/*

 * Copyright (c) 2019, SAP SE. All rights reserved.

 * Copyright (c) 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 "memory/metaspace/commitLimiter.hpp"

#include "memory/metaspace.hpp"

#include "utilities/debug.hpp"

#include "utilities/globalDefinitions.hpp"

namespace metaspace {

// Returns the size, in words, by which we may expand the metaspace committed area without:

// - _cap == 0: hitting GC threshold or the MaxMetaspaceSize

// - _cap > 0: hitting cap (this is just for testing purposes)

size_t CommitLimiter::possible_expansion_words() const {

  if (_cap > 0) { // Testing.

    assert(_cnt.get() <= _cap, "Beyond limit?");

    return _cap - _cnt.get();

  }

  assert(_cnt.get() * BytesPerWord <= MaxMetaspaceSize, "Beyond limit?");

  const size_t words_left_below_max = MaxMetaspaceSize / BytesPerWord - _cnt.get();

  const size_t words_left_below_gc_threshold = MetaspaceGC::allowed_expansion();

  return MIN2(words_left_below_max, words_left_below_gc_threshold);

}

static CommitLimiter g_global_limiter(0);

// Returns the global metaspace commit counter

CommitLimiter* CommitLimiter::globalLimiter() {

  return &g_global_limiter;

}

} // namespace metaspace