How to deadlock a Java ExecutorService

- Java's ExecutorService is a framework for running tasks concurrently (in parallel) using a pool of reusable threads. Developers submit tasks to it instead of manually creating threads. - A "thread pool" with a fixed number of threads (e.g., 2 threads) can only run that many tasks at once. Extra tasks wait in a queue. - This article shows a subtle deadlock bug: if a task running in the pool submits another task to the same pool and then waits for its result (via Future.get()), it can hang forever — the waiting task occupies one thread, but the subtask needs a thread from the same pool. If all threads are occupied waiting, no thread remains to run the subtask, so nothing progresses. - This is a well-known trap called "thread starvation deadlock" or "ExecutorService deadlock". It's a common interview question and a real bug in production code.