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/StampedLock/OOMEInStampedLock.java

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+/*
+ * Copyright (c) 2013, 2025, 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.
+ */
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.Phaser;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.StampedLock;
+import java.util.function.Consumer;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+/**
+ * @test
+ * @bug 8066859
+ * @summary An adaptation of OOMEInAQS test for StampedLocks
+ * @requires vm.gc.G1
+ * @requires !(vm.graal.enabled & vm.compMode == "Xcomp")
+ * @run main/othervm -XX:+UseG1GC -XX:-UseGCOverheadLimit -Xmx48M -XX:-UseTLAB OOMEInStampedLock
+ */
+
+public class OOMEInStampedLock extends Thread {
+    static final int NTHREADS = 3;
+    static final int NREPS = 100;
+    // statically allocate
+    static final StampedLock stampedLock = new StampedLock();
+    static final Lock wLock = stampedLock.asWriteLock();
+    static final Lock rLock = stampedLock.asReadLock();
+    static final CountDownLatch started = new CountDownLatch(1);
+    static final CountDownLatch filled = new CountDownLatch(1);
+    static final CountDownLatch canFill = new CountDownLatch(NTHREADS);
+    static volatile Object data;
+    static volatile Throwable exception;
+    static int turn;
+
+    /**
+     * For each of NTHREADS threads, REPS times: Take turns
+     * executing. Introduce OOM using fillHeap during runs. In
+     * addition to testing AQS, the CountDownLatches ensure that
+     * methods execute at least once before OutOfMemory occurs, to
+     * avoid uncontrollable impact of OOME during class-loading.
+     */
+    public static void main(String[] args) throws Throwable {
+        OOMEInStampedLock[] threads = new OOMEInStampedLock[NTHREADS];
+        for (int i = 0; i < NTHREADS; ++i)
+            (threads[i] = new OOMEInStampedLock(i)).start();
+        started.countDown();
+        canFill.await();
+        long t0 = System.nanoTime();
+        data = fillHeap();
+        filled.countDown();
+        long t1 = System.nanoTime();
+        for (int i = 0; i < NTHREADS; ++i)
+            threads[i].join();
+        data = null;  // free heap before reporting and terminating
+        System.gc();
+        Throwable ex = exception;
+        if (ex != null)
+            throw ex;
+        System.out.println(
+            "fillHeap time: " + (t1 - t0) / 1000_000 +
+            " millis, whole test time: " + (System.nanoTime() - t0) / 1000_000 +
+            " millis"
+        );
+    }
+
+    final int tid;
+    OOMEInStampedLock(int tid) {
+        this.tid = tid;
+    }
+
+    @Override
+    public void run() {
+        int id = tid, nextId = (id + 1) % NTHREADS;
+        final Lock wl = wLock, rl = rLock;
+        try {
+            started.await();
+            for (int i = 0; i < NREPS; i++) {
+                int t;
+                rl.lock(); t = turn; rl.unlock();
+                wl.lock();
+                try {
+                    if (turn == t && turn == id)
+                        turn = nextId;
+                } finally {
+                    wl.unlock();
+                }
+                if (i == 2) {  // Subsequent AQS methods encounter OOME
+                    canFill.countDown();
+                    filled.await();
+                }
+            }
+            data = null;
+            System.gc(); // avoid getting stuck while exiting
+        } catch (Throwable ex) {
+            data = null;
+            System.gc(); // avoid nested OOME
+            exception = ex;
+        }
+    }
+
+    static Object[] fillHeap() {
+        Object[] first = null, last = null;
+        int size = 1 << 20;
+        while (size > 0) {
+            try {
+                Object[] array = new Object[size];
+                if (first == null) {
+                    first = array;
+                } else {
+                    last[0] = array;
+                }
+                last = array;
+            } catch (OutOfMemoryError oome) {
+                size = size >>> 1;
+            }
+        }
+        return first;
+    }
+}