e336fe80d2
The anonymous future returned from an `async fn` captures all input lifetimes. This was not being taken into account. See https://github.com/rust-lang/rfcs/blob/master/text/2394-async_await.md#lifetime-capture-in-the-anonymous-future
66 lines
1.1 KiB
Rust
66 lines
1.1 KiB
Rust
// edition:2018
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#![warn(clippy::await_holding_lock)]
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use std::sync::Mutex;
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async fn bad(x: &Mutex<u32>) -> u32 {
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let guard = x.lock().unwrap();
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baz().await
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}
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async fn good(x: &Mutex<u32>) -> u32 {
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{
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let guard = x.lock().unwrap();
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let y = *guard + 1;
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}
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baz().await;
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let guard = x.lock().unwrap();
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47
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}
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async fn baz() -> u32 {
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42
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}
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async fn also_bad(x: &Mutex<u32>) -> u32 {
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let first = baz().await;
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let guard = x.lock().unwrap();
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let second = baz().await;
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let third = baz().await;
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first + second + third
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}
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async fn not_good(x: &Mutex<u32>) -> u32 {
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let first = baz().await;
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let second = {
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let guard = x.lock().unwrap();
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baz().await
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};
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let third = baz().await;
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first + second + third
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}
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#[allow(clippy::manual_async_fn)]
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fn block_bad(x: &Mutex<u32>) -> impl std::future::Future<Output = u32> + '_ {
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async move {
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let guard = x.lock().unwrap();
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baz().await
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}
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}
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fn main() {
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let m = Mutex::new(100);
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good(&m);
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bad(&m);
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also_bad(&m);
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not_good(&m);
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block_bad(&m);
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}
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