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 "gc_implementation/shared/gcTrace.hpp" 31 #include "runtime/perfData.hpp" 32 33 /* Copyright (c) 1992-2009 Oracle and/or its affiliates, and Stanford University. 34 See the LICENSE file for license information. */ 35 36 // Age table for adaptive feedback-mediated tenuring (scavenging) 37 // 38 // Note: all sizes are in oops 39 40 class ageTable VALUE_OBJ_CLASS_SPEC { 41 friend class VMStructs; 42 43 public: 44 // constants 45 enum { table_size = markOopDesc::max_age + 1 }; 46 47 // instance variables 48 size_t sizes[table_size]; 49 50 // constructor. "global" indicates that this is the global age table 51 // (as opposed to gc-thread-local) 52 ageTable(bool global = true); 53 54 // clear table 55 void clear(); 56 57 // add entry 58 void add(oop p, size_t oop_size) { 59 add(p->age(), oop_size); 60 } 61 62 void add(uint age, size_t oop_size) { 63 assert(age > 0 && age < table_size, "invalid age of object"); 64 sizes[age] += oop_size; 65 } 66 67 // Merge another age table with the current one. Used 68 // for parallel young generation gc. 69 void merge(ageTable* subTable); 70 void merge_par(ageTable* subTable); 71 72 // calculate new tenuring threshold based on age information 73 uint compute_tenuring_threshold(size_t survivor_capacity, GCTracer &tracer); 74 75 private: 76 PerfVariable* _perf_sizes[table_size]; 77 }; 78 79 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_AGETABLE_HPP