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

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Reviewed-by: alanb
This commit is contained in:
Brian Burkhalter 2022-02-22 17:24:15 +00:00
parent 7feabee426
commit 6445ee46b5
9 changed files with 247 additions and 45 deletions
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32
src/java.base/share/classes/java/nio/channels/AsynchronousFileChannel.java
View file

@ -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 abstract class AsynchronousFileChannel
* 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 abstract class AsynchronousFileChannel
* 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 abstract class AsynchronousFileChannel
* 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);
@ -586,7 +595,9 @@ public abstract class AsynchronousFileChannel
* 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
@ -594,7 +605,10 @@ public abstract class AsynchronousFileChannel
*
* @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,

18
src/java.base/share/classes/java/nio/channels/FileChannel.java
View file

@ -996,7 +996,9 @@ public abstract class FileChannel
* 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 class FileChannel
*
* @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 abstract class FileChannel
* 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 abstract class FileChannel
*
* @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,

36
src/java.base/share/classes/java/nio/channels/FileLock.java
View file

@ -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 abstract class FileLock implements AutoCloseable {
* @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;
}