Make sleep between attempts interruptible by stop signals

Cargo.toml

@@ -15,4 +15,4 @@ humantime = "2.1"
 libc = "0.2"
 signal-hook = "0.3"
 signal-hook-tokio = { version = "0.3", features = ["futures-v0_3"] }
-tokio = { version = "1", features = ["macros", "process", "rt-multi-thread"] }
+tokio = { version = "1", features = ["macros", "process", "rt-multi-thread", "time"] }

src/main.rs

@@ -2,9 +2,8 @@ use clap::Parser;
 use futures::stream::StreamExt;
 use signal_hook::consts::signal;
 use signal_hook_tokio::Signals;
-use std::thread::sleep;
 use std::time::Duration;
-use tokio::process::Command;
+use tokio::{process::Command, time::sleep};
 
 /// A utility for retrying failed console commands
 #[derive(Parser)]
@@ -111,7 +110,17 @@ async fn run(args: Args) -> i32 {
                 num_attempts,
                 humantime::Duration::from(delay)
             ));
-            sleep(delay);
+
+            let backoff_sleep = sleep(delay);
+            tokio::pin!(backoff_sleep);
+
+            tokio::select! {
+                Some(_signal) = signals.next() => {
+                    return last_exit_code;
+                }
+                _ = &mut backoff_sleep => {}
+            }
+
             delay *= args.delay_multiplier;
         }
     }

test.sh

@@ -148,6 +148,38 @@ assertEqual \
   "child received TERM signal" \
   "$(tail -n 1 ./output)"
 
+#
+# Given: The child exit code is non-zero,
+#        and we are sleeping before the next attempt
+#  When: A stop signal is received
+#  Then: The sleep is interrupted
+#
+givenScript "exit 1"
+${binPath} --attempts 2 --delay 5s -- ./script >output 2>&1 &
+processId=$!
+
+# Wait until we enter sleep by detecting the 'retrying in' output
+for i in $(seq 1 100); do
+  if grep -q 'retrying in' ./output; then
+    break
+  fi
+  sleep 0.05
+done
+
+beforeTs=$(date +%s)
+kill -s TERM ${processId}
+wait ${processId} 2>/dev/null
+afterTs=$(date +%s)
+elapsed=$((afterTs-beforeTs))
+
+interrupted=false
+[ ${elapsed} -lt 2 ] && interrupted=true
+
+assertEqual \
+  "Sleep between attempts is interrupted when a stop signal is received" \
+  "true" \
+  "${interrupted}"
+
 rm ./script ./output >/dev/null 2>&1
 
 [ ${failCount} = 0 ] && exit 0 || exit 1