EventWriter in query.par_for_each or query.par_for_each_mut

[urben1680]

Hello,

I am aware I can use ParallelCommands to bring commands into said query functions, but what is the idiomatic way to do this with EventWriter?

[urben1680]

I noticed a few days ago that the EventWriter contains a ResMut<Events<T>> field. This is another brick in the way to send events in parallel.

It also made me realize that systems with the same EventWriter cannot run in parallel which I did not know so far. I assumed EventWriter behaves like std::sync::mpsc::SyncSender. It might be a nice addition to Bevy if a SyncEventWriter was supported.

I solved my issue here by setting up such a resource myself. I put the receivers into a NonSend resource which works well for my use case. If the buffer went full I fall back to writing the event into a vector using (parallel) commands.