fix(shutdown): fix shutdown logic (#800)

* fix shutdown logic
* simplify

src/bin/inx-chronicle/main.rs

@@ -121,7 +121,7 @@ async fn main() -> Result<(), Error> {
 
     // We wait for either the interrupt signal to arrive or for a component of our system to signal a shutdown.
     tokio::select! {
-        _ = process::interupt_or_terminate() => {
+        _ = process::interrupt_or_terminate() => {
             tracing::info!("received ctrl-c or terminate");
         },
         res = tasks.join_next() => {
@@ -135,7 +135,7 @@ async fn main() -> Result<(), Error> {
 
     // Allow the user to abort if the tasks aren't shutting down quickly.
     tokio::select! {
-        _ = process::interupt_or_terminate() => {
+        _ = process::interrupt_or_terminate() => {
             tracing::info!("received second ctrl-c or terminate - aborting");
             tasks.shutdown().await;
             tracing::info!("Abort successful");

src/bin/inx-chronicle/process.rs

@@ -1,30 +1,18 @@
 // Copyright 2022 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-use tokio::{
-    signal::unix::{signal, SignalKind},
-    sync::mpsc,
-};
+use tokio::signal::unix::{signal, SignalKind};
 
-pub async fn interupt_or_terminate() -> mpsc::UnboundedReceiver<()> {
-    let (shutdown_send, shutdown_recv) = mpsc::unbounded_channel();
+pub async fn interrupt_or_terminate() {
+    let mut sigterm = signal(SignalKind::terminate()).expect("cannot listen to `SIGTERM`");
+    let mut sigint = signal(SignalKind::interrupt()).expect("cannot listen to `SIGINT`");
 
-    let _ = tokio::spawn(async move {
-        let mut sigterm = signal(SignalKind::terminate()).expect("cannot listen to `SIGTERM`");
-        let mut sigint = signal(SignalKind::interrupt()).expect("cannot listen to `SIGINT`");
-
-        tokio::select! {
-            _ = sigterm.recv() => {
-                tracing::info!("received `SIGTERM`, sending shutdown signal")
-            }
-            _ = sigint.recv() => {
-                tracing::info!("received `SIGTERM`, sending shutdown signal")
-            }
+    tokio::select! {
+        _ = sigterm.recv() => {
+            tracing::info!("received `SIGTERM`, sending shutdown signal")
         }
-
-        shutdown_send.send(()).expect("Could not send shutdown signal");
-    })
-    .await;
-
-    shutdown_recv
+        _ = sigint.recv() => {
+            tracing::info!("received `SIGTERM`, sending shutdown signal")
+        }
+    }
 }