/*

 * 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/zGlobals.hpp"

#include "gc/z/zVirtualMemory.inline.hpp"

#include "logging/log.hpp"

#include "services/memTracker.hpp"

ZVirtualMemoryManager::ZVirtualMemoryManager(size_t max_capacity) :

    _manager(),

    _initialized(false) {

  // Check max supported heap size

  if (max_capacity > ZAddressOffsetMax) {

    log_error(gc)("Java heap too large (max supported heap size is " SIZE_FORMAT "G)",

                  ZAddressOffsetMax / G);

    return;

  }

  log_info(gc, init)("Address Space: " SIZE_FORMAT "T", ZAddressOffsetMax / K / G);

  // Reserve address space

  if (reserve(0, ZAddressOffsetMax) < max_capacity) {

    log_error(gc)("Failed to reserve address space for Java heap");

    return;

  }

  // Successfully initialized

  _initialized = true;

}

size_t ZVirtualMemoryManager::reserve(uintptr_t start, size_t size) {

  if (size < ZGranuleSize) {

    // Too small

    return 0;

  }

  if (!reserve_platform(start, size)) {

    const size_t half = size / 2;

    return reserve(start, half) + reserve(start + half, half);

  }

  // Make the address range free

  _manager.free(start, size);

  return size;

}

void ZVirtualMemoryManager::nmt_reserve(uintptr_t start, size_t size) {

  MemTracker::record_virtual_memory_reserve((void*)start, size, CALLER_PC);

  MemTracker::record_virtual_memory_type((void*)start, mtJavaHeap);

}

bool ZVirtualMemoryManager::is_initialized() const {

  return _initialized;

}

ZVirtualMemory ZVirtualMemoryManager::alloc(size_t size, bool alloc_from_front) {

  uintptr_t start;

  if (alloc_from_front || size <= ZPageSizeSmall) {

    // Small page

    start = _manager.alloc_from_front(size);

  } else {

    // Medium/Large page

    start = _manager.alloc_from_back(size);

  }

  return ZVirtualMemory(start, size);

}

void ZVirtualMemoryManager::free(const ZVirtualMemory& vmem) {

  _manager.free(vmem.start(), vmem.size());

}