1 /*
   2  * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_MEMORY_METASPACE_CONSTANTS_HPP
  26 #define SHARE_MEMORY_METASPACE_CONSTANTS_HPP
  27 
  28 #include "utilities/globalDefinitions.hpp"
  29 #include "memory/metaspace/chunkLevel.hpp"
  30 
  31 namespace metaspace {
  32 
  33 // Constants to be used throughout metaspace
  34 
  35 namespace constants {
  36 
  37 // Granularity, in bytes, metaspace is committed with.
  38 static const size_t commit_granule_bytes = K * 64;
  39 static const size_t commit_granule_words = commit_granule_bytes * BytesPerWord;
  40 
  41 
  42 // Whether or not commit new-born chunks thru after creation.
  43 static const bool newborn_chunks_are_fully_committed = true;
  44 
  45 // When a chunk is handed out by the ChunkManager to a class loader, how much
  46 // of a chunk should be committed up-front?
  47 // Size in words. Must be a multiple of commit_granule_words.
  48 // (Note: 0 is possible but inefficient, since it will cause the ClassLoaderMetaspace
  49 //        to commit the first granule right away anyway, so nothing is saved.
  50 //        chklvl::MAX_CHUNK_WORD_SIZE pretty much means every chunk is committed thru
  51 //        from the start.
  52 static const size_t committed_words_on_fresh_chunks = commit_granule_bytes * 2;
  53 
  54 // The default size of a non-class VirtualSpaceNode (unless created differently).
  55 // Must be a multiple of the root chunk size.
  56 static const size_t virtual_space_node_default_size = chklvl::MAX_CHUNK_BYTE_SIZE * 4;
  57 
  58 static const size_t allocation_from_dictionary_limit = 4 * K;
  59 
  60 } // namespace constants
  61 
  62 } // namespace metaspace
  63 
  64 #endif // SHARE_MEMORY_METASPACE_BLOCKFREELIST_HPP