diff --git a/jdk/src/java.base/share/classes/java/io/ByteArrayOutputStream.java b/jdk/src/java.base/share/classes/java/io/ByteArrayOutputStream.java index 71be2db3b47..3d199579249 100644 --- a/jdk/src/java.base/share/classes/java/io/ByteArrayOutputStream.java +++ b/jdk/src/java.base/share/classes/java/io/ByteArrayOutputStream.java @@ -93,6 +93,14 @@ public class ByteArrayOutputStream extends OutputStream { grow(minCapacity); } + /** + * The maximum size of array to allocate. + * Some VMs reserve some header words in an array. + * Attempts to allocate larger arrays may result in + * OutOfMemoryError: Requested array size exceeds VM limit + */ + private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; + /** * Increases the capacity to ensure that it can hold at least the * number of elements specified by the minimum capacity argument. @@ -105,14 +113,19 @@ public class ByteArrayOutputStream extends OutputStream { int newCapacity = oldCapacity << 1; if (newCapacity - minCapacity < 0) newCapacity = minCapacity; - if (newCapacity < 0) { - if (minCapacity < 0) // overflow - throw new OutOfMemoryError(); - newCapacity = Integer.MAX_VALUE; - } + if (newCapacity - MAX_ARRAY_SIZE > 0) + newCapacity = hugeCapacity(minCapacity); buf = Arrays.copyOf(buf, newCapacity); } + private static int hugeCapacity(int minCapacity) { + if (minCapacity < 0) // overflow + throw new OutOfMemoryError(); + return (minCapacity > MAX_ARRAY_SIZE) ? + Integer.MAX_VALUE : + MAX_ARRAY_SIZE; + } + /** * Writes the specified byte to this byte array output stream. * diff --git a/jdk/test/java/io/ByteArrayOutputStream/MaxCapacity.java b/jdk/test/java/io/ByteArrayOutputStream/MaxCapacity.java new file mode 100644 index 00000000000..e46786cca27 --- /dev/null +++ b/jdk/test/java/io/ByteArrayOutputStream/MaxCapacity.java @@ -0,0 +1,65 @@ +/* + * Copyright (c) 2014 Google Inc. 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 + * @ignore This test has huge memory requirements + * @run main/timeout=1800/othervm -Xmx8g MaxCapacity + * @bug 8055949 + * @summary Check that we can write (almost) Integer.MAX_VALUE bytes + * to a ByteArrayOutputStream. + * @author Martin Buchholz + */ +import java.io.ByteArrayOutputStream; + +public class MaxCapacity { + public static void main(String[] args) { + long maxHeap = Runtime.getRuntime().maxMemory(); + if (maxHeap < 3L * Integer.MAX_VALUE) { + System.out.printf("Skipping test; max memory %sM too small%n", + maxHeap/(1024*1024)); + return; + } + ByteArrayOutputStream baos = new ByteArrayOutputStream(); + for (long n = 0; ; n++) { + try { + baos.write((byte)'x'); + } catch (Throwable t) { + // check data integrity while we're here + byte[] bytes = baos.toByteArray(); + if (bytes.length != n) + throw new AssertionError("wrong length"); + if (bytes[0] != 'x' || + bytes[bytes.length - 1] != 'x') + throw new AssertionError("wrong contents"); + + long gap = Integer.MAX_VALUE - n; + System.out.printf("gap=%dM %d%n", gap/(1024*1024), gap); + if (gap > 1024) + throw t; + // t.printStackTrace(); + break; + } + } + } +}