net.server_epoll: Ensure timeouts match epoll flags Read and write timeouts should usually match whether we want to read or write.

net.server_epoll: Skip reset of read timeout when not reading Should avoid rare but needless timer interactions

net.server_epoll: Reduce timer churn during TLS handshake Instead of removing and readding the timer, keep it and adjust it instead. Should reduce garbage production a bit.

net.server_epoll: Use only fatal "write" timeout during TLS negotiation Only real difference between the read and write timeouts is that the former has a callback that allows the higher levels to keep the connection alive, while hitting the later is immediately fatal. We want the later behavior for TLS negotiation.

net.server_epoll: Optimize concatenation of exactly 2 buffer chunks Saves a function call. I forget if I measured this kind of thing but IIRC infix concatenation is faster than a function call up to some number of items, but let's stop at 2 here.

net.server_epoll: Avoid allocating a buffer table for single writes writebuffer is now string | { string } Saves the allocation of a buffer table until the second write, which could be rare, especially with opportunistic writes.

net.server_epoll: Optionally let go of buffers Reusing an already existing buffer table would reduce garbage, but keeping it while idle is a waste.

net.server_epoll: Propagate returns from opportunistic writes So that if a write ends up writing directly to the socket, it gets the actual return value

net.server_epoll: Set minimum wait time to 1ms, matching epoll A timeout value less than 0.001 gets turned into zero on the C side, so epoll_wait() returns instantly and essentially busy-loops up to 1ms, e.g. when a timer event ends up scheduled (0, 0.001)ms into the future. Unsure if this has much effect in practice, but it may waste a small amount of CPU time. How much would depend on how often this ends up happening and how fast the CPU gets trough main loop iterations.

prosodyctl: Add a note about checking the order of listed commands Should Plugin really be first? What order makes the most sense?