| /* |
| * Copyright (c) 2012, 2016, 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 "memory/allocation.hpp" |
| #include "memory/metachunk.hpp" |
| #include "utilities/align.hpp" |
| #include "utilities/copy.hpp" |
| #include "utilities/debug.hpp" |
| |
| class VirtualSpaceNode; |
| |
| size_t Metachunk::object_alignment() { |
| // Must align pointers and sizes to 8, |
| // so that 64 bit types get correctly aligned. |
| const size_t alignment = 8; |
| |
| // Make sure that the Klass alignment also agree. |
| STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes); |
| |
| return alignment; |
| } |
| |
| size_t Metachunk::overhead() { |
| return align_up(sizeof(Metachunk), object_alignment()) / BytesPerWord; |
| } |
| |
| // Metachunk methods |
| |
| Metachunk::Metachunk(size_t word_size, |
| VirtualSpaceNode* container) |
| : Metabase<Metachunk>(word_size), |
| _top(NULL), |
| _container(container) |
| { |
| _top = initial_top(); |
| #ifdef ASSERT |
| set_is_tagged_free(false); |
| mangle(uninitMetaWordVal); |
| #endif |
| } |
| |
| MetaWord* Metachunk::allocate(size_t word_size) { |
| MetaWord* result = NULL; |
| // If available, bump the pointer to allocate. |
| if (free_word_size() >= word_size) { |
| result = _top; |
| _top = _top + word_size; |
| } |
| return result; |
| } |
| |
| // _bottom points to the start of the chunk including the overhead. |
| size_t Metachunk::used_word_size() const { |
| return pointer_delta(_top, bottom(), sizeof(MetaWord)); |
| } |
| |
| size_t Metachunk::free_word_size() const { |
| return pointer_delta(end(), _top, sizeof(MetaWord)); |
| } |
| |
| void Metachunk::print_on(outputStream* st) const { |
| st->print_cr("Metachunk:" |
| " bottom " PTR_FORMAT " top " PTR_FORMAT |
| " end " PTR_FORMAT " size " SIZE_FORMAT, |
| p2i(bottom()), p2i(_top), p2i(end()), word_size()); |
| if (Verbose) { |
| st->print_cr(" used " SIZE_FORMAT " free " SIZE_FORMAT, |
| used_word_size(), free_word_size()); |
| } |
| } |
| |
| #ifndef PRODUCT |
| void Metachunk::mangle(juint word_value) { |
| // Overwrite the payload of the chunk and not the links that |
| // maintain list of chunks. |
| HeapWord* start = (HeapWord*)initial_top(); |
| size_t size = word_size() - overhead(); |
| Copy::fill_to_words(start, size, word_value); |
| } |
| #endif // PRODUCT |
| |
| void Metachunk::verify() { |
| #ifdef ASSERT |
| // Cannot walk through the blocks unless the blocks have |
| // headers with sizes. |
| assert(bottom() <= _top && |
| _top <= (MetaWord*)end(), |
| "Chunk has been smashed"); |
| #endif |
| return; |
| } |
| |