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/util/concurrent/locks/ReentrantLock/LockOncePerThreadLoops.java

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+/*
+ * 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.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/*
+ * @test
+ * @bug 4486658
+ * @summary Checks for missed signals by locking and unlocking each of an array of locks once per thread
+ * @library /test/lib
+ */
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.locks.ReentrantLock;
+import jdk.test.lib.Utils;
+
+public final class LockOncePerThreadLoops {
+    static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
+    static final ExecutorService pool = Executors.newCachedThreadPool();
+    static boolean print = false;
+    static int nlocks = 20_000;
+    static int nthreads = 20;
+    static int replications = 3;
+
+    public static void main(String[] args) throws Exception {
+        if (args.length > 0)
+            replications = Integer.parseInt(args[0]);
+
+        if (args.length > 1)
+            nlocks = Integer.parseInt(args[1]);
+
+        print = true;
+
+        for (int i = 0; i < replications; ++i) {
+            System.out.print("Iteration: " + i);
+            new ReentrantLockLoop().test();
+        }
+        pool.shutdown();
+        if (! pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS))
+            throw new Error();
+    }
+
+    static final class ReentrantLockLoop implements Runnable {
+        private int v = ThreadLocalRandom.current().nextInt();
+        private volatile int result = 17;
+        final ReentrantLock[]locks = new ReentrantLock[nlocks];
+
+        private final ReentrantLock lock = new ReentrantLock();
+        private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
+        private final CyclicBarrier barrier;
+        ReentrantLockLoop() {
+            barrier = new CyclicBarrier(nthreads+1, timer);
+            for (int i = 0; i < nlocks; ++i)
+                locks[i] = new ReentrantLock();
+        }
+
+        final void test() throws Exception {
+            for (int i = 0; i < nthreads; ++i)
+                pool.execute(this);
+            barrier.await();
+            barrier.await();
+            if (print) {
+                long time = timer.getTime();
+                double secs = (double)time / 1000000000.0;
+                System.out.println("\t " + secs + "s run time");
+            }
+
+            int r = result;
+            if (r == 0) // avoid overoptimization
+                System.out.println("useless result: " + r);
+        }
+
+        public final void run() {
+            try {
+                barrier.await();
+                int sum = v;
+                int x = 0;
+                for (int i = 0; i < locks.length; ++i) {
+                    locks[i].lock();
+                    try {
+                        v = x += ~(v - i);
+                    }
+                    finally {
+                        locks[i].unlock();
+                    }
+                    // Once in a while, do something more expensive
+                    if ((~i & 255) == 0) {
+                        sum += LoopHelpers.compute1(LoopHelpers.compute2(x));
+                    }
+                    else
+                        sum += sum ^ x;
+                }
+                barrier.await();
+                result += sum;
+            }
+            catch (Exception ex) {
+                return;
+            }
+        }
+    }
+
+}