Move as much I/O as possible off of native::io

When uv's TTY I/O is used for the stdio streams, the file descriptors are put
into a non-blocking mode. This means that other concurrent writes to the same
stream can fail with EAGAIN or EWOULDBLOCK. By all I/O to event-loop I/O, we
avoid this error.

There is one location which cannot move, which is the runtime's dumb_println
function. This was implemented to handle the EAGAIN and EWOULDBLOCK errors and
simply retry again and again.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/rt/rust_uv.cpp b/src/rt/rust_uv.cpp
index a47b3446d34..7ab57e6909a 100644
--- a/src/rt/rust_uv.cpp
+++ b/src/rt/rust_uv.cpp
@@ -681,3 +681,8 @@ extern "C" int
 rust_uv_tty_get_winsize(uv_tty_t *tty, int *width, int *height) {
     return uv_tty_get_winsize(tty, width, height);
 }
+
+extern "C" uv_handle_type
+rust_uv_guess_handle(int fd) {
+    return uv_guess_handle(fd);
+}