abstract async shutdown waiting loop

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/server.rs

@@ -1,5 +1,8 @@
 use std::{
-	sync::atomic::{AtomicBool, Ordering},
+	sync::{
+		atomic::{AtomicBool, Ordering},
+		Arc,
+	},
 	time::SystemTime,
 };
 
@@ -102,6 +105,13 @@ impl Server {
 		Ok(())
 	}
 
+	#[inline]
+	pub async fn until_shutdown(self: Arc<Self>) {
+		while self.running() {
+			self.signal.subscribe().recv().await.ok();
+		}
+	}
+
 	#[inline]
 	pub fn runtime(&self) -> &runtime::Handle {
 		self.runtime