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