Remove tokio dependency from serai-coordinator-p2p

Re-implements tokio::mpsc::oneshot with a thin wrapper around async-channel.

Also replaces futures-util with futures-lite.

Cargo.lock

@@ -840,6 +840,18 @@ dependencies = [
  "futures-core",
 ]
 
+[[package]]
+name = "async-channel"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89b47800b0be77592da0afd425cc03468052844aff33b84e33cc696f64e77b6a"
+dependencies = [
+ "concurrent-queue",
+ "event-listener-strategy",
+ "futures-core",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "async-io"
 version = "2.4.0"
@@ -2528,7 +2540,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "33d852cb9b869c2a9b3df2f71a3074817f01e1844f839a144f5fcef059a4eb5d"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -3047,7 +3059,10 @@ version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cef40d21ae2c515b51041df9ed313ed21e572df340ea58a922a0aefe7e8891a1"
 dependencies = [
+ "fastrand",
  "futures-core",
+ "futures-io",
+ "parking",
  "pin-project-lite",
 ]
 
@@ -3548,7 +3563,7 @@ dependencies = [
  "httpdate",
  "itoa",
  "pin-project-lite",
- "socket2 0.4.10",
+ "socket2 0.5.8",
  "tokio",
  "tower-service",
  "tracing",
@@ -4112,7 +4127,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc2f4eb4bc735547cfed7c0a4922cbd04a4655978c09b54f1f7b228750664c34"
 dependencies = [
  "cfg-if",
- "windows-targets 0.48.5",
+ "windows-targets 0.52.6",
 ]
 
 [[package]]
@@ -6907,7 +6922,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -7450,7 +7465,7 @@ version = "0.10.0-dev"
 source = "git+https://github.com/serai-dex/substrate#6e3f07bf5c98a6a3ec15f2b1a46148aa8c7d737a"
 dependencies = [
  "array-bytes",
- "async-channel",
+ "async-channel 1.9.0",
  "async-trait",
  "asynchronous-codec",
  "bytes",
@@ -7491,7 +7506,7 @@ name = "sc-network-bitswap"
 version = "0.10.0-dev"
 source = "git+https://github.com/serai-dex/substrate#6e3f07bf5c98a6a3ec15f2b1a46148aa8c7d737a"
 dependencies = [
- "async-channel",
+ "async-channel 1.9.0",
  "cid",
  "futures",
  "libp2p-identity",
@@ -7548,7 +7563,7 @@ version = "0.10.0-dev"
 source = "git+https://github.com/serai-dex/substrate#6e3f07bf5c98a6a3ec15f2b1a46148aa8c7d737a"
 dependencies = [
  "array-bytes",
- "async-channel",
+ "async-channel 1.9.0",
  "futures",
  "libp2p-identity",
  "log",
@@ -7569,7 +7584,7 @@ version = "0.10.0-dev"
 source = "git+https://github.com/serai-dex/substrate#6e3f07bf5c98a6a3ec15f2b1a46148aa8c7d737a"
 dependencies = [
  "array-bytes",
- "async-channel",
+ "async-channel 1.9.0",
  "async-trait",
  "fork-tree",
  "futures",
@@ -7943,7 +7958,7 @@ name = "sc-utils"
 version = "4.0.0-dev"
 source = "git+https://github.com/serai-dex/substrate#6e3f07bf5c98a6a3ec15f2b1a46148aa8c7d737a"
 dependencies = [
- "async-channel",
+ "async-channel 1.9.0",
  "futures",
  "futures-timer",
  "lazy_static",
@@ -8369,14 +8384,14 @@ dependencies = [
 name = "serai-coordinator-p2p"
 version = "0.1.0"
 dependencies = [
+ "async-channel 2.3.1",
  "borsh",
- "futures-util",
+ "futures-lite",
  "log",
  "serai-client",
  "serai-cosign",
  "serai-db",
  "serai-task",
- "tokio",
  "tributary-chain",
 ]
 
@@ -10528,7 +10543,7 @@ dependencies = [
  "getrandom",
  "once_cell",
  "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -11752,7 +11767,7 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
 dependencies = [
- "windows-sys 0.48.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]

coordinator/p2p/Cargo.toml

@@ -26,8 +26,8 @@ serai-client = { path = "../../substrate/client", default-features = false, feat
 serai-cosign = { path = "../cosign" }
 tributary = { package = "tributary-chain", path = "../tributary" }
 
-futures-util = { version = "0.3", default-features = false, features = ["std"] }
-tokio = { version = "1", default-features = false, features = ["sync"] }
+async-channel = { version = "2", default-features = false, features = ["std"] }
+futures-lite = { version = "2", default-features = false, features = ["std"] }
 
 log = { version = "0.4", default-features = false, features = ["std"] }
 serai-task = { path = "../../common/task", version = "0.1" }

coordinator/p2p/libp2p/src/lib.rs

@@ -19,7 +19,7 @@ use serai_client::{
   Serai,
 };
 
-use tokio::sync::{mpsc, oneshot, Mutex, RwLock};
+use tokio::sync::{mpsc, Mutex, RwLock};
 
 use serai_task::{Task, ContinuallyRan};
 
@@ -35,7 +35,7 @@ use libp2p::{
   SwarmBuilder,
 };
 
-use serai_coordinator_p2p::{Heartbeat, TributaryBlockWithCommit};
+use serai_coordinator_p2p::{oneshot, Heartbeat, TributaryBlockWithCommit};
 
 /// A struct to sync the validators from the Serai node in order to keep track of them.
 mod validators;

coordinator/p2p/libp2p/src/swarm.rs

@@ -8,7 +8,7 @@ use borsh::BorshDeserialize;
 
 use serai_client::validator_sets::primitives::ValidatorSet;
 
-use tokio::sync::{mpsc, oneshot, RwLock};
+use tokio::sync::{mpsc, RwLock};
 
 use serai_task::TaskHandle;
 
@@ -21,7 +21,7 @@ use libp2p::{
   swarm::{dial_opts::DialOpts, SwarmEvent, Swarm},
 };
 
-use serai_coordinator_p2p::Heartbeat;
+use serai_coordinator_p2p::{oneshot, Heartbeat};
 
 use crate::{
   Peers, BehaviorEvent, Behavior,

coordinator/p2p/src/heartbeat.rs

@@ -3,7 +3,7 @@ use std::time::{Duration, SystemTime};
 
 use serai_client::validator_sets::primitives::ValidatorSet;
 
-use futures_util::FutureExt;
+use futures_lite::FutureExt;
 
 use tributary::{ReadWrite, TransactionTrait, Block, Tributary, TributaryReader};
 

coordinator/p2p/src/lib.rs

@@ -8,10 +8,11 @@ use borsh::{BorshSerialize, BorshDeserialize};
 
 use serai_client::{primitives::NetworkId, validator_sets::primitives::ValidatorSet};
 
-use tokio::sync::oneshot;
-
 use serai_cosign::SignedCosign;
 
+/// A oneshot channel.
+pub mod oneshot;
+
 /// The heartbeat task, effecting sync of Tributaries
 pub mod heartbeat;
 

coordinator/p2p/src/oneshot.rs

@@ -0,0 +1,35 @@
+use core::{
+  pin::Pin,
+  task::{Poll, Context},
+  future::Future,
+};
+
+pub use async_channel::{SendError, RecvError};
+
+/// The sender for a oneshot channel.
+pub struct Sender<T: Send>(async_channel::Sender<T>);
+impl<T: Send> Sender<T> {
+  /// Send a value down the channel.
+  ///
+  /// Returns an error if the channel's receiver was dropped.
+  pub fn send(self, msg: T) -> Result<(), SendError<T>> {
+    self.0.send_blocking(msg)
+  }
+}
+
+/// The receiver for a oneshot channel.
+pub struct Receiver<T: Send>(async_channel::Receiver<T>);
+impl<T: Send> Future for Receiver<T> {
+  type Output = Result<T, RecvError>;
+  fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+    let recv = self.0.recv();
+    futures_lite::pin!(recv);
+    recv.poll(cx)
+  }
+}
+
+/// Create a new oneshot channel.
+pub fn channel<T: Send>() -> (Sender<T>, Receiver<T>) {
+  let (send, recv) = async_channel::bounded(1);
+  (Sender(send), Receiver(recv))
+}