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//! Tests for the `select!` macro.
#![forbid(unsafe_code)] // select! is safe.
#![allow(clippy::match_single_binding)]
use std::any::Any;
use std::cell::Cell;
use std::ops::Deref;
use std::thread;
use std::time::{Duration, Instant};
use crossbeam_channel::{after, bounded, never, select, select_biased, tick, unbounded};
use crossbeam_channel::{Receiver, RecvError, SendError, Sender, TryRecvError};
use crossbeam_utils::thread::scope;
fn ms(ms: u64) -> Duration {
Duration::from_millis(ms)
}
#[test]
fn smoke1() {
let (s1, r1) = unbounded::<usize>();
let (s2, r2) = unbounded::<usize>();
s1.send(1).unwrap();
select! {
recv(r1) -> v => assert_eq!(v, Ok(1)),
recv(r2) -> _ => panic!(),
}
s2.send(2).unwrap();
select! {
recv(r1) -> _ => panic!(),
recv(r2) -> v => assert_eq!(v, Ok(2)),
}
}
#[test]
fn smoke2() {
let (_s1, r1) = unbounded::<i32>();
let (_s2, r2) = unbounded::<i32>();
let (_s3, r3) = unbounded::<i32>();
let (_s4, r4) = unbounded::<i32>();
let (s5, r5) = unbounded::<i32>();
s5.send(5).unwrap();
select! {
recv(r1) -> _ => panic!(),
recv(r2) -> _ => panic!(),
recv(r3) -> _ => panic!(),
recv(r4) -> _ => panic!(),
recv(r5) -> v => assert_eq!(v, Ok(5)),
}
}
#[test]
fn disconnected() {
let (s1, r1) = unbounded::<i32>();
let (s2, r2) = unbounded::<i32>();
scope(|scope| {
scope.spawn(|_| {
drop(s1);
thread::sleep(ms(500));
s2.send(5).unwrap();
});
select! {
recv(r1) -> v => assert!(v.is_err()),
recv(r2) -> _ => panic!(),
default(ms(1000)) => panic!(),
}
r2.recv().unwrap();
})
.unwrap();
select! {
recv(r1) -> v => assert!(v.is_err()),
recv(r2) -> _ => panic!(),
default(ms(1000)) => panic!(),
}
scope(|scope| {
scope.spawn(|_| {
thread::sleep(ms(500));
drop(s2);
});
select! {
recv(r2) -> v => assert!(v.is_err()),
default(ms(1000)) => panic!(),
}
})
.unwrap();
}
#[test]
fn default() {
let (s1, r1) = unbounded::<i32>();
let (s2, r2) = unbounded::<i32>();
select! {
recv(r1) -> _ => panic!(),
recv(r2) -> _ => panic!(),
default => {}
}
drop(s1);
select! {
recv(r1) -> v => assert!(v.is_err()),
recv(r2) -> _ => panic!(),
default => panic!(),
}
s2.send(2).unwrap();
select! {
recv(r2) -> v => assert_eq!(v, Ok(2)),
default => panic!(),
}
select! {
recv(r2) -> _ => panic!(),
default => {},
}
select! {
default => {},
}
}
#[test]
fn timeout() {
let (_s1, r1) = unbounded::<i32>();
let (s2, r2) = unbounded::<i32>();
scope(|scope| {
scope.spawn(|_| {
thread::sleep(ms(1500));
s2.send(2).unwrap();
});
select! {
recv(r1) -> _ => panic!(),
recv(r2) -> _ => panic!(),
default(ms(1000)) => {},
}
select! {
recv(r1) -> _ => panic!(),
recv(r2) -> v => assert_eq!(v, Ok(2)),
default(ms(1000)) => panic!(),
}
})
.unwrap();
scope(|scope| {
let (s, r) = unbounded::<i32>();
scope.spawn(move |_| {
thread::sleep(ms(500));
drop(s);
});
select! {
default(ms(1000)) => {
select! {
recv(r) -> v => assert!(v.is_err()),
default => panic!(),
}
}
}
})
.unwrap();
}
#[test]
fn default_when_disconnected() {
let (_, r) = unbounded::<i32>();
select! {
recv(r) -> res => assert!(res.is_err()),
default => panic!(),
}
let (_, r) = unbounded::<i32>();
select! {
recv(r) -> res => assert!(res.is_err()),
default(ms(1000)) => panic!(),
}
let (s, _) = bounded::<i32>(0);
select! {
send(s, 0) -> res => assert!(res.is_err()),
default => panic!(),
}
let (s, _) = bounded::<i32>(0);
select! {
send(s, 0) -> res => assert!(res.is_err()),
default(ms(1000)) => panic!(),
}
}
#[test]
fn default_only() {
let start = Instant::now();
select! {
default => {}
}
let now = Instant::now();
assert!(now - start <= ms(50));
let start = Instant::now();
select! {
default(ms(500)) => {}
}
let now = Instant::now();
assert!(now - start >= ms(450));
assert!(now - start <= ms(550));
}
#[test]
fn unblocks() {
let (s1, r1) = bounded::<i32>(0);
let (s2, r2) = bounded::<i32>(0);
scope(|scope| {
scope.spawn(|_| {
thread::sleep(ms(500));
s2.send(2).unwrap();
});
select! {
recv(r1) -> _ => panic!(),
recv(r2) -> v => assert_eq!(v, Ok(2)),
default(ms(1000)) => panic!(),
}
})
.unwrap();
scope(|scope| {
scope.spawn(|_| {
thread::sleep(ms(500));
assert_eq!(r1.recv().unwrap(), 1);
});
select! {
send(s1, 1) -> _ => {},
send(s2, 2) -> _ => panic!(),
default(ms(1000)) => panic!(),
}
})
.unwrap();
}
#[test]
fn both_ready() {
let (s1, r1) = bounded(0);
let (s2, r2) = bounded(0);
scope(|scope| {
scope.spawn(|_| {
thread::sleep(ms(500));
s1.send(1).unwrap();
assert_eq!(r2.recv().unwrap(), 2);
});
for _ in 0..2 {
select! {
recv(r1) -> v => assert_eq!(v, Ok(1)),
send(s2, 2) -> _ => {},
}
}
})
.unwrap();
}
#[test]
fn loop_try() {
const RUNS: usize = 20;
for _ in 0..RUNS {
let (s1, r1) = bounded::<i32>(0);
let (s2, r2) = bounded::<i32>(0);
let (s_end, r_end) = bounded::<()>(0);
scope(|scope| {
scope.spawn(|_| loop {
select! {
send(s1, 1) -> _ => break,
default => {}
}
select! {
recv(r_end) -> _ => break,
default => {}
}
});
scope.spawn(|_| loop {
if let Ok(x) = r2.try_recv() {
assert_eq!(x, 2);
break;
}
select! {
recv(r_end) -> _ => break,
default => {}
}
});
scope.spawn(|_| {
thread::sleep(ms(500));
select! {
recv(r1) -> v => assert_eq!(v, Ok(1)),
send(s2, 2) -> _ => {},
default(ms(500)) => panic!(),
}
drop(s_end);
});
})
.unwrap();
}
}
#[test]
fn cloning1() {
scope(|scope| {
let (s1, r1) = unbounded::<i32>();
let (_s2, r2) = unbounded::<i32>();
let (s3, r3) = unbounded::<()>();
scope.spawn(move |_| {
r3.recv().unwrap();
drop(s1.clone());
assert_eq!(r3.try_recv(), Err(TryRecvError::Empty));
s1.send(1).unwrap();
r3.recv().unwrap();
});
s3.send(()).unwrap();
select! {
recv(r1) -> _ => {},
recv(r2) -> _ => {},
}
s3.send(()).unwrap();
})
.unwrap();
}
#[test]
fn cloning2() {
let (s1, r1) = unbounded::<()>();
let (s2, r2) = unbounded::<()>();
let (_s3, _r3) = unbounded::<()>();
scope(|scope| {
scope.spawn(move |_| {
select! {
recv(r1) -> _ => panic!(),
recv(r2) -> _ => {},
}
});
thread::sleep(ms(500));
drop(s1.clone());
s2.send(()).unwrap();
})
.unwrap();
}
#[test]
fn preflight1() {
let (s, r) = unbounded();
s.send(()).unwrap();
select! {
recv(r) -> _ => {}
}
}
#[test]
fn preflight2() {
let (s, r) = unbounded();
drop(s.clone());
s.send(()).unwrap();
drop(s);
select! {
recv(r) -> v => assert!(v.is_ok()),
}
assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected));
}
#[test]
fn preflight3() {
let (s, r) = unbounded();
drop(s.clone());
s.send(()).unwrap();
drop(s);
r.recv().unwrap();
select! {
recv(r) -> v => assert!(v.is_err())
}
}
#[test]
fn duplicate_operations() {
let (s, r) = unbounded::<i32>();
let mut hit = [false; 4];
while hit.iter().any(|hit| !hit) {
select! {
recv(r) -> _ => hit[0] = true,
recv(r) -> _ => hit[1] = true,
send(s, 0) -> _ => hit[2] = true,
send(s, 0) -> _ => hit[3] = true,
}
}
}
#[test]
fn nesting() {
let (s, r) = unbounded::<i32>();
select! {
send(s, 0) -> _ => {
select! {
recv(r) -> v => {
assert_eq!(v, Ok(0));
select! {
send(s, 1) -> _ => {
select! {
recv(r) -> v => {
assert_eq!(v, Ok(1));
}
}
}
}
}
}
}
}
}
#[test]
#[should_panic(expected = "send panicked")]
fn panic_sender() {
fn get() -> Sender<i32> {
panic!("send panicked")
}
#[allow(unreachable_code)]
{
select! {
send(get(), panic!()) -> _ => {}
}
}
}
#[test]
#[should_panic(expected = "recv panicked")]
fn panic_receiver() {
fn get() -> Receiver<i32> {
panic!("recv panicked")
}
select! {
recv(get()) -> _ => {}
}
}
#[test]
fn stress_recv() {
#[cfg(miri)]
const COUNT: usize = 50;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = unbounded();
let (s2, r2) = bounded(5);
let (s3, r3) = bounded(100);
scope(|scope| {
scope.spawn(|_| {
for i in 0..COUNT {
s1.send(i).unwrap();
r3.recv().unwrap();
s2.send(i).unwrap();
r3.recv().unwrap();
}
});
for i in 0..COUNT {
for _ in 0..2 {
select! {
recv(r1) -> v => assert_eq!(v, Ok(i)),
recv(r2) -> v => assert_eq!(v, Ok(i)),
}
s3.send(()).unwrap();
}
}
})
.unwrap();
}
#[test]
fn stress_send() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = bounded(0);
let (s2, r2) = bounded(0);
let (s3, r3) = bounded(100);
scope(|scope| {
scope.spawn(|_| {
for i in 0..COUNT {
assert_eq!(r1.recv().unwrap(), i);
assert_eq!(r2.recv().unwrap(), i);
r3.recv().unwrap();
}
});
for i in 0..COUNT {
for _ in 0..2 {
select! {
send(s1, i) -> _ => {},
send(s2, i) -> _ => {},
}
}
s3.send(()).unwrap();
}
})
.unwrap();
}
#[test]
fn stress_mixed() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = bounded(0);
let (s2, r2) = bounded(0);
let (s3, r3) = bounded(100);
scope(|scope| {
scope.spawn(|_| {
for i in 0..COUNT {
s1.send(i).unwrap();
assert_eq!(r2.recv().unwrap(), i);
r3.recv().unwrap();
}
});
for i in 0..COUNT {
for _ in 0..2 {
select! {
recv(r1) -> v => assert_eq!(v, Ok(i)),
send(s2, i) -> _ => {},
}
}
s3.send(()).unwrap();
}
})
.unwrap();
}
#[test]
fn stress_timeout_two_threads() {
const COUNT: usize = 20;
let (s, r) = bounded(2);
scope(|scope| {
scope.spawn(|_| {
for i in 0..COUNT {
if i % 2 == 0 {
thread::sleep(ms(500));
}
loop {
select! {
send(s, i) -> _ => break,
default(ms(100)) => {}
}
}
}
});
scope.spawn(|_| {
for i in 0..COUNT {
if i % 2 == 0 {
thread::sleep(ms(500));
}
loop {
select! {
recv(r) -> v => {
assert_eq!(v, Ok(i));
break;
}
default(ms(100)) => {}
}
}
}
});
})
.unwrap();
}
#[test]
fn send_recv_same_channel() {
let (s, r) = bounded::<i32>(0);
select! {
send(s, 0) -> _ => panic!(),
recv(r) -> _ => panic!(),
default(ms(500)) => {}
}
let (s, r) = unbounded::<i32>();
select! {
send(s, 0) -> _ => {},
recv(r) -> _ => panic!(),
default(ms(500)) => panic!(),
}
}
#[test]
fn matching() {
const THREADS: usize = 44;
let (s, r) = &bounded::<usize>(0);
scope(|scope| {
for i in 0..THREADS {
scope.spawn(move |_| {
select! {
recv(r) -> v => assert_ne!(v.unwrap(), i),
send(s, i) -> _ => {},
}
});
}
})
.unwrap();
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
}
#[test]
fn matching_with_leftover() {
const THREADS: usize = 55;
let (s, r) = &bounded::<usize>(0);
scope(|scope| {
for i in 0..THREADS {
scope.spawn(move |_| {
select! {
recv(r) -> v => assert_ne!(v.unwrap(), i),
send(s, i) -> _ => {},
}
});
}
s.send(!0).unwrap();
})
.unwrap();
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
}
#[test]
fn channel_through_channel() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 1000;
type T = Box<dyn Any + Send>;
for cap in 0..3 {
let (s, r) = bounded::<T>(cap);
scope(|scope| {
scope.spawn(move |_| {
let mut s = s;
for _ in 0..COUNT {
let (new_s, new_r) = bounded(cap);
let new_r: T = Box::new(Some(new_r));
select! {
send(s, new_r) -> _ => {}
}
s = new_s;
}
});
scope.spawn(move |_| {
let mut r = r;
for _ in 0..COUNT {
r = select! {
recv(r) -> msg => {
msg.unwrap()
.downcast_mut::<Option<Receiver<T>>>()
.unwrap()
.take()
.unwrap()
}
}
}
});
})
.unwrap();
}
}
#[test]
fn linearizable_default() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 100_000;
for step in 0..2 {
let (start_s, start_r) = bounded::<()>(0);
let (end_s, end_r) = bounded::<()>(0);
let ((s1, r1), (s2, r2)) = if step == 0 {
(bounded::<i32>(1), bounded::<i32>(1))
} else {
(unbounded::<i32>(), unbounded::<i32>())
};
scope(|scope| {
scope.spawn(|_| {
for _ in 0..COUNT {
start_s.send(()).unwrap();
s1.send(1).unwrap();
select! {
recv(r1) -> _ => {}
recv(r2) -> _ => {}
default => unreachable!()
}
end_s.send(()).unwrap();
let _ = r2.try_recv();
}
});
for _ in 0..COUNT {
start_r.recv().unwrap();
s2.send(1).unwrap();
let _ = r1.try_recv();
end_r.recv().unwrap();
}
})
.unwrap();
}
}
#[test]
fn linearizable_timeout() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 100_000;
for step in 0..2 {
let (start_s, start_r) = bounded::<()>(0);
let (end_s, end_r) = bounded::<()>(0);
let ((s1, r1), (s2, r2)) = if step == 0 {
(bounded::<i32>(1), bounded::<i32>(1))
} else {
(unbounded::<i32>(), unbounded::<i32>())
};
scope(|scope| {
scope.spawn(|_| {
for _ in 0..COUNT {
start_s.send(()).unwrap();
s1.send(1).unwrap();
select! {
recv(r1) -> _ => {}
recv(r2) -> _ => {}
default(ms(0)) => unreachable!()
}
end_s.send(()).unwrap();
let _ = r2.try_recv();
}
});
for _ in 0..COUNT {
start_r.recv().unwrap();
s2.send(1).unwrap();
let _ = r1.try_recv();
end_r.recv().unwrap();
}
})
.unwrap();
}
}
#[test]
fn fairness1() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = bounded::<()>(COUNT);
let (s2, r2) = unbounded::<()>();
for _ in 0..COUNT {
s1.send(()).unwrap();
s2.send(()).unwrap();
}
let mut hits = [0usize; 4];
for _ in 0..COUNT {
select! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
recv(after(ms(0))) -> _ => hits[2] += 1,
recv(tick(ms(0))) -> _ => hits[3] += 1,
}
}
assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
}
#[test]
fn fairness2() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = unbounded::<()>();
let (s2, r2) = bounded::<()>(1);
let (s3, r3) = bounded::<()>(0);
scope(|scope| {
scope.spawn(|_| {
let (hole, _r) = bounded(0);
for _ in 0..COUNT {
let s1 = if s1.is_empty() { &s1 } else { &hole };
let s2 = if s2.is_empty() { &s2 } else { &hole };
select! {
send(s1, ()) -> res => assert!(res.is_ok()),
send(s2, ()) -> res => assert!(res.is_ok()),
send(s3, ()) -> res => assert!(res.is_ok()),
}
}
});
let hits = vec![Cell::new(0usize); 3];
for _ in 0..COUNT {
select! {
recv(r1) -> _ => hits[0].set(hits[0].get() + 1),
recv(r2) -> _ => hits[1].set(hits[1].get() + 1),
recv(r3) -> _ => hits[2].set(hits[2].get() + 1),
}
}
assert!(hits.iter().all(|x| x.get() >= COUNT / hits.len() / 50));
})
.unwrap();
}
#[test]
fn fairness_recv() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = bounded::<()>(COUNT);
let (s2, r2) = unbounded::<()>();
for _ in 0..COUNT {
s1.send(()).unwrap();
s2.send(()).unwrap();
}
let mut hits = [0usize; 2];
while hits[0] + hits[1] < COUNT {
select! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
}
}
assert!(hits.iter().all(|x| *x >= COUNT / 4));
}
#[test]
fn fairness_send() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, _r1) = bounded::<()>(COUNT);
let (s2, _r2) = unbounded::<()>();
let mut hits = [0usize; 2];
for _ in 0..COUNT {
select! {
send(s1, ()) -> _ => hits[0] += 1,
send(s2, ()) -> _ => hits[1] += 1,
}
}
assert!(hits.iter().all(|x| *x >= COUNT / 4));
}
#[test]
fn unfairness() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = unbounded::<()>();
let (s2, r2) = unbounded::<()>();
let (s3, r3) = unbounded::<()>();
for _ in 0..COUNT {
s1.send(()).unwrap();
s2.send(()).unwrap();
}
s3.send(()).unwrap();
let mut hits = [0usize; 3];
for _ in 0..COUNT {
select_biased! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
recv(r3) -> _ => hits[2] += 1,
}
}
assert_eq!(hits, [COUNT, 0, 0]);
for _ in 0..COUNT {
select_biased! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
recv(r3) -> _ => hits[2] += 1,
}
}
assert_eq!(hits, [COUNT, COUNT, 0]);
}
#[test]
fn unfairness_timeout() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = unbounded::<()>();
let (s2, r2) = unbounded::<()>();
let (s3, r3) = unbounded::<()>();
for _ in 0..COUNT {
s1.send(()).unwrap();
s2.send(()).unwrap();
}
s3.send(()).unwrap();
let mut hits = [0usize; 3];
for _ in 0..COUNT {
select_biased! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
recv(r3) -> _ => hits[2] += 1,
default(ms(1000)) => unreachable!(),
}
}
assert_eq!(hits, [COUNT, 0, 0]);
for _ in 0..COUNT {
select_biased! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
recv(r3) -> _ => hits[2] += 1,
default(ms(1000)) => unreachable!(),
}
}
assert_eq!(hits, [COUNT, COUNT, 0]);
}
#[test]
fn unfairness_try() {
#[cfg(miri)]
const COUNT: usize = 100;
#[cfg(not(miri))]
const COUNT: usize = 10_000;
let (s1, r1) = unbounded::<()>();
let (s2, r2) = unbounded::<()>();
let (s3, r3) = unbounded::<()>();
for _ in 0..COUNT {
s1.send(()).unwrap();
s2.send(()).unwrap();
}
s3.send(()).unwrap();
let mut hits = [0usize; 3];
for _ in 0..COUNT {
select_biased! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
recv(r3) -> _ => hits[2] += 1,
default() => unreachable!(),
}
}
assert_eq!(hits, [COUNT, 0, 0]);
for _ in 0..COUNT {
select_biased! {
recv(r1) -> _ => hits[0] += 1,
recv(r2) -> _ => hits[1] += 1,
recv(r3) -> _ => hits[2] += 1,
default() => unreachable!(),
}
}
assert_eq!(hits, [COUNT, COUNT, 0]);
}
#[allow(clippy::or_fun_call, clippy::unnecessary_literal_unwrap)] // This is intentional.
#[test]
fn references() {
let (s, r) = unbounded::<i32>();
select! {
send(s, 0) -> _ => {}
recv(r) -> _ => {}
}
select! {
send(&&&&s, 0) -> _ => {}
recv(&&&&r) -> _ => {}
}
select! {
recv(Some(&r).unwrap_or(&never())) -> _ => {},
default => {}
}
select! {
recv(Some(r).unwrap_or(never())) -> _ => {},
default => {}
}
}
#[test]
fn case_blocks() {
let (s, r) = unbounded::<i32>();
select! {
recv(r) -> _ => 3.0,
recv(r) -> _ => loop {
unreachable!()
},
recv(r) -> _ => match 7 + 3 {
_ => unreachable!()
},
default => 7.
};
select! {
recv(r) -> msg => if msg.is_ok() {
unreachable!()
},
default => ()
}
drop(s);
}
#[allow(clippy::redundant_closure_call)] // This is intentional.
#[test]
fn move_handles() {
let (s, r) = unbounded::<i32>();
select! {
recv((move || r)()) -> _ => {}
send((move || s)(), 0) -> _ => {}
}
}
#[test]
fn infer_types() {
let (s, r) = unbounded();
select! {
recv(r) -> _ => {}
default => {}
}
s.send(()).unwrap();
let (s, r) = unbounded();
select! {
send(s, ()) -> _ => {}
}
r.recv().unwrap();
}
#[test]
fn default_syntax() {
let (s, r) = bounded::<i32>(0);
select! {
recv(r) -> _ => panic!(),
default => {}
}
select! {
send(s, 0) -> _ => panic!(),
default() => {}
}
select! {
default => {}
}
select! {
default() => {}
}
}
#[test]
fn same_variable_name() {
let (_, r) = unbounded::<i32>();
select! {
recv(r) -> r => assert!(r.is_err()),
}
}
#[test]
fn handles_on_heap() {
let (s, r) = unbounded::<i32>();
let (s, r) = (Box::new(s), Box::new(r));
select! {
send(*s, 0) -> _ => {}
recv(*r) -> _ => {}
default => {}
}
drop(s);
drop(r);
}
#[test]
fn once_blocks() {
let (s, r) = unbounded::<i32>();
let once = Box::new(());
select! {
send(s, 0) -> _ => drop(once),
}
let once = Box::new(());
select! {
recv(r) -> _ => drop(once),
}
let once1 = Box::new(());
let once2 = Box::new(());
select! {
send(s, 0) -> _ => drop(once1),
default => drop(once2),
}
let once1 = Box::new(());
let once2 = Box::new(());
select! {
recv(r) -> _ => drop(once1),
default => drop(once2),
}
let once1 = Box::new(());
let once2 = Box::new(());
select! {
recv(r) -> _ => drop(once1),
send(s, 0) -> _ => drop(once2),
}
}
#[test]
fn once_receiver() {
let (_, r) = unbounded::<i32>();
let once = Box::new(());
let get = move || {
drop(once);
r
};
select! {
recv(get()) -> _ => {}
}
}
#[test]
fn once_sender() {
let (s, _) = unbounded::<i32>();
let once = Box::new(());
let get = move || {
drop(once);
s
};
select! {
send(get(), 5) -> _ => {}
}
}
#[test]
fn parse_nesting() {
let (_, r) = unbounded::<i32>();
select! {
recv(r) -> _ => {}
recv(r) -> _ => {
select! {
recv(r) -> _ => {}
recv(r) -> _ => {
select! {
recv(r) -> _ => {}
recv(r) -> _ => {
select! {
default => {}
}
}
}
}
}
}
}
}
#[test]
fn evaluate() {
let (s, r) = unbounded::<i32>();
let v = select! {
recv(r) -> _ => "foo".into(),
send(s, 0) -> _ => "bar".to_owned(),
default => "baz".to_string(),
};
assert_eq!(v, "bar");
let v = select! {
recv(r) -> _ => "foo".into(),
default => "baz".to_string(),
};
assert_eq!(v, "foo");
let v = select! {
recv(r) -> _ => "foo".into(),
default => "baz".to_string(),
};
assert_eq!(v, "baz");
}
#[test]
fn deref() {
use crossbeam_channel as cc;
struct Sender<T>(cc::Sender<T>);
struct Receiver<T>(cc::Receiver<T>);
impl<T> Deref for Receiver<T> {
type Target = cc::Receiver<T>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<T> Deref for Sender<T> {
type Target = cc::Sender<T>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
let (s, r) = bounded::<i32>(0);
let (s, r) = (Sender(s), Receiver(r));
select! {
send(s, 0) -> _ => panic!(),
recv(r) -> _ => panic!(),
default => {}
}
}
#[test]
fn result_types() {
let (s, _) = bounded::<i32>(0);
let (_, r) = bounded::<i32>(0);
select! {
recv(r) -> res => { let _: Result<i32, RecvError> = res; },
}
select! {
recv(r) -> res => { let _: Result<i32, RecvError> = res; },
default => {}
}
select! {
recv(r) -> res => { let _: Result<i32, RecvError> = res; },
default(ms(0)) => {}
}
select! {
send(s, 0) -> res => { let _: Result<(), SendError<i32>> = res; },
}
select! {
send(s, 0) -> res => { let _: Result<(), SendError<i32>> = res; },
default => {}
}
select! {
send(s, 0) -> res => { let _: Result<(), SendError<i32>> = res; },
default(ms(0)) => {}
}
select! {
send(s, 0) -> res => { let _: Result<(), SendError<i32>> = res; },
recv(r) -> res => { let _: Result<i32, RecvError> = res; },
}
}
#[test]
fn try_recv() {
let (s, r) = bounded(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
recv(r) -> _ => panic!(),
default => {}
}
thread::sleep(ms(1500));
select! {
recv(r) -> v => assert_eq!(v, Ok(7)),
default => panic!(),
}
thread::sleep(ms(500));
select! {
recv(r) -> v => assert_eq!(v, Err(RecvError)),
default => panic!(),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1000));
select! {
send(s, 7) -> res => res.unwrap(),
}
});
})
.unwrap();
}
#[test]
fn recv() {
let (s, r) = bounded(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
recv(r) -> v => assert_eq!(v, Ok(7)),
}
thread::sleep(ms(1000));
select! {
recv(r) -> v => assert_eq!(v, Ok(8)),
}
thread::sleep(ms(1000));
select! {
recv(r) -> v => assert_eq!(v, Ok(9)),
}
select! {
recv(r) -> v => assert_eq!(v, Err(RecvError)),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1500));
select! {
send(s, 7) -> res => res.unwrap(),
}
select! {
send(s, 8) -> res => res.unwrap(),
}
select! {
send(s, 9) -> res => res.unwrap(),
}
});
})
.unwrap();
}
#[test]
fn recv_timeout() {
let (s, r) = bounded::<i32>(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
recv(r) -> _ => panic!(),
default(ms(1000)) => {}
}
select! {
recv(r) -> v => assert_eq!(v, Ok(7)),
default(ms(1000)) => panic!(),
}
select! {
recv(r) -> v => assert_eq!(v, Err(RecvError)),
default(ms(1000)) => panic!(),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1500));
select! {
send(s, 7) -> res => res.unwrap(),
}
});
})
.unwrap();
}
#[test]
fn try_send() {
let (s, r) = bounded(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
send(s, 7) -> _ => panic!(),
default => {}
}
thread::sleep(ms(1500));
select! {
send(s, 8) -> res => res.unwrap(),
default => panic!(),
}
thread::sleep(ms(500));
select! {
send(s, 8) -> res => assert_eq!(res, Err(SendError(8))),
default => panic!(),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1000));
select! {
recv(r) -> v => assert_eq!(v, Ok(8)),
}
});
})
.unwrap();
}
#[test]
fn send() {
let (s, r) = bounded(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
send(s, 7) -> res => res.unwrap(),
}
thread::sleep(ms(1000));
select! {
send(s, 8) -> res => res.unwrap(),
}
thread::sleep(ms(1000));
select! {
send(s, 9) -> res => res.unwrap(),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1500));
select! {
recv(r) -> v => assert_eq!(v, Ok(7)),
}
select! {
recv(r) -> v => assert_eq!(v, Ok(8)),
}
select! {
recv(r) -> v => assert_eq!(v, Ok(9)),
}
});
})
.unwrap();
}
#[test]
fn send_timeout() {
let (s, r) = bounded(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
send(s, 7) -> _ => panic!(),
default(ms(1000)) => {}
}
select! {
send(s, 8) -> res => res.unwrap(),
default(ms(1000)) => panic!(),
}
select! {
send(s, 9) -> res => assert_eq!(res, Err(SendError(9))),
default(ms(1000)) => panic!(),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1500));
select! {
recv(r) -> v => assert_eq!(v, Ok(8)),
}
});
})
.unwrap();
}
#[test]
fn disconnect_wakes_sender() {
let (s, r) = bounded(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
send(s, ()) -> res => assert_eq!(res, Err(SendError(()))),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1000));
drop(r);
});
})
.unwrap();
}
#[test]
fn disconnect_wakes_receiver() {
let (s, r) = bounded::<()>(0);
scope(|scope| {
scope.spawn(move |_| {
select! {
recv(r) -> res => assert_eq!(res, Err(RecvError)),
}
});
scope.spawn(move |_| {
thread::sleep(ms(1000));
drop(s);
});
})
.unwrap();
}
#[test]
fn trailing_comma() {
let (s, r) = unbounded::<usize>();
select! {
send(s, 1,) -> _ => {},
recv(r,) -> _ => {},
default(ms(1000),) => {},
}
}