[Jtsummers]

You can have deadlock in Erlang, it's just a bit harder. It happens when two processes are both waiting on the other to send them a message which is analogous to two threads each waiting for a mutex the other holds. The same thing can happen in Go with its channels, another message passing based concurrency control mechanism.

[orthoxerox]

Two deadlocked processes won't exhaust the thread pool in Erlang, they will simply never wake up.

[jake_morrison]

Sure, you can make deadlocks in any language, but it's uncommon in Erlang. Shared state is the exception, and message passing means that things that manage state, such as gen_servers, only process one message at a time from their inbox.

Contrast this with languages like Java where every object is a potential concurrency problem. Or the 10+ years of trying to make Python async (see Twisted).