1 /* 2 * Copyright (c) 1997, 2015, 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_SHARED_AGETABLE_HPP 26 #define SHARE_VM_GC_SHARED_AGETABLE_HPP 27 28 #include "oops/markOop.hpp" 29 #include "oops/oop.hpp" 30 #include "runtime/perfData.hpp" 31 32 class GCPolicyCounters; 33 34 /* Copyright (c) 1992, 2015, Oracle and/or its affiliates, and Stanford University. 35 See the LICENSE file for license information. */ 36 37 // Age table for adaptive feedback-mediated tenuring (scavenging) 38 // 39 // Note: all sizes are in oops 40 41 class ageTable VALUE_OBJ_CLASS_SPEC { 42 friend class VMStructs; 43 44 public: 45 // constants 46 enum { table_size = markOopDesc::max_age + 1 }; 47 48 // instance variables 49 size_t sizes[table_size]; 50 51 // constructor. "global" indicates that this is the global age table 52 // (as opposed to gc-thread-local) 53 ageTable(bool global = true); 54 55 // clear table 56 void clear(); 57 58 // add entry 59 void add(oop p, size_t oop_size); 60 61 void add(uint age, size_t oop_size) { 62 assert(age > 0 && age < table_size, "invalid age of object"); 63 sizes[age] += oop_size; 64 } 65 66 // Merge another age table with the current one. Used 67 // for parallel young generation gc. 68 void merge(ageTable* subTable); 69 70 // calculate new tenuring threshold based on age information 71 uint compute_tenuring_threshold(size_t survivor_capacity, GCPolicyCounters* gc_counters); 72 73 private: 74 PerfVariable* _perf_sizes[table_size]; 75 }; 76 77 #endif // SHARE_VM_GC_SHARED_AGETABLE_HPP