Deadlock and the Failures Near It

Deadlock: threads that stop forever because each holds a lock another is waiting for. It has a reputation for being mysterious and is the opposite: it needs four conditions at once, and removing one of them removes it. It covers what a deadlock is, a transfer that deadlocks, the four conditions, fixing it with a lock order, livelock and starvation, and what a timeout does and does not do. It leaves out deadlocks inside databases, which follow the same rules with different tools.