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/lang/management/BufferPoolMXBean/Basic.java

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+/*
+ * Copyright (c) 2007, 2016, 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 6606598 7024172
+ * @summary Unit test for java.lang.management.BufferPoolMXBean
+ * @modules jdk.management
+ * @run main/othervm Basic
+ * @key randomness
+ */
+
+import java.nio.ByteBuffer;
+import java.nio.MappedByteBuffer;
+import java.nio.file.Path;
+import java.nio.file.Files;
+import static java.nio.file.StandardOpenOption.*;
+import java.nio.channels.FileChannel;
+import java.lang.management.BufferPoolMXBean;
+import java.lang.management.ManagementFactory;
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
+import java.lang.ref.WeakReference;
+import java.util.*;
+
+public class Basic {
+
+    // static fields to ensure buffers aren't GC'ed
+    static List<ByteBuffer> buffers;
+    static MappedByteBuffer mbb;
+
+    // check counters
+    static void check(List<BufferPoolMXBean> pools,
+                      int minBufferCount,
+                      long minTotalCapacity)
+    {
+        int bufferCount = 0;
+        long totalCap = 0;
+        long totalMem = 0;
+        for (BufferPoolMXBean pool: pools) {
+            bufferCount += pool.getCount();
+            totalCap += pool.getTotalCapacity();
+            totalMem += pool.getMemoryUsed();
+        }
+        if (bufferCount < minBufferCount)
+            throw new RuntimeException("Count less than expected");
+        if (totalMem < minTotalCapacity)
+            throw new RuntimeException("Memory usage less than expected");
+        if (totalCap < minTotalCapacity)
+            throw new RuntimeException("Total capacity less than expected");
+    }
+
+    public static void main(String[] args) throws Exception {
+        Random rand = new Random();
+
+        // allocate a few direct buffers
+        int bufferCount = 5 + rand.nextInt(20);
+        buffers = new ArrayList<ByteBuffer>(bufferCount);
+        long totalCapacity = 0L;
+        for (int i=0; i<bufferCount; i++) {
+            int cap = 1024 + rand.nextInt(4096);
+            buffers.add( ByteBuffer.allocateDirect(cap) );
+            totalCapacity += cap;
+        }
+
+        // create a mapped buffer
+        Path tmpfile = Files.createTempFile("blah", null);
+        tmpfile.toFile().deleteOnExit();
+        try (FileChannel fc = FileChannel.open(tmpfile, READ, WRITE)) {
+            mbb = fc.map(FileChannel.MapMode.READ_WRITE, 10, 100);
+            bufferCount++;
+            totalCapacity += mbb.capacity();
+        }
+
+        // use platform MXBeans directly
+        List<BufferPoolMXBean> pools =
+            ManagementFactory.getPlatformMXBeans(BufferPoolMXBean.class);
+        check(pools, bufferCount, totalCapacity);
+
+        // use MBeanServer
+        MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+        Set<ObjectName> mbeans = server.queryNames(
+            new ObjectName("java.nio:type=BufferPool,*"), null);
+        pools = new ArrayList<BufferPoolMXBean>();
+        for (ObjectName name: mbeans) {
+            BufferPoolMXBean pool = ManagementFactory
+                .newPlatformMXBeanProxy(server, name.toString(), BufferPoolMXBean.class);
+            pools.add(pool);
+        }
+        check(pools, bufferCount, totalCapacity);
+
+        // attempt to unmap mapped buffer
+        WeakReference<MappedByteBuffer> ref = new WeakReference<>(mbb);
+        mbb = null;
+        do {
+            System.gc();
+            Thread.sleep(250);
+        } while (ref.get() != null);
+    }
+}