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/ScheduledThreadPoolExecutor/GCRetention.java

@@ -0,0 +1,141 @@
+/*
+ * 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 and Martin Buchholz 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
+ * @summary Ensure that waiting pool threads don't retain refs to tasks.
+ */
+
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Delayed;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.RunnableScheduledFuture;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+public class GCRetention {
+
+    /**
+     * A custom thread pool with a custom RunnableScheduledFuture, for the
+     * sole purpose of ensuring that the task retains a strong reference to
+     * the Runnable even after cancellation.
+     */
+    static class CustomPool extends ScheduledThreadPoolExecutor {
+        CustomPool(int n) { super(n); }
+        protected <V> RunnableScheduledFuture<V> decorateTask(
+            final Runnable r,
+            final RunnableScheduledFuture<V> task) {
+            return new RunnableScheduledFuture<V>() {
+                public void run() { System.err.println(r); task.run(); }
+                public boolean isPeriodic() { return task.isPeriodic(); }
+                public V get()
+                    throws InterruptedException,ExecutionException
+                    { return task.get(); }
+                public V get(long x, TimeUnit y)
+                    throws InterruptedException,ExecutionException,TimeoutException
+                    { return task.get(x, y); }
+                public boolean isDone() { return task.isDone(); }
+                public boolean isCancelled() { return task.isCancelled(); }
+                public boolean cancel(boolean x) { return task.cancel(x); }
+                public long getDelay(TimeUnit x) { return task.getDelay(x); }
+                public int compareTo(Delayed x) { return task.compareTo(x); }
+            };
+        }
+    }
+
+    void removeAll(ReferenceQueue<?> q, int n) throws InterruptedException {
+        for (int j = n; j--> 0; ) {
+            if (q.poll() == null) {
+                for (;;) {
+                    System.gc();
+                    if (q.remove(1000) != null)
+                        break;
+                    System.out.printf(
+                        "%d/%d unqueued references remaining%n", j + 1, n);
+                }
+            }
+        }
+        check(q.poll() == null);
+    }
+
+    void test(String[] args) throws Throwable {
+        final CustomPool pool = new CustomPool(10);
+        final int size = 100;
+        final ReferenceQueue<Object> q = new ReferenceQueue<>();
+        final List<WeakReference<?>> refs = new ArrayList<>(size);
+        final List<Future<?>> futures = new ArrayList<>(size);
+
+        // Schedule custom tasks with strong references.
+        class Task implements Runnable {
+            final Object x;
+            Task() { refs.add(new WeakReference<>(x = new Object(), q)); }
+            public void run() { System.out.println(x); }
+        }
+        // Give tasks added later earlier expiration, to ensure
+        // multiple residents of queue head.
+        for (int i = size; i--> 0; )
+            futures.add(pool.schedule(new Task(), i + 1, TimeUnit.MINUTES));
+        futures.forEach(future -> future.cancel(false));
+        futures.clear();
+
+        pool.purge();
+        removeAll(q, size);
+        for (WeakReference<?> ref : refs) check(ref.get() == null);
+
+        pool.shutdown();
+        // rely on test harness to handle timeout
+        pool.awaitTermination(1L, TimeUnit.DAYS);
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    volatile int passed = 0, failed = 0;
+    void pass() {passed++;}
+    void fail() {failed++; Thread.dumpStack();}
+    void fail(String msg) {System.err.println(msg); fail();}
+    void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    void check(boolean cond) {if (cond) pass(); else fail();}
+    void equal(Object x, Object y) {
+        if (x == null ? y == null : x.equals(y)) pass();
+        else fail(x + " not equal to " + y);}
+    public static void main(String[] args) throws Throwable {
+        new GCRetention().instanceMain(args);}
+    void instanceMain(String[] args) throws Throwable {
+        try {test(args);} catch (Throwable t) {unexpected(t);}
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) throw new AssertionError("Some tests failed");}
+}