jmasa@4327: /*
drchase@6680:  * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
jmasa@4327:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jmasa@4327:  *
jmasa@4327:  * This code is free software; you can redistribute it and/or modify it
jmasa@4327:  * under the terms of the GNU General Public License version 2 only, as
jmasa@4327:  * published by the Free Software Foundation.
jmasa@4327:  *
jmasa@4327:  * This code is distributed in the hope that it will be useful, but WITHOUT
jmasa@4327:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jmasa@4327:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jmasa@4327:  * version 2 for more details (a copy is included in the LICENSE file that
jmasa@4327:  * accompanied this code).
jmasa@4327:  *
jmasa@4327:  * You should have received a copy of the GNU General Public License version
jmasa@4327:  * 2 along with this work; if not, write to the Free Software Foundation,
jmasa@4327:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jmasa@4327:  *
jmasa@4327:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jmasa@4327:  * or visit www.oracle.com if you need additional information or have any
jmasa@4327:  * questions.
jmasa@4327:  *
jmasa@4327:  */
jmasa@4327: 
jmasa@4327: #include "precompiled.hpp"
jmasa@4327: #include "memory/allocation.hpp"
jmasa@4327: #include "memory/metachunk.hpp"
jmasa@4327: #include "utilities/copy.hpp"
jmasa@4327: #include "utilities/debug.hpp"
jmasa@4327: 
drchase@6680: PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
drchase@6680: 
jmasa@5007: class VirtualSpaceNode;
jmasa@4327: 
jmasa@4327: const size_t metadata_chunk_initialize = 0xf7f7f7f7;
jmasa@4327: 
stefank@5941: size_t Metachunk::object_alignment() {
stefank@5942:   // Must align pointers and sizes to 8,
stefank@5942:   // so that 64 bit types get correctly aligned.
stefank@5942:   const size_t alignment = 8;
stefank@5942: 
stefank@5942:   // Make sure that the Klass alignment also agree.
stefank@5942:   STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes);
stefank@5942: 
stefank@5942:   return alignment;
stefank@5941: }
stefank@5941: 
stefank@5941: size_t Metachunk::overhead() {
stefank@5941:   return align_size_up(sizeof(Metachunk), object_alignment()) / BytesPerWord;
stefank@5941: }
jmasa@4327: 
jmasa@4327: // Metachunk methods
jmasa@4327: 
jmasa@5007: Metachunk::Metachunk(size_t word_size,
stefank@5941:                      VirtualSpaceNode* container)
stefank@5941:     : Metabase<Metachunk>(word_size),
jmasa@5007:     _top(NULL),
jmasa@5007:     _container(container)
jmasa@5007: {
stefank@5941:   _top = initial_top();
jmasa@4327: #ifdef ASSERT
stefank@5941:   set_is_tagged_free(false);
jmasa@5007:   size_t data_word_size = pointer_delta(end(),
stefank@5941:                                         _top,
jmasa@5007:                                         sizeof(MetaWord));
stefank@5941:   Copy::fill_to_words((HeapWord*)_top,
jmasa@5007:                       data_word_size,
jmasa@5007:                       metadata_chunk_initialize);
jmasa@4327: #endif
jmasa@4327: }
jmasa@4327: 
jmasa@4327: MetaWord* Metachunk::allocate(size_t word_size) {
jmasa@4327:   MetaWord* result = NULL;
jmasa@4327:   // If available, bump the pointer to allocate.
jmasa@4327:   if (free_word_size() >= word_size) {
jmasa@4327:     result = _top;
jmasa@4327:     _top = _top + word_size;
jmasa@4327:   }
jmasa@4327:   return result;
jmasa@4327: }
jmasa@4327: 
jmasa@4327: // _bottom points to the start of the chunk including the overhead.
jmasa@4382: size_t Metachunk::used_word_size() const {
stefank@5941:   return pointer_delta(_top, bottom(), sizeof(MetaWord));
jmasa@4327: }
jmasa@4327: 
jmasa@4382: size_t Metachunk::free_word_size() const {
stefank@5941:   return pointer_delta(end(), _top, sizeof(MetaWord));
jmasa@4327: }
jmasa@4327: 
jmasa@4327: void Metachunk::print_on(outputStream* st) const {
jmasa@4327:   st->print_cr("Metachunk:"
jmasa@4327:                " bottom " PTR_FORMAT " top " PTR_FORMAT
jmasa@4327:                " end " PTR_FORMAT " size " SIZE_FORMAT,
stefank@5941:                bottom(), _top, end(), word_size());
jmasa@4382:   if (Verbose) {
jmasa@4382:     st->print_cr("    used " SIZE_FORMAT " free " SIZE_FORMAT,
jmasa@4382:                  used_word_size(), free_word_size());
jmasa@4382:   }
jmasa@4327: }
jmasa@4327: 
jmasa@4327: #ifndef PRODUCT
jmasa@4327: void Metachunk::mangle() {
jmasa@4327:   // Mangle the payload of the chunk and not the links that
jmasa@4327:   // maintain list of chunks.
jmasa@4327:   HeapWord* start = (HeapWord*)(bottom() + overhead());
stefank@5941:   size_t size = word_size() - overhead();
stefank@5941:   Copy::fill_to_words(start, size, metadata_chunk_initialize);
jmasa@4327: }
jmasa@4327: #endif // PRODUCT
jmasa@4327: 
jmasa@4327: void Metachunk::verify() {
jmasa@4327: #ifdef ASSERT
jmasa@4327:   // Cannot walk through the blocks unless the blocks have
jmasa@4327:   // headers with sizes.
stefank@5941:   assert(bottom() <= _top &&
stefank@5941:          _top <= (MetaWord*)end(),
jmasa@4327:          "Chunk has been smashed");
jmasa@4327: #endif
jmasa@4327:   return;
jmasa@4327: }
stefank@5941: 
stefank@5941: /////////////// Unit tests ///////////////
stefank@5941: 
stefank@5941: #ifndef PRODUCT
stefank@5941: 
stefank@5941: class TestMetachunk {
stefank@5941:  public:
stefank@5941:   static void test() {
stefank@5941:     size_t size = 2 * 1024 * 1024;
stefank@5941:     void* memory = malloc(size);
stefank@5941:     assert(memory != NULL, "Failed to malloc 2MB");
stefank@5941: 
stefank@5941:     Metachunk* metachunk = ::new (memory) Metachunk(size / BytesPerWord, NULL);
stefank@5941: 
stefank@5941:     assert(metachunk->bottom() == (MetaWord*)metachunk, "assert");
stefank@5941:     assert(metachunk->end() == (uintptr_t*)metachunk + metachunk->size(), "assert");
stefank@5941: 
stefank@5941:     // Check sizes
stefank@5941:     assert(metachunk->size() == metachunk->word_size(), "assert");
stefank@5941:     assert(metachunk->word_size() == pointer_delta(metachunk->end(), metachunk->bottom(),
stefank@5941:         sizeof(MetaWord*)), "assert");
stefank@5941: 
stefank@5941:     // Check usage
stefank@5941:     assert(metachunk->used_word_size() == metachunk->overhead(), "assert");
stefank@5941:     assert(metachunk->free_word_size() == metachunk->word_size() - metachunk->used_word_size(), "assert");
stefank@5941:     assert(metachunk->top() == metachunk->initial_top(), "assert");
stefank@5941:     assert(metachunk->is_empty(), "assert");
stefank@5941: 
stefank@5941:     // Allocate
stefank@5941:     size_t alloc_size = 64; // Words
stefank@5941:     assert(is_size_aligned(alloc_size, Metachunk::object_alignment()), "assert");
stefank@5941: 
stefank@5941:     MetaWord* mem = metachunk->allocate(alloc_size);
stefank@5941: 
stefank@5941:     // Check post alloc
stefank@5941:     assert(mem == metachunk->initial_top(), "assert");
stefank@5941:     assert(mem + alloc_size == metachunk->top(), "assert");
stefank@5941:     assert(metachunk->used_word_size() == metachunk->overhead() + alloc_size, "assert");
stefank@5941:     assert(metachunk->free_word_size() == metachunk->word_size() - metachunk->used_word_size(), "assert");
stefank@5941:     assert(!metachunk->is_empty(), "assert");
stefank@5941: 
stefank@5941:     // Clear chunk
stefank@5941:     metachunk->reset_empty();
stefank@5941: 
stefank@5941:     // Check post clear
stefank@5941:     assert(metachunk->used_word_size() == metachunk->overhead(), "assert");
stefank@5941:     assert(metachunk->free_word_size() == metachunk->word_size() - metachunk->used_word_size(), "assert");
stefank@5941:     assert(metachunk->top() == metachunk->initial_top(), "assert");
stefank@5941:     assert(metachunk->is_empty(), "assert");
stefank@5941: 
stefank@5941:     free(memory);
stefank@5941:   }
stefank@5941: };
stefank@5941: 
stefank@5941: void TestMetachunk_test() {
stefank@5941:   TestMetachunk::test();
stefank@5941: }
stefank@5941: 
stefank@5941: #endif