1 /* 2 * Copyright (c) 2014, 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_VM_GC_IMPLEMENTATION_G1_HEAPREGIONBOUNDS_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONBOUNDS_HPP 27 28 class HeapRegionBounds : public AllStatic { 29 private: 30 // Minimum region size; we won't go lower than that. 31 // We might want to decrease this in the future, to deal with small 32 // heaps a bit more efficiently. 33 static const size_t MIN_REGION_SIZE = 1024 * 1024; 34 35 // Maximum region size; we don't go higher than that. There's a good 36 // reason for having an upper bound. We don't want regions to get too 37 // large, otherwise cleanup's effectiveness would decrease as there 38 // will be fewer opportunities to find totally empty regions after 39 // marking. 40 static const size_t MAX_REGION_SIZE = 32 * 1024 * 1024; 41 42 // The automatic region size calculation will try to have around this 43 // many regions in the heap (based on the min heap size). 44 static const size_t TARGET_REGION_NUMBER = 2048; 45 46 public: 47 static inline size_t min_size(); 48 static inline size_t max_size(); 49 static inline size_t target_number(); 50 }; 51 52 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONBOUNDS_HPP