rust/tests/ui/await_holding_lock.rs
Andy Weiss 6c25c3c381 Lint for holding locks across await points
Fixes #4226

This introduces the lint await_holding_lock. For async functions, we iterate
over all types in generator_interior_types and look for types named MutexGuard,
RwLockReadGuard, or RwLockWriteGuard. If we find one then we emit a lint.
2020-04-21 21:07:43 -07:00

43 lines
671 B
Rust

// edition:2018
#![warn(clippy::await_holding_lock)]
use std::sync::Mutex;
async fn bad(x: &Mutex<u32>) -> u32 {
let guard = x.lock().unwrap();
baz().await
}
async fn good(x: &Mutex<u32>) -> u32 {
{
let guard = x.lock().unwrap();
let y = *guard + 1;
}
baz().await;
let guard = x.lock().unwrap();
47
}
async fn baz() -> u32 {
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}
async fn also_bad(x: &Mutex<u32>) -> u32 {
let first = baz().await;
let guard = x.lock().unwrap();
let second = baz().await;
let third = baz().await;
first + second + third
}
fn main() {
let m = Mutex::new(100);
good(&m);
bad(&m);
also_bad(&m);
}