async_backplane/
panic.rs

1//! Utilities for dealing with panics (and unlocking better debugging).
2//!
3//! Important: be careful about installing panic handlers. Do it only
4//! once per thread and pick your function carefully.
5use futures_micro::poll_state;
6use maybe_unwind::{capture_panic_info, maybe_unwind};
7use std::future::Future;
8use std::panic::{self, AssertUnwindSafe};
9use std::pin::Pin;
10use std::task::Poll;
11
12pub use maybe_unwind::Unwind;
13
14/// Sets the thread local panic handler to record the unwind information.
15pub fn replace_panic_hook() {
16    panic::set_hook(Box::new(|info| { capture_panic_info(info); }));
17}
18
19/// Sets the thread local panic handler to record the unwind information
20/// and then execute the existing hook.
21pub fn chain_panic_hook() {
22    let old = panic::take_hook();
23    panic::set_hook(Box::new(move |info| {
24        capture_panic_info(info);
25        old(info);
26    }));
27}
28
29/// Run a future such that panics are converted into Unwinds.
30pub async fn dont_panic<F, T>(future: F) -> Result<T, Unwind>
31where F: Future<Output = T> {
32    poll_state(Some(future), |future, ctx| {
33        if let Some(ref mut fut) = future {
34            let pin = unsafe { Pin::new_unchecked(fut) };
35            match maybe_unwind(AssertUnwindSafe(|| <F as Future>::poll(pin, ctx))) {
36                Ok(Poll::Ready(val)) => Poll::Ready(Ok(val)),
37                Err(unwind) => Poll::Ready(Err(unwind)),
38                Ok(Poll::Pending) => Poll::Pending,
39            }
40        } else { Poll::Pending }
41    }).await
42}
async_backplane/panic.rs

async_backplane/
panic.rs
