Use AtomicU64 after updating to Rust >=1.34

Cargo.toml

@@ -15,7 +15,7 @@ edition = "2018"
 lto = true
 
 [features]
-latest_rust = []  # use latest Rust features (otherwise, support Rust 1.32)
+latest_rust = []  # use latest Rust features (otherwise, support Rust 1.34)
 
 [dependencies]
 base64 = "0.10"

src/daemon.rs

@@ -13,7 +13,6 @@ use std::collections::{HashMap, HashSet};
 use std::io::{BufRead, BufReader, Lines, Write};
 use std::net::{SocketAddr, TcpStream};
 use std::path::PathBuf;
-#[cfg(feature = "latest_rust")]
 use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
@@ -269,12 +268,10 @@ impl Connection {
     }
 }
 
-#[cfg(feature = "latest_rust")]
 struct Counter {
     value: AtomicU64,
 }
 
-#[cfg(feature = "latest_rust")]
 impl Counter {
     fn new() -> Self {
         Counter { value: 0.into() }
@@ -286,26 +283,6 @@ impl Counter {
     }
 }
 
-#[cfg(not(feature = "latest_rust"))]
-struct Counter {
-    value: Mutex<u64>,
-}
-
-#[cfg(not(feature = "latest_rust"))]
-impl Counter {
-    fn new() -> Self {
-        Counter {
-            value: Mutex::new(0),
-        }
-    }
-
-    fn next(&self) -> u64 {
-        let mut value = self.value.lock().unwrap();
-        *value += 1;
-        *value
-    }
-}
-
 pub struct Daemon {
     daemon_dir: PathBuf,
     network: Network,