8373120: Virtual thread stuck in BLOCKED state

src/java.base/share/classes/java/lang/VirtualThread.java

@@ -620,9 +620,12 @@ private void afterYield() {
         // Object.wait
         if (s == WAITING || s == TIMED_WAITING) {
             int newState;
+            boolean blocked;
             boolean interruptible = interruptibleWait;
             if (s == WAITING) {
                 setState(newState = WAIT);
+                // may have been notified while in transition
+                blocked = notified && compareAndSetState(WAIT, BLOCKED);
             } else {
                 // For timed-wait, a timeout task is scheduled to execute. The timeout
                 // task will change the thread state to UNBLOCKED and submit the thread
@@ -637,22 +640,22 @@ private void afterYield() {
                     byte seqNo = ++timedWaitSeqNo;
                     timeoutTask = schedule(() -> waitTimeoutExpired(seqNo), timeout, MILLISECONDS);
                     setState(newState = TIMED_WAIT);
+                    // May have been notified while in transition. This must be done while
+                    // holding the monitor to avoid changing the state of a new timed wait call.
+                    blocked = notified && compareAndSetState(TIMED_WAIT, BLOCKED);
                 }
             }
 
-            // may have been notified while in transition to wait state
-            if (notified && compareAndSetState(newState, BLOCKED)) {
-                // may have even been unblocked already
+            if (blocked) {
+                // may have been unblocked already
                 if (blockPermit && compareAndSetState(BLOCKED, UNBLOCKED)) {
-                    submitRunContinuation();
+                    lazySubmitRunContinuation();
+                }
+            } else {
+                // may have been interrupted while in transition to wait state
+                if (interruptible && interrupted && compareAndSetState(newState, UNBLOCKED)) {
+                    lazySubmitRunContinuation();
                 }
-                return;
-            }
-
-            // may have been interrupted while in transition to wait state
-            if (interruptible && interrupted && compareAndSetState(newState, UNBLOCKED)) {
-                submitRunContinuation();
-                return;
             }
             return;
         }

test/jdk/java/lang/Thread/virtual/stress/NotifiedThenTimedOutWait.java

@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2026, 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 8373120
+ * @summary Stress test two consecutive timed Object.wait calls where only the first one is notified.
+ * @run main/othervm -XX:CompileCommand=exclude,java.lang.VirtualThread::afterYield NotifiedThenTimedOutWait 1 100 100
+ */
+
+/*
+ * @test
+ * @run main/othervm -XX:CompileCommand=exclude,java.lang.VirtualThread::afterYield NotifiedThenTimedOutWait 2 100 100
+ */
+
+import java.time.Instant;
+import java.util.concurrent.Phaser;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.ThreadLocalRandom;
+
+public class NotifiedThenTimedOutWait {
+    public static void main(String[] args) throws Exception {
+        int race = (args.length > 0) ? Integer.parseInt(args[0]) : 1;
+        int nruns = (args.length > 1) ? Integer.parseInt(args[1]) : 100;
+        int iterations = (args.length > 2) ? Integer.parseInt(args[2]) : 100;
+
+        for (int i = 1; i <= nruns; i++) {
+            System.out.println(Instant.now() + " => " + i + " of " + nruns);
+            switch (race) {
+                case 1 -> race1(iterations);
+                case 2 -> race2(iterations);
+            }
+        }
+    }
+
+    /**
+     * Barrier in synchronized block.
+     */
+    private static void race1(int iterations) throws InterruptedException {
+        final int timeout = 1;
+        var lock = new Object();
+        var start = new Phaser(2);
+        var end = new Phaser(2);
+
+        var vthread = Thread.ofVirtual().start(() -> {
+            try {
+                for (int j = 0; j < iterations; j++) {
+                    synchronized (lock) {
+                        start.arriveAndAwaitAdvance();
+                        lock.wait(timeout);
+                        lock.wait(timeout);
+                    }
+                    end.arriveAndAwaitAdvance();
+                }
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        });
+
+        ThreadFactory factory = ThreadLocalRandom.current().nextBoolean()
+                    ? Thread.ofPlatform().factory() : Thread.ofVirtual().factory();
+        var notifier = factory.newThread(() -> {
+            for (int j = 0; j < iterations; j++) {
+                start.arriveAndAwaitAdvance();
+                synchronized (lock) {
+                    lock.notify();
+                }
+                end.arriveAndAwaitAdvance();
+            }
+        });
+        notifier.start();
+
+        vthread.join();
+        notifier.join();
+    }
+
+    /**
+     * Barrier before synchronized block.
+     */
+    private static void race2(int iterations) throws InterruptedException {
+        final int timeout = 1;
+        var lock = new Object();
+        var start = new Phaser(2);
+
+        var vthread = Thread.startVirtualThread(() -> {
+            try {
+                for (int i = 0; i < iterations; i++) {
+                    start.arriveAndAwaitAdvance();
+                    synchronized (lock) {
+                        lock.wait(timeout);
+                        lock.wait(timeout);
+                    }
+                }
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        });
+
+        ThreadFactory factory = ThreadLocalRandom.current().nextBoolean()
+                    ? Thread.ofPlatform().factory() : Thread.ofVirtual().factory();
+        var notifier = factory.newThread(() -> {
+            for (int i = 0; i < iterations; i++) {
+                start.arriveAndAwaitAdvance();
+                synchronized (lock) {
+                    lock.notify();
+                }
+            }
+        });
+        notifier.start();
+
+        vthread.join();
+        notifier.join();
+    }
+}