| /* |
| * Copyright (c) 2013, 2014 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 8024521 |
| * @summary Closing ProcessPipeInputStream at the time the process exits is racy |
| * and leads to data corruption. Run this test manually (as |
| * an ordinary java program) with -Xmx8M to repro bug 8024521. |
| * @run main/othervm -Xmx8M -Dtest.duration=2 CloseRace |
| */ |
| |
| import java.io.*; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.concurrent.CountDownLatch; |
| |
| public class CloseRace { |
| private static final String BIG_FILE = "bigfile"; |
| |
| private static final int[] procFDs = new int[6]; |
| |
| /** default value sufficient to repro bug 8024521. */ |
| private static final int testDurationSeconds |
| = Integer.getInteger("test.duration", 600); |
| |
| private static final CountDownLatch threadsStarted |
| = new CountDownLatch(2); |
| |
| static boolean fdInUse(int i) { |
| return new File("/proc/self/fd/" + i).exists(); |
| } |
| |
| static boolean[] procFDsInUse() { |
| boolean[] inUse = new boolean[procFDs.length]; |
| for (int i = 0; i < procFDs.length; i++) |
| inUse[i] = fdInUse(procFDs[i]); |
| return inUse; |
| } |
| |
| static int count(boolean[] bits) { |
| int count = 0; |
| for (int i = 0; i < bits.length; i++) |
| count += bits[i] ? 1 : 0; |
| return count; |
| } |
| |
| static void dumpAllStacks() { |
| System.err.println("Start of dump"); |
| final Map<Thread, StackTraceElement[]> allStackTraces |
| = Thread.getAllStackTraces(); |
| for (Thread thread : allStackTraces.keySet()) { |
| System.err.println("Thread " + thread.getName()); |
| for (StackTraceElement element : allStackTraces.get(thread)) |
| System.err.println("\t" + element); |
| } |
| System.err.println("End of dump"); |
| } |
| |
| public static void main(String args[]) throws Exception { |
| if (!(new File("/proc/self/fd").isDirectory())) |
| return; |
| |
| // Catch Errors from process reaper |
| Thread.setDefaultUncaughtExceptionHandler |
| ((t, e) -> { e.printStackTrace(); System.exit(1); }); |
| |
| try (RandomAccessFile f = new RandomAccessFile(BIG_FILE, "rw")) { |
| f.setLength(Runtime.getRuntime().maxMemory()); // provoke OOME |
| } |
| |
| for (int i = 0, j = 0; j < procFDs.length; i++) |
| if (!fdInUse(i)) |
| procFDs[j++] = i; |
| |
| Thread[] threads = { |
| new Thread(new OpenLoop()), |
| new Thread(new ExecLoop()), |
| }; |
| for (Thread thread : threads) |
| thread.start(); |
| |
| threadsStarted.await(); |
| Thread.sleep(testDurationSeconds * 1000); |
| |
| for (Thread thread : threads) |
| thread.interrupt(); |
| for (Thread thread : threads) { |
| thread.join(10_000); |
| if (thread.isAlive()) { |
| dumpAllStacks(); |
| throw new Error("At least one child thread (" |
| + thread.getName() |
| + ") failed to finish gracefully"); |
| } |
| } |
| } |
| |
| static class OpenLoop implements Runnable { |
| public void run() { |
| threadsStarted.countDown(); |
| while (!Thread.interrupted()) { |
| try { |
| // wait for ExecLoop to finish creating process |
| do { |
| if (Thread.interrupted()) |
| return; |
| } while (count(procFDsInUse()) != 3); |
| List<InputStream> iss = new ArrayList<>(4); |
| |
| // eat up three "holes" (closed ends of pipe fd pairs) |
| for (int i = 0; i < 3; i++) |
| iss.add(new FileInputStream(BIG_FILE)); |
| do { |
| if (Thread.interrupted()) |
| return; |
| } while (count(procFDsInUse()) == procFDs.length); |
| // hopefully this will racily occupy empty fd slot |
| iss.add(new FileInputStream(BIG_FILE)); |
| Thread.sleep(1); // Widen race window |
| for (InputStream is : iss) |
| is.close(); |
| } catch (InterruptedException e) { |
| break; |
| } catch (Exception e) { |
| throw new Error(e); |
| } |
| } |
| } |
| } |
| |
| static class ExecLoop implements Runnable { |
| public void run() { |
| threadsStarted.countDown(); |
| ProcessBuilder builder = new ProcessBuilder("/bin/true"); |
| while (!Thread.interrupted()) { |
| try { |
| // wait for OpenLoop to finish |
| do { |
| if (Thread.interrupted()) |
| return; |
| } while (count(procFDsInUse()) > 0); |
| Process process = builder.start(); |
| InputStream is = process.getInputStream(); |
| process.waitFor(); |
| is.close(); |
| } catch (InterruptedException e) { |
| break; |
| } catch (Exception e) { |
| throw new Error(e); |
| } |
| } |
| } |
| } |
| } |