Update signal-hook to 0.3

Author: taiki-e

crossbeam-channel/Cargo.toml

@@ -35,4 +35,4 @@ optional = true
 [dev-dependencies]
 num_cpus = "1.13.0"
 rand = "0.8"
-signal-hook = "0.2"
+signal-hook = "0.3"

crossbeam-channel/examples/stopwatch.rs

@@ -12,13 +12,13 @@ fn main() {
     use std::time::{Duration, Instant};
 
     use crossbeam_channel::{bounded, select, tick, Receiver};
+    use signal_hook::consts::SIGINT;
     use signal_hook::iterator::Signals;
-    use signal_hook::SIGINT;
 
     // Creates a channel that gets a message every time `SIGINT` is signalled.
     fn sigint_notifier() -> io::Result<Receiver<()>> {
         let (s, r) = bounded(100);
-        let signals = Signals::new(&[SIGINT])?;
+        let mut signals = Signals::new(&[SIGINT])?;
 
         thread::spawn(move || {
             for _ in signals.forever() {