reactor: turn bench-poll into a proper benchmark (#662)

tokio-reactor/benches/basic.rs

@@ -0,0 +1,61 @@
+#![feature(test)]
+#![deny(warnings)]
+
+extern crate futures;
+extern crate mio;
+extern crate num_cpus;
+extern crate test;
+extern crate tokio;
+extern crate tokio_reactor;
+
+use std::sync::mpsc;
+
+use futures::{future, Async};
+use self::test::Bencher;
+use tokio_reactor::Registration;
+
+const NUM_YIELD: usize = 1_000;
+const TASKS_PER_CPU: usize = 50;
+
+#[bench]
+fn notify_many(b: &mut Bencher) {
+    let mut rt = tokio::runtime::Runtime::new().unwrap();
+
+    let tasks = TASKS_PER_CPU * num_cpus::get();
+    let (tx, rx) = mpsc::channel();
+
+    b.iter(|| {
+        for _ in 0..tasks {
+            let (r, s) = mio::Registration::new2();
+            let registration = Registration::new();
+            registration.register(&r).unwrap();
+
+            let mut rem = NUM_YIELD;
+            let mut r = Some(r);
+            let tx = tx.clone();
+
+            rt.spawn(future::poll_fn(move || {
+                loop {
+                    let is_ready = registration.poll_read_ready().unwrap().is_ready();
+
+                    if is_ready {
+                        rem -= 1;
+
+                        if rem == 0 {
+                            r.take().unwrap();
+                            tx.send(()).unwrap();
+                            return Ok(Async::Ready(()));
+                        }
+                    } else {
+                        s.set_readiness(mio::Ready::readable()).unwrap();
+                        return Ok(Async::NotReady);
+                    }
+                }
+            }));
+        }
+
+        for _ in 0..tasks {
+            rx.recv().unwrap();
+        }
+    });
+}