1/* 2 * Copyright (c) 2015, 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 * @test 26 * @bug 8143394 27 * @summary Check for NullPointerException in race between read() and close(). 28 */ 29import java.io.CharArrayReader; 30import java.io.IOException; 31import java.io.PushbackReader; 32import java.io.Reader; 33import java.io.StringReader; 34import java.util.ArrayList; 35import java.util.List; 36import java.util.concurrent.atomic.AtomicBoolean; 37import java.util.concurrent.atomic.AtomicReference; 38import java.util.function.Supplier; 39 40public class ReadCloseRaceNPE { 41 42 private static final int BUF_SIZE = 1000; 43 private static final long TIMEOUT_MS = 3000; 44 45 private static final List<Exception> failures = new ArrayList<>(); 46 47 private static void testReader(final Supplier<Reader> readerSupplier) 48 throws InterruptedException { 49 AtomicReference<Reader> readerRef = 50 new AtomicReference<>(readerSupplier.get()); 51 52 AtomicBoolean isFinished = new AtomicBoolean(); 53 54 Runnable readTask = () -> { 55 long startTime = System.currentTimeMillis(); 56 while (System.currentTimeMillis() - startTime < TIMEOUT_MS) { 57 try { 58 readerRef.get().read(); 59 } catch (Exception e) { 60 if (!(e instanceof IOException)) { 61 failures.add(e); 62 break; 63 } 64 readerRef.set(readerSupplier.get()); 65 } 66 } 67 isFinished.set(true); 68 }; 69 70 Runnable closeTask = () -> { 71 while (!isFinished.get()) { 72 try { 73 readerRef.get().close(); 74 } catch (Exception e) { 75 if (!(e instanceof IOException)) { 76 e.printStackTrace(); 77 } 78 } 79 } 80 }; 81 82 Thread readThread = new Thread(readTask); 83 Thread closeThread = new Thread(closeTask); 84 85 readThread.start(); 86 closeThread.start(); 87 readThread.join(); 88 closeThread.join(); 89 } 90 91 public static void main(String[] args) throws Throwable { 92 final String s = "Two riders were approaching.\\n"; 93 94 Supplier<Reader> charPushbackReaderSupplier = () -> { 95 char buf[] = new char[s.length()]; 96 s.getChars(0, s.length(), buf, 0); 97 CharArrayReader in = new CharArrayReader(buf); 98 return new PushbackReader(in, BUF_SIZE); 99 }; 100 101 testReader(charPushbackReaderSupplier); 102 103 Supplier<Reader> stringPushbackReaderSupplier = () -> { 104 StringReader in = new StringReader(s); 105 return new PushbackReader(in, BUF_SIZE); 106 }; 107 108 testReader(stringPushbackReaderSupplier); 109 110 if (!failures.isEmpty()) { 111 failures.stream().forEach((x) -> ((Exception) x).printStackTrace()); 112 throw new RuntimeException("PushbackReaderNPE failed"); 113 } 114 } 115} 116