Skip to content

In tor-proto, can manually closing a StreamTarget collide with dropping it?

Right now there are two paths into the circuit reactor's close_stream() method:

  • First, from run_once() when it gets a Ok(None) from a StreamTarget, indicating that the StreamTarget has dropped its half of the mpsc::Sender.
  • Second, from handle_control() when it gets a ClosePendingStream control message, indicating that the StreamTarget has been manually closed from IncomingStream::reject() via StreamTarget::close().

I think that it's possible for both of those paths to get triggered for the same stream.

But if we call close_stream() twice on the same stream, the reactor will panic in StreamMap::terminate().

Here is a thought: perhaps we should just remove StreamTarget::close() and CtrlMsg::ClosePendingStream, and handle IncomingStream::reject() by dropping the StreamTarget?

(Found while working on a branch to make StreamTarget::close() safer to use. I'll link this ticket with that MR, since it clarifies stuff and adds comments.)