Hi guys I’m having trouble with actors, can’t an actor send a message to itself? somehow ,

channel.send()

blocks, what’s the properway to do it?

It doesn't block, it suspends. You can use

offer

here.

offer

returns false.

I think the only way you can do this safely is to set capacity to UNLIMITED, because with a fixed capacity you run into a danger of deadlock like you’ve mentioned: 1. The actor receives a message 2. While the actor processes, another coroutine pushes something onto the actor’s channel 3. The actor tries to send a message into its own channel, but it suspends because the channel is full 4. The channel now can’t be emptied because the actor needs to pull the next message from the channel, but can’t do that until it completes the send

@tmg Check out the docs regarding capacity, you'll see capacity 0 means something special, the french translation of appointment, and in your case, an appointment between receive and offer is impossible.

The problem with setting to unlimited though is the lack of backpressure, so if the actor processes messages slower than senders are sending the channel will continue to grow in size and your memory usage will balloon

@Evan R. yeah, when sending a message to itself it can indeed reach a deadlock without unlimited, but for this use case, there is an actual limit on the messages the actor will receive, so with a proper capacity value, it would never reach it, or if I use unlimited it would never grow too much @louiscad I don’t understood your comment. Is changing from capacity 0 here wrong in my case? (the only thing i get from your comment is that i should read the doc 😅 which I will do

@tmg In the docs of

Channel

, which is used and exposed in

actor

, you'll find

RENDEZ_VOUS

, which is equal to

0

.