Thu, 30 Jul 2009 10:29:53 +0100
6827648: Extremely slow compilation time for visitor pattern code + generics
Summary: Javac unnecessarily recomputates type-substitutions multiple times
Reviewed-by: jjg
duke@1 | 1 | /* |
duke@1 | 2 | * Copyright 2002 Sun Microsystems, Inc. All Rights Reserved. |
duke@1 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@1 | 4 | * |
duke@1 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@1 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@1 | 7 | * published by the Free Software Foundation. |
duke@1 | 8 | * |
duke@1 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@1 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@1 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@1 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@1 | 13 | * accompanied this code). |
duke@1 | 14 | * |
duke@1 | 15 | * You should have received a copy of the GNU General Public License version |
duke@1 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@1 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@1 | 18 | * |
duke@1 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@1 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@1 | 21 | * have any questions. |
duke@1 | 22 | */ |
duke@1 | 23 | |
duke@1 | 24 | /* |
duke@1 | 25 | * @test |
duke@1 | 26 | * @bug 4509267 |
duke@1 | 27 | * @summary generics: parametric exception type versus overriding |
duke@1 | 28 | * @author gafter |
duke@1 | 29 | * |
darcy@289 | 30 | * @compile ParametricException.java |
duke@1 | 31 | */ |
duke@1 | 32 | |
duke@1 | 33 | import java.io.*; |
duke@1 | 34 | |
duke@1 | 35 | abstract class AChurchBoolean { |
duke@1 | 36 | public abstract <Return, Parameter, Throws extends Throwable> |
duke@1 | 37 | Return accept(IVisitor<Return, Parameter, Throws> visitor, Parameter parameter) throws Throws; |
duke@1 | 38 | |
duke@1 | 39 | public interface IVisitor<Return, Parameter, Throws extends Throwable> { |
duke@1 | 40 | public Return caseTrue(Parameter parameter) throws Throws; |
duke@1 | 41 | public Return caseFalse(Parameter parameter) throws Throws; |
duke@1 | 42 | } |
duke@1 | 43 | } |
duke@1 | 44 | |
duke@1 | 45 | class TrueChurchBoolean extends AChurchBoolean { |
duke@1 | 46 | private static TrueChurchBoolean instance = new TrueChurchBoolean(); |
duke@1 | 47 | private TrueChurchBoolean() {} |
duke@1 | 48 | public static TrueChurchBoolean singleton() { |
duke@1 | 49 | return instance; |
duke@1 | 50 | } |
duke@1 | 51 | public <Return, Parameter, Throws extends Throwable> |
duke@1 | 52 | Return accept(IVisitor<Return, Parameter, Throws> visitor, Parameter parameter) throws Throws { |
duke@1 | 53 | return visitor.caseTrue(parameter); |
duke@1 | 54 | } |
duke@1 | 55 | } |
duke@1 | 56 | |
duke@1 | 57 | class FalseChurchBoolean extends AChurchBoolean { |
duke@1 | 58 | private static FalseChurchBoolean instance = new FalseChurchBoolean(); |
duke@1 | 59 | private FalseChurchBoolean() {} |
duke@1 | 60 | public static FalseChurchBoolean singleton() { |
duke@1 | 61 | return instance; |
duke@1 | 62 | } |
duke@1 | 63 | public <Return, Parameter, Throws extends Throwable> |
duke@1 | 64 | Return accept(IVisitor<Return, Parameter, Throws> visitor, Parameter parameter) throws Throws { |
duke@1 | 65 | return visitor.caseFalse(parameter); |
duke@1 | 66 | } |
duke@1 | 67 | } |
duke@1 | 68 | |
duke@1 | 69 | class Pair<T,U> { |
duke@1 | 70 | private T first; |
duke@1 | 71 | private U second; |
duke@1 | 72 | Pair(T first, U second) { |
duke@1 | 73 | this.first = first; |
duke@1 | 74 | this.second = second; |
duke@1 | 75 | } |
duke@1 | 76 | T getFirst() { |
duke@1 | 77 | return first; |
duke@1 | 78 | } |
duke@1 | 79 | U getSecond() { |
duke@1 | 80 | return second; |
duke@1 | 81 | } |
duke@1 | 82 | } |
duke@1 | 83 | |
duke@1 | 84 | // Perhaps a bit of a toy example, but relevant nonetheless. |
duke@1 | 85 | class ChurchBooleanTest { |
duke@1 | 86 | private AChurchBoolean bool; |
duke@1 | 87 | public ChurchBooleanTest(AChurchBoolean bool) { |
duke@1 | 88 | this.bool = bool; |
duke@1 | 89 | } |
duke@1 | 90 | public AChurchBoolean readIf(File file, byte[] output) throws IOException { |
duke@1 | 91 | return bool.accept(new AChurchBoolean.IVisitor<AChurchBoolean, Pair<File, byte[]>, IOException>() { |
duke@1 | 92 | public AChurchBoolean caseTrue(Pair<File, byte[]> parameter) throws IOException { |
duke@1 | 93 | FileInputStream input = new FileInputStream(parameter.getFirst()); // throws |
duke@1 | 94 | input.read(parameter.getSecond()); // throws |
duke@1 | 95 | input.close(); // throws |
duke@1 | 96 | return TrueChurchBoolean.singleton(); |
duke@1 | 97 | } |
duke@1 | 98 | public AChurchBoolean caseFalse(Pair<File, byte[]> parameter) throws IOException { |
duke@1 | 99 | return FalseChurchBoolean.singleton(); |
duke@1 | 100 | } |
duke@1 | 101 | }, new Pair<File, byte[]>(file, output)); |
duke@1 | 102 | } |
duke@1 | 103 | } |