/*

 * Copyright (c) 2018, 2019, 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 "logging/log.hpp"

#include "memory/metaspace.hpp"

#include "memory/metaspace/chunkAllocSequence.hpp"

#include "memory/metaspace/classLoaderMetaspace.hpp"

#include "memory/metaspace/metaspaceCommon.hpp"

#include "runtime/atomic.hpp"

#include "utilities/debug.hpp"

namespace metaspace {

ClassLoaderMetaspace::ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType space_type)

  : _lock(lock)

  , _space_type(space_type)

  , _non_class_space_manager(NULL)

  , _class_space_manager(NULL)

{

  DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_metaspace_births));

  // Initialize non-class spacemanager

  _non_class_space_manager = new SpaceManager(

      Metaspace::chunk_manager_metadata(),

      ChunkAllocSequence::alloc_sequence_by_space_type(space_type, false),

      lock);

  // If needed, initialize class spacemanager

  if (Metaspace::using_class_space()) {

    _class_space_manager = new SpaceManager(

        Metaspace::chunk_manager_class(),

        ChunkAllocSequence::alloc_sequence_by_space_type(space_type, true),

        lock);

  }

}

ClassLoaderMetaspace::~ClassLoaderMetaspace() {

  Metaspace::assert_not_frozen();

  DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_metaspace_deaths));

  delete _non_class_space_manager;

  delete _class_space_manager;

}

// Allocate word_size words from Metaspace.

MetaWord* ClassLoaderMetaspace::allocate(size_t word_size, bool is_class) {

  Metaspace::assert_not_frozen();

  DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs));

  if (is_class && Metaspace::using_class_space()) {

    return class_space_manager()->allocate(word_size);

  } else {

    return non_class_space_manager()->allocate(word_size);

  }

}

// Attempt to expand the GC threshold to be good for at least another word_size words

// and allocate. Returns NULL if failure. Used during Metaspace GC.

MetaWord* ClassLoaderMetaspace::expand_GC_threshold_and_allocate(size_t word_size, bool is_class) {

  Metaspace::assert_not_frozen();

  size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord);

  assert(delta_bytes > 0, "Must be");

  size_t before = 0;

  size_t after = 0;

  bool can_retry = true;

  MetaWord* res;

  bool incremented;

  // Each thread increments the HWM at most once. Even if the thread fails to increment

  // the HWM, an allocation is still attempted. This is because another thread must then

  // have incremented the HWM and therefore the allocation might still succeed.

  do {

    incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before, &can_retry);

    res = allocate(word_size, is_class);

  } while (!incremented && res == NULL && can_retry);

  if (incremented) {

    Metaspace::tracer()->report_gc_threshold(before, after,

                                  MetaspaceGCThresholdUpdater::ExpandAndAllocate);

    log_trace(gc, metaspace)("Increase capacity to GC from " SIZE_FORMAT " to " SIZE_FORMAT, before, after);

  }

  return res;

}

// Prematurely returns a metaspace allocation to the _block_freelists

// because it is not needed anymore.

void ClassLoaderMetaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {

  Metaspace::assert_not_frozen();

  DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_external_deallocs));

  if (is_class && Metaspace::using_class_space()) {

    class_space_manager()->deallocate(ptr, word_size);

  } else {

    non_class_space_manager()->deallocate(ptr, word_size);

  }

}