1 #ifdef USE_PRAGMA_IDENT_HDR 2 #pragma ident "@(#)ageTable.hpp 1.29 07/05/05 17:05:32 JVM" 3 #endif 4 /* 5 * Copyright 1997-2003 Sun Microsystems, Inc. All Rights Reserved. 6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 7 * 8 * This code is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License version 2 only, as 10 * published by the Free Software Foundation. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 23 * CA 95054 USA or visit www.sun.com if you need additional information or 24 * have any questions. 25 * 26 */ 27 28 /* Copyright 1992 Sun Microsystems, Inc. and Stanford University. 29 See the LICENSE file for license information. */ 30 31 // Age table for adaptive feedback-mediated tenuring (scavenging) 32 // 33 // Note: all sizes are in oops 34 35 class ageTable VALUE_OBJ_CLASS_SPEC { 36 friend class VMStructs; 37 38 public: 39 // constants 40 enum { table_size = markOopDesc::max_age + 1 }; 41 42 // instance variables 43 size_t sizes[table_size]; 44 45 // constructor. "global" indicates that this is the global age table 46 // (as opposed to gc-thread-local) 47 ageTable(bool global = true); 48 49 // clear table 50 void clear(); 51 52 // add entry 53 void add(oop p, size_t oop_size) { 54 int age = p->age(); 55 assert(age > 0 && age < table_size, "invalid age of object"); 56 sizes[age] += oop_size; 57 } 58 59 // Merge another age table with the current one. Used 60 // for parallel young generation gc. 61 void merge(ageTable* subTable); 62 void merge_par(ageTable* subTable); 63 64 // calculate new tenuring threshold based on age information 65 int compute_tenuring_threshold(size_t survivor_capacity); 66 67 private: 68 PerfVariable* _perf_sizes[table_size]; 69 };