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// aux-build:arc_wake.rs
// edition:2018
// run-pass
#![allow(unused_variables)]
// Test that the drop order for parameters in a fn and async fn matches up. Also test that
// parameters (used or unused) are not dropped until the async fn completes execution.
// See also #54716.
extern crate arc_wake;
use arc_wake::ArcWake;
use std::cell::RefCell;
use std::future::Future;
use std::marker::PhantomData;
use std::sync::Arc;
use std::rc::Rc;
use std::task::Context;
struct EmptyWaker;
impl ArcWake for EmptyWaker {
fn wake(self: Arc<Self>) {}
}
#[derive(Debug, Eq, PartialEq)]
enum DropOrder {
Function,
Val(&'static str),
}
type DropOrderListPtr = Rc<RefCell<Vec<DropOrder>>>;
struct D(&'static str, DropOrderListPtr);
impl Drop for D {
fn drop(&mut self) {
self.1.borrow_mut().push(DropOrder::Val(self.0));
}
}
/// Check that unused bindings are dropped after the function is polled.
async fn foo_async(ref mut x: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn foo_sync(ref mut x: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns are dropped after the function is polled.
async fn bar_async(ref mut x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn bar_sync(ref mut x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns within more complex patterns are dropped after the function
/// is polled.
async fn baz_async((ref mut x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn baz_sync((ref mut x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore and unused bindings within and outwith more complex patterns are dropped
/// after the function is polled.
async fn foobar_async(ref mut x: D, (ref mut a, _, ref mut _c): (D, D, D), _: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn foobar_sync(ref mut x: D, (ref mut a, _, ref mut _c): (D, D, D), _: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
struct Foo;
impl Foo {
/// Check that unused bindings are dropped after the method is polled.
async fn foo_async(ref mut x: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn foo_sync(ref mut x: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns are dropped after the method is polled.
async fn bar_async(ref mut x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn bar_sync(ref mut x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns within more complex patterns are dropped after the method
/// is polled.
async fn baz_async((ref mut x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn baz_sync((ref mut x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore and unused bindings within and outwith more complex patterns are
/// dropped after the method is polled.
async fn foobar_async(
ref mut x: D, (ref mut a, _, ref mut _c): (D, D, D), _: D, ref mut _y: D,
) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn foobar_sync(
ref mut x: D, (ref mut a, _, ref mut _c): (D, D, D), _: D, ref mut _y: D,
) {
x.1.borrow_mut().push(DropOrder::Function);
}
}
struct Bar<'a>(PhantomData<&'a ()>);
impl<'a> Bar<'a> {
/// Check that unused bindings are dropped after the method with self is polled.
async fn foo_async(&'a self, ref mut x: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn foo_sync(&'a self, ref mut x: D, ref mut _y: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns are dropped after the method with self is polled.
async fn bar_async(&'a self, ref mut x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn bar_sync(&'a self, ref mut x: D, _: D) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore patterns within more complex patterns are dropped after the method
/// with self is polled.
async fn baz_async(&'a self, (ref mut x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn baz_sync(&'a self, (ref mut x, _): (D, D)) {
x.1.borrow_mut().push(DropOrder::Function);
}
/// Check that underscore and unused bindings within and outwith more complex patterns are
/// dropped after the method with self is polled.
async fn foobar_async(
&'a self, ref mut x: D, (ref mut a, _, ref mut _c): (D, D, D), _: D, ref mut _y: D,
) {
x.1.borrow_mut().push(DropOrder::Function);
}
fn foobar_sync(
&'a self, ref mut x: D, (ref mut a, _, ref mut _c): (D, D, D), _: D, ref mut _y: D,
) {
x.1.borrow_mut().push(DropOrder::Function);
}
}
fn assert_drop_order_after_poll<Fut: Future<Output = ()>>(
f: impl FnOnce(DropOrderListPtr) -> Fut,
g: impl FnOnce(DropOrderListPtr),
) {
let empty = Arc::new(EmptyWaker);
let waker = ArcWake::into_waker(empty);
let mut cx = Context::from_waker(&waker);
let actual_order = Rc::new(RefCell::new(Vec::new()));
let mut fut = Box::pin(f(actual_order.clone()));
let _ = fut.as_mut().poll(&mut cx);
let expected_order = Rc::new(RefCell::new(Vec::new()));
g(expected_order.clone());
assert_eq!(*actual_order.borrow(), *expected_order.borrow());
}
fn main() {
// Free functions (see doc comment on function for what it tests).
assert_drop_order_after_poll(|l| foo_async(D("x", l.clone()), D("_y", l.clone())),
|l| foo_sync(D("x", l.clone()), D("_y", l.clone())));
assert_drop_order_after_poll(|l| bar_async(D("x", l.clone()), D("_", l.clone())),
|l| bar_sync(D("x", l.clone()), D("_", l.clone())));
assert_drop_order_after_poll(|l| baz_async((D("x", l.clone()), D("_", l.clone()))),
|l| baz_sync((D("x", l.clone()), D("_", l.clone()))));
assert_drop_order_after_poll(
|l| {
foobar_async(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
},
|l| {
foobar_sync(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
},
);
// Methods w/out self (see doc comment on function for what it tests).
assert_drop_order_after_poll(|l| Foo::foo_async(D("x", l.clone()), D("_y", l.clone())),
|l| Foo::foo_sync(D("x", l.clone()), D("_y", l.clone())));
assert_drop_order_after_poll(|l| Foo::bar_async(D("x", l.clone()), D("_", l.clone())),
|l| Foo::bar_sync(D("x", l.clone()), D("_", l.clone())));
assert_drop_order_after_poll(|l| Foo::baz_async((D("x", l.clone()), D("_", l.clone()))),
|l| Foo::baz_sync((D("x", l.clone()), D("_", l.clone()))));
assert_drop_order_after_poll(
|l| {
Foo::foobar_async(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
},
|l| {
Foo::foobar_sync(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
},
);
// Methods (see doc comment on function for what it tests).
let b = Bar(Default::default());
assert_drop_order_after_poll(|l| b.foo_async(D("x", l.clone()), D("_y", l.clone())),
|l| b.foo_sync(D("x", l.clone()), D("_y", l.clone())));
assert_drop_order_after_poll(|l| b.bar_async(D("x", l.clone()), D("_", l.clone())),
|l| b.bar_sync(D("x", l.clone()), D("_", l.clone())));
assert_drop_order_after_poll(|l| b.baz_async((D("x", l.clone()), D("_", l.clone()))),
|l| b.baz_sync((D("x", l.clone()), D("_", l.clone()))));
assert_drop_order_after_poll(
|l| {
b.foobar_async(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
},
|l| {
b.foobar_sync(
D("x", l.clone()),
(D("a", l.clone()), D("_", l.clone()), D("_c", l.clone())),
D("_", l.clone()),
D("_y", l.clone()),
)
},
);
}
|
