/*

 * Copyright (c) 2015, 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 "gc/z/zAddress.inline.hpp"

#include "gc/z/zVirtualMemory.hpp"

#include "logging/log.hpp"

#include <sys/mman.h>

#include <sys/types.h>

static void unmap(uintptr_t start, size_t size) {

  const int res = munmap((void*)start, size);

  assert(res == 0, "Failed to unmap memory");

}

static bool map(uintptr_t start, size_t size) {

  const void* const res = mmap((void*)start, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0);

  if (res == MAP_FAILED) {

    // Failed to reserve memory

    return false;

  }

  if ((uintptr_t)res != start) {

    // Failed to reserve memory at the requested address

    return false;

  }

  // Success

  return true;

}

bool ZVirtualMemoryManager::reserve_platform(uintptr_t start, size_t size) {

  // Reserve address views

  const uintptr_t marked0 = ZAddress::marked0(start);

  const uintptr_t marked1 = ZAddress::marked1(start);

  const uintptr_t remapped = ZAddress::remapped(start);

  if (!map(marked0, size)) {

    return false;

  }

  if (!map(marked1, size)) {

    unmap(marked0, size);

    return false;

  }

  if (!map(remapped, size)) {

    unmap(marked0, size);

    unmap(marked1, size);

    return false;

  }

  // Register address views with native memory tracker

  nmt_reserve(marked0, size);

  nmt_reserve(marked1, size);

  nmt_reserve(remapped, size);

  return true;

}