use crate::fmt;
use crate::io::prelude::*;
use crate::io::{ErrorKind, IoSlice, IoSliceMut};
use crate::net::test::{next_test_ip4, next_test_ip6};
use crate::net::*;
use crate::sync::mpsc::channel;
use crate::thread;
use crate::time::{Duration, Instant};

fn each_ip(f: &mut dyn FnMut(SocketAddr)) {
    f(next_test_ip4());
    f(next_test_ip6());
}

macro_rules! t {
    ($e:expr) => {
        match $e {
            Ok(t) => t,
            Err(e) => panic!("received error for `{}`: {}", stringify!($e), e),
        }
    };
}

#[test]
fn bind_error() {
    match TcpListener::bind("1.1.1.1:9999") {
        Ok(..) => panic!(),
        Err(e) => assert_eq!(e.kind(), ErrorKind::AddrNotAvailable),
    }
}

#[test]
fn connect_error() {
    match TcpStream::connect("0.0.0.0:1") {
        Ok(..) => panic!(),
        Err(e) => assert!(
            e.kind() == ErrorKind::ConnectionRefused
                || e.kind() == ErrorKind::InvalidInput
                || e.kind() == ErrorKind::AddrInUse
                || e.kind() == ErrorKind::AddrNotAvailable,
            "bad error: {} {:?}",
            e,
            e.kind()
        ),
    }
}

#[test]
fn listen_localhost() {
    let socket_addr = next_test_ip4();
    let listener = t!(TcpListener::bind(&socket_addr));

    let _t = thread::spawn(move || {
        let mut stream = t!(TcpStream::connect(&("localhost", socket_addr.port())));
        t!(stream.write(&[144]));
    });

    let mut stream = t!(listener.accept()).0;
    let mut buf = [0];
    t!(stream.read(&mut buf));
    assert!(buf[0] == 144);
}

#[test]
fn connect_loopback() {
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let _t = thread::spawn(move || {
            let host = match addr {
                SocketAddr::V4(..) => "127.0.0.1",
                SocketAddr::V6(..) => "::1",
            };
            let mut stream = t!(TcpStream::connect(&(host, addr.port())));
            t!(stream.write(&[66]));
        });

        let mut stream = t!(acceptor.accept()).0;
        let mut buf = [0];
        t!(stream.read(&mut buf));
        assert!(buf[0] == 66);
    })
}

#[test]
fn smoke_test() {
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let (tx, rx) = channel();
        let _t = thread::spawn(move || {
            let mut stream = t!(TcpStream::connect(&addr));
            t!(stream.write(&[99]));
            tx.send(t!(stream.local_addr())).unwrap();
        });

        let (mut stream, addr) = t!(acceptor.accept());
        let mut buf = [0];
        t!(stream.read(&mut buf));
        assert!(buf[0] == 99);
        assert_eq!(addr, t!(rx.recv()));
    })
}

#[test]
fn read_eof() {
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let _t = thread::spawn(move || {
            let _stream = t!(TcpStream::connect(&addr));
            // Close
        });

        let mut stream = t!(acceptor.accept()).0;
        let mut buf = [0];
        let nread = t!(stream.read(&mut buf));
        assert_eq!(nread, 0);
        let nread = t!(stream.read(&mut buf));
        assert_eq!(nread, 0);
    })
}

#[test]
fn write_close() {
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let (tx, rx) = channel();
        let _t = thread::spawn(move || {
            drop(t!(TcpStream::connect(&addr)));
            tx.send(()).unwrap();
        });

        let mut stream = t!(acceptor.accept()).0;
        rx.recv().unwrap();
        let buf = [0];
        match stream.write(&buf) {
            Ok(..) => {}
            Err(e) => {
                assert!(
                    e.kind() == ErrorKind::ConnectionReset
                        || e.kind() == ErrorKind::BrokenPipe
                        || e.kind() == ErrorKind::ConnectionAborted,
                    "unknown error: {e}"
                );
            }
        }
    })
}

#[test]
fn multiple_connect_serial() {
    each_ip(&mut |addr| {
        let max = 10;
        let acceptor = t!(TcpListener::bind(&addr));

        let _t = thread::spawn(move || {
            for _ in 0..max {
                let mut stream = t!(TcpStream::connect(&addr));
                t!(stream.write(&[99]));
            }
        });

        for stream in acceptor.incoming().take(max) {
            let mut stream = t!(stream);
            let mut buf = [0];
            t!(stream.read(&mut buf));
            assert_eq!(buf[0], 99);
        }
    })
}

#[test]
fn multiple_connect_interleaved_greedy_schedule() {
    const MAX: usize = 10;
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let _t = thread::spawn(move || {
            let acceptor = acceptor;
            for (i, stream) in acceptor.incoming().enumerate().take(MAX) {
                // Start another thread to handle the connection
                let _t = thread::spawn(move || {
                    let mut stream = t!(stream);
                    let mut buf = [0];
                    t!(stream.read(&mut buf));
                    assert!(buf[0] == i as u8);
                });
            }
        });

        connect(0, addr);
    });

    fn connect(i: usize, addr: SocketAddr) {
        if i == MAX {
            return;
        }

        let t = thread::spawn(move || {
            let mut stream = t!(TcpStream::connect(&addr));
            // Connect again before writing
            connect(i + 1, addr);
            t!(stream.write(&[i as u8]));
        });
        t.join().ok().expect("thread panicked");
    }
}

#[test]
fn multiple_connect_interleaved_lazy_schedule() {
    const MAX: usize = 10;
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let _t = thread::spawn(move || {
            for stream in acceptor.incoming().take(MAX) {
                // Start another thread to handle the connection
                let _t = thread::spawn(move || {
                    let mut stream = t!(stream);
                    let mut buf = [0];
                    t!(stream.read(&mut buf));
                    assert!(buf[0] == 99);
                });
            }
        });

        connect(0, addr);
    });

    fn connect(i: usize, addr: SocketAddr) {
        if i == MAX {
            return;
        }

        let t = thread::spawn(move || {
            let mut stream = t!(TcpStream::connect(&addr));
            connect(i + 1, addr);
            t!(stream.write(&[99]));
        });
        t.join().ok().expect("thread panicked");
    }
}

#[test]
fn socket_and_peer_name() {
    each_ip(&mut |addr| {
        let listener = t!(TcpListener::bind(&addr));
        let so_name = t!(listener.local_addr());
        assert_eq!(addr, so_name);
        let _t = thread::spawn(move || {
            t!(listener.accept());
        });

        let stream = t!(TcpStream::connect(&addr));
        assert_eq!(addr, t!(stream.peer_addr()));
    })
}

#[test]
fn partial_read() {
    each_ip(&mut |addr| {
        let (tx, rx) = channel();
        let srv = t!(TcpListener::bind(&addr));
        let _t = thread::spawn(move || {
            let mut cl = t!(srv.accept()).0;
            cl.write(&[10]).unwrap();
            let mut b = [0];
            t!(cl.read(&mut b));
            tx.send(()).unwrap();
        });

        let mut c = t!(TcpStream::connect(&addr));
        let mut b = [0; 10];
        assert_eq!(c.read(&mut b).unwrap(), 1);
        t!(c.write(&[1]));
        rx.recv().unwrap();
    })
}

#[test]
fn read_vectored() {
    each_ip(&mut |addr| {
        let srv = t!(TcpListener::bind(&addr));
        let mut s1 = t!(TcpStream::connect(&addr));
        let mut s2 = t!(srv.accept()).0;

        let len = s1.write(&[10, 11, 12]).unwrap();
        assert_eq!(len, 3);

        let mut a = [];
        let mut b = [0];
        let mut c = [0; 3];
        let len = t!(s2.read_vectored(&mut [
            IoSliceMut::new(&mut a),
            IoSliceMut::new(&mut b),
            IoSliceMut::new(&mut c)
        ],));
        assert!(len > 0);
        assert_eq!(b, [10]);
        // some implementations don't support readv, so we may only fill the first buffer
        assert!(len == 1 || c == [11, 12, 0]);
    })
}

#[test]
fn write_vectored() {
    each_ip(&mut |addr| {
        let srv = t!(TcpListener::bind(&addr));
        let mut s1 = t!(TcpStream::connect(&addr));
        let mut s2 = t!(srv.accept()).0;

        let a = [];
        let b = [10];
        let c = [11, 12];
        t!(s1.write_vectored(&[IoSlice::new(&a), IoSlice::new(&b), IoSlice::new(&c)]));

        let mut buf = [0; 4];
        let len = t!(s2.read(&mut buf));
        // some implementations don't support writev, so we may only write the first buffer
        if len == 1 {
            assert_eq!(buf, [10, 0, 0, 0]);
        } else {
            assert_eq!(len, 3);
            assert_eq!(buf, [10, 11, 12, 0]);
        }
    })
}

#[test]
fn double_bind() {
    each_ip(&mut |addr| {
        let listener1 = t!(TcpListener::bind(&addr));
        match TcpListener::bind(&addr) {
            Ok(listener2) => panic!(
                "This system (perhaps due to options set by TcpListener::bind) \
                 permits double binding: {:?} and {:?}",
                listener1, listener2
            ),
            Err(e) => {
                assert!(
                    e.kind() == ErrorKind::ConnectionRefused
                        || e.kind() == ErrorKind::Uncategorized
                        || e.kind() == ErrorKind::AddrInUse,
                    "unknown error: {} {:?}",
                    e,
                    e.kind()
                );
            }
        }
    })
}

#[test]
fn tcp_clone_smoke() {
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let _t = thread::spawn(move || {
            let mut s = t!(TcpStream::connect(&addr));
            let mut buf = [0, 0];
            assert_eq!(s.read(&mut buf).unwrap(), 1);
            assert_eq!(buf[0], 1);
            t!(s.write(&[2]));
        });

        let mut s1 = t!(acceptor.accept()).0;
        let s2 = t!(s1.try_clone());

        let (tx1, rx1) = channel();
        let (tx2, rx2) = channel();
        let _t = thread::spawn(move || {
            let mut s2 = s2;
            rx1.recv().unwrap();
            t!(s2.write(&[1]));
            tx2.send(()).unwrap();
        });
        tx1.send(()).unwrap();
        let mut buf = [0, 0];
        assert_eq!(s1.read(&mut buf).unwrap(), 1);
        rx2.recv().unwrap();
    })
}

#[test]
fn tcp_clone_two_read() {
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));
        let (tx1, rx) = channel();
        let tx2 = tx1.clone();

        let _t = thread::spawn(move || {
            let mut s = t!(TcpStream::connect(&addr));
            t!(s.write(&[1]));
            rx.recv().unwrap();
            t!(s.write(&[2]));
            rx.recv().unwrap();
        });

        let mut s1 = t!(acceptor.accept()).0;
        let s2 = t!(s1.try_clone());

        let (done, rx) = channel();
        let _t = thread::spawn(move || {
            let mut s2 = s2;
            let mut buf = [0, 0];
            t!(s2.read(&mut buf));
            tx2.send(()).unwrap();
            done.send(()).unwrap();
        });
        let mut buf = [0, 0];
        t!(s1.read(&mut buf));
        tx1.send(()).unwrap();

        rx.recv().unwrap();
    })
}

#[test]
fn tcp_clone_two_write() {
    each_ip(&mut |addr| {
        let acceptor = t!(TcpListener::bind(&addr));

        let _t = thread::spawn(move || {
            let mut s = t!(TcpStream::connect(&addr));
            let mut buf = [0, 1];
            t!(s.read(&mut buf));
            t!(s.read(&mut buf));
        });

        let mut s1 = t!(acceptor.accept()).0;
        let s2 = t!(s1.try_clone());

        let (done, rx) = channel();
        let _t = thread::spawn(move || {
            let mut s2 = s2;
            t!(s2.write(&[1]));
            done.send(()).unwrap();
        });
        t!(s1.write(&[2]));

        rx.recv().unwrap();
    })
}

#[test]
// FIXME: https://github.com/fortanix/rust-sgx/issues/110
#[cfg_attr(target_env = "sgx", ignore)]
fn shutdown_smoke() {
    each_ip(&mut |addr| {
        let a = t!(TcpListener::bind(&addr));
        let _t = thread::spawn(move || {
            let mut c = t!(a.accept()).0;
            let mut b = [0];
            assert_eq!(c.read(&mut b).unwrap(), 0);
            t!(c.write(&[1]));
        });

        let mut s = t!(TcpStream::connect(&addr));
        t!(s.shutdown(Shutdown::Write));
        assert!(s.write(&[1]).is_err());
        let mut b = [0, 0];
        assert_eq!(t!(s.read(&mut b)), 1);
        assert_eq!(b[0], 1);
    })
}

#[test]
// FIXME: https://github.com/fortanix/rust-sgx/issues/110
#[cfg_attr(target_env = "sgx", ignore)]
fn close_readwrite_smoke() {
    each_ip(&mut |addr| {
        let a = t!(TcpListener::bind(&addr));
        let (tx, rx) = channel::<()>();
        let _t = thread::spawn(move || {
            let _s = t!(a.accept());
            let _ = rx.recv();
        });

        let mut b = [0];
        let mut s = t!(TcpStream::connect(&addr));
        let mut s2 = t!(s.try_clone());

        // closing should prevent reads/writes
        t!(s.shutdown(Shutdown::Write));
        assert!(s.write(&[0]).is_err());
        t!(s.shutdown(Shutdown::Read));
        assert_eq!(s.read(&mut b).unwrap(), 0);

        // closing should affect previous handles
        assert!(s2.write(&[0]).is_err());
        assert_eq!(s2.read(&mut b).unwrap(), 0);

        // closing should affect new handles
        let mut s3 = t!(s.try_clone());
        assert!(s3.write(&[0]).is_err());
        assert_eq!(s3.read(&mut b).unwrap(), 0);

        // make sure these don't die
        let _ = s2.shutdown(Shutdown::Read);
        let _ = s2.shutdown(Shutdown::Write);
        let _ = s3.shutdown(Shutdown::Read);
        let _ = s3.shutdown(Shutdown::Write);
        drop(tx);
    })
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)]
fn close_read_wakes_up() {
    each_ip(&mut |addr| {
        let a = t!(TcpListener::bind(&addr));
        let (tx1, rx) = channel::<()>();
        let _t = thread::spawn(move || {
            let _s = t!(a.accept());
            let _ = rx.recv();
        });

        let s = t!(TcpStream::connect(&addr));
        let s2 = t!(s.try_clone());
        let (tx, rx) = channel();
        let _t = thread::spawn(move || {
            let mut s2 = s2;
            assert_eq!(t!(s2.read(&mut [0])), 0);
            tx.send(()).unwrap();
        });
        // this should wake up the child thread
        t!(s.shutdown(Shutdown::Read));

        // this test will never finish if the child doesn't wake up
        rx.recv().unwrap();
        drop(tx1);
    })
}

#[test]
fn clone_while_reading() {
    each_ip(&mut |addr| {
        let accept = t!(TcpListener::bind(&addr));

        // Enqueue a thread to write to a socket
        let (tx, rx) = channel();
        let (txdone, rxdone) = channel();
        let txdone2 = txdone.clone();
        let _t = thread::spawn(move || {
            let mut tcp = t!(TcpStream::connect(&addr));
            rx.recv().unwrap();
            t!(tcp.write(&[0]));
            txdone2.send(()).unwrap();
        });

        // Spawn off a reading clone
        let tcp = t!(accept.accept()).0;
        let tcp2 = t!(tcp.try_clone());
        let txdone3 = txdone.clone();
        let _t = thread::spawn(move || {
            let mut tcp2 = tcp2;
            t!(tcp2.read(&mut [0]));
            txdone3.send(()).unwrap();
        });

        // Try to ensure that the reading clone is indeed reading
        for _ in 0..50 {
            thread::yield_now();
        }

        // clone the handle again while it's reading, then let it finish the
        // read.
        let _ = t!(tcp.try_clone());
        tx.send(()).unwrap();
        rxdone.recv().unwrap();
        rxdone.recv().unwrap();
    })
}

#[test]
fn clone_accept_smoke() {
    each_ip(&mut |addr| {
        let a = t!(TcpListener::bind(&addr));
        let a2 = t!(a.try_clone());

        let _t = thread::spawn(move || {
            let _ = TcpStream::connect(&addr);
        });
        let _t = thread::spawn(move || {
            let _ = TcpStream::connect(&addr);
        });

        t!(a.accept());
        t!(a2.accept());
    })
}

#[test]
fn clone_accept_concurrent() {
    each_ip(&mut |addr| {
        let a = t!(TcpListener::bind(&addr));
        let a2 = t!(a.try_clone());

        let (tx, rx) = channel();
        let tx2 = tx.clone();

        let _t = thread::spawn(move || {
            tx.send(t!(a.accept())).unwrap();
        });
        let _t = thread::spawn(move || {
            tx2.send(t!(a2.accept())).unwrap();
        });

        let _t = thread::spawn(move || {
            let _ = TcpStream::connect(&addr);
        });
        let _t = thread::spawn(move || {
            let _ = TcpStream::connect(&addr);
        });

        rx.recv().unwrap();
        rx.recv().unwrap();
    })
}

#[test]
fn debug() {
    #[cfg(not(target_env = "sgx"))]
    fn render_socket_addr<'a>(addr: &'a SocketAddr) -> impl fmt::Debug + 'a {
        addr
    }
    #[cfg(target_env = "sgx")]
    fn render_socket_addr<'a>(addr: &'a SocketAddr) -> impl fmt::Debug + 'a {
        addr.to_string()
    }

    #[cfg(target_env = "sgx")]
    use crate::os::fortanix_sgx::io::AsRawFd;
    #[cfg(unix)]
    use crate::os::unix::io::AsRawFd;
    #[cfg(not(windows))]
    fn render_inner(addr: &dyn AsRawFd) -> impl fmt::Debug {
        addr.as_raw_fd()
    }
    #[cfg(windows)]
    fn render_inner(addr: &dyn crate::os::windows::io::AsRawSocket) -> impl fmt::Debug {
        addr.as_raw_socket()
    }

    let inner_name = if cfg!(windows) { "socket" } else { "fd" };
    let socket_addr = next_test_ip4();

    let listener = t!(TcpListener::bind(&socket_addr));
    let compare = format!(
        "TcpListener {{ addr: {:?}, {}: {:?} }}",
        render_socket_addr(&socket_addr),
        inner_name,
        render_inner(&listener)
    );
    assert_eq!(format!("{listener:?}"), compare);

    let stream = t!(TcpStream::connect(&("localhost", socket_addr.port())));
    let compare = format!(
        "TcpStream {{ addr: {:?}, peer: {:?}, {}: {:?} }}",
        render_socket_addr(&stream.local_addr().unwrap()),
        render_socket_addr(&stream.peer_addr().unwrap()),
        inner_name,
        render_inner(&stream)
    );
    assert_eq!(format!("{stream:?}"), compare);
}

// FIXME: re-enabled openbsd tests once their socket timeout code
//        no longer has rounding errors.
// VxWorks ignores SO_SNDTIMEO.
#[cfg_attr(any(target_os = "netbsd", target_os = "openbsd", target_os = "vxworks"), ignore)]
#[cfg_attr(target_env = "sgx", ignore)] // FIXME: https://github.com/fortanix/rust-sgx/issues/31
#[test]
fn timeouts() {
    let addr = next_test_ip4();
    let listener = t!(TcpListener::bind(&addr));

    let stream = t!(TcpStream::connect(&("localhost", addr.port())));
    let dur = Duration::new(15410, 0);

    assert_eq!(None, t!(stream.read_timeout()));

    t!(stream.set_read_timeout(Some(dur)));
    assert_eq!(Some(dur), t!(stream.read_timeout()));

    assert_eq!(None, t!(stream.write_timeout()));

    t!(stream.set_write_timeout(Some(dur)));
    assert_eq!(Some(dur), t!(stream.write_timeout()));

    t!(stream.set_read_timeout(None));
    assert_eq!(None, t!(stream.read_timeout()));

    t!(stream.set_write_timeout(None));
    assert_eq!(None, t!(stream.write_timeout()));
    drop(listener);
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)] // FIXME: https://github.com/fortanix/rust-sgx/issues/31
fn test_read_timeout() {
    let addr = next_test_ip4();
    let listener = t!(TcpListener::bind(&addr));

    let mut stream = t!(TcpStream::connect(&("localhost", addr.port())));
    t!(stream.set_read_timeout(Some(Duration::from_millis(1000))));

    let mut buf = [0; 10];
    let start = Instant::now();
    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);
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)] // FIXME: https://github.com/fortanix/rust-sgx/issues/31
fn test_read_with_timeout() {
    let addr = next_test_ip4();
    let listener = t!(TcpListener::bind(&addr));

    let mut stream = t!(TcpStream::connect(&("localhost", addr.port())));
    t!(stream.set_read_timeout(Some(Duration::from_millis(1000))));

    let mut other_end = t!(listener.accept()).0;
    t!(other_end.write_all(b"hello world"));

    let mut buf = [0; 11];
    t!(stream.read(&mut buf));
    assert_eq!(b"hello world", &buf[..]);

    let start = Instant::now();
    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);
}

// Ensure the `set_read_timeout` and `set_write_timeout` calls return errors
// when passed zero Durations
#[test]
fn test_timeout_zero_duration() {
    let addr = next_test_ip4();

    let listener = t!(TcpListener::bind(&addr));
    let stream = t!(TcpStream::connect(&addr));

    let result = stream.set_write_timeout(Some(Duration::new(0, 0)));
    let err = result.unwrap_err();
    assert_eq!(err.kind(), ErrorKind::InvalidInput);

    let result = stream.set_read_timeout(Some(Duration::new(0, 0)));
    let err = result.unwrap_err();
    assert_eq!(err.kind(), ErrorKind::InvalidInput);

    drop(listener);
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)]
fn linger() {
    let addr = next_test_ip4();
    let _listener = t!(TcpListener::bind(&addr));

    let stream = t!(TcpStream::connect(&("localhost", addr.port())));

    assert_eq!(None, t!(stream.linger()));
    t!(stream.set_linger(Some(Duration::from_secs(1))));
    assert_eq!(Some(Duration::from_secs(1)), t!(stream.linger()));
    t!(stream.set_linger(None));
    assert_eq!(None, t!(stream.linger()));
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)]
fn nodelay() {
    let addr = next_test_ip4();
    let _listener = t!(TcpListener::bind(&addr));

    let stream = t!(TcpStream::connect(&("localhost", addr.port())));

    assert_eq!(false, t!(stream.nodelay()));
    t!(stream.set_nodelay(true));
    assert_eq!(true, t!(stream.nodelay()));
    t!(stream.set_nodelay(false));
    assert_eq!(false, t!(stream.nodelay()));
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)]
fn ttl() {
    let ttl = 100;

    let addr = next_test_ip4();
    let listener = t!(TcpListener::bind(&addr));

    t!(listener.set_ttl(ttl));
    assert_eq!(ttl, t!(listener.ttl()));

    let stream = t!(TcpStream::connect(&("localhost", addr.port())));

    t!(stream.set_ttl(ttl));
    assert_eq!(ttl, t!(stream.ttl()));
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)]
fn set_nonblocking() {
    let addr = next_test_ip4();
    let listener = t!(TcpListener::bind(&addr));

    t!(listener.set_nonblocking(true));
    t!(listener.set_nonblocking(false));

    let mut stream = t!(TcpStream::connect(&("localhost", addr.port())));

    t!(stream.set_nonblocking(false));
    t!(stream.set_nonblocking(true));

    let mut buf = [0];
    match stream.read(&mut buf) {
        Ok(_) => panic!("expected error"),
        Err(ref e) if e.kind() == ErrorKind::WouldBlock => {}
        Err(e) => panic!("unexpected error {e}"),
    }
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)] // FIXME: https://github.com/fortanix/rust-sgx/issues/31
fn peek() {
    each_ip(&mut |addr| {
        let (txdone, rxdone) = channel();

        let srv = t!(TcpListener::bind(&addr));
        let _t = thread::spawn(move || {
            let mut cl = t!(srv.accept()).0;
            cl.write(&[1, 3, 3, 7]).unwrap();
            t!(rxdone.recv());
        });

        let mut c = t!(TcpStream::connect(&addr));
        let mut b = [0; 10];
        for _ in 1..3 {
            let len = c.peek(&mut b).unwrap();
            assert_eq!(len, 4);
        }
        let len = c.read(&mut b).unwrap();
        assert_eq!(len, 4);

        t!(c.set_nonblocking(true));
        match c.peek(&mut b) {
            Ok(_) => panic!("expected error"),
            Err(ref e) if e.kind() == ErrorKind::WouldBlock => {}
            Err(e) => panic!("unexpected error {e}"),
        }
        t!(txdone.send(()));
    })
}

#[test]
#[cfg_attr(target_env = "sgx", ignore)] // FIXME: https://github.com/fortanix/rust-sgx/issues/31
fn connect_timeout_valid() {
    let listener = TcpListener::bind("127.0.0.1:0").unwrap();
    let addr = listener.local_addr().unwrap();
    TcpStream::connect_timeout(&addr, Duration::from_secs(2)).unwrap();
}