Merge pull request #95 from shnmorimoto/add_4_5

add 4_5

Author: yuk1ty

chapter4/Cargo.toml

@@ -26,6 +26,10 @@ path = "src/4_2_5/main.rs"
 name = "4_3_1"
 path = "src/4_3_1/main.rs"
 
+[[bin]]
+name = "4_5"
+path = "src/4_5/main.rs"
+
 [dependencies]
 lib = { path = "../lib" }
 tokio = { version = "1.5.0", features = ["full"] }

chapter4/src/4_5/main.rs

@@ -0,0 +1,20 @@
+use tokio::time::{self, Duration};
+
+// tokio::time::sleepを使って、決まった時間を図るタイマーを作る
+#[tokio::main]
+async fn main() {
+    let wait_sec = 5;
+    let (_, mut wait) = tokio::sync::oneshot::channel::<()>();
+    let sleep = time::sleep(Duration::from_secs(wait_sec));
+    tokio::pin!(sleep);
+
+    loop {
+        tokio::select! {
+            _ = &mut sleep => {
+                 println!("{} secondes elapsed", wait_sec);
+                 break;
+            }
+            _ = &mut wait => {}
+        }
+    }
+}