fix filedescriptor::poll on macos

Need to use the subsecond microsecond value, rather than the total
microsecond value, otherwise `select(2)` will yield EINVAL.

The wezterm changes show where this error was bubbling up
and breaking the tls client code.

filedescriptor/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "filedescriptor"
-version = "0.7.2"
+version = "0.7.3"
 authors = ["Wez Furlong"]
 edition = "2018"
 repository = "https://github.com/wez/wezterm"

filedescriptor/src/unix.rs

@@ -440,7 +440,7 @@ mod macos {
 
         let mut timeout = duration.map(|d| timeval {
             tv_sec: d.as_secs() as _,
-            tv_usec: d.as_micros() as _,
+            tv_usec: d.subsec_micros() as _,
         });
 
         let res = unsafe {

src/server/client.rs

@@ -11,7 +11,7 @@ use crate::server::UnixStream;
 use crate::ssh::ssh_connect_with_ui;
 use anyhow::{anyhow, bail, Context, Error};
 use crossbeam::channel::TryRecvError;
-use filedescriptor::{pollfd, AsRawSocketDescriptor};
+use filedescriptor::{poll, pollfd, AsRawSocketDescriptor};
 use log::info;
 use openssl::ssl::{SslConnector, SslFiletype, SslMethod};
 use openssl::x509::X509;
@@ -174,7 +174,17 @@ fn client_thread(
 
         let mut poll_array = [rx.as_poll_fd(), reconnectable.stream().as_poll_fd()];
         if !reconnectable.stream().has_read_buffered() {
-            poll_for_read(&mut poll_array);
+            if let Err(err) = poll(
+                &mut poll_array,
+                Some(std::time::Duration::from_millis(1000)),
+            ) {
+                let reason = format!("Error while polling: {} {:?}", err, poll_array);
+                log::error!("{}", reason);
+                for (_, mut promise) in promises.into_iter() {
+                    promise.result(Err(anyhow!("{}", reason)));
+                }
+                return Err(err).context("Error while polling");
+            }
         }
 
         if poll_array[1].revents != 0 || reconnectable.stream().has_read_buffered() {

src/server/listener/clientsession.rs

@@ -4,6 +4,7 @@ use crate::server::listener::sessionhandler::SessionHandler;
 use crate::server::pollable::*;
 use anyhow::{bail, Context, Error};
 use crossbeam::channel::TryRecvError;
+use filedescriptor::poll;
 use log::error;
 use std::collections::HashSet;
 
@@ -71,7 +72,10 @@ impl<S: ReadAndWrite> ClientSession<S> {
                 self.stream.as_poll_fd(),
                 self.mux_rx.as_poll_fd(),
             ];
-            poll_for_read(&mut poll_array);
+            poll(
+                &mut poll_array,
+                Some(std::time::Duration::from_millis(1000)),
+            )?;
 
             if poll_array[1].revents != 0 || self.stream.has_read_buffered() {
                 loop {

src/server/pollable.rs

@@ -129,9 +129,3 @@ impl AsPollFd for UnixStream {
         self.as_socket_descriptor().as_poll_fd()
     }
 }
-
-pub fn poll_for_read(pfd: &mut [pollfd]) {
-    if let Err(e) = poll(pfd, Some(std::time::Duration::from_millis(1000))) {
-        log::error!("poll failed for {}", e);
-    }
-}