/*

 * Copyright (c) 2014, 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_implementation/g1/g1PageBasedVirtualSpace.hpp"

#include "oops/markOop.hpp"

#include "oops/oop.inline.hpp"

#include "services/memTracker.hpp"

#ifdef TARGET_OS_FAMILY_linux

# include "os_linux.inline.hpp"

#endif

#ifdef TARGET_OS_FAMILY_solaris

# include "os_solaris.inline.hpp"

#endif

#ifdef TARGET_OS_FAMILY_windows

# include "os_windows.inline.hpp"

#endif

#ifdef TARGET_OS_FAMILY_aix

# include "os_aix.inline.hpp"

#endif

#ifdef TARGET_OS_FAMILY_bsd

# include "os_bsd.inline.hpp"

#endif

#include "utilities/bitMap.inline.hpp"

G1PageBasedVirtualSpace::G1PageBasedVirtualSpace() : _low_boundary(NULL),

  _high_boundary(NULL), _committed(), _page_size(0), _special(false), _executable(false) {

}

bool G1PageBasedVirtualSpace::initialize_with_granularity(ReservedSpace rs, size_t page_size) {

  if (!rs.is_reserved()) {

    return false;  // Allocation failed.

  }

  assert(_low_boundary == NULL, "VirtualSpace already initialized");

  assert(page_size > 0, "Granularity must be non-zero.");

  _low_boundary  = rs.base();

  _high_boundary = _low_boundary + rs.size();

  _special = rs.special();

  _executable = rs.executable();

  _page_size = page_size;

  assert(_committed.size() == 0, "virtual space initialized more than once");

  uintx size_in_bits = rs.size() / page_size;

  _committed.resize(size_in_bits, /* in_resource_area */ false);

  return true;

}

G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() {

  release();

}

void G1PageBasedVirtualSpace::release() {

  // This does not release memory it never reserved.

  // Caller must release via rs.release();

  _low_boundary           = NULL;

  _high_boundary          = NULL;

  _special                = false;

  _executable             = false;

  _page_size              = 0;

  _committed.resize(0, false);

}

size_t G1PageBasedVirtualSpace::committed_size() const {

  return _committed.count_one_bits() * _page_size;

}

size_t G1PageBasedVirtualSpace::reserved_size() const {

  return pointer_delta(_high_boundary, _low_boundary, sizeof(char));

}

size_t G1PageBasedVirtualSpace::uncommitted_size()  const {

  return reserved_size() - committed_size();

}

uintptr_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const {

  return (addr - _low_boundary) / _page_size;

}

bool G1PageBasedVirtualSpace::is_area_committed(uintptr_t start, size_t size_in_pages) const {

  uintptr_t end = start + size_in_pages;

  return _committed.get_next_zero_offset(start, end) >= end;

}

bool G1PageBasedVirtualSpace::is_area_uncommitted(uintptr_t start, size_t size_in_pages) const {

  uintptr_t end = start + size_in_pages;

  return _committed.get_next_one_offset(start, end) >= end;

}

char* G1PageBasedVirtualSpace::page_start(uintptr_t index) {

  return _low_boundary + index * _page_size;

}

size_t G1PageBasedVirtualSpace::byte_size_for_pages(size_t num) {

  return num * _page_size;

}

MemRegion G1PageBasedVirtualSpace::commit(uintptr_t start, size_t size_in_pages) {

  // We need to make sure to commit all pages covered by the given area.

  guarantee(is_area_uncommitted(start, size_in_pages), "Specified area is not uncommitted");

  if (!_special) {

    os::commit_memory_or_exit(page_start(start), byte_size_for_pages(size_in_pages), _executable,

                              err_msg("Failed to commit pages from "SIZE_FORMAT" of length "SIZE_FORMAT, start, size_in_pages));

  }

  _committed.set_range(start, start + size_in_pages);

  MemRegion result((HeapWord*)page_start(start), byte_size_for_pages(size_in_pages) / HeapWordSize);

  return result;

}

MemRegion G1PageBasedVirtualSpace::uncommit(uintptr_t start, size_t size_in_pages) {

  guarantee(is_area_committed(start, size_in_pages), "checking");

  if (!_special) {

    os::uncommit_memory(page_start(start), byte_size_for_pages(size_in_pages));

  }

  _committed.clear_range(start, start + size_in_pages);

  MemRegion result((HeapWord*)page_start(start), byte_size_for_pages(size_in_pages) / HeapWordSize);

  return result;

}

bool G1PageBasedVirtualSpace::contains(const void* p) const {

  return _low_boundary <= (const char*) p && (const char*) p < _high_boundary;

}

#ifndef PRODUCT

void G1PageBasedVirtualSpace::print_on(outputStream* out) {

  out->print   ("Virtual space:");

  if (special()) out->print(" (pinned in memory)");

  out->cr();

  out->print_cr(" - committed: " SIZE_FORMAT, committed_size());

  out->print_cr(" - reserved:  " SIZE_FORMAT, reserved_size());

  out->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]",  p2i(_low_boundary), p2i(_high_boundary));

}

void G1PageBasedVirtualSpace::print() {

  print_on(tty);

}

#endif