8027348: (process) Enhancement of handling async close of ProcessInputStream
Reviewed-by: martin
--- a/jdk/src/solaris/classes/java/lang/UNIXProcess.java.bsd Fri Jan 31 11:10:36 2014 +0000
+++ b/jdk/src/solaris/classes/java/lang/UNIXProcess.java.bsd Thu Jan 30 00:02:46 2014 +0400
@@ -342,47 +342,39 @@
ProcessPipeInputStream(int fd) {
super(new FileInputStream(newFileDescriptor(fd)));
}
-
- private InputStream drainInputStream(InputStream in)
+ private static byte[] drainInputStream(InputStream in)
throws IOException {
int n = 0;
int j;
byte[] a = null;
- synchronized (closeLock) {
- if (buf == null) // asynchronous close()?
- return null; // discard
- j = in.available();
- }
- while (j > 0) {
+ while ((j = in.available()) > 0) {
a = (a == null) ? new byte[j] : Arrays.copyOf(a, n + j);
- synchronized (closeLock) {
- if (buf == null) // asynchronous close()?
- return null; // discard
- n += in.read(a, n, j);
- j = in.available();
- }
+ n += in.read(a, n, j);
}
- return (a == null) ?
- ProcessBuilder.NullInputStream.INSTANCE :
- new ByteArrayInputStream(n == a.length ? a : Arrays.copyOf(a, n));
+ return (a == null || n == a.length) ? a : Arrays.copyOf(a, n);
}
/** Called by the process reaper thread when the process exits. */
synchronized void processExited() {
- try {
- InputStream in = this.in;
- if (in != null) {
- InputStream stragglers = drainInputStream(in);
- in.close();
- this.in = stragglers;
- }
- } catch (IOException ignored) { }
+ synchronized (closeLock) {
+ try {
+ InputStream in = this.in;
+ // this stream is closed if and only if: in == null
+ if (in != null) {
+ byte[] stragglers = drainInputStream(in);
+ in.close();
+ this.in = (stragglers == null) ?
+ ProcessBuilder.NullInputStream.INSTANCE :
+ new ByteArrayInputStream(stragglers);
+ }
+ } catch (IOException ignored) {}
+ }
}
@Override
public void close() throws IOException {
// BufferedInputStream#close() is not synchronized unlike most other methods.
- // Synchronizing helps avoid racing with drainInputStream().
+ // Synchronizing helps avoid race with processExited().
synchronized (closeLock) {
super.close();
}
--- a/jdk/src/solaris/classes/java/lang/UNIXProcess.java.linux Fri Jan 31 11:10:36 2014 +0000
+++ b/jdk/src/solaris/classes/java/lang/UNIXProcess.java.linux Thu Jan 30 00:02:46 2014 +0400
@@ -344,47 +344,39 @@
ProcessPipeInputStream(int fd) {
super(new FileInputStream(newFileDescriptor(fd)));
}
-
- private InputStream drainInputStream(InputStream in)
+ private static byte[] drainInputStream(InputStream in)
throws IOException {
int n = 0;
int j;
byte[] a = null;
- synchronized (closeLock) {
- if (buf == null) // asynchronous close()?
- return null; // discard
- j = in.available();
- }
- while (j > 0) {
+ while ((j = in.available()) > 0) {
a = (a == null) ? new byte[j] : Arrays.copyOf(a, n + j);
- synchronized (closeLock) {
- if (buf == null) // asynchronous close()?
- return null; // discard
- n += in.read(a, n, j);
- j = in.available();
- }
+ n += in.read(a, n, j);
}
- return (a == null) ?
- ProcessBuilder.NullInputStream.INSTANCE :
- new ByteArrayInputStream(n == a.length ? a : Arrays.copyOf(a, n));
+ return (a == null || n == a.length) ? a : Arrays.copyOf(a, n);
}
/** Called by the process reaper thread when the process exits. */
synchronized void processExited() {
- try {
- InputStream in = this.in;
- if (in != null) {
- InputStream stragglers = drainInputStream(in);
- in.close();
- this.in = stragglers;
- }
- } catch (IOException ignored) { }
+ synchronized (closeLock) {
+ try {
+ InputStream in = this.in;
+ // this stream is closed if and only if: in == null
+ if (in != null) {
+ byte[] stragglers = drainInputStream(in);
+ in.close();
+ this.in = (stragglers == null) ?
+ ProcessBuilder.NullInputStream.INSTANCE :
+ new ByteArrayInputStream(stragglers);
+ }
+ } catch (IOException ignored) {}
+ }
}
@Override
public void close() throws IOException {
// BufferedInputStream#close() is not synchronized unlike most other methods.
- // Synchronizing helps avoid racing with drainInputStream().
+ // Synchronizing helps avoid race with processExited().
synchronized (closeLock) {
super.close();
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/ProcessBuilder/CloseRace.java Thu Jan 30 00:02:46 2014 +0400
@@ -0,0 +1,140 @@
+/*
+ * 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;
+
+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);
+ }
+ }
+ }
+ }
+}
--- a/jdk/test/java/lang/Runtime/exec/CloseRace.java Fri Jan 31 11:10:36 2014 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,146 +0,0 @@
-/*
- * 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 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 the data corruption.
- * @library /lib/testlibrary
- * @run main/othervm/timeout=80 CloseRace
- */
-
-/**
- * This test has a little chance to catch the race during the given default
- * time gap of 20 seconds. To increase the time gap, set the system property
- * CloseRaceTimeGap=N to the number of seconds.
- * Jtreg's timeoutFactor should also be set appropriately.
- *
- * For example, to run the test for 10 minutes:
- * > jtreg \
- * -testjdk:$(PATH_TO_TESTED_JDK) \
- * -timeoutFactor:10 \
- * -DCloseRaceTimeGap=600 \
- * $(PATH_TO_TESTED_JDK_SOURCE)/test/java/lang/Runtime/exec/CloseRace.java
- */
-
-import java.io.*;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.LinkedList;
-import java.util.List;
-import jdk.testlibrary.OutputAnalyzer;
-import static jdk.testlibrary.ProcessTools.*;
-
-public class CloseRace {
-
- public static void main(String args[]) throws Exception {
- ProcessBuilder pb = createJavaProcessBuilder("-Xmx64M", "CloseRace$Child",
- System.getProperty("CloseRaceTimeGap", "20"));
- OutputAnalyzer oa = new OutputAnalyzer(pb.start());
- oa.stderrShouldNotContain("java.lang.OutOfMemoryError");
- }
-
- public static class Child {
- private static final String BIG_FILE = "bigfile";
- private static final String SMALL_FILE = "smallfile";
- private static int timeGap = 20; // seconds
-
- public static void main(String args[]) throws Exception {
- if (args.length > 0) {
- try {
- timeGap = Integer.parseUnsignedInt(args[0]);
- timeGap = Integer.max(timeGap, 10);
- timeGap = Integer.min(timeGap, 10 * 60 * 60); // no more than 10 hours
- } catch (NumberFormatException ignore) {}
- }
- try (RandomAccessFile f = new RandomAccessFile(BIG_FILE, "rw")) {
- f.setLength(1024 * 1024 * 1024); // 1 Gb, greater than max heap size
- }
- try (FileOutputStream fs = new FileOutputStream(SMALL_FILE);
- PrintStream ps = new PrintStream(fs)) {
- for (int i = 0; i < 128; ++i)
- ps.println("line of text");
- }
-
- List<Thread> threads = new LinkedList<>();
- for (int i = 0; i < 99; ++i) {
- Thread t = new Thread (new OpenLoop());
- t.start();
- threads.add(t);
- }
- Thread t2 = new Thread (new ExecLoop());
- t2.start();
- threads.add(t2);
-
- Thread.sleep(timeGap);
-
- for (Thread t : threads) {
- t.interrupt();
- t.join();
- }
- }
-
- private static class OpenLoop implements Runnable {
- public void run() {
- final Path bigFilePath = Paths.get(BIG_FILE);
- while (!Thread.interrupted()) {
- try (InputStream in = Files.newInputStream(bigFilePath)) {
- // Widen the race window by sleeping 1ms
- Thread.sleep(1);
- } catch (InterruptedException e) {
- break;
- } catch (Exception e) {
- System.err.println(e);
- }
- }
- }
- }
-
- private static class ExecLoop implements Runnable {
- public void run() {
- List<String> command = new ArrayList<>(
- Arrays.asList("/bin/cat", SMALL_FILE));
- while (!Thread.interrupted()) {
- try {
- ProcessBuilder builder = new ProcessBuilder(command);
- final Process process = builder.start();
- InputStream is = process.getInputStream();
- InputStreamReader isr = new InputStreamReader(is);
- BufferedReader br = new BufferedReader(isr);
- while (br.readLine() != null) {}
- process.waitFor();
- isr.close();
- } catch (InterruptedException e) {
- break;
- } catch (Exception e) {
- System.err.println(e);
- }
- }
- }
- }
- }
-}