1 /* 2 * Copyright (c) 2005, 2006, 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 // A Generation that does parallel young-gen collection extended 26 // for adaptive size policy. 27 28 // Division of generation into spaces 29 // done by DefNewGeneration::compute_space_boundaries() 30 // +---------------+ 31 // | uncommitted | 32 // |---------------| 33 // | ss0 | 34 // |---------------| 35 // | ss1 | 36 // |---------------| 37 // | | 38 // | eden | 39 // | | 40 // +---------------+ <-- low end of VirtualSpace 41 // 42 class ASParNewGeneration: public ParNewGeneration { 43 44 size_t _min_gen_size; 45 46 // Resize the generation based on the desired sizes of 47 // the constituent spaces. 48 bool resize_generation(size_t eden_size, size_t survivor_size); 49 // Resize the spaces based on their desired sizes but 50 // respecting the maximum size of the generation. 51 void resize_spaces(size_t eden_size, size_t survivor_size); 52 // Return the byte size remaining to the minimum generation size. 53 size_t available_to_min_gen(); 54 // Return the byte size remaining to the live data in the generation. 55 size_t available_to_live() const; 56 // Return the byte size that the generation is allowed to shrink. 57 size_t limit_gen_shrink(size_t bytes); 58 // Reset the size of the spaces after a shrink of the generation. 59 void reset_survivors_after_shrink(); 60 61 // Accessor 62 VirtualSpace* virtual_space() { return &_virtual_space; } 63 64 virtual void adjust_desired_tenuring_threshold(); 65 66 public: 67 68 ASParNewGeneration(ReservedSpace rs, 69 size_t initial_byte_size, 70 size_t min_byte_size, 71 int level); 72 73 virtual const char* short_name() const { return "ASParNew"; } 74 virtual const char* name() const; 75 virtual Generation::Name kind() { return ASParNew; } 76 77 // Change the sizes of eden and the survivor spaces in 78 // the generation. The parameters are desired sizes 79 // and are not guaranteed to be met. For example, if 80 // the total is larger than the generation. 81 void resize(size_t eden_size, size_t survivor_size); 82 83 virtual void compute_new_size(); 84 85 size_t max_gen_size() { return _reserved.byte_size(); } 86 size_t min_gen_size() const { return _min_gen_size; } 87 88 // Space boundary invariant checker 89 void space_invariants() PRODUCT_RETURN; 90 };