Inotify::read_events does not read all events about inotify-sys

[jimblandy]

The notify crate registers its inotify file descriptor with mio::PollOpt::edge(), which requests edge-triggered notifications, as described here: https://docs.rs/mio/0.6.15/mio/struct.Poll.html#edge-triggered-and-level-triggered

If when the socket was registered with Poll, edge triggered events were requested, then the call to Poll::poll done in step 5 will (probably) hang despite there being another 1kb still present in the socket read buffer. The reason for this is that edge-triggered mode delivers events only when changes occur on the monitored Evented. So, in step 5 the caller might end up waiting for some data that is already present inside the socket buffer.

This means that notify::inotify::EventLoop::handle_inotify is indeed counting on inotify::Inotify::read_events to behave as documented: to fully consume all available data from the file descriptor.

[jimblandy]

Indeed, if I change notify::inotify::EventLoop::new to request level-triggered events on inotify_fd, I get all my file creation notifications.

[jimblandy]

Ah, crud, this is the inotify-sys crate, not inotify.