Switch to unbounded channels for Reply (#207)

CHANGELOG.md

@@ -27,6 +27,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Rename `GenericServerRef` to `ServerRef` and remove `ServerRef` trait,
   refactoring `TcpServerRef`, `UnixSocketServerRef`, and `WindowsPipeServerRef`
   to use the struct instead of `Box<dyn ServerRef>`
+- Update `Reply` trait and associated implementations to be non-blocking &
+  synchronous as opposed to asynchronous to avoid deadlocks and also be more
+  performant
 
 ## [0.20.0-alpha.8]
 

distant-core/src/api.rs

@@ -495,12 +495,12 @@ where
         // Queue up our result to go before ANY of the other messages that might be sent.
         // This is important to avoid situations such as when a process is started, but before
         // the confirmation can be sent some stdout or stderr is captured and sent first.
-        if let Err(x) = reply.send_before(response).await {
+        if let Err(x) = reply.send_before(response) {
             error!("[Conn {}] Failed to send response: {}", connection_id, x);
         }
 
         // Flush out all of our replies thus far and toggle to no longer hold submissions
-        if let Err(x) = reply.flush(false).await {
+        if let Err(x) = reply.flush(false) {
             error!(
                 "[Conn {}] Failed to flush response queue: {}",
                 connection_id, x

distant-core/src/api/reply.rs

@@ -1,6 +1,4 @@
-use std::future::Future;
 use std::io;
-use std::pin::Pin;
 
 use distant_net::server::Reply;
 
@@ -19,14 +17,10 @@ impl From<Box<dyn Reply<Data = protocol::Msg<protocol::Response>>>> for DistantS
 impl Reply for DistantSingleReply {
     type Data = protocol::Response;
 
-    fn send(&self, data: Self::Data) -> Pin<Box<dyn Future<Output = io::Result<()>> + Send + '_>> {
+    fn send(&self, data: Self::Data) -> io::Result<()> {
         self.0.send(protocol::Msg::Single(data))
     }
 
-    fn blocking_send(&self, data: Self::Data) -> io::Result<()> {
-        self.0.blocking_send(protocol::Msg::Single(data))
-    }
-
     fn clone_reply(&self) -> Box<dyn Reply<Data = Self::Data>> {
         Box::new(Self(self.0.clone_reply()))
     }