make into handle

fuel-core/src/service.rs

@@ -24,6 +24,14 @@ pub mod metrics;
 pub mod modules;
 
 pub struct FuelService {
+    handle: JoinHandle<()>,
+    /// Shutdown the fuel service.
+    shutdown: oneshot::Sender<()>,
+    /// The address bound by the system for serving the API
+    pub bound_address: SocketAddr,
+}
+
+struct FuelServiceInner {
     tasks: Vec<JoinHandle<Result<(), AnyError>>>,
     /// handler for all modules.
     modules: Modules,
@@ -47,7 +55,33 @@ impl FuelService {
             _ => Database::in_memory(),
         };
         // initialize service
-        Self::init_service(database, config).await
+        Ok(Self::spawn_service(
+            Self::init_service(database, config).await?,
+        ))
+    }
+
+    fn spawn_service(service: FuelServiceInner) -> Self {
+        let bound_address = service.bound_address.clone();
+        let (shutdown, stop_rx) = oneshot::channel();
+        let handle = tokio::spawn(async move {
+            let run_fut = service.run();
+            let shutdown_fut = stop_rx.then(|stop| async move {
+                if stop.is_error() {
+                    // If the handle is dropped we don't want
+                    // this to ever shutdown the service.
+                    futures::future::pending().await;
+                }
+                // Only a successful recv results in a shutdown.
+            });
+            tokio::pin!(run_fut);
+            tokio::pin!(shutdown_fut);
+            futures::future::select(shutdown_fut, run_fut).await;
+        });
+        Self {
+            handle,
+            shutdown,
+            bound_address,
+        }
     }
 
     // TODO: Rework our configs system to avoid nesting of the same configs.
@@ -71,11 +105,16 @@ impl FuelService {
         database: Database,
         config: Config,
     ) -> Result<Self, AnyError> {
-        Self::init_service(database, config).await
+        Ok(Self::spawn_service(
+            Self::init_service(database, config).await?,
+        ))
     }
 
     /// Private inner method for initializing the fuel service
-    async fn init_service(database: Database, config: Config) -> Result<Self, AnyError> {
+    async fn init_service(
+        database: Database,
+        config: Config,
+    ) -> Result<FuelServiceInner, AnyError> {
         // initialize state
         Self::initialize_state(&config, &database)?;
 
@@ -91,14 +130,32 @@ impl FuelService {
         // Socket is ignored for now, but as more services are added
         // it may be helpful to have a way to list all services and their ports
 
-        Ok(FuelService {
+        Ok(FuelServiceInner {
             tasks,
             bound_address,
             modules,
             stop_graphql_api: stop_tx,
         })
     }
 
+    /// Awaits for the completion of any server background tasks
+    pub async fn run(self) {
+        if let Err(e) = self.handle.await {
+            if err.is_panic() {
+                // Resume the panic on the main task
+                panic::resume_unwind(err.into_panic());
+            }
+        }
+    }
+
+    /// Shutdown background tasks
+    pub async fn stop(self) {
+        let _ = self.shutdown.send(());
+        self.run();
+    }
+}
+
+impl FuelServiceInner {
     /// Awaits for the completion of any server background tasks
     pub async fn run(self) {
         let Self {