RFR [8024521] (process) Async close issues with Process InputStream

[Ivan Gerasimov]

Thanks a lot, Martin!

I created the Jira issue for your proposal: 
https://bugs.openjdk.java.net/browse/JDK-8027348.

Sincerely yours,
Ivan

On 25.10.2013 20:06, Martin Buchholz wrote:
>
>
> I propose the test for this be in test/java/lang/ProcessBuilder/ 
> instead of test/java/lang/Runtime/exec and that
>
> - it runs for only 2 seconds by default.  This is the shortest time 
> that a failure was detected. 20 seconds is way too long.
> - it is much more likely to fail quickly than the original version.
>
> Only tested on Linux.  There is porting work to be done (testing other 
> platforms).
> I would like y'all (Ivan?) to adopt this.
>
> /*
>  * Copyright (c) 2013, 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 <http://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;
>
> 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);
>     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;
>     }
>
>     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();
>
>         Thread.sleep(testDurationSeconds * 1000);
>
>         for (Thread thread : threads)
>             thread.interrupt();
>         for (Thread thread : threads)
>             thread.join();
>     }
>
>     static class OpenLoop implements Runnable {
>         public void run() {
>             while (!Thread.interrupted()) {
>                 try {
>                     // wait for ExecLoop to finish creating process
>                     do {} 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 {} 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() {
>             ProcessBuilder builder = new ProcessBuilder("/bin/true");
>             while (!Thread.interrupted()) {
>                 try {
>                     // wait for OpenLoop to finish
>                     do {} 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);
>                 }
>             }
>         }
>     }
> }
>