Revision control
Copy as Markdown
Other Tools
#![allow(unknown_lints, unexpected_cfgs)]
#![cfg(feature = "macros")]
#![allow(clippy::disallowed_names)]
#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
use wasm_bindgen_test::wasm_bindgen_test as maybe_tokio_test;
#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
use tokio::test as maybe_tokio_test;
use tokio::sync::oneshot;
use tokio_test::{assert_ok, assert_pending, assert_ready};
use futures::future::poll_fn;
use std::task::Poll::Ready;
#[maybe_tokio_test]
async fn sync_one_lit_expr_comma() {
let foo = tokio::select! {
foo = async { 1 } => foo,
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn no_branch_else_only() {
let foo = tokio::select! {
else => 1,
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn no_branch_else_only_biased() {
let foo = tokio::select! {
biased;
else => 1,
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn nested_one() {
let foo = tokio::select! {
foo = async { 1 } => tokio::select! {
bar = async { foo } => bar,
},
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn sync_one_lit_expr_no_comma() {
let foo = tokio::select! {
foo = async { 1 } => foo
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn sync_one_lit_expr_block() {
let foo = tokio::select! {
foo = async { 1 } => { foo }
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn sync_one_await() {
let foo = tokio::select! {
foo = one() => foo,
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn sync_one_ident() {
let one = one();
let foo = tokio::select! {
foo = one => foo,
};
assert_eq!(foo, 1);
}
#[maybe_tokio_test]
async fn sync_two() {
use std::cell::Cell;
let cnt = Cell::new(0);
let res = tokio::select! {
foo = async {
cnt.set(cnt.get() + 1);
1
} => foo,
bar = async {
cnt.set(cnt.get() + 1);
2
} => bar,
};
assert_eq!(1, cnt.get());
assert!(res == 1 || res == 2);
}
#[maybe_tokio_test]
async fn drop_in_fut() {
let s = "hello".to_string();
let res = tokio::select! {
foo = async {
let v = one().await;
drop(s);
v
} => foo
};
assert_eq!(res, 1);
}
#[maybe_tokio_test]
#[cfg(feature = "full")]
async fn one_ready() {
let (tx1, rx1) = oneshot::channel::<i32>();
let (_tx2, rx2) = oneshot::channel::<i32>();
tx1.send(1).unwrap();
let v = tokio::select! {
res = rx1 => {
assert_ok!(res)
},
_ = rx2 => unreachable!(),
};
assert_eq!(1, v);
}
#[maybe_tokio_test]
#[cfg(feature = "full")]
async fn select_streams() {
use tokio::sync::mpsc;
let (tx1, mut rx1) = mpsc::unbounded_channel::<i32>();
let (tx2, mut rx2) = mpsc::unbounded_channel::<i32>();
tokio::spawn(async move {
assert_ok!(tx2.send(1));
tokio::task::yield_now().await;
assert_ok!(tx1.send(2));
tokio::task::yield_now().await;
assert_ok!(tx2.send(3));
tokio::task::yield_now().await;
drop((tx1, tx2));
});
let mut rem = true;
let mut msgs = vec![];
while rem {
tokio::select! {
Some(x) = rx1.recv() => {
msgs.push(x);
}
Some(y) = rx2.recv() => {
msgs.push(y);
}
else => {
rem = false;
}
}
}
msgs.sort_unstable();
assert_eq!(&msgs[..], &[1, 2, 3]);
}
#[maybe_tokio_test]
async fn move_uncompleted_futures() {
let (tx1, mut rx1) = oneshot::channel::<i32>();
let (tx2, mut rx2) = oneshot::channel::<i32>();
tx1.send(1).unwrap();
tx2.send(2).unwrap();
let ran;
tokio::select! {
res = &mut rx1 => {
assert_eq!(1, assert_ok!(res));
assert_eq!(2, assert_ok!(rx2.await));
ran = true;
},
res = &mut rx2 => {
assert_eq!(2, assert_ok!(res));
assert_eq!(1, assert_ok!(rx1.await));
ran = true;
},
}
assert!(ran);
}
#[maybe_tokio_test]
async fn nested() {
let res = tokio::select! {
x = async { 1 } => {
tokio::select! {
y = async { 2 } => x + y,
}
}
};
assert_eq!(res, 3);
}
#[cfg(target_pointer_width = "64")]
mod pointer_64_tests {
use super::maybe_tokio_test;
use futures::future;
use std::mem;
#[maybe_tokio_test]
async fn struct_size_1() {
let fut = async {
let ready = future::ready(0i32);
tokio::select! {
_ = ready => {},
}
};
assert_eq!(mem::size_of_val(&fut), 32);
}
#[maybe_tokio_test]
async fn struct_size_2() {
let fut = async {
let ready1 = future::ready(0i32);
let ready2 = future::ready(0i32);
tokio::select! {
_ = ready1 => {},
_ = ready2 => {},
}
};
assert_eq!(mem::size_of_val(&fut), 40);
}
#[maybe_tokio_test]
async fn struct_size_3() {
let fut = async {
let ready1 = future::ready(0i32);
let ready2 = future::ready(0i32);
let ready3 = future::ready(0i32);
tokio::select! {
_ = ready1 => {},
_ = ready2 => {},
_ = ready3 => {},
}
};
assert_eq!(mem::size_of_val(&fut), 48);
}
}
#[maybe_tokio_test]
async fn mutable_borrowing_future_with_same_borrow_in_block() {
let mut value = 234;
tokio::select! {
_ = require_mutable(&mut value) => { },
_ = async_noop() => {
value += 5;
},
}
assert!(value >= 234);
}
#[maybe_tokio_test]
async fn mutable_borrowing_future_with_same_borrow_in_block_and_else() {
let mut value = 234;
tokio::select! {
_ = require_mutable(&mut value) => { },
_ = async_noop() => {
value += 5;
},
else => {
value += 27;
},
}
assert!(value >= 234);
}
#[maybe_tokio_test]
async fn future_panics_after_poll() {
use tokio_test::task;
let (tx, rx) = oneshot::channel();
let mut polled = false;
let f = poll_fn(|_| {
assert!(!polled);
polled = true;
Ready(None::<()>)
});
let mut f = task::spawn(async {
tokio::select! {
Some(_) = f => unreachable!(),
ret = rx => ret.unwrap(),
}
});
assert_pending!(f.poll());
assert_pending!(f.poll());
assert_ok!(tx.send(1));
let res = assert_ready!(f.poll());
assert_eq!(1, res);
}
#[maybe_tokio_test]
async fn disable_with_if() {
use tokio_test::task;
let f = poll_fn(|_| panic!());
let (tx, rx) = oneshot::channel();
let mut f = task::spawn(async {
tokio::select! {
_ = f, if false => unreachable!(),
_ = rx => (),
}
});
assert_pending!(f.poll());
assert_ok!(tx.send(()));
assert!(f.is_woken());
assert_ready!(f.poll());
}
#[maybe_tokio_test]
async fn join_with_select() {
use tokio_test::task;
let (tx1, mut rx1) = oneshot::channel();
let (tx2, mut rx2) = oneshot::channel();
let mut f = task::spawn(async {
let mut a = None;
let mut b = None;
while a.is_none() || b.is_none() {
tokio::select! {
v1 = &mut rx1, if a.is_none() => a = Some(assert_ok!(v1)),
v2 = &mut rx2, if b.is_none() => b = Some(assert_ok!(v2))
}
}
(a.unwrap(), b.unwrap())
});
assert_pending!(f.poll());
assert_ok!(tx1.send(123));
assert!(f.is_woken());
assert_pending!(f.poll());
assert_ok!(tx2.send(456));
assert!(f.is_woken());
let (a, b) = assert_ready!(f.poll());
assert_eq!(a, 123);
assert_eq!(b, 456);
}
#[tokio::test]
#[cfg(feature = "full")]
async fn use_future_in_if_condition() {
use tokio::time::{self, Duration};
tokio::select! {
_ = time::sleep(Duration::from_millis(10)), if false => {
panic!("if condition ignored")
}
_ = async { 1u32 } => {
}
}
}
#[tokio::test]
#[cfg(feature = "full")]
async fn use_future_in_if_condition_biased() {
use tokio::time::{self, Duration};
tokio::select! {
biased;
_ = time::sleep(Duration::from_millis(10)), if false => {
panic!("if condition ignored")
}
_ = async { 1u32 } => {
}
}
}
#[maybe_tokio_test]
async fn many_branches() {
let num = tokio::select! {
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
x = async { 1 } => x,
};
assert_eq!(1, num);
}
#[maybe_tokio_test]
async fn never_branch_no_warnings() {
let t = tokio::select! {
_ = async_never() => 0,
one_async_ready = one() => one_async_ready,
};
assert_eq!(t, 1);
}
async fn one() -> usize {
1
}
async fn require_mutable(_: &mut i32) {}
async fn async_noop() {}
async fn async_never() -> ! {
futures::future::pending().await
}
#[maybe_tokio_test]
async fn mut_on_left_hand_side() {
let v = async move {
let ok = async { 1 };
tokio::pin!(ok);
tokio::select! {
mut a = &mut ok => {
a += 1;
a
}
}
}
.await;
assert_eq!(v, 2);
}
#[maybe_tokio_test]
async fn biased_one_not_ready() {
let (_tx1, rx1) = oneshot::channel::<i32>();
let (tx2, rx2) = oneshot::channel::<i32>();
let (tx3, rx3) = oneshot::channel::<i32>();
tx2.send(2).unwrap();
tx3.send(3).unwrap();
let v = tokio::select! {
biased;
_ = rx1 => unreachable!(),
res = rx2 => {
assert_ok!(res)
},
_ = rx3 => {
panic!("This branch should never be activated because `rx2` should be polled before `rx3` due to `biased;`.")
}
};
assert_eq!(2, v);
}
#[maybe_tokio_test]
#[cfg(feature = "full")]
async fn biased_eventually_ready() {
use tokio::task::yield_now;
let one = async {};
let two = async { yield_now().await };
let three = async { yield_now().await };
let mut count = 0u8;
tokio::pin!(one, two, three);
loop {
tokio::select! {
biased;
_ = &mut two, if count < 2 => {
count += 1;
assert_eq!(count, 2);
}
_ = &mut three, if count < 3 => {
count += 1;
assert_eq!(count, 3);
}
_ = &mut one, if count < 1 => {
count += 1;
assert_eq!(count, 1);
}
else => break,
}
}
assert_eq!(count, 3);
}
#[warn(clippy::default_numeric_fallback)]
pub async fn default_numeric_fallback() {
tokio::select! {
_ = async {} => (),
else => (),
}
}
#[maybe_tokio_test]
async fn mut_ref_patterns() {
tokio::select! {
Some(mut foo) = async { Some("1".to_string()) } => {
assert_eq!(foo, "1");
foo = "2".to_string();
assert_eq!(foo, "2");
},
};
tokio::select! {
Some(ref foo) = async { Some("1".to_string()) } => {
assert_eq!(*foo, "1");
},
};
tokio::select! {
Some(ref mut foo) = async { Some("1".to_string()) } => {
assert_eq!(*foo, "1");
*foo = "2".to_string();
assert_eq!(*foo, "2");
},
};
}
#[cfg(tokio_unstable)]
mod unstable {
use tokio::runtime::RngSeed;
#[test]
fn deterministic_select_current_thread() {
let seed = b"bytes used to generate seed";
let rt1 = tokio::runtime::Builder::new_current_thread()
.rng_seed(RngSeed::from_bytes(seed))
.build()
.unwrap();
let rt1_values = rt1.block_on(async { (select_0_to_9().await, select_0_to_9().await) });
let rt2 = tokio::runtime::Builder::new_current_thread()
.rng_seed(RngSeed::from_bytes(seed))
.build()
.unwrap();
let rt2_values = rt2.block_on(async { (select_0_to_9().await, select_0_to_9().await) });
assert_eq!(rt1_values, rt2_values);
}
#[test]
#[cfg(all(feature = "rt-multi-thread", not(target_os = "wasi")))]
fn deterministic_select_multi_thread() {
let seed = b"bytes used to generate seed";
let rt1 = tokio::runtime::Builder::new_multi_thread()
.worker_threads(1)
.rng_seed(RngSeed::from_bytes(seed))
.build()
.unwrap();
let rt1_values = rt1.block_on(async {
let _ = tokio::spawn(async { (select_0_to_9().await, select_0_to_9().await) }).await;
});
let rt2 = tokio::runtime::Builder::new_multi_thread()
.worker_threads(1)
.rng_seed(RngSeed::from_bytes(seed))
.build()
.unwrap();
let rt2_values = rt2.block_on(async {
let _ = tokio::spawn(async { (select_0_to_9().await, select_0_to_9().await) }).await;
});
assert_eq!(rt1_values, rt2_values);
}
async fn select_0_to_9() -> u32 {
tokio::select!(
x = async { 0 } => x,
x = async { 1 } => x,
x = async { 2 } => x,
x = async { 3 } => x,
x = async { 4 } => x,
x = async { 5 } => x,
x = async { 6 } => x,
x = async { 7 } => x,
x = async { 8 } => x,
x = async { 9 } => x,
)
}
}
#[tokio::test]
async fn select_into_future() {
struct NotAFuture;
impl std::future::IntoFuture for NotAFuture {
type Output = ();
type IntoFuture = std::future::Ready<()>;
fn into_future(self) -> Self::IntoFuture {
std::future::ready(())
}
}
tokio::select! {
() = NotAFuture => {},
}
}
#[tokio::test]
async fn temporary_lifetime_extension() {
tokio::select! {
() = &mut std::future::ready(()) => {},
}
}