/*

 * Copyright (c) 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "classfile/systemDictionary.hpp"

#include "gc/shared/oopStorage.hpp"

#include "oops/access.inline.hpp"

#include "oops/oop.hpp"

#include "oops/weakHandle.inline.hpp"

#include "utilities/debug.hpp"

#include "utilities/ostream.hpp"

template <> OopStorage* WeakHandle<vm_class_loader_data>::get_storage() {

  return SystemDictionary::vm_weak_oop_storage();

}

template <WeakHandleType T>

WeakHandle<T> WeakHandle<T>::create(Handle obj) {

  assert(obj() != NULL, "no need to create weak null oop");

  oop* oop_addr = get_storage()->allocate();

  if (oop_addr == NULL) {

    vm_exit_out_of_memory(sizeof(oop*), OOM_MALLOC_ERROR, "Unable to create new weak oop handle in OopStorage");

  }

  // Create WeakHandle with address returned and store oop into it.

  RootAccess<ON_PHANTOM_OOP_REF>::oop_store(oop_addr, obj());

  return WeakHandle(oop_addr);

}

template <WeakHandleType T>

void WeakHandle<T>::release() const {

  // Only release if the pointer to the object has been created.

  if (_obj != NULL) {

    // Clear the WeakHandle.  For class loader data race, the handle may not have

    // been previously cleared by GC.

    RootAccess<ON_PHANTOM_OOP_REF>::oop_store(_obj, (oop)NULL);

    get_storage()->release(_obj);

  }

}

template <WeakHandleType T>

void WeakHandle<T>::print() const { print_on(tty); }

template <WeakHandleType T>

void WeakHandle<T>::print_on(outputStream* st) const {

  st->print("WeakHandle: " PTR_FORMAT, p2i(peek()));

}

// Provide instantiation.

template class WeakHandle<vm_class_loader_data>;