/*

 * Copyright (c) 2011, 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/heapRegionSet.inline.hpp"

size_t HeapRegionSetBase::_unrealistically_long_length = 0;

//////////////////// HeapRegionSetBase ////////////////////

void HeapRegionSetBase::set_unrealistically_long_length(size_t len) {

  guarantee(_unrealistically_long_length == 0, "should only be set once");

  _unrealistically_long_length = len;

}

size_t HeapRegionSetBase::calculate_region_num(HeapRegion* hr) {

  assert(hr->startsHumongous(), "pre-condition");

  assert(hr->capacity() % HeapRegion::GrainBytes == 0, "invariant");

  size_t region_num = hr->capacity() >> HeapRegion::LogOfHRGrainBytes;

  assert(region_num > 0, "sanity");

  return region_num;

}

void HeapRegionSetBase::fill_in_ext_msg(hrs_ext_msg* msg, const char* message) {

  msg->append("[%s] %s "

              "ln: "SIZE_FORMAT" rn: "SIZE_FORMAT" "

              "cy: "SIZE_FORMAT" ud: "SIZE_FORMAT,

              name(), message, length(), region_num(),

              total_capacity_bytes(), total_used_bytes());

  fill_in_ext_msg_extra(msg);

}

bool HeapRegionSetBase::verify_region(HeapRegion* hr,

                                  HeapRegionSetBase* expected_containing_set) {

  const char* error_message = NULL;

  if (!regions_humongous()) {

    if (hr->isHumongous()) {

      error_message = "the region should not be humongous";

    }

  } else {

    if (!hr->isHumongous() || !hr->startsHumongous()) {

      error_message = "the region should be 'starts humongous'";

    }

  }

  if (!regions_empty()) {

    if (hr->is_empty()) {

      error_message = "the region should not be empty";

    }

  } else {

    if (!hr->is_empty()) {

      error_message = "the region should be empty";

    }

  }

#ifdef ASSERT

  // The _containing_set field is only available when ASSERT is defined.

  if (hr->containing_set() != expected_containing_set) {

    error_message = "inconsistent containing set found";

  }

#endif // ASSERT

  const char* extra_error_message = verify_region_extra(hr);

  if (extra_error_message != NULL) {

    error_message = extra_error_message;

  }

  if (error_message != NULL) {

    outputStream* out = tty;

    out->cr();

    out->print_cr("## [%s] %s", name(), error_message);

    out->print_cr("## Offending Region: "PTR_FORMAT, hr);

    out->print_cr("   "HR_FORMAT, HR_FORMAT_PARAMS(hr));

#ifdef ASSERT

    out->print_cr("   containing set: "PTR_FORMAT, hr->containing_set());

#endif // ASSERT

    out->print_cr("## Offending Region Set: "PTR_FORMAT, this);

    print_on(out);

    return false;

  } else {

    return true;

  }

}

void HeapRegionSetBase::verify() {

  // It's important that we also observe the MT safety protocol even

  // for the verification calls. If we do verification without the

  // appropriate locks and the set changes underneath our feet

  // verification might fail and send us on a wild goose chase.

  hrs_assert_mt_safety_ok(this);

  guarantee(( is_empty() && length() == 0 && region_num() == 0 &&

              total_used_bytes() == 0 && total_capacity_bytes() == 0) ||

            (!is_empty() && length() >= 0 && region_num() >= 0 &&

              total_used_bytes() >= 0 && total_capacity_bytes() >= 0),

            hrs_ext_msg(this, "invariant"));

  guarantee((!regions_humongous() && region_num() == length()) ||

            ( regions_humongous() && region_num() >= length()),

            hrs_ext_msg(this, "invariant"));

  guarantee(!regions_empty() || total_used_bytes() == 0,

            hrs_ext_msg(this, "invariant"));

  guarantee(total_used_bytes() <= total_capacity_bytes(),

            hrs_ext_msg(this, "invariant"));

}

void HeapRegionSetBase::verify_start() {

  // See comment in verify() about MT safety and verification.

  hrs_assert_mt_safety_ok(this);

  assert(!_verify_in_progress,

         hrs_ext_msg(this, "verification should not be in progress"));

  // Do the basic verification first before we do the checks over the regions.

  HeapRegionSetBase::verify();

  _calc_length               = 0;

  _calc_region_num           = 0;

  _calc_total_capacity_bytes = 0;

  _calc_total_used_bytes     = 0;

  _verify_in_progress        = true;

}

void HeapRegionSetBase::verify_next_region(HeapRegion* hr) {

  // See comment in verify() about MT safety and verification.

  hrs_assert_mt_safety_ok(this);

  assert(_verify_in_progress,

         hrs_ext_msg(this, "verification should be in progress"));

  guarantee(verify_region(hr, this), hrs_ext_msg(this, "region verification"));

  _calc_length               += 1;

  if (!hr->isHumongous()) {

    _calc_region_num         += 1;

  } else {

    _calc_region_num         += calculate_region_num(hr);

  }

  _calc_total_capacity_bytes += hr->capacity();

  _calc_total_used_bytes     += hr->used();

}

void HeapRegionSetBase::verify_end() {

  // See comment in verify() about MT safety and verification.

  hrs_assert_mt_safety_ok(this);

  assert(_verify_in_progress,

         hrs_ext_msg(this, "verification should be in progress"));

  guarantee(length() == _calc_length,

            hrs_err_msg("[%s] length: "SIZE_FORMAT" should be == "

                        "calc length: "SIZE_FORMAT,

                        name(), length(), _calc_length));

  guarantee(region_num() == _calc_region_num,

            hrs_err_msg("[%s] region num: "SIZE_FORMAT" should be == "

                        "calc region num: "SIZE_FORMAT,

                        name(), region_num(), _calc_region_num));

  guarantee(total_capacity_bytes() == _calc_total_capacity_bytes,

            hrs_err_msg("[%s] capacity bytes: "SIZE_FORMAT" should be == "

                        "calc capacity bytes: "SIZE_FORMAT,

                        name(),

                        total_capacity_bytes(), _calc_total_capacity_bytes));

  guarantee(total_used_bytes() == _calc_total_used_bytes,

            hrs_err_msg("[%s] used bytes: "SIZE_FORMAT" should be == "

                        "calc used bytes: "SIZE_FORMAT,

                        name(), total_used_bytes(), _calc_total_used_bytes));

  _verify_in_progress = false;

}

void HeapRegionSetBase::print_on(outputStream* out, bool print_contents) {

  out->cr();

  out->print_cr("Set: %s ("PTR_FORMAT")", name(), this);

  out->print_cr("  Region Assumptions");

  out->print_cr("    humongous         : %s", BOOL_TO_STR(regions_humongous()));

  out->print_cr("    empty             : %s", BOOL_TO_STR(regions_empty()));

  out->print_cr("  Attributes");

  out->print_cr("    length            : "SIZE_FORMAT_W(14), length());

  out->print_cr("    region num        : "SIZE_FORMAT_W(14), region_num());

  out->print_cr("    total capacity    : "SIZE_FORMAT_W(14)" bytes",

                total_capacity_bytes());

  out->print_cr("    total used        : "SIZE_FORMAT_W(14)" bytes",

                total_used_bytes());

}

void HeapRegionSetBase::clear() {

  _length           = 0;

  _region_num       = 0;

  _total_used_bytes = 0;

}

HeapRegionSetBase::HeapRegionSetBase(const char* name)

  : _name(name), _verify_in_progress(false),

    _calc_length(0), _calc_region_num(0),

    _calc_total_capacity_bytes(0), _calc_total_used_bytes(0) { }

//////////////////// HeapRegionSet ////////////////////

void HeapRegionSet::update_from_proxy(HeapRegionSet* proxy_set) {

  hrs_assert_mt_safety_ok(this);

  hrs_assert_mt_safety_ok(proxy_set);

  hrs_assert_sets_match(this, proxy_set);

  verify_optional();

  proxy_set->verify_optional();

  if (proxy_set->is_empty()) return;

  assert(proxy_set->length() <= _length,

         hrs_err_msg("[%s] proxy set length: "SIZE_FORMAT" "

                     "should be <= length: "SIZE_FORMAT,

                     name(), proxy_set->length(), _length));

  _length -= proxy_set->length();

  assert(proxy_set->region_num() <= _region_num,

         hrs_err_msg("[%s] proxy set region num: "SIZE_FORMAT" "

                     "should be <= region num: "SIZE_FORMAT,

                     name(), proxy_set->region_num(), _region_num));

  _region_num -= proxy_set->region_num();

  assert(proxy_set->total_used_bytes() <= _total_used_bytes,

         hrs_err_msg("[%s] proxy set used bytes: "SIZE_FORMAT" "

                     "should be <= used bytes: "SIZE_FORMAT,

                     name(), proxy_set->total_used_bytes(),

                     _total_used_bytes));

  _total_used_bytes -= proxy_set->total_used_bytes();

  proxy_set->clear();

  verify_optional();

  proxy_set->verify_optional();

}

//////////////////// HeapRegionLinkedList ////////////////////

void HeapRegionLinkedList::fill_in_ext_msg_extra(hrs_ext_msg* msg) {

  msg->append(" hd: "PTR_FORMAT" tl: "PTR_FORMAT, head(), tail());

}

void HeapRegionLinkedList::add_as_head(HeapRegionLinkedList* from_list) {

  hrs_assert_mt_safety_ok(this);

  hrs_assert_mt_safety_ok(from_list);

  verify_optional();

  from_list->verify_optional();

  if (from_list->is_empty()) return;

#ifdef ASSERT

  HeapRegionLinkedListIterator iter(from_list);

  while (iter.more_available()) {

    HeapRegion* hr = iter.get_next();

    // In set_containing_set() we check that we either set the value

    // from NULL to non-NULL or vice versa to catch bugs. So, we have

    // to NULL it first before setting it to the value.

    hr->set_containing_set(NULL);

    hr->set_containing_set(this);

  }

#endif // ASSERT

  if (_head != NULL) {

    assert(length() >  0 && _tail != NULL, hrs_ext_msg(this, "invariant"));

    from_list->_tail->set_next(_head);

  } else {

    assert(length() == 0 && _head == NULL, hrs_ext_msg(this, "invariant"));

    _tail = from_list->_tail;

  }

  _head = from_list->_head;

  _length           += from_list->length();

  _region_num       += from_list->region_num();

  _total_used_bytes += from_list->total_used_bytes();

  from_list->clear();

  verify_optional();

  from_list->verify_optional();

}

void HeapRegionLinkedList::add_as_tail(HeapRegionLinkedList* from_list) {

  hrs_assert_mt_safety_ok(this);

  hrs_assert_mt_safety_ok(from_list);

  verify_optional();

  from_list->verify_optional();

  if (from_list->is_empty()) return;

#ifdef ASSERT

  HeapRegionLinkedListIterator iter(from_list);

  while (iter.more_available()) {

    HeapRegion* hr = iter.get_next();

    // In set_containing_set() we check that we either set the value

    // from NULL to non-NULL or vice versa to catch bugs. So, we have

    // to NULL it first before setting it to the value.

    hr->set_containing_set(NULL);

    hr->set_containing_set(this);

  }

#endif // ASSERT

  if (_tail != NULL) {

    assert(length() >  0 && _head != NULL, hrs_ext_msg(this, "invariant"));

    _tail->set_next(from_list->_head);

  } else {

    assert(length() == 0 && _head == NULL, hrs_ext_msg(this, "invariant"));

    _head = from_list->_head;

  }

  _tail = from_list->_tail;

  _length           += from_list->length();

  _region_num       += from_list->region_num();

  _total_used_bytes += from_list->total_used_bytes();

  from_list->clear();

  verify_optional();

  from_list->verify_optional();

}

void HeapRegionLinkedList::remove_all() {

  hrs_assert_mt_safety_ok(this);

  verify_optional();

  HeapRegion* curr = _head;

  while (curr != NULL) {

    hrs_assert_region_ok(this, curr, this);

    HeapRegion* next = curr->next();

    curr->set_next(NULL);

    curr->set_containing_set(NULL);

    curr = next;

  }

  clear();

  verify_optional();

}

void HeapRegionLinkedList::remove_all_pending(size_t target_count) {

  hrs_assert_mt_safety_ok(this);

  assert(target_count > 1, hrs_ext_msg(this, "pre-condition"));

  assert(!is_empty(), hrs_ext_msg(this, "pre-condition"));

  verify_optional();

  DEBUG_ONLY(size_t old_length = length();)

  HeapRegion* curr = _head;

  HeapRegion* prev = NULL;

  size_t count = 0;

  while (curr != NULL) {

    hrs_assert_region_ok(this, curr, this);

    HeapRegion* next = curr->next();

    if (curr->pending_removal()) {

      assert(count < target_count,

             hrs_err_msg("[%s] should not come across more regions "

                         "pending for removal than target_count: "SIZE_FORMAT,

                         name(), target_count));

      if (prev == NULL) {

        assert(_head == curr, hrs_ext_msg(this, "invariant"));

        _head = next;

      } else {

        assert(_head != curr, hrs_ext_msg(this, "invariant"));

        prev->set_next(next);

      }

      if (next == NULL) {

        assert(_tail == curr, hrs_ext_msg(this, "invariant"));

        _tail = prev;

      } else {

        assert(_tail != curr, hrs_ext_msg(this, "invariant"));

      }

      curr->set_next(NULL);

      remove_internal(curr);

      curr->set_pending_removal(false);

      count += 1;

      // If we have come across the target number of regions we can

      // just bail out. However, for debugging purposes, we can just

      // carry on iterating to make sure there are not more regions

      // tagged with pending removal.

      DEBUG_ONLY(if (count == target_count) break;)

    } else {

      prev = curr;

    }

    curr = next;

  }

  assert(count == target_count,

         hrs_err_msg("[%s] count: "SIZE_FORMAT" should be == "

                     "target_count: "SIZE_FORMAT, name(), count, target_count));

  assert(length() + target_count == old_length,

         hrs_err_msg("[%s] new length should be consistent "

                     "new length: "SIZE_FORMAT" old length: "SIZE_FORMAT" "

                     "target_count: "SIZE_FORMAT,

                     name(), length(), old_length, target_count));

  verify_optional();

}

void HeapRegionLinkedList::verify() {

  // See comment in HeapRegionSetBase::verify() about MT safety and

  // verification.

  hrs_assert_mt_safety_ok(this);

  // This will also do the basic verification too.

  verify_start();

  HeapRegion* curr  = _head;

  HeapRegion* prev1 = NULL;

  HeapRegion* prev0 = NULL;

  size_t      count = 0;

  while (curr != NULL) {

    verify_next_region(curr);

    count += 1;

    guarantee(count < _unrealistically_long_length,

              hrs_err_msg("[%s] the calculated length: "SIZE_FORMAT" "

                          "seems very long, is there maybe a cycle? "

                          "curr: "PTR_FORMAT" prev0: "PTR_FORMAT" "

                          "prev1: "PTR_FORMAT" length: "SIZE_FORMAT,

                          name(), count, curr, prev0, prev1, length()));

    prev1 = prev0;

    prev0 = curr;

    curr  = curr->next();

  }

  guarantee(_tail == prev0, hrs_ext_msg(this, "post-condition"));

  verify_end();

}

void HeapRegionLinkedList::clear() {

  HeapRegionSetBase::clear();

  _head = NULL;

  _tail = NULL;

}

void HeapRegionLinkedList::print_on(outputStream* out, bool print_contents) {

  HeapRegionSetBase::print_on(out, print_contents);

  out->print_cr("  Linking");

  out->print_cr("    head              : "PTR_FORMAT, _head);

  out->print_cr("    tail              : "PTR_FORMAT, _tail);

  if (print_contents) {

    out->print_cr("  Contents");

    HeapRegionLinkedListIterator iter(this);

    while (iter.more_available()) {

      HeapRegion* hr = iter.get_next();

      hr->print_on(out);

    }

  }

}