/*

 * Copyright (c) 2002, 2018, 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

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 */

#ifndef SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP

#define SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP

#include "gc/parallel/parallelScavengeHeap.hpp"

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

#include "gc/parallel/psScavenge.hpp"

#include "logging/log.hpp"

#include "memory/iterator.hpp"

#include "memory/resourceArea.hpp"

#include "oops/access.inline.hpp"

#include "utilities/globalDefinitions.hpp"

inline void PSScavenge::save_to_space_top_before_gc() {

  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  _to_space_top_before_gc = heap->young_gen()->to_space()->top();

}

template <class T> inline bool PSScavenge::should_scavenge(T* p) {

  T heap_oop = RawAccess<>::oop_load(p);

  return PSScavenge::is_obj_in_young(heap_oop);

}

template <class T>

inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {

  if (should_scavenge(p)) {

    oop obj = RawAccess<OOP_NOT_NULL>::oop_load(p);

    // Skip objects copied to to_space since the scavenge started.

    HeapWord* const addr = (HeapWord*)obj;

    return addr < to_space_top_before_gc() || addr >= to_space->end();

  }

  return false;

}

template <class T>

inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {

  if (check_to_space) {

    ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

    return should_scavenge(p, heap->young_gen()->to_space());

  }

  return should_scavenge(p);

}

template<bool promote_immediately>

class PSRootsClosure: public OopClosure {

 private:

  PSPromotionManager* _promotion_manager;

 protected:

  template <class T> void do_oop_work(T *p) {

    if (PSScavenge::should_scavenge(p)) {

      // We never card mark roots, maybe call a func without test?

      _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p);

    }

  }

 public:

  PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }

  void do_oop(oop* p)       { PSRootsClosure::do_oop_work(p); }

  void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }

};

typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;

typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;

// Scavenges a single oop in a ClassLoaderData.

class PSScavengeFromCLDClosure: public OopClosure {

 private:

  PSPromotionManager* _pm;

  // Used to redirty a scanned cld if it has oops

  // pointing to the young generation after being scanned.

  ClassLoaderData*    _scanned_cld;

 public:

  PSScavengeFromCLDClosure(PSPromotionManager* pm) : _pm(pm), _scanned_cld(NULL) { }

  void do_oop(narrowOop* p) { ShouldNotReachHere(); }

  void do_oop(oop* p)       {

    ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();

    assert(!psh->is_in_reserved(p), "GC barrier needed");

    if (PSScavenge::should_scavenge(p)) {

      assert(PSScavenge::should_scavenge(p, true), "revisiting object?");

      oop o = *p;

      oop new_obj;

      if (o->is_forwarded()) {

        new_obj = o->forwardee();

      } else {

        new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);

      }

      RawAccess<OOP_NOT_NULL>::oop_store(p, new_obj);

      if (PSScavenge::is_obj_in_young(new_obj)) {

        do_cld_barrier();

      }

    }

  }

  void set_scanned_cld(ClassLoaderData* cld) {

    assert(_scanned_cld == NULL || cld == NULL, "Should always only handling one cld at a time");

    _scanned_cld = cld;

  }

 private:

  void do_cld_barrier() {

    assert(_scanned_cld != NULL, "Should not be called without having a scanned cld");

    _scanned_cld->record_modified_oops();

  }

};

// Scavenges the oop in a ClassLoaderData.

class PSScavengeCLDClosure: public CLDClosure {

 private:

  PSScavengeFromCLDClosure _oop_closure;

 protected:

 public:

  PSScavengeCLDClosure(PSPromotionManager* pm) : _oop_closure(pm) { }

  void do_cld(ClassLoaderData* cld) {

    // If the cld has not been dirtied we know that there's

    // no references into  the young gen and we can skip it.

    if (cld->has_modified_oops()) {

      // Setup the promotion manager to redirty this cld

      // if references are left in the young gen.

      _oop_closure.set_scanned_cld(cld);

      // Clean the cld since we're going to scavenge all the metadata.

      cld->oops_do(&_oop_closure, false, /*clear_modified_oops*/true);

      _oop_closure.set_scanned_cld(NULL);

    }

  }

};

#endif // SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP