1 /* 2 * Copyright (c) 2018, 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_SMALLBLOCKS_HPP_ 26 #define SHARE_MEMORY_METASPACE_SMALLBLOCKS_HPP_ 27 28 #include "memory/allocation.hpp" 29 #include "memory/binaryTreeDictionary.hpp" 30 #include "memory/metaspace/metablock.hpp" 31 #include "utilities/globalDefinitions.hpp" 32 33 class outputStream; 34 35 namespace metaspace { 36 namespace internals { 37 38 class SmallBlocks : public CHeapObj<mtClass> { 39 40 const static uint _small_block_max_size = sizeof(TreeChunk<Metablock, FreeList<Metablock> >)/HeapWordSize; 41 // Note: this corresponds to the imposed miminum allocation size, see SpaceManager::get_allocation_word_size() 42 const static uint _small_block_min_size = sizeof(Metablock)/HeapWordSize; 43 44 private: 45 FreeList<Metablock> _small_lists[_small_block_max_size - _small_block_min_size]; 46 47 FreeList<Metablock>& list_at(size_t word_size) { 48 assert(word_size >= _small_block_min_size, "There are no metaspace objects less than %u words", _small_block_min_size); 49 return _small_lists[word_size - _small_block_min_size]; 50 } 51 52 public: 53 SmallBlocks() { 54 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 55 uint k = i - _small_block_min_size; 56 _small_lists[k].set_size(i); 57 } 58 } 59 60 // Returns the total size, in words, of all blocks, across all block sizes. 61 size_t total_size() const; 62 63 // Returns the total number of all blocks across all block sizes. 64 uintx total_num_blocks() const; 65 66 static uint small_block_max_size() { return _small_block_max_size; } 67 static uint small_block_min_size() { return _small_block_min_size; } 68 69 MetaWord* get_block(size_t word_size) { 70 if (list_at(word_size).count() > 0) { 71 MetaWord* new_block = (MetaWord*) list_at(word_size).get_chunk_at_head(); 72 return new_block; 73 } else { 74 return NULL; 75 } 76 } 77 void return_block(Metablock* free_chunk, size_t word_size) { 78 list_at(word_size).return_chunk_at_head(free_chunk, false); 79 assert(list_at(word_size).count() > 0, "Should have a chunk"); 80 } 81 82 void print_on(outputStream* st) const; 83 84 }; 85 86 } // namespace metaspace 87 } // namespace internals 88 89 90 #endif /* SHARE_MEMORY_METASPACE_SMALLBLOCKS_HPP_ */