jdk

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/*
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 * Copyright (c) 2001, 2023, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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#include "precompiled.hpp"
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#include "gc/shared/collectedHeap.hpp"
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#include "gc/shared/gc_globals.hpp"
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#include "gc/shared/plab.inline.hpp"
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#include "gc/shared/threadLocalAllocBuffer.hpp"
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#include "gc/shared/tlab_globals.hpp"
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#include "logging/log.hpp"
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#include "memory/universe.hpp"
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#include "oops/oop.inline.hpp"
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#include "runtime/globals_extension.hpp"
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size_t PLAB::min_size() {
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  // Make sure that we return something that is larger than AlignmentReserve
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  return align_object_size(MAX2(MinTLABSize / HeapWordSize, (size_t)oopDesc::header_size())) + CollectedHeap::lab_alignment_reserve();
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}
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size_t PLAB::max_size() {
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  return ThreadLocalAllocBuffer::max_size();
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}
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void PLAB::startup_initialization() {
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  if (!FLAG_IS_DEFAULT(MinTLABSize)) {
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    if (FLAG_IS_DEFAULT(YoungPLABSize)) {
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      FLAG_SET_ERGO(YoungPLABSize, MAX2(ThreadLocalAllocBuffer::min_size(), YoungPLABSize));
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    }
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    if (FLAG_IS_DEFAULT(OldPLABSize)) {
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      FLAG_SET_ERGO(OldPLABSize, MAX2(ThreadLocalAllocBuffer::min_size(), OldPLABSize));
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    }
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  }
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  uint obj_alignment = checked_cast<uint>(ObjectAlignmentInBytes / HeapWordSize);
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  if (!is_aligned(YoungPLABSize, obj_alignment)) {
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    FLAG_SET_ERGO(YoungPLABSize, align_up(YoungPLABSize, obj_alignment));
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  }
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  if (!is_aligned(OldPLABSize, obj_alignment)) {
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    FLAG_SET_ERGO(OldPLABSize, align_up(OldPLABSize, obj_alignment));
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  }
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}
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PLAB::PLAB(size_t desired_plab_sz_) :
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  _word_sz(desired_plab_sz_), _bottom(nullptr), _top(nullptr),
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  _end(nullptr), _hard_end(nullptr), _allocated(0), _wasted(0), _undo_wasted(0)
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{
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  assert(min_size() > CollectedHeap::lab_alignment_reserve(),
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         "Minimum PLAB size " SIZE_FORMAT " must be larger than alignment reserve " SIZE_FORMAT " "
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         "to be able to contain objects", min_size(), CollectedHeap::lab_alignment_reserve());
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}
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void PLAB::flush_and_retire_stats(PLABStats* stats) {
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  // Retire the last allocation buffer.
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  size_t unused = retire_internal();
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  // Now flush the statistics.
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  stats->add_allocated(_allocated);
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  stats->add_wasted(_wasted);
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  stats->add_undo_wasted(_undo_wasted);
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  stats->add_unused(unused);
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  // Since we have flushed the stats we need to clear  the _allocated and _wasted
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  // fields in case somebody retains an instance of this over GCs. Not doing so
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  // will artificially inflate the values in the statistics.
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  _allocated   = 0;
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  _wasted      = 0;
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  _undo_wasted = 0;
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}
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void PLAB::retire() {
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  _wasted += retire_internal();
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}
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size_t PLAB::retire_internal() {
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  size_t result = 0;
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  if (_top < _hard_end) {
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    Universe::heap()->fill_with_dummy_object(_top, _hard_end, true);
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    result += invalidate();
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  }
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  return result;
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}
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void PLAB::add_undo_waste(HeapWord* obj, size_t word_sz) {
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  Universe::heap()->fill_with_dummy_object(obj, obj + word_sz, true);
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  _undo_wasted += word_sz;
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}
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void PLAB::undo_last_allocation(HeapWord* obj, size_t word_sz) {
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  assert(pointer_delta(_top, _bottom) >= word_sz, "Bad undo");
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  assert(pointer_delta(_top, obj) == word_sz, "Bad undo");
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  _top = obj;
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}
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void PLAB::undo_allocation(HeapWord* obj, size_t word_sz) {
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  // Is the alloc in the current alloc buffer?
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  if (contains(obj)) {
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    assert(contains(obj + word_sz - 1),
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      "should contain whole object");
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    undo_last_allocation(obj, word_sz);
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  } else {
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    add_undo_waste(obj, word_sz);
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  }
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}
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