undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

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

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+/*
+ * Copyright (c) 2010, 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 6913877
+ * @summary Stress AsynchronousFileChannel.write
+ * @key randomness
+ */
+
+import java.io.*;
+import java.nio.ByteBuffer;
+import static java.nio.file.StandardOpenOption.*;
+import java.nio.channels.*;
+import java.util.Random;
+import java.util.concurrent.CountDownLatch;
+
+public class LotsOfWrites {
+    static final Random rand = new Random();
+
+    /**
+     * Asynchronously writes a known pattern to a file up to a given size,
+     * counting down a latch to release waiters when done.
+     */
+    static class Writer implements CompletionHandler<Integer,ByteBuffer> {
+        private final File file;
+        private final long size;
+        private final CountDownLatch latch;
+        private final AsynchronousFileChannel channel;
+
+        private volatile long position;
+        private volatile byte nextByte;
+
+        private long updatePosition(long nwrote) {
+            position += nwrote;
+            return position;
+        }
+
+        private ByteBuffer genNextBuffer() {
+            int n = Math.min(8192 + rand.nextInt(8192), (int)(size - position));
+            ByteBuffer buf = ByteBuffer.allocate(n);
+            for (int i=0; i<n; i++) {
+                buf.put(nextByte++);
+            }
+            buf.flip();
+            return buf;
+        }
+
+        // close channel and release any waiters
+        private void done() {
+            try {
+                channel.close();
+            } catch (IOException ignore) { }
+            latch.countDown();
+        }
+
+        Writer(File file, long size, CountDownLatch latch) throws IOException {
+            this.file = file;
+            this.size = size;
+            this.latch = latch;
+            this.channel = AsynchronousFileChannel.open(file.toPath(), WRITE);
+        }
+
+        File file() {
+            return file;
+        }
+
+        long size() {
+            return size;
+        }
+
+        // initiate first write
+        void start() {
+            ByteBuffer buf = genNextBuffer();
+            channel.write(buf, 0L, buf, this);
+        }
+
+        @Override
+        public void completed(Integer nwrote, ByteBuffer buf) {
+            long pos = updatePosition(nwrote);
+            if (!buf.hasRemaining()) {
+                // buffer has been completely written; decide if we need to
+                // write more
+                if (position >= size) {
+                    done();
+                    return;
+                }
+                buf = genNextBuffer();
+            }
+            channel.write(buf, pos, buf, this);
+        }
+
+        @Override
+        public void failed(Throwable exc, ByteBuffer buf) {
+            exc.printStackTrace();
+            done();
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        // random number of writers
+        int count = 20 + rand.nextInt(16);
+        Writer[] writers = new Writer[count];
+        CountDownLatch latch = new CountDownLatch(count);
+
+        // initiate writing to each file
+        for (int i=0; i<count; i++) {
+            long size = 512*1024 + rand.nextInt(512*1024);
+            File blah = File.createTempFile("blah", null);
+            blah.deleteOnExit();
+            Writer writer = new Writer(blah, size, latch);
+            writers[i] = writer;
+            writer.start();
+        }
+
+        // wait for writing to complete
+        latch.await();
+
+        // verify content of each file
+        boolean failed = false;
+        byte[] buf = new byte[8192];
+        for (int i=0; i<count ;i++) {
+            Writer writer = writers[i];
+            FileInputStream in = new FileInputStream(writer.file());
+            try {
+                long size = 0L;
+                byte expected = 0;
+                int nread = in.read(buf);
+                while (nread > 0) {
+                    for (int j=0; j<nread; j++) {
+                        if (buf[j] != expected) {
+                            System.err.println("Unexpected contents");
+                            failed = true;
+                            break;
+                        }
+                        expected++;
+                    }
+                    if (failed)
+                        break;
+                    size += nread;
+                    nread = in.read(buf);
+                }
+                if (!failed && size != writer.size()) {
+                    System.err.println("Unexpected size");
+                    failed = true;
+                }
+                if (failed)
+                    break;
+            } finally {
+                in.close();
+            }
+        }
+
+        // clean-up
+        for (int i=0; i<count; i++) {
+            writers[i].file().delete();
+        }
+
+        if (failed)
+            throw new RuntimeException("Test failed");
+    }
+}