Deal with EINTR in net timeout tests

We've seen sporadic QE failures in the timeout tests on this assertion:

    assert!(kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut);

So there's an error, but not either of the expected kinds.  Adding a
format to show the kind revealed `ErrorKind::Interrupted` (`EINTR`).

For the cases that were using `read`, we can just use `read_exact` to
keep trying after interruption.  For those using `recv_from`, we have to
manually loop until we get a non-interrupted result.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/libstd/net/tcp.rs b/src/libstd/net/tcp.rs
index ad212a54757..be797803233 100644
--- a/src/libstd/net/tcp.rs
+++ b/src/libstd/net/tcp.rs
@@ -1548,8 +1548,9 @@ mod tests {
 
         let mut buf = [0; 10];
         let start = Instant::now();
-        let kind = stream.read(&mut buf).err().expect("expected error").kind();
-        assert!(kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut);
+        let kind = stream.read_exact(&mut buf).err().expect("expected error").kind();
+        assert!(kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut,
+                "unexpected_error: {:?}", kind);
         assert!(start.elapsed() > Duration::from_millis(400));
         drop(listener);
     }
@@ -1570,8 +1571,9 @@ mod tests {
         assert_eq!(b"hello world", &buf[..]);
 
         let start = Instant::now();
-        let kind = stream.read(&mut buf).err().expect("expected error").kind();
-        assert!(kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut);
+        let kind = stream.read_exact(&mut buf).err().expect("expected error").kind();
+        assert!(kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut,
+                "unexpected_error: {:?}", kind);
         assert!(start.elapsed() > Duration::from_millis(400));
         drop(listener);
     }