/*
 * Copyright (c) 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.
 *
 */

#ifndef SHARE_VM_UTILITIES_TASKQUEUE_INLINE_HPP
#define SHARE_VM_UTILITIES_TASKQUEUE_INLINE_HPP

#include "utilities/debug.hpp"
#include "utilities/taskqueue.hpp"
#include "utilities/stack.inline.hpp"
#include "runtime/orderAccess.inline.hpp"

template<class E, MEMFLAGS F, unsigned int N>
bool GenericTaskQueue<E, F, N>::push_slow(E t, uint dirty_n_elems) {
  if (dirty_n_elems == N - 1) {
    // Actually means 0, so do the push.
    uint localBot = _bottom;
    // g++ complains if the volatile result of the assignment is
    // unused, so we cast the volatile away.  We cannot cast directly
    // to void, because gcc treats that as not using the result of the
    // assignment.  However, casting to E& means that we trigger an
    // unused-value warning.  So, we cast the E& to void.
    (void)const_cast<E&>(_elems[localBot] = t);
    OrderAccess::release_store(&_bottom, increment_index(localBot));
    TASKQUEUE_STATS_ONLY(stats.record_push());
    return true;
  }
  return false;
}

template<class E, MEMFLAGS F, unsigned int N> inline bool
GenericTaskQueue<E, F, N>::push(E t) {
  uint localBot = _bottom;
  assert(localBot < N, "_bottom out of range.");
  idx_t top = _age.top();
  uint dirty_n_elems = dirty_size(localBot, top);
  assert(dirty_n_elems < N, "n_elems out of range.");
  if (dirty_n_elems < max_elems()) {
    // g++ complains if the volatile result of the assignment is
    // unused, so we cast the volatile away.  We cannot cast directly
    // to void, because gcc treats that as not using the result of the
    // assignment.  However, casting to E& means that we trigger an
    // unused-value warning.  So, we cast the E& to void.
    (void) const_cast<E&>(_elems[localBot] = t);
    OrderAccess::release_store(&_bottom, increment_index(localBot));
    TASKQUEUE_STATS_ONLY(stats.record_push());
    return true;
  } else {
    return push_slow(t, dirty_n_elems);
  }
}

template <class E, MEMFLAGS F, unsigned int N>
inline bool OverflowTaskQueue<E, F, N>::push(E t)
{
  if (!taskqueue_t::push(t)) {
    overflow_stack()->push(t);
    TASKQUEUE_STATS_ONLY(stats.record_overflow(overflow_stack()->size()));
  }
  return true;
}

#endif // SHARE_VM_UTILITIES_TASKQUEUE_INLINE_HPP