5041655: (ch) FileLock: negative param and overflow issues

Reviewed-by: alanb

Author: Brian Burkhalter

src/java.base/share/classes/java/nio/channels/AsynchronousFileChannel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 2022, 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
@@ -425,10 +425,13 @@ public static AsynchronousFileChannel open(Path file, OpenOption... options)
      * required then a region starting at zero, and no smaller than the
      * expected maximum size of the file, should be locked.  The two-argument
      * {@link #lock(Object,CompletionHandler)} method simply locks a region
-     * of size {@link Long#MAX_VALUE}. If a lock that overlaps the requested
-     * region is already held by this Java virtual machine, or this method has
-     * been invoked to lock an overlapping region and that operation has not
-     * completed, then this method throws {@link OverlappingFileLockException}.
+     * of size {@link Long#MAX_VALUE}.  If the {@code position} is non-negative
+     * and the {@code size} is zero, then a lock of size
+     * {@code Long.MAX_VALUE - position} is returned.  If a lock that
+     * overlaps the requested region is already held by this Java virtual
+     * machine, or this method has been invoked to lock an overlapping region
+     * and that operation has not completed, then this method throws
+     * {@link OverlappingFileLockException}.
      *
      * <p> Some operating systems do not support a mechanism to acquire a file
      * lock in an asynchronous manner. Consequently an implementation may
@@ -454,7 +457,10 @@ public static AsynchronousFileChannel open(Path file, OpenOption... options)
      *          non-negative
      * @param   size
      *          The size of the locked region; must be non-negative, and the sum
-     *          {@code position}&nbsp;+&nbsp;{@code size} must be non-negative
+     *          {@code position}&nbsp;+&nbsp;{@code size} must be non-negative.
+     *          A value of zero means to lock all bytes from the specified
+     *          starting position to the end of the file, regardless of whether
+     *          the file is subsequently extended or truncated
      * @param   shared
      *          {@code true} to request a shared lock, in which case this
      *          channel must be open for reading (and possibly writing);
@@ -532,7 +538,10 @@ public final <A> void lock(A attachment,
      *          non-negative
      * @param   size
      *          The size of the locked region; must be non-negative, and the sum
-     *          {@code position}&nbsp;+&nbsp;{@code size} must be non-negative
+     *          {@code position}&nbsp;+&nbsp;{@code size} must be non-negative.
+     *          A value of zero means to lock all bytes from the specified
+     *          starting position to the end of the file, regardless of whether
+     *          the file is subsequently extended or truncated
      * @param   shared
      *          {@code true} to request a shared lock, in which case this
      *          channel must be open for reading (and possibly writing);
@@ -586,15 +595,20 @@ public final Future<FileLock> lock() {
      * either having acquired a lock on the requested region or having failed to
      * do so.  If it fails to acquire a lock because an overlapping lock is held
      * by another program then it returns {@code null}.  If it fails to acquire
-     * a lock for any other reason then an appropriate exception is thrown.
+     * a lock for any other reason then an appropriate exception is thrown.  If
+     * the {@code position} is non-negative and the {@code size} is zero, then a
+     * lock of size {@code Long.MAX_VALUE - position} is returned.
      *
      * @param  position
      *         The position at which the locked region is to start; must be
      *         non-negative
      *
      * @param  size
      *         The size of the locked region; must be non-negative, and the sum
-     *         {@code position}&nbsp;+&nbsp;{@code size} must be non-negative
+     *         {@code position}&nbsp;+&nbsp;{@code size} must be non-negative.
+     *         A value of zero means to lock all bytes from the specified
+     *         starting position to the end of the file, regardless of whether
+     *         the file is subsequently extended or truncated
      *
      * @param  shared
      *         {@code true} to request a shared lock,

src/java.base/share/classes/java/nio/channels/FileChannel.java

@@ -996,7 +996,9 @@ public abstract MappedByteBuffer map(MapMode mode, long position, long size)
      * required then a region starting at zero, and no smaller than the
      * expected maximum size of the file, should be locked.  The zero-argument
      * {@link #lock()} method simply locks a region of size {@link
-     * Long#MAX_VALUE}.
+     * Long#MAX_VALUE}.  If the {@code position} is non-negative and the
+     * {@code size} is zero, then a lock of size
+     * {@code Long.MAX_VALUE - position} is returned.
      *
      * <p> Some operating systems do not support shared locks, in which case a
      * request for a shared lock is automatically converted into a request for
@@ -1014,7 +1016,10 @@ public abstract MappedByteBuffer map(MapMode mode, long position, long size)
      *
      * @param  size
      *         The size of the locked region; must be non-negative, and the sum
-     *         {@code position}&nbsp;+&nbsp;{@code size} must be non-negative
+     *         {@code position}&nbsp;+&nbsp;{@code size} must be non-negative.
+     *         A value of zero means to lock all bytes from the specified
+     *         starting position to the end of the file, regardless of whether
+     *         the file is subsequently extended or truncated
      *
      * @param  shared
      *         {@code true} to request a shared lock, in which case this
@@ -1123,7 +1128,9 @@ public final FileLock lock() throws IOException {
      * required then a region starting at zero, and no smaller than the
      * expected maximum size of the file, should be locked.  The zero-argument
      * {@link #tryLock()} method simply locks a region of size {@link
-     * Long#MAX_VALUE}.
+     * Long#MAX_VALUE}.  If the {@code position} is non-negative and the
+     * {@code size} is zero, then a lock of size
+     * {@code Long.MAX_VALUE - position} is returned.
      *
      * <p> Some operating systems do not support shared locks, in which case a
      * request for a shared lock is automatically converted into a request for
@@ -1141,7 +1148,10 @@ public final FileLock lock() throws IOException {
      *
      * @param  size
      *         The size of the locked region; must be non-negative, and the sum
-     *         {@code position}&nbsp;+&nbsp;{@code size} must be non-negative
+     *         {@code position}&nbsp;+&nbsp;{@code size} must be non-negative.
+     *         A value of zero means to lock all bytes from the specified
+     *         starting position to the end of the file, regardless of whether
+     *         the file is subsequently extended or truncated
      *
      * @param  shared
      *         {@code true} to request a shared lock,

src/java.base/share/classes/java/nio/channels/FileLock.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2022, 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
@@ -269,14 +269,36 @@ public final boolean isShared() {
      * @param   size
      *          The size of the lock range
      *
-     * @return  {@code true} if, and only if, this lock and the given lock
-     *          range overlap by at least one byte
+     * @return  {@code true} if this lock and the given lock range overlap
+     *          by at least one byte; {@code false} if {@code size} is
+     *          negative or the lock range does not overlap this lock
      */
     public final boolean overlaps(long position, long size) {
-        if (position + size <= this.position)
-            return false;               // That is below this
-        if (this.position + this.size <= position)
-            return false;               // This is below that
+        if (size < 0)
+            return false;
+
+        // Test whether this is below that
+        try {
+            if (Math.addExact(this.position, this.size) <= position)
+                return false;
+        } catch (ArithmeticException ignored) {
+            // the sum of this.position and this.size overflows the range of
+            // long hence their mathematical sum is greater than position
+        }
+
+        // if size == 0 then the specified lock range is unbounded and
+        // cannot be below the range of this lock
+        if (size > 0) {
+            // Test whether that is below this
+            try {
+                if (Math.addExact(position, size) <= this.position)
+                    return false;
+            } catch (ArithmeticException ignored) {
+                // the sum of position and size overflows the range of long
+                // hence their mathematical sum is greater than this.position
+            }
+        }
+
         return true;
     }
 

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2022, 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
@@ -1271,6 +1271,8 @@ public FileLock lock(long position, long size, boolean shared)
             throw new NonReadableChannelException();
         if (!shared && !writable)
             throw new NonWritableChannelException();
+        if (size == 0)
+            size = Long.MAX_VALUE - Math.max(0, position);
         FileLockImpl fli = new FileLockImpl(this, position, size, shared);
         FileLockTable flt = fileLockTable();
         flt.add(fli);
@@ -1316,6 +1318,8 @@ public FileLock tryLock(long position, long size, boolean shared)
             throw new NonReadableChannelException();
         if (!shared && !writable)
             throw new NonWritableChannelException();
+        if (size == 0)
+            size = Long.MAX_VALUE - Math.max(0, position);
         FileLockImpl fli = new FileLockImpl(this, position, size, shared);
         FileLockTable flt = fileLockTable();
         flt.add(fli);

src/java.base/share/classes/sun/nio/ch/SimpleAsynchronousFileChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2022, 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
@@ -181,8 +181,10 @@ <A> Future<FileLock> implLock(final long position,
         if (!shared && !writing)
             throw new NonWritableChannelException();
 
+        long len = (size != 0) ? size : Long.MAX_VALUE - Math.max(0, position);
+
         // add to lock table
-        final FileLockImpl fli = addToFileLockTable(position, size, shared);
+        final FileLockImpl fli = addToFileLockTable(position, len, shared);
         if (fli == null) {
             Throwable exc = new ClosedChannelException();
             if (handler == null)
@@ -203,7 +205,7 @@ public void run() {
                     try {
                         begin();
                         do {
-                            n = nd.lock(fdObj, true, position, size, shared);
+                            n = nd.lock(fdObj, true, position, len, shared);
                         } while ((n == FileDispatcher.INTERRUPTED) && isOpen());
                         if (n != FileDispatcher.LOCKED || !isOpen()) {
                             throw new AsynchronousCloseException();
@@ -248,6 +250,9 @@ public FileLock tryLock(long position, long size, boolean shared)
         if (!shared && !writing)
             throw new NonWritableChannelException();
 
+        if (size == 0)
+            size = Long.MAX_VALUE - Math.max(0, position);
+
         // add to lock table
         FileLockImpl fli = addToFileLockTable(position, size, shared);
         if (fli == null)

src/java.base/windows/classes/sun/nio/ch/WindowsAsynchronousFileChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2022, 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
@@ -299,8 +299,10 @@ <A> Future<FileLock> implLock(final long position,
         if (!shared && !writing)
             throw new NonWritableChannelException();
 
+        long len = (size != 0) ? size : Long.MAX_VALUE - Math.max(0, position);
+
         // add to lock table
-        FileLockImpl fli = addToFileLockTable(position, size, shared);
+        FileLockImpl fli = addToFileLockTable(position, len, shared);
         if (fli == null) {
             Throwable exc = new ClosedChannelException();
             if (handler == null)
@@ -332,6 +334,9 @@ public FileLock tryLock(long position, long size, boolean shared)
         if (!shared && !writing)
             throw new NonWritableChannelException();
 
+        if (size == 0)
+            size = Long.MAX_VALUE - Math.max(0, position);
+
         // add to lock table
         final FileLockImpl fli = addToFileLockTable(position, size, shared);
         if (fli == null)

test/jdk/java/nio/channels/AsynchronousFileChannel/Basic.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2022, 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
@@ -22,18 +22,37 @@
  */
 
 /* @test
- * @bug 4607272 6822643 6830721 6842687
+ * @bug 4607272 5041655 6822643 6830721 6842687
  * @summary Unit test for AsynchronousFileChannel
  * @key randomness
  */
 
-import java.nio.file.*;
-import java.nio.channels.*;
-import java.nio.ByteBuffer;
 import java.io.File;
 import java.io.IOException;
-import java.util.*;
-import java.util.concurrent.*;
+import java.nio.ByteBuffer;
+import java.nio.channels.AsynchronousCloseException;
+import java.nio.channels.AsynchronousFileChannel;
+import java.nio.channels.ClosedChannelException;
+import java.nio.channels.CompletionHandler;
+import java.nio.channels.FileLock;
+import java.nio.channels.NonWritableChannelException;
+import java.nio.channels.OverlappingFileLockException;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.ArrayList;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Random;
+import java.util.Set;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeoutException;;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import static java.nio.file.StandardOpenOption.*;
 
@@ -176,7 +195,12 @@ static void testLocking(Path file) throws IOException {
             // test 1 - acquire lock and check that tryLock throws
             // OverlappingFileLockException
             try {
-                fl = ch.lock().get();
+                long pos = rand.nextInt(Integer.MAX_VALUE);
+                fl = ch.lock(pos, 0, false).get();
+                long expectedSize = Long.MAX_VALUE - pos;
+                if(fl.size() != expectedSize)
+                    throw new RuntimeException("Lock size " + fl.size() +
+                        " != " + expectedSize + " for position " + pos);
             } catch (ExecutionException x) {
                 throw new RuntimeException(x);
             } catch (InterruptedException x) {
@@ -192,7 +216,12 @@ static void testLocking(Path file) throws IOException {
             fl.release();
 
             // test 2 - acquire try and check that lock throws OverlappingFileLockException
-            fl = ch.tryLock();
+            long pos = rand.nextInt(Integer.MAX_VALUE);
+            fl = ch.tryLock(pos, 0, false);
+            long expectedSize = Long.MAX_VALUE - pos;
+            if(fl.size() != expectedSize)
+                throw new RuntimeException("Lock size " + fl.size() + " != " +
+                    expectedSize + " for position " + pos);
             if (fl == null)
                 throw new RuntimeException("Unable to acquire lock");
             try {

test/jdk/java/nio/channels/FileChannel/Lock.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2022, 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
@@ -22,12 +22,19 @@
  */
 
 /* @test
- * @bug 4429043 4493595 6332756 6709457 7146506
+ * @bug 4429043 4493595 5041655 6332756 6709457 7146506
  * @summary Test FileChannel file locking
  */
 
-import java.io.*;
-import java.nio.channels.*;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.InputStreamReader;
+import java.io.RandomAccessFile;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileLock;
+import java.nio.channels.OverlappingFileLockException;
+import java.util.Random;
 import static java.nio.file.StandardOpenOption.*;
 
 /**
@@ -126,12 +133,23 @@ static void test1(File blah, String str) throws Exception {
     static void test2(File blah, boolean b) throws Exception {
         try (RandomAccessFile raf = new RandomAccessFile(blah, "rw")) {
             FileChannel channel = raf.getChannel();
-            FileLock lock;
-            if (b)
-                lock = channel.lock();
-            else
-                lock = channel.tryLock();
-            lock.release();
+            try (FileLock lock = b ? channel.lock() : channel.tryLock()) {
+            }
+
+            Random rnd = new Random(System.currentTimeMillis());
+            long position = rnd.nextInt(Integer.MAX_VALUE);
+            long expectedSize = Long.MAX_VALUE - position;
+
+            for (boolean shared : new boolean[] {false, true}) {
+                try (FileLock lock = b ? channel.lock(position, 0, false) :
+                    channel.tryLock(position, 0, false)) {
+                    if(lock.size() != expectedSize)
+                        throw new RuntimeException("Lock size " + lock.size() +
+                            " != " + expectedSize +
+                            " for position " + position + " of " +
+                            (shared ? "exclusive" : "shared") + " lock");
+                }
+            }
         }
     }