jdk8-mips64-public/hotspot: src/share/vm/memory/metachunk.cpp@86e6d691f2e1 (annotated)

src/share/vm/memory/metachunk.cpp@86e6d691f2e1 (annotated)

src/share/vm/memory/metachunk.cpp

Sat, 23 Nov 2013 12:25:13 +0100

author: mgronlun
date: Sat, 23 Nov 2013 12:25:13 +0100
changeset 6131: 86e6d691f2e1
parent 5942: ec2e26e26183
child 6680: 78bbf4d43a14
permissions: -rw-r--r--

8028128: Add a type safe alternative for working with counter based data
Reviewed-by: dholmes, egahlin

 /*
  * Copyright (c) 2012, 2013, 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/copy.hpp"
 #include "utilities/debug.hpp"
 class VirtualSpaceNode;
 const size_t metadata_chunk_initialize = 0xf7f7f7f7;
 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_size_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);
   size_t data_word_size = pointer_delta(end(),
                                         _top,
                                         sizeof(MetaWord));
   Copy::fill_to_words((HeapWord*)_top,
                       data_word_size,
                       metadata_chunk_initialize);
 #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,
                bottom(), _top, 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() {
   // Mangle the payload of the chunk and not the links that
   // maintain list of chunks.
   HeapWord* start = (HeapWord*)(bottom() + overhead());
   size_t size = word_size() - overhead();
   Copy::fill_to_words(start, size, metadata_chunk_initialize);
 }
 #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;
 }
 /////////////// Unit tests ///////////////
 #ifndef PRODUCT
 class TestMetachunk {
  public:
   static void test() {
     size_t size = 2 * 1024 * 1024;
     void* memory = malloc(size);
     assert(memory != NULL, "Failed to malloc 2MB");
     Metachunk* metachunk = ::new (memory) Metachunk(size / BytesPerWord, NULL);
     assert(metachunk->bottom() == (MetaWord*)metachunk, "assert");
     assert(metachunk->end() == (uintptr_t*)metachunk + metachunk->size(), "assert");
     // Check sizes
     assert(metachunk->size() == metachunk->word_size(), "assert");
     assert(metachunk->word_size() == pointer_delta(metachunk->end(), metachunk->bottom(),
         sizeof(MetaWord*)), "assert");
     // Check usage
     assert(metachunk->used_word_size() == metachunk->overhead(), "assert");
     assert(metachunk->free_word_size() == metachunk->word_size() - metachunk->used_word_size(), "assert");
     assert(metachunk->top() == metachunk->initial_top(), "assert");
     assert(metachunk->is_empty(), "assert");
     // Allocate
     size_t alloc_size = 64; // Words
     assert(is_size_aligned(alloc_size, Metachunk::object_alignment()), "assert");
     MetaWord* mem = metachunk->allocate(alloc_size);
     // Check post alloc
     assert(mem == metachunk->initial_top(), "assert");
     assert(mem + alloc_size == metachunk->top(), "assert");
     assert(metachunk->used_word_size() == metachunk->overhead() + alloc_size, "assert");
     assert(metachunk->free_word_size() == metachunk->word_size() - metachunk->used_word_size(), "assert");
     assert(!metachunk->is_empty(), "assert");
     // Clear chunk
     metachunk->reset_empty();
     // Check post clear
     assert(metachunk->used_word_size() == metachunk->overhead(), "assert");
     assert(metachunk->free_word_size() == metachunk->word_size() - metachunk->used_word_size(), "assert");
     assert(metachunk->top() == metachunk->initial_top(), "assert");
     assert(metachunk->is_empty(), "assert");
     free(memory);
   }
 };
 void TestMetachunk_test() {
   TestMetachunk::test();
 }
 #endif

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/memory/metachunk.cpp@86e6d691f2e1 (annotated)

src/share/vm/memory/metachunk.cpp