/*

 * Copyright (c) 2015, 2018, 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.

 *

 */

#ifndef SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP

#define SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP

#include "gc/shared/barrierSet.hpp"

#include "gc/shenandoah/shenandoahBarrierSet.hpp"

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

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

#include "gc/shenandoah/shenandoahHeapRegion.hpp"

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

#include "gc/shenandoah/shenandoahThreadLocalData.hpp"

bool ShenandoahBarrierSet::need_update_refs_barrier() {

  return _heap->is_update_refs_in_progress() ||

         _heap->is_concurrent_traversal_in_progress() ||

         (_heap->is_concurrent_mark_in_progress() && _heap->has_forwarded_objects());

}

inline oop ShenandoahBarrierSet::resolve_forwarded_not_null(oop p) {

  return ShenandoahBrooksPointer::forwardee(p);

}

inline oop ShenandoahBarrierSet::resolve_forwarded(oop p) {

  if (((HeapWord*) p) != NULL) {

    return resolve_forwarded_not_null(p);

  } else {

    return p;

  }

}

template <DecoratorSet decorators, typename BarrierSetT>

template <typename T>

  oop res;

  oop expected = compare_value;

  do {

    compare_value = expected;

    res = Raw::oop_atomic_cmpxchg(new_value, addr, compare_value);

    expected = res;

  } while ((! oopDesc::equals_raw(compare_value, expected)) && oopDesc::equals_raw(resolve_forwarded(compare_value), resolve_forwarded(expected)));

  }

}

template <DecoratorSet decorators, typename BarrierSetT>

template <typename T>

inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(oop new_value, T* addr) {

}

template <DecoratorSet decorators, typename BarrierSetT>

}

template <typename T>

bool ShenandoahBarrierSet::arraycopy_loop_1(T* src, T* dst, size_t length, Klass* bound,

                                            bool checkcast, bool satb, bool disjoint,

                                            ShenandoahBarrierSet::ArrayCopyStoreValMode storeval_mode) {

  if (checkcast) {

    return arraycopy_loop_2<T, true>(src, dst, length, bound, satb, disjoint, storeval_mode);

  } else {

    return arraycopy_loop_2<T, false>(src, dst, length, bound, satb, disjoint, storeval_mode);

  }

}

template <typename T, bool CHECKCAST>

bool ShenandoahBarrierSet::arraycopy_loop_2(T* src, T* dst, size_t length, Klass* bound,

                                            bool satb, bool disjoint,

                                            ShenandoahBarrierSet::ArrayCopyStoreValMode storeval_mode) {

  if (satb) {

    return arraycopy_loop_3<T, CHECKCAST, true>(src, dst, length, bound, disjoint, storeval_mode);

  } else {

    return arraycopy_loop_3<T, CHECKCAST, false>(src, dst, length, bound, disjoint, storeval_mode);

  }

}

template <typename T, bool CHECKCAST, bool SATB>

bool ShenandoahBarrierSet::arraycopy_loop_3(T* src, T* dst, size_t length, Klass* bound, bool disjoint,

                                            ShenandoahBarrierSet::ArrayCopyStoreValMode storeval_mode) {

  switch (storeval_mode) {

    case NONE:

      return arraycopy_loop<T, CHECKCAST, SATB, NONE>(src, dst, length, bound, disjoint);

    case READ_BARRIER:

      return arraycopy_loop<T, CHECKCAST, SATB, READ_BARRIER>(src, dst, length, bound, disjoint);

    case WRITE_BARRIER:

      return arraycopy_loop<T, CHECKCAST, SATB, WRITE_BARRIER>(src, dst, length, bound, disjoint);

    default:

      ShouldNotReachHere();

      return true; // happy compiler

  }

}

template <typename T, bool CHECKCAST, bool SATB, ShenandoahBarrierSet::ArrayCopyStoreValMode STOREVAL_MODE>

bool ShenandoahBarrierSet::arraycopy_loop(T* src, T* dst, size_t length, Klass* bound, bool disjoint) {

  Thread* thread = Thread::current();

  ShenandoahMarkingContext* ctx = _heap->marking_context();

  ShenandoahEvacOOMScope oom_evac_scope;

  // We need to handle four cases:

  //

  // a) src < dst, conjoint, can only copy backward only

  //   [...src...]

  //         [...dst...]

  //

  // b) src < dst, disjoint, can only copy forward, because types may mismatch

  //   [...src...]

  //              [...dst...]

  //

  // c) src > dst, conjoint, can copy forward only

  //         [...src...]

  //   [...dst...]

  //

  // d) src > dst, disjoint, can only copy forward, because types may mismatch

  //              [...src...]

  //   [...dst...]

  //

  if (src > dst || disjoint) {

    // copy forward:

    T* cur_src = src;

    T* cur_dst = dst;

    T* src_end = src + length;

    for (; cur_src < src_end; cur_src++, cur_dst++) {

      if (!arraycopy_element<T, CHECKCAST, SATB, STOREVAL_MODE>(cur_src, cur_dst, bound, thread, ctx)) {

        return false;

      }

    }

  } else {

    // copy backward:

    T* cur_src = src + length - 1;

    T* cur_dst = dst + length - 1;

    for (; cur_src >= src; cur_src--, cur_dst--) {

      if (!arraycopy_element<T, CHECKCAST, SATB, STOREVAL_MODE>(cur_src, cur_dst, bound, thread, ctx)) {

        return false;

      }

    }

  }

  return true;

}

template <typename T, bool CHECKCAST, bool SATB, ShenandoahBarrierSet::ArrayCopyStoreValMode STOREVAL_MODE>

bool ShenandoahBarrierSet::arraycopy_element(T* cur_src, T* cur_dst, Klass* bound, Thread* const thread, ShenandoahMarkingContext* const ctx) {

  T o = RawAccess<>::oop_load(cur_src);

  if (SATB) {

    assert(ShenandoahThreadLocalData::satb_mark_queue(thread).is_active(), "Shouldn't be here otherwise");

    T prev = RawAccess<>::oop_load(cur_dst);

    if (!CompressedOops::is_null(prev)) {

      oop prev_obj = CompressedOops::decode_not_null(prev);

      switch (STOREVAL_MODE) {

      case NONE:

        break;

      case READ_BARRIER:

      case WRITE_BARRIER:

        // The write-barrier case cannot really happen. It's traversal-only and traversal

        // doesn't currently use SATB. And even if it did, it would not be fatal to just do the normal RB here.

        prev_obj = ShenandoahBarrierSet::resolve_forwarded_not_null(prev_obj);

      }

      if (!ctx->is_marked(prev_obj)) {

        ShenandoahThreadLocalData::satb_mark_queue(thread).enqueue_known_active(prev_obj);

      }

    }

  }

  if (!CompressedOops::is_null(o)) {

    oop obj = CompressedOops::decode_not_null(o);

    if (CHECKCAST) {

      assert(bound != NULL, "need element klass for checkcast");

      if (!oopDesc::is_instanceof_or_null(obj, bound)) {

        return false;

      }

    }

    switch (STOREVAL_MODE) {

    case NONE:

      break;

    case READ_BARRIER:

      obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);

      break;

    case WRITE_BARRIER:

      if (_heap->in_collection_set(obj)) {

        oop forw = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);

        if (oopDesc::equals_raw(forw, obj)) {

          forw = _heap->evacuate_object(forw, thread);

        }

        obj = forw;

      }

      enqueue(obj);

      break;

    default:

      ShouldNotReachHere();

    }

    RawAccess<IS_NOT_NULL>::oop_store(cur_dst, obj);

  } else {

    // Store null.

    RawAccess<>::oop_store(cur_dst, o);

  }

  return true;

}

// Clone barrier support

template <DecoratorSet decorators, typename BarrierSetT>

void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t size) {

  Raw::clone(src, dst, size);

  ShenandoahBarrierSet::barrier_set()->write_region(MemRegion((HeapWord*) dst, size));

}

template <DecoratorSet decorators, typename BarrierSetT>

template <typename T>

bool ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,

                                                                                         arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,

                                                                                         size_t length) {

  ShenandoahHeap* heap = ShenandoahHeap::heap();

  bool satb = ShenandoahSATBBarrier && heap->is_concurrent_mark_in_progress();

  bool checkcast = HasDecorator<decorators, ARRAYCOPY_CHECKCAST>::value;

  bool disjoint = HasDecorator<decorators, ARRAYCOPY_DISJOINT>::value;

  ArrayCopyStoreValMode storeval_mode;

  if (heap->has_forwarded_objects()) {

    if (heap->is_concurrent_traversal_in_progress()) {

      storeval_mode = WRITE_BARRIER;

    } else if (heap->is_concurrent_mark_in_progress() || heap->is_update_refs_in_progress()) {

      storeval_mode = READ_BARRIER;

    } else {

      assert(heap->is_idle() || heap->is_evacuation_in_progress(), "must not have anything in progress");

      storeval_mode = NONE; // E.g. during evac or outside cycle

    }

  } else {

    assert(heap->is_stable() || heap->is_concurrent_mark_in_progress(), "must not have anything in progress");

    storeval_mode = NONE;

  }

  if (!satb && !checkcast && storeval_mode == NONE) {

    // Short-circuit to bulk copy.

    return Raw::oop_arraycopy(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);

  }

  src_raw = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw);

  dst_raw = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw);

  Klass* bound = objArrayOop(dst_obj)->element_klass();

  ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();

  return bs->arraycopy_loop_1(src_raw, dst_raw, length, bound, checkcast, satb, disjoint, storeval_mode);

}

#endif // SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP