Use evented I/O for the pty

This was largely an experiment to see whether writing and reading from a
separate thread was causing terminal state corruption as described in
https://github.com/jwilm/alacritty/issues/9. Although this doesn't seem
to fix that particular issue.

Keeping this because it generally seems more correct than
reading/writing from separate locations.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/tty.rs b/src/tty.rs
index accf0226..988db37e 100644
--- a/src/tty.rs
+++ b/src/tty.rs
@@ -274,6 +274,12 @@ pub fn new(rows: u8, cols: u8) -> Tty {
                 libc::close(slave);
             }
 
+            unsafe {
+                // Maybe this should be done outside of this function so nonblocking
+                // isn't forced upon consumers. Although maybe it should be?
+                set_nonblocking(master);
+            }
+
             Tty { fd: master }
         }
     }
@@ -320,6 +326,13 @@ impl Tty {
     }
 }
 
+unsafe fn set_nonblocking(fd: c_int) {
+    use libc::{fcntl, F_SETFL, F_GETFL, O_NONBLOCK};
+
+    let res = fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK);
+    assert_eq!(res, 0);
+}
+
 #[test]
 fn test_get_pw_entry() {
     let mut buf: [i8; 1024] = [0; 1024];