spawn_blocking metrics collection

adria0 · adria0 · commit e49f538e87e2 · 2020-07-18T14:08:05.000+02:00
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -81,6 +81,7 @@ stats = { path = "util/stats" }
 term_size = "0.3"
 textwrap = "0.11.0"
 toml = "0.5.6"
+tokio = { version = "0.2", features = ["blocking"] }
 verification = { path = "ethcore/verification" }
 prometheus = "0.9.0"
 
diff --git a/parity/main.rs b/parity/main.rs
@@ -28,6 +28,7 @@ extern crate openethereum;
 extern crate parking_lot;
 extern crate parity_daemonize;
 extern crate ansi_term;
+extern crate tokio;
 
 #[cfg(windows)] extern crate winapi;
 extern crate ethcore_logger;
diff --git a/parity/metrics.rs b/parity/metrics.rs
@@ -45,19 +45,19 @@ struct State {
 	rpc_apis: Arc<rpc_apis::FullDependencies>,
 }
 
-fn handle_request(req: Request<Body>, state: &Arc<Mutex<State>>) -> Response<Body> {
+async fn handle_request(req: Request<Body>, state: Arc<Mutex<State>>) -> Response<Body> {
     let (parts, _body) = req.into_parts();
     match (parts.method, parts.uri.path()) {
         (Method::GET, "/metrics") => {
             let start = Instant::now();
-            let mut reg = prometheus::Registry::new();
 
-            let state = state.lock();
-
-            state.rpc_apis.client.prometheus_metrics(&mut reg);
-            state.rpc_apis.sync.prometheus_metrics(&mut reg);
-
-            drop(state);
+            let mut reg = tokio::task::spawn_blocking(move || {
+                let mut reg = prometheus::Registry::new();
+                let state = state.lock();
+                state.rpc_apis.client.prometheus_metrics(&mut reg);
+                state.rpc_apis.sync.prometheus_metrics(&mut reg);
+                reg
+            }).await.expect("The prometheus collection has panicked");
 
             let elapsed = start.elapsed();
             let ms = (elapsed.as_secs() as i64)*1000 + (elapsed.subsec_millis() as i64);
@@ -98,12 +98,12 @@ pub fn start_prometheus_metrics(conf: &MetricsConfiguration, deps: &rpc::Depende
     let state = Arc::new(Mutex::new(state));
 
     deps.executor.spawn_std( async move {
-        let make_service = make_service_fn(move |_| {
-            let state = state.clone();
-            async move {
-                Ok::<_, hyper::Error>(service_fn(move |req| {
-                    let response = handle_request(req,&state);
-                    async move { Ok::<_, hyper::Error>(response) }
+            let make_service = make_service_fn(move |_| {
+                let state = state.clone();
+                async move {
+                    Ok::<_, hyper::Error>(service_fn(move |req| {
+                    let response = handle_request(req, state.clone());
+                    async move { Ok::<_, hyper::Error>(response.await) }
                 }))
             }
         });
