/*

 * 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

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 */

#include "precompiled.hpp"

#include "gc_implementation/parallelScavenge/psVirtualspace.hpp"

#include "runtime/os.hpp"

// PSVirtualSpace

PSVirtualSpace::PSVirtualSpace(ReservedSpace rs, size_t alignment) :

  _alignment(alignment)

{

  set_reserved(rs);

  set_committed(reserved_low_addr(), reserved_low_addr());

  DEBUG_ONLY(verify());

}

PSVirtualSpace::PSVirtualSpace(ReservedSpace rs) :

  _alignment(os::vm_page_size())

{

  set_reserved(rs);

  set_committed(reserved_low_addr(), reserved_low_addr());

  DEBUG_ONLY(verify());

}

// Deprecated.

PSVirtualSpace::PSVirtualSpace(): _alignment(os::vm_page_size()) {

}

// Deprecated.

bool PSVirtualSpace::initialize(ReservedSpace rs,

                                size_t commit_size) {

  set_reserved(rs);

  set_committed(reserved_low_addr(), reserved_low_addr());

  // Commit to initial size.

  assert(commit_size <= rs.size(), "commit_size too big");

  bool result = commit_size > 0 ? expand_by(commit_size) : true;

  DEBUG_ONLY(verify());

  return result;

}

PSVirtualSpace::~PSVirtualSpace() {

  release();

}

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

  char* const cp = (char*)p;

  return cp >= committed_low_addr() && cp < committed_high_addr();

}

void PSVirtualSpace::release() {

  DEBUG_ONLY(PSVirtualSpaceVerifier this_verifier(this));

  // This may not release memory it didn't reserve.

  // Use rs.release() to release the underlying memory instead.

  _reserved_low_addr = _reserved_high_addr = NULL;

  _committed_low_addr = _committed_high_addr = NULL;

  _special = false;

}

bool PSVirtualSpace::expand_by(size_t bytes) {

  assert(is_aligned(bytes), "arg not aligned");

  DEBUG_ONLY(PSVirtualSpaceVerifier this_verifier(this));

  if (uncommitted_size() < bytes) {

    return false;

  }

  char* const base_addr = committed_high_addr();

  bool result = special() ||

         os::commit_memory(base_addr, bytes, alignment(), !ExecMem);

  if (result) {

    _committed_high_addr += bytes;

  }

  return result;

}

bool PSVirtualSpace::shrink_by(size_t bytes) {

  assert(is_aligned(bytes), "arg not aligned");

  DEBUG_ONLY(PSVirtualSpaceVerifier this_verifier(this));

  if (committed_size() < bytes) {

    return false;

  }

  char* const base_addr = committed_high_addr() - bytes;

  bool result = special() || os::uncommit_memory(base_addr, bytes);

  if (result) {

    _committed_high_addr -= bytes;

  }

  return result;

}

size_t

PSVirtualSpace::expand_into(PSVirtualSpace* other_space, size_t bytes) {

  assert(is_aligned(bytes), "arg not aligned");

  assert(grows_up(), "this space must grow up");

  assert(other_space->grows_down(), "other space must grow down");

  assert(reserved_high_addr() == other_space->reserved_low_addr(),

         "spaces not contiguous");

  assert(special() == other_space->special(), "one space is special, the other is not");

  DEBUG_ONLY(PSVirtualSpaceVerifier this_verifier(this));

  DEBUG_ONLY(PSVirtualSpaceVerifier other_verifier(other_space));

  size_t bytes_needed = bytes;

  // First use the uncommitted region in this space.

  size_t tmp_bytes = MIN2(uncommitted_size(), bytes_needed);

  if (tmp_bytes > 0) {

    if (expand_by(tmp_bytes)) {

      bytes_needed -= tmp_bytes;

    } else {

      return 0;

    }

  }

  // Next take from the uncommitted region in the other space, and commit it.

  tmp_bytes = MIN2(other_space->uncommitted_size(), bytes_needed);

  if (tmp_bytes > 0) {

    char* const commit_base = committed_high_addr();

    if (other_space->special() ||

        os::commit_memory(commit_base, tmp_bytes, alignment(), !ExecMem)) {

      // Reduce the reserved region in the other space.

      other_space->set_reserved(other_space->reserved_low_addr() + tmp_bytes,

                                other_space->reserved_high_addr(),

                                other_space->special());

      // Grow both reserved and committed in this space.

      _reserved_high_addr += tmp_bytes;

      _committed_high_addr += tmp_bytes;

      bytes_needed -= tmp_bytes;

    } else {

      return bytes - bytes_needed;

    }

  }

  // Finally take from the already committed region in the other space.

  tmp_bytes = bytes_needed;

  if (tmp_bytes > 0) {

    // Reduce both committed and reserved in the other space.

    other_space->set_committed(other_space->committed_low_addr() + tmp_bytes,

                               other_space->committed_high_addr());

    other_space->set_reserved(other_space->reserved_low_addr() + tmp_bytes,

                              other_space->reserved_high_addr(),

                              other_space->special());

    // Grow both reserved and committed in this space.

    _reserved_high_addr += tmp_bytes;

    _committed_high_addr += tmp_bytes;

  }

  return bytes;

}

#ifndef PRODUCT

bool PSVirtualSpace::is_aligned(size_t value, size_t align) {

  const size_t tmp_value = value + align - 1;

  const size_t mask = ~(align - 1);

  return (tmp_value & mask) == value;

}

bool PSVirtualSpace::is_aligned(size_t value) const {

  return is_aligned(value, alignment());

}

bool PSVirtualSpace::is_aligned(char* value) const {

  return is_aligned((size_t)value);

}

void PSVirtualSpace::verify() const {

  assert(is_aligned(alignment(), os::vm_page_size()), "bad alignment");

  assert(is_aligned(reserved_low_addr()), "bad reserved_low_addr");

  assert(is_aligned(reserved_high_addr()), "bad reserved_high_addr");

  assert(is_aligned(committed_low_addr()), "bad committed_low_addr");

  assert(is_aligned(committed_high_addr()), "bad committed_high_addr");

  // Reserved region must be non-empty or both addrs must be 0.

  assert(reserved_low_addr() < reserved_high_addr() ||

         reserved_low_addr() == NULL && reserved_high_addr() == NULL,

         "bad reserved addrs");

  assert(committed_low_addr() <= committed_high_addr(), "bad committed addrs");

  if (grows_up()) {

    assert(reserved_low_addr() == committed_low_addr(), "bad low addrs");

    assert(reserved_high_addr() >= committed_high_addr(), "bad high addrs");

  } else {

    assert(reserved_high_addr() == committed_high_addr(), "bad high addrs");

    assert(reserved_low_addr() <= committed_low_addr(), "bad low addrs");

  }

}

void PSVirtualSpace::print() const {

  gclog_or_tty->print_cr("virtual space [" PTR_FORMAT "]:  alignment="

                         SIZE_FORMAT "K grows %s%s",

                         p2i(this), alignment() / K, grows_up() ? "up" : "down",

                         special() ? " (pinned in memory)" : "");

  gclog_or_tty->print_cr("    reserved=" SIZE_FORMAT "K"

                         " [" PTR_FORMAT "," PTR_FORMAT "]"

                         " committed=" SIZE_FORMAT "K"

                         " [" PTR_FORMAT "," PTR_FORMAT "]",

                         reserved_size() / K,

                         p2i(reserved_low_addr()), p2i(reserved_high_addr()),

                         committed_size() / K,

                         p2i(committed_low_addr()), p2i(committed_high_addr()));

}

#endif // #ifndef PRODUCT

void PSVirtualSpace::print_space_boundaries_on(outputStream* st) const {

  st->print_cr(" [" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT ")",

               p2i(low_boundary()), p2i(high()), p2i(high_boundary()));

}

PSVirtualSpaceHighToLow::PSVirtualSpaceHighToLow(ReservedSpace rs,

                                                 size_t alignment) :

  PSVirtualSpace(alignment)

{

  set_reserved(rs);

  set_committed(reserved_high_addr(), reserved_high_addr());

  DEBUG_ONLY(verify());

}

PSVirtualSpaceHighToLow::PSVirtualSpaceHighToLow(ReservedSpace rs) {

  set_reserved(rs);

  set_committed(reserved_high_addr(), reserved_high_addr());

  DEBUG_ONLY(verify());

}

bool PSVirtualSpaceHighToLow::expand_by(size_t bytes) {

  assert(is_aligned(bytes), "arg not aligned");

  DEBUG_ONLY(PSVirtualSpaceVerifier this_verifier(this));

  if (uncommitted_size() < bytes) {

    return false;

  }

  char* const base_addr = committed_low_addr() - bytes;

  bool result = special() ||

         os::commit_memory(base_addr, bytes, alignment(), !ExecMem);

  if (result) {

    _committed_low_addr -= bytes;

  }

  return result;

}

bool PSVirtualSpaceHighToLow::shrink_by(size_t bytes) {

  assert(is_aligned(bytes), "arg not aligned");

  DEBUG_ONLY(PSVirtualSpaceVerifier this_verifier(this));

  if (committed_size() < bytes) {

    return false;

  }

  char* const base_addr = committed_low_addr();

  bool result = special() || os::uncommit_memory(base_addr, bytes);

  if (result) {

    _committed_low_addr += bytes;

  }

  return result;

}

size_t PSVirtualSpaceHighToLow::expand_into(PSVirtualSpace* other_space,

                                            size_t bytes) {

  assert(is_aligned(bytes), "arg not aligned");

  assert(grows_down(), "this space must grow down");

  assert(other_space->grows_up(), "other space must grow up");

  assert(reserved_low_addr() == other_space->reserved_high_addr(),

         "spaces not contiguous");

  assert(special() == other_space->special(), "one space is special in memory, the other is not");

  DEBUG_ONLY(PSVirtualSpaceVerifier this_verifier(this));

  DEBUG_ONLY(PSVirtualSpaceVerifier other_verifier(other_space));

  size_t bytes_needed = bytes;

  // First use the uncommitted region in this space.

  size_t tmp_bytes = MIN2(uncommitted_size(), bytes_needed);

  if (tmp_bytes > 0) {

    if (expand_by(tmp_bytes)) {

      bytes_needed -= tmp_bytes;

    } else {

      return 0;

    }

  }

  // Next take from the uncommitted region in the other space, and commit it.

  tmp_bytes = MIN2(other_space->uncommitted_size(), bytes_needed);

  if (tmp_bytes > 0) {

    char* const commit_base = committed_low_addr() - tmp_bytes;

    if (other_space->special() ||

        os::commit_memory(commit_base, tmp_bytes, alignment(), !ExecMem)) {

      // Reduce the reserved region in the other space.

      other_space->set_reserved(other_space->reserved_low_addr(),

                                other_space->reserved_high_addr() - tmp_bytes,

                                other_space->special());

      // Grow both reserved and committed in this space.

      _reserved_low_addr -= tmp_bytes;

      _committed_low_addr -= tmp_bytes;

      bytes_needed -= tmp_bytes;

    } else {

      return bytes - bytes_needed;

    }

  }

  // Finally take from the already committed region in the other space.

  tmp_bytes = bytes_needed;

  if (tmp_bytes > 0) {

    // Reduce both committed and reserved in the other space.

    other_space->set_committed(other_space->committed_low_addr(),

                               other_space->committed_high_addr() - tmp_bytes);

    other_space->set_reserved(other_space->reserved_low_addr(),

                              other_space->reserved_high_addr() - tmp_bytes,

                              other_space->special());

    // Grow both reserved and committed in this space.

    _reserved_low_addr -= tmp_bytes;

    _committed_low_addr -= tmp_bytes;

  }

  return bytes;

}

void

PSVirtualSpaceHighToLow::print_space_boundaries_on(outputStream* st) const {

  st->print_cr(" (" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT "]",

               p2i(high_boundary()), p2i(low()), p2i(low_boundary()));

}