example: add some misbehaving options to example app (#54)

Author: seanmonstar

Diff for: console-subscriber/examples/app.rs

@@ -1,11 +1,49 @@
 use std::time::Duration;
 
+static HELP: &'static str = r#"
+Example console-instrumented app
+
+USAGE:
+    app [OPTIONS]
+
+OPTIONS:
+    -h, help    prints this message
+    blocks      Includes a (misbehaving) blocking task
+    burn        Includes a (misbehaving) task that spins CPU with self-wakes
+    coma        Includes a (misbehaving) task that forgets to register a waker
+"#;
+
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     console_subscriber::init();
+    // spawn optional extras from CLI args
+    // skip first which is command name
+    for opt in std::env::args().skip(1) {
+        match &*opt {
+            "blocks" => {
+                tokio::spawn(double_sleepy(1, 10));
+            }
+            "coma" => {
+                tokio::spawn(std::future::pending::<()>());
+            }
+            "burn" => {
+                tokio::spawn(burn(1, 10));
+            }
+            "help" | "-h" => {
+                eprintln!("{}", HELP);
+                return Ok(());
+            }
+            wat => {
+                return Err(
+                    format!("unknown option: {:?}, run with '-h' to see options", wat).into(),
+                )
+            }
+        }
+    }
 
     let task1 = tokio::spawn(spawn_tasks(1, 10));
-    let task2 = tokio::spawn(spawn_tasks(10, 100));
+    let task2 = tokio::spawn(spawn_tasks(10, 30));
+
     let result = tokio::try_join! {
         task1,
         task2,
@@ -29,3 +67,26 @@ async fn spawn_tasks(min: u64, max: u64) {
 async fn wait(seconds: u64) {
     tokio::time::sleep(Duration::from_secs(seconds)).await;
 }
+
+#[tracing::instrument]
+async fn double_sleepy(min: u64, max: u64) {
+    loop {
+        for i in min..max {
+            // woops!
+            std::thread::sleep(Duration::from_secs(i));
+            tokio::time::sleep(Duration::from_secs(max - i)).await;
+        }
+    }
+}
+
+#[tracing::instrument]
+async fn burn(min: u64, max: u64) {
+    loop {
+        for i in min..max {
+            for _ in 0..i {
+                tokio::task::yield_now().await;
+            }
+            tokio::time::sleep(Duration::from_secs(i - min)).await;
+        }
+    }
+}