2. Communication in Erlang

2 Communication in Erlang

Communication in Erlang is conceptually performed using asynchronous signaling. All different executing entities, such as processes and ports, communicate through asynchronous signals. The most commonly used signal is a message. Other common signals are exit, link, unlink, monitor, and demonitor signals.

2.1 Passing of Signals

The amount of time that passes between a signal is sent and the arrival of the signal at the destination is unspecified but positive. If the receiver has terminated, the signal does not arrive, but it can trigger another signal. For example, a link signal sent to a non-existing process triggers an exit signal, which is sent back to where the link signal originated from. When communicating over the distribution, signals can be lost if the distribution channel goes down.

The only signal ordering guarantee given is the following: if an entity sends multiple signals to the same d