94-wait-timeout

Example 94 — Wait Timeout

Demonstrates WaitTimeoutDetector catching wait() calls with no timeout.

The Problem

MessageRouter.waitForMessage() calls synchronized(lock) { lock.wait(); } with no timeout argument. If deliver() is never called — due to a race, a dropped message, or a bug — the waiting thread blocks forever. In a test suite this silently hangs the build.

The fix is to supply a timeout (lock.wait(timeoutMs)) inside a while loop so the thread can detect a stall and fail fast.

How to Reproduce

1. Remove @Disabled from test_concurrent_detectsInfiniteWait in MessageRouterTest.
2. Run the test with Maven or Gradle:

   mvn test
   gradle test
   

3. WaitTimeoutDetector will report the infinite wait() on the message lock.

The Fix

Replace lock.wait() with lock.wait(5000) inside a while (!messageAvailable) loop, then throw or log if the timeout expires without a message arriving.