,

                                                         _space_id,

                                                         _region_index_start,

                                                         _region_index_end);

}

void DrainStacksCompactionTask::do_it(GCTaskManager* manager, uint which) {

  assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

  NOT_PRODUCT(GCTraceTime tm("DrainStacksCompactionTask",

    PrintGCDetails && TraceParallelOldGCTasks, true, NULL, PSParallelCompact::gc_tracer()->gc_id()));

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  uint which_stack_index;

  bool use_all_workers = manager->all_workers_active();

  if (use_all_workers) {

    which_stack_index = which;

    assert(manager->active_workers() == ParallelGCThreads,

  } else {

    which_stack_index = stack_index();

  }

  cm->set_region_stack(ParCompactionManager::region_list(which_stack_index));

  if (TraceDynamicGCThreads) {

    gclog_or_tty->print_cr("DrainStacksCompactionTask::do_it which = %d "

                           "which_stack_index = %d/empty(%d) "

                           "use all workers %d",

                           which, which_stack_index,

                           cm->region_stack()->is_empty(),

                           use_all_workers);

  }

  cm->set_region_stack_index(which_stack_index);

  // Process any regions already in the compaction managers stacks.

  cm->drain_region_stacks();

  assert(cm->region_stack()->is_empty(), "Not empty");

  if (!use_all_workers) {

    // Always give up the region stack.

    assert(cm->region_stack() ==

           ParCompactionManager::region_list(cm->region_stack_index()),

           "region_stack and region_stack_index are inconsistent");

    ParCompactionManager::push_recycled_stack_index(cm->region_stack_index());

    if (TraceDynamicGCThreads) {

      void* old_region_stack = (void*) cm->region_stack();

      int old_region_stack_index = cm->region_stack_index();

      gclog_or_tty->print_cr("Pushing region stack " PTR_FORMAT "/%d",

        p2i(old_region_stack), old_region_stack_index);

    }

    cm->set_region_stack(NULL);

    cm->set_region_stack_index((uint)max_uintx);

  }

}