1 /* 2 * Copyright (c) 1997, 2010, 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_SHARED_AGETABLE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_AGETABLE_HPP 27 28 #include "oops/markOop.hpp" 29 #include "oops/oop.hpp" 30 #include "runtime/perfData.hpp" 31 32 /* Copyright (c) 1992-2009 Oracle and/or its affiliates, and Stanford University. 33 See the LICENSE file for license information. */ 34 35 // Age table for adaptive feedback-mediated tenuring (scavenging) 36 // 37 // Note: all sizes are in oops 38 39 class ageTable VALUE_OBJ_CLASS_SPEC { 40 friend class VMStructs; 41 42 public: 43 // constants 44 enum { table_size = markOopDesc::max_age + 1 }; 45 46 // instance variables 47 size_t sizes[table_size]; 48 49 // constructor. "global" indicates that this is the global age table 50 // (as opposed to gc-thread-local) 51 ageTable(bool global = true); 52 53 // clear table 54 void clear(); 55 56 // add entry 57 void add(oop p, size_t oop_size) { 58 uint age = p->age(); 59 assert(age > 0 && age < table_size, "invalid age of object"); 60 sizes[age] += oop_size; 61 } 62 63 // Merge another age table with the current one. Used 64 // for parallel young generation gc. 65 void merge(ageTable* subTable); 66 void merge_par(ageTable* subTable); 67 68 // calculate new tenuring threshold based on age information 69 uint compute_tenuring_threshold(size_t survivor_capacity); 70 71 private: 72 PerfVariable* _perf_sizes[table_size]; 73 }; 74 75 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_AGETABLE_HPP