| /* |
| * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @test |
| * @bug 4823133 |
| * @summary optimize RandomAccessFile.length() and length() is thread safe now. |
| */ |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.RandomAccessFile; |
| |
| /** |
| * |
| * @author vyom.tewari@oracle.com |
| */ |
| public class FileLengthTest { |
| |
| private static final int BUF_SIZE = 4096; |
| private static RandomAccessFile randomAccessFile; |
| private static Thread fileLengthCaller; |
| private static Thread fileContentReader; |
| private static StringBuilder fileContents; |
| private static volatile boolean isFailed = false; |
| |
| /** |
| * this thread will call length() in loop |
| */ |
| private static void startLengthThread() { |
| if (randomAccessFile == null) { |
| return; |
| } |
| fileLengthCaller = new Thread(() -> { |
| while (true) { |
| try { |
| long length = randomAccessFile.length(); |
| if (length < 0) { |
| return; |
| } |
| } catch (IOException ex) { |
| return; |
| } |
| } |
| }); |
| fileLengthCaller.setName("RandomAccessFile-length-caller"); |
| fileLengthCaller.setDaemon(true); |
| fileLengthCaller.start(); |
| } |
| |
| /** |
| * this thread will call read() and store the content in internal buffer. |
| */ |
| private static void startReaderThread() { |
| if (randomAccessFile == null) { |
| return; |
| } |
| fileContentReader = new Thread(() -> { |
| StringBuilder sb = new StringBuilder(BUF_SIZE); |
| int i; |
| byte arr[] = new byte[8]; |
| try { |
| while ((i = randomAccessFile.read(arr)) != -1) { |
| sb.append(new String(arr, 0, i)); |
| } |
| if (!sb.toString().equals(fileContents.toString())) { |
| isFailed = true; |
| } |
| } catch (IOException ex) { |
| } |
| }); |
| fileContentReader.setName("RandomAccessFile-content-reader"); |
| fileContentReader.setDaemon(true); |
| fileContentReader.start(); |
| } |
| |
| public static void main(String args[]) { |
| byte arr[] = new byte[BUF_SIZE]; |
| String testFile = "testfile.txt"; |
| try { |
| createDummyFile(testFile); |
| File file = new File(testFile); |
| file.deleteOnExit(); |
| randomAccessFile = new RandomAccessFile(file, "r"); |
| int count = randomAccessFile.read(arr); |
| randomAccessFile.seek(0); |
| fileContents = new StringBuilder(BUF_SIZE); |
| fileContents.append(new String(arr, 0, count)); |
| startLengthThread(); |
| startReaderThread(); |
| fileContentReader.join(); |
| } catch (FileNotFoundException | InterruptedException ex) { |
| } catch (IOException ex) { |
| } finally { |
| try { |
| randomAccessFile.close(); |
| } catch (IOException ex) { |
| } |
| } |
| if (isFailed) { |
| throw new RuntimeException("RandomAccessFile.length() changed the underlying file pointer."); |
| } |
| } |
| |
| private static void createDummyFile(String fileName) throws FileNotFoundException, IOException { |
| try (FileOutputStream outputStream = new FileOutputStream(new File(fileName))) { |
| String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"; |
| int count = 0; |
| while ((count + str.length()) < BUF_SIZE) { |
| outputStream.write(str.getBytes()); |
| count += str.length(); |
| } |
| outputStream.flush(); |
| } |
| } |
| } |