fix ring example

examples/ring.rs

@@ -1,23 +1,20 @@
-/*
- * Ring benchmark inspired by Programming Erlang: Software for a
- * Concurrent World, by Joe Armstrong, Chapter 8.11.2
- *
- * "Write a ring benchmark. Create N processes in a ring. Send a
- * message round the ring M times so that a total of N * M messages
- * get sent. Time how long this takes for different values of N and M."
- */
-use actix::*;
+//! Ring benchmark inspired by Programming Erlang: Software for a
+//! Concurrent World, by Joe Armstrong, Chapter 8.11.2
+//!
+//! "Write a ring benchmark. Create N processes in a ring. Send a
+//! message round the ring M times so that a total of N * M messages
+//! get sent. Time how long this takes for different values of N and M."
 
-use std::env;
-use std::time::SystemTime;
+use std::{env, io, time::SystemTime};
+
+use actix::prelude::*;
 
 /// A payload with a counter
+#[derive(Debug, Message)]
+#[rtype(result = "()")]
 struct Payload(usize);
 
-impl Message for Payload {
-    type Result = ();
-}
-
+#[derive(Debug)]
 struct Node {
     id: usize,
     limit: usize,
@@ -37,9 +34,11 @@ impl Handler<Payload> for Node {
                 "Actor {} reached limit of {} (payload was {})",
                 self.id, self.limit, msg.0
             );
+
             System::current().stop();
             return;
         }
+
         // Some prime in order for different actors to report progress.
         // Large enough to print about once per second in debug mode.
         if msg.0 % 498989 == 1 {
@@ -51,99 +50,103 @@ impl Handler<Payload> for Node {
                 100.0 * msg.0 as f32 / self.limit as f32
             );
         }
+
         self.next
             .do_send(Payload(msg.0 + 1))
             .expect("Unable to send payload");
     }
 }
 
-fn print_usage_and_exit() -> ! {
-    eprintln!("Usage; actix-test <num-nodes> <num-times-message-around-ring>");
-    ::std::process::exit(1);
-}
+fn main() -> io::Result<()> {
+    let sys = System::new();
 
-fn main() -> std::io::Result<()> {
-    let system = System::new();
+    let (n_nodes, n_rounds) = parse_args();
 
-    let args = env::args().collect::<Vec<_>>();
-    if args.len() < 3 {
-        print_usage_and_exit();
-    }
-    let n_nodes = if let Ok(arg_num_nodes) = args[1].parse::<usize>() {
-        if arg_num_nodes <= 1 {
-            eprintln!("Number of nodes must be > 1");
-            ::std::process::exit(1);
-        }
-        arg_num_nodes
-    } else {
-        print_usage_and_exit();
-    };
+    let now = SystemTime::now();
 
-    let n_times = if let Ok(arg_ntimes) = args[2].parse::<usize>() {
-        arg_ntimes
-    } else {
-        print_usage_and_exit()
-    };
+    sys.block_on(async {
+        println!("Setting up {} nodes", n_nodes);
+        let limit = n_nodes * n_rounds;
 
-    let setup = SystemTime::now();
+        let node = Node::create(move |ctx| {
+            let first_addr = ctx.address();
 
-    println!("Setting up {} nodes", n_nodes);
-    let limit = n_nodes * n_times;
-    let node = Node::create(move |ctx| {
-        let first_addr = ctx.address();
-        let mut prev_addr = Node {
-            id: 1,
-            limit,
-            next: first_addr.recipient(),
-        }
-        .start();
+            let mut prev_addr = Node {
+                id: 1,
+                limit,
+                next: first_addr.recipient(),
+            }
+            .start();
 
-        for id in 2..n_nodes {
-            prev_addr = Node {
-                id,
+            for id in 2..n_nodes {
+                prev_addr = Node {
+                    id,
+                    limit,
+                    next: prev_addr.recipient(),
+                }
+                .start();
+            }
+
+            Node {
+                id: n_nodes,
                 limit,
                 next: prev_addr.recipient(),
             }
-            .start();
-        }
+        });
 
-        Node {
-            id: n_nodes,
-            limit,
-            next: prev_addr.recipient(),
-        }
+        println!(
+            "Sending start message and waiting for termination after {} messages...",
+            limit
+        );
+
+        node.send(Payload(1)).await.unwrap();
     });
 
-    match setup.elapsed() {
-        Ok(elapsed) => println!(
-            "Time taken: {}.{:06} seconds",
-            elapsed.as_secs(),
-            elapsed.subsec_micros()
-        ),
-        Err(e) => println!("An error occured: {:?}", e),
-    }
-    println!(
-        "Sending start message and waiting for termination after {} messages...",
-        limit
-    );
-    let now = SystemTime::now();
-
-    let _req = node.send(Payload(1));
-
-    match system.run() {
-        Ok(_) => println!("Completed"),
-        Err(e) => println!("An error occured: {:?}", e),
-    }
+    sys.run().unwrap();
 
     match now.elapsed() {
         Ok(elapsed) => println!(
             "Time taken: {}.{:06} seconds ({} msg/second)",
             elapsed.as_secs(),
             elapsed.subsec_micros(),
-            (n_nodes * n_times * 1000000) as u128 / elapsed.as_micros()
+            (n_nodes * n_rounds * 1000000) as u128 / elapsed.as_micros()
         ),
-        Err(e) => println!("An error occured: {:?}", e),
+        Err(e) => println!("An error occurred: {:?}", e),
     }
 
     Ok(())
 }
+
+fn parse_args() -> (usize, usize) {
+    let mut args = env::args();
+
+    // skip first arg
+    args.next();
+
+    let n_nodes = args
+        .next()
+        .and_then(|val| val.parse::<usize>().ok())
+        .unwrap_or_else(|| print_usage_and_exit());
+
+    if n_nodes <= 1 {
+        eprintln!("Number of nodes must be > 1");
+        ::std::process::exit(1);
+    }
+
+    let n_rounds = args
+        .next()
+        .and_then(|val| val.parse::<usize>().ok())
+        .unwrap_or_else(|| print_usage_and_exit());
+
+    if args.next().is_some() {
+        print_usage_and_exit();
+    }
+
+    (n_nodes, n_rounds)
+}
+
+fn print_usage_and_exit() -> ! {
+    eprintln!("Usage:");
+    eprintln!("cargo run --example ring -- <num-nodes> <num-times-message-around-ring>");
+    ::std::process::exit(1);
+}