Commit f122b4b1 authored by eta's avatar eta
Browse files

Merge branch 'no_empty_select' into 'main' 

ptmgr: Do not construct an empty select_all future.

Closes #672 and #670

See merge request tpo/core/arti!907
parents e068c5c2 d853fdb5

crates/tor-ptmgr/src/lib.rs

+9 −1
Original line number Diff line number Diff line
@@ -193,6 +193,8 @@ impl<R: Runtime> PtReactor<R> { 


    /// Run one step of the reactor. Returns true if the reactor should terminate.

    async fn run_one_step(&mut self) -> err::Result<bool> {

        use futures::future::Either;



        // FIXME(eta): This allocates a lot, which is technically unnecessary but requires careful

        //             engineering to get right. It's not really in the hot path, at least.

        let mut all_next_messages = self
@@ -202,7 +204,13 @@ impl<R: Runtime> PtReactor<R> { 
            // does under the hood.

            .map(|pt| Box::pin(pt.next_message()))

            .collect::<Vec<_>>();

        let mut next_message = futures::future::select_all(all_next_messages.iter_mut()).fuse();



        // We can't construct a select_all if all_next_messages is empty.

        let mut next_message = if all_next_messages.is_empty() {

            Either::Left(futures::future::pending())

        } else {

            Either::Right(futures::future::select_all(all_next_messages.iter_mut()).fuse())

        };



        select! {

            (result, idx, _) = next_message => {