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//@ aux-build:arc_wake.rs
//@ edition:2018
//@ run-pass
#![deny(dead_code)]
#![allow(unused_variables)]
#![allow(unused_must_use)]
#![allow(path_statements)]
// Test that the drop order for locals in a fn and async fn matches up.
extern crate arc_wake;
use arc_wake::ArcWake;
use std::cell::RefCell;
use std::future::Future;
use std::pin::Pin;
use std::rc::Rc;
use std::sync::Arc;
use std::task::{Context, Poll};
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));
}
}
struct NeverReady;
impl Future for NeverReady {
type Output = ();
fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
Poll::Pending
}
}
async fn simple_variable_declaration_async(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
let x = D("x", l.clone());
let y = D("y", l.clone());
NeverReady.await;
}
fn simple_variable_declaration_sync(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
let x = D("x", l.clone());
let y = D("y", l.clone());
}
async fn varable_completely_contained_within_block_async(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
async {
let x = D("x", l.clone());
}
.await;
let y = D("y", l.clone());
NeverReady.await;
}
fn varable_completely_contained_within_block_sync(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
{
let x = D("x", l.clone());
}
let y = D("y", l.clone());
}
async fn variables_moved_into_separate_blocks_async(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
let x = D("x", l.clone());
let y = D("y", l.clone());
async move { x }.await;
async move { y }.await;
NeverReady.await;
}
fn variables_moved_into_separate_blocks_sync(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
let x = D("x", l.clone());
let y = D("y", l.clone());
{
x
};
{
y
};
}
async fn variables_moved_into_same_block_async(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
let x = D("x", l.clone());
let y = D("y", l.clone());
async move {
x;
y;
};
NeverReady.await;
}
fn variables_moved_into_same_block_sync(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
let x = D("x", l.clone());
let y = D("y", l.clone());
{
x;
y;
};
return;
}
async fn move_after_current_await_doesnt_affect_order(l: DropOrderListPtr) {
l.borrow_mut().push(DropOrder::Function);
let x = D("x", l.clone());
let y = D("y", l.clone());
NeverReady.await;
async move {
x;
y;
};
}
fn assert_drop_order_after_cancel<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);
drop(fut);
let expected_order = Rc::new(RefCell::new(Vec::new()));
g(expected_order.clone());
assert_eq!(*actual_order.borrow(), *expected_order.borrow());
}
fn main() {
assert_drop_order_after_cancel(
simple_variable_declaration_async,
simple_variable_declaration_sync,
);
assert_drop_order_after_cancel(
varable_completely_contained_within_block_async,
varable_completely_contained_within_block_sync,
);
assert_drop_order_after_cancel(
variables_moved_into_separate_blocks_async,
variables_moved_into_separate_blocks_sync,
);
assert_drop_order_after_cancel(
variables_moved_into_same_block_async,
variables_moved_into_same_block_sync,
);
assert_drop_order_after_cancel(
move_after_current_await_doesnt_affect_order,
simple_variable_declaration_sync,
);
}
|
