/
macros_join.rs
122 lines (91 loc) · 2.94 KB
/
macros_join.rs
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#![cfg(feature = "macros")]
#![allow(clippy::blacklisted_name)]
use std::{sync::Arc, time::Duration};
#[cfg(target_arch = "wasm32")]
use wasm_bindgen_test::wasm_bindgen_test as test;
#[cfg(target_arch = "wasm32")]
use wasm_bindgen_test::wasm_bindgen_test as maybe_tokio_test;
#[cfg(not(target_arch = "wasm32"))]
use tokio::test as maybe_tokio_test;
use tokio::sync::{oneshot, Semaphore};
use tokio_test::{assert_pending, assert_ready, task};
#[maybe_tokio_test]
async fn sync_one_lit_expr_comma() {
let foo = tokio::join!(async { 1 },);
assert_eq!(foo, (1,));
}
#[maybe_tokio_test]
async fn sync_one_lit_expr_no_comma() {
let foo = tokio::join!(async { 1 });
assert_eq!(foo, (1,));
}
#[maybe_tokio_test]
async fn sync_two_lit_expr_comma() {
let foo = tokio::join!(async { 1 }, async { 2 },);
assert_eq!(foo, (1, 2));
}
#[maybe_tokio_test]
async fn sync_two_lit_expr_no_comma() {
let foo = tokio::join!(async { 1 }, async { 2 });
assert_eq!(foo, (1, 2));
}
#[maybe_tokio_test]
async fn two_await() {
let (tx1, rx1) = oneshot::channel::<&str>();
let (tx2, rx2) = oneshot::channel::<u32>();
let mut join = task::spawn(async {
tokio::join!(async { rx1.await.unwrap() }, async { rx2.await.unwrap() })
});
assert_pending!(join.poll());
tx2.send(123).unwrap();
assert!(join.is_woken());
assert_pending!(join.poll());
tx1.send("hello").unwrap();
assert!(join.is_woken());
let res = assert_ready!(join.poll());
assert_eq!(("hello", 123), res);
}
#[test]
fn join_size() {
use futures::future;
use std::mem;
let fut = async {
let ready = future::ready(0i32);
tokio::join!(ready)
};
assert_eq!(mem::size_of_val(&fut), 16);
let fut = async {
let ready1 = future::ready(0i32);
let ready2 = future::ready(0i32);
tokio::join!(ready1, ready2)
};
assert_eq!(mem::size_of_val(&fut), 28);
}
async fn non_cooperative_task(permits: Arc<Semaphore>) -> usize {
let mut exceeded_budget = 0;
for _ in 0..5 {
// Another task should run after after this task uses its whole budget
for _ in 0..128 {
let _permit = permits.clone().acquire_owned().await.unwrap();
}
exceeded_budget += 1;
}
exceeded_budget
}
async fn poor_little_task() -> usize {
let mut how_many_times_i_got_to_run = 0;
for _ in 0..5 {
tokio::time::sleep(Duration::from_millis(100)).await;
how_many_times_i_got_to_run += 1;
}
how_many_times_i_got_to_run
}
#[tokio::test]
async fn join_does_not_allow_tasks_to_starve() {
let permits = Arc::new(Semaphore::new(10));
// non_cooperative_task should yield after its budget is exceeded and then poor_little_task should run.
let (non_cooperative_result, little_task_result) =
tokio::join!(non_cooperative_task(permits), poor_little_task());
assert_eq!(5, non_cooperative_result);
assert_eq!(5, little_task_result);
}