Remove dependency on async-trait.

Cargo.toml

@@ -40,7 +40,6 @@ arbitrary = { version = "1.0" }
 libc = "0.2.150"
 tokio = "1.32"
 toml = { version = ">=0.6.0,<0.9.0", default-features = false, features = ["parse"] }
-async-trait = "0.1.67"
 timestamped-socket = "0.2.2"
 clock-steering = "0.2.1"
 pps-time = "0.2.3"

ntpd/Cargo.toml

@@ -20,7 +20,6 @@ tracing-subscriber.workspace = true
 toml.workspace = true
 rand.workspace = true
 libc.workspace = true
-async-trait.workspace = true
 timestamped-socket.workspace = true
 clock-steering.workspace = true
 pps-time = { workspace = true, optional = true }

ntpd/src/daemon/spawn/mod.rs

@@ -1,4 +1,4 @@
-use std::{net::SocketAddr, path::PathBuf, sync::atomic::AtomicU64};
+use std::{future::Future, net::SocketAddr, path::PathBuf, sync::atomic::AtomicU64};
 
 use ntp_proto::{ProtocolVersion, SourceConfig, SourceNtsData};
 use serde::{Deserialize, Serialize};
@@ -190,7 +190,6 @@ pub struct PpsSourceCreateParameters {
     pub period: f64,
 }
 
-#[async_trait::async_trait]
 pub trait Spawner {
     type Error: std::error::Error + Send;
 
@@ -199,7 +198,10 @@ pub trait Spawner {
     /// It is ok for this function to use some time when spawning a new client.
     /// However, it should not implement it's own retry or backoff feature, but
     /// rather rely on that provided by the basic spawner.
-    async fn try_spawn(&mut self, action_tx: &mpsc::Sender<SpawnEvent>) -> Result<(), Self::Error>;
+    fn try_spawn(
+        &mut self,
+        action_tx: &mpsc::Sender<SpawnEvent>,
+    ) -> impl Future<Output = Result<(), Self::Error>> + Send;
 
     /// Is there desire to spawn new sources?
     fn is_complete(&self) -> bool;
@@ -213,8 +215,10 @@ pub trait Spawner {
     ///
     /// This should just do bookkeeping, any adding of sources should be done
     /// in try_add.
-    async fn handle_source_removed(&mut self, event: SourceRemovedEvent)
-    -> Result<(), Self::Error>;
+    fn handle_source_removed(
+        &mut self,
+        event: SourceRemovedEvent,
+    ) -> impl Future<Output = Result<(), Self::Error>> + Send;
 
     /// Event handler for when a source is successfully registered in the system
     ///
@@ -224,11 +228,11 @@ pub trait Spawner {
     ///
     /// This should just do bookkeeping, any adding of sources should be done
     /// in try_add.
-    async fn handle_registered(
+    fn handle_registered(
         &mut self,
         _event: SourceCreateParameters,
-    ) -> Result<(), Self::Error> {
-        Ok(())
+    ) -> impl Future<Output = Result<(), Self::Error>> + Send {
+        async { Ok(()) }
     }
 
     /// Get the id of the spawner

ntpd/src/daemon/spawn/nts.rs

@@ -76,7 +76,6 @@ impl NtsSpawner {
     }
 }
 
-#[async_trait::async_trait]
 impl Spawner for NtsSpawner {
     type Error = NtsSpawnError;
 

ntpd/src/daemon/spawn/nts_pool.rs

@@ -74,7 +74,6 @@ impl NtsPoolSpawner {
     }
 }
 
-#[async_trait::async_trait]
 impl Spawner for NtsPoolSpawner {
     type Error = NtsPoolSpawnError;
 

ntpd/src/daemon/spawn/pool.rs

@@ -45,7 +45,6 @@ impl PoolSpawner {
     }
 }
 
-#[async_trait::async_trait]
 impl Spawner for PoolSpawner {
     type Error = PoolSpawnError;
 

ntpd/src/daemon/spawn/pps.rs

@@ -26,7 +26,6 @@ impl PpsSpawner {
     }
 }
 
-#[async_trait::async_trait]
 impl Spawner for PpsSpawner {
     type Error = StandardSpawnError;
 

ntpd/src/daemon/spawn/sock.rs

@@ -26,7 +26,6 @@ impl SockSpawner {
     }
 }
 
-#[async_trait::async_trait]
 impl Spawner for SockSpawner {
     type Error = StandardSpawnError;
 

ntpd/src/daemon/spawn/standard.rs

@@ -75,7 +75,6 @@ impl StandardSpawner {
     }
 }
 
-#[async_trait::async_trait]
 impl Spawner for StandardSpawner {
     type Error = StandardSpawnError;