1 /* 2 * Copyright (c) 2001, 2008, 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 // 26 // A PSMarkSweepDecorator is used to add "ParallelScavenge" style mark sweep operations 27 // to a MutableSpace. 28 // 29 30 class ObjectStartArray; 31 32 class PSMarkSweepDecorator: public CHeapObj { 33 private: 34 static PSMarkSweepDecorator* _destination_decorator; 35 36 protected: 37 MutableSpace* _space; 38 ObjectStartArray* _start_array; 39 HeapWord* _first_dead; 40 HeapWord* _end_of_live; 41 HeapWord* _compaction_top; 42 size_t _allowed_dead_ratio; 43 44 bool insert_deadspace(size_t& allowed_deadspace_words, HeapWord* q, 45 size_t word_len); 46 47 public: 48 PSMarkSweepDecorator(MutableSpace* space, ObjectStartArray* start_array, 49 size_t allowed_dead_ratio) : 50 _space(space), _start_array(start_array), 51 _allowed_dead_ratio(allowed_dead_ratio) { } 52 53 // During a compacting collection, we need to collapse objects into 54 // spaces in a given order. We want to fill space A, space B, and so 55 // on. The code that controls that order is in the following methods. 56 static void set_destination_decorator_tenured(); 57 static void set_destination_decorator_perm_gen(); 58 static void advance_destination_decorator(); 59 static PSMarkSweepDecorator* destination_decorator(); 60 61 // Accessors 62 MutableSpace* space() { return _space; } 63 ObjectStartArray* start_array() { return _start_array; } 64 65 HeapWord* compaction_top() { return _compaction_top; } 66 void set_compaction_top(HeapWord* value) { _compaction_top = value; } 67 68 size_t allowed_dead_ratio() { return _allowed_dead_ratio; } 69 void set_allowed_dead_ratio(size_t value) { _allowed_dead_ratio = value; } 70 71 // Work methods 72 void adjust_pointers(); 73 void precompact(); 74 void compact(bool mangle_free_space); 75 };