feat: send signals in parallel (#51)

Co-authored-by: Bernhard Schuster <bernhard@ahoi.io>

orchestra/proc-macro/src/impl_orchestra.rs

@@ -61,6 +61,9 @@ pub(crate) fn impl_orchestra_struct(info: &OrchestraInfo) -> proc_macro2::TokenS
 
 		/// Capacity of a signal channel between a subsystem and the orchestra.
 		const SIGNAL_CHANNEL_CAPACITY: usize = #signal_channel_capacity;
+		/// Timeout to wait for a signal to be processed by the target subsystem. If this timeout is exceeded, the
+		/// orchestra terminates with an error.
+		const SIGNAL_TIMEOUT: ::std::time::Duration = ::std::time::Duration::from_secs(10);
 
 		/// The log target tag.
 		const LOG_TARGET: &str = #log_target;
@@ -129,12 +132,45 @@ pub(crate) fn impl_orchestra_struct(info: &OrchestraInfo) -> proc_macro2::TokenS
 
 			/// Broadcast a signal to all subsystems.
 			pub async fn broadcast_signal(&mut self, signal: #signal_ty) -> ::std::result::Result<(), #error_ty > {
+				let mut delayed_signals : #support_crate ::futures::stream::FuturesUnordered<::std::pin::Pin<::std::boxed::Box<dyn #support_crate::futures::Future<Output = ::std::result::Result<(), #error_ty>>>>>
+					= #support_crate ::futures::stream::FuturesUnordered::new();
 				#(
+					// Use fast path if possible.
 					#feature_gates
-					self. #subsystem_name .send_signal(signal.clone()).await?;
+					if let Err(e) = self. #subsystem_name .try_send_signal(signal.clone()) {
+							match e {
+								#support_crate::TrySendError::Full(sig) => {
+									let instance = self. #subsystem_name .instance.as_mut().expect("checked in try_send_signal");
+									delayed_signals.push(::std::boxed::Box::pin(async move {
+										match instance.tx_signal.send(sig).timeout(SIGNAL_TIMEOUT).await {
+											None => {
+												Err(#error_ty :: from(
+													#support_crate ::OrchestraError::SubsystemStalled(instance.name, "signal", ::std::any::type_name::<#signal_ty>())
+												))
+											}
+											Some(res) => {
+												let res = res.map_err(|_| #error_ty :: from(
+													#support_crate ::OrchestraError::QueueError
+												));
+												if res.is_ok() {
+													instance.signals_received += 1;
+												}
+												res
+											}
+										}
+									}));
+								},
+								_ => return Err(#error_ty :: from(#support_crate ::OrchestraError::QueueError))
+							}
+					}
 				)*
 				let _ = signal;
 
+				// If fast path failed, wait for all delayed signals with no specific order
+				while let Some(res) = delayed_signals.next().await {
+					res?;
+				}
+
 				Ok(())
 			}
 
@@ -255,12 +291,21 @@ pub(crate) fn impl_orchestrated_subsystem(info: &OrchestraInfo) -> proc_macro2::
 				}
 			}
 
+			/// Tries to send a signal to the wrapped subsystem without waiting.
+			pub fn try_send_signal(&mut self, signal: #signal) -> ::std::result::Result<(), #support_crate :: TrySendError<#signal> > {
+				if let Some(ref mut instance) = self.instance {
+					instance.tx_signal.try_send(signal)?;
+					instance.signals_received += 1;
+					Ok(())
+				} else {
+					Ok(())
+				}
+			}
+
 			/// Send a signal to the wrapped subsystem.
 			///
 			/// If the inner `instance` is `None`, nothing is happening.
 			pub async fn send_signal(&mut self, signal: #signal) -> ::std::result::Result<(), #error_ty > {
-				const SIGNAL_TIMEOUT: ::std::time::Duration = ::std::time::Duration::from_secs(10);
-
 				if let Some(ref mut instance) = self.instance {
 					match instance.tx_signal.send(signal).timeout(SIGNAL_TIMEOUT).await {
 						None => {

orchestra/src/lib.rs

@@ -90,6 +90,9 @@ use std::sync::{
 #[doc(hidden)]
 pub use std::time::Duration;
 
+#[doc(hidden)]
+pub use metered::TrySendError;
+
 #[doc(hidden)]
 pub use futures_timer::Delay;