threadpool: spawn new tasks onto a random worker (#683)

* threadpool: submit new tasks to a random worker

* Revert unnecessary version bumps

Cargo.toml

@@ -89,3 +89,20 @@ serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
 time = "0.1"
+
+[patch.crates-io]
+tokio = { path = "." }
+tokio-async-await  = { path = "./tokio-async-await" }
+tokio-codec = { path = "./tokio-codec" }
+tokio-current-thread = { path = "./tokio-current-thread" }
+tokio-executor = { path = "./tokio-executor" }
+tokio-fs = { path = "./tokio-fs" }
+tokio-io = { path = "./tokio-io" }
+tokio-reactor = { path = "./tokio-reactor" }
+tokio-signal = { path = "./tokio-signal" }
+tokio-tcp = { path = "./tokio-tcp" }
+tokio-threadpool = { path = "./tokio-threadpool" }
+tokio-timer = { path = "./tokio-timer" }
+tokio-tls = { path = "./tokio-tls" }
+tokio-udp = { path = "./tokio-udp" }
+tokio-uds = { path = "./tokio-uds" }

tokio-reactor/Cargo.toml

@@ -33,3 +33,4 @@ tokio-io = { version = "0.1.6", path = "../tokio-io" }
 [dev-dependencies]
 num_cpus = "1.8.0"
 tokio = { version = "0.1.7", path = ".." }
+tokio-io-pool = "0.1.4"

tokio-reactor/benches/basic.rs

@@ -6,56 +6,134 @@ extern crate mio;
 extern crate num_cpus;
 extern crate test;
 extern crate tokio;
+extern crate tokio_io_pool;
 extern crate tokio_reactor;
 
-use std::sync::mpsc;
+const NUM_YIELD: usize = 500;
+const TASKS_PER_CPU: usize = 100;
 
-use futures::{future, Async};
-use self::test::Bencher;
-use tokio_reactor::Registration;
+mod threadpool {
+    use super::*;
+    use std::sync::mpsc;
 
-const NUM_YIELD: usize = 1_000;
-const TASKS_PER_CPU: usize = 50;
+    use test::Bencher;
+    use futures::{future, Async};
+    use tokio_reactor::Registration;
+    use tokio::runtime::Runtime;
 
-#[bench]
-fn notify_many(b: &mut Bencher) {
-    let mut rt = tokio::runtime::Runtime::new().unwrap();
+    #[bench]
+    fn notify_many(b: &mut Bencher) {
+        let mut rt = Runtime::new().unwrap();
+        let tasks = TASKS_PER_CPU * num_cpus::get();
 
-    let tasks = TASKS_PER_CPU * num_cpus::get();
-    let (tx, rx) = mpsc::channel();
+        b.iter(|| {
+            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();
+            rt.block_on::<_, (), ()>(future::lazy(move || {
+                for _ in 0..tasks {
+                    let tx = tx.clone();
 
-            let mut rem = NUM_YIELD;
-            let mut r = Some(r);
-            let tx = tx.clone();
+                    tokio::spawn(future::lazy(move || {
+                        let (r, s) = mio::Registration::new2();
+                        let registration = Registration::new();
+                        registration.register(&r).unwrap();
 
-            rt.spawn(future::poll_fn(move || {
-                loop {
-                    let is_ready = registration.poll_read_ready().unwrap().is_ready();
+                        let mut rem = NUM_YIELD;
+                        let mut r = Some(r);
+                        let tx = tx.clone();
 
-                    if is_ready {
-                        rem -= 1;
+                        tokio::spawn(future::poll_fn(move || {
+                            loop {
+                                let is_ready = registration.poll_read_ready().unwrap().is_ready();
 
-                        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);
-                    }
+                                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);
+                                }
+                            }
+                        }));
+
+                        Ok(())
+                    }));
                 }
-            }));
-        }
 
-        for _ in 0..tasks {
-            rx.recv().unwrap();
-        }
-    });
+                Ok(())
+            })).unwrap();
+
+            for _ in 0..tasks {
+                rx.recv().unwrap();
+            }
+        })
+    }
+}
+
+mod io_pool {
+    use super::*;
+    use std::sync::mpsc;
+
+    use futures::{future, Async};
+    use test::Bencher;
+    use tokio_io_pool::Runtime;
+    use tokio_reactor::Registration;
+
+    #[bench]
+    fn notify_many(b: &mut Bencher) {
+        let mut rt = Runtime::new();
+        let tasks = TASKS_PER_CPU * num_cpus::get();
+
+        b.iter(|| {
+            let (tx, rx) = mpsc::channel();
+
+            rt.block_on::<_, (), ()>(future::lazy(move || {
+                for _ in 0..tasks {
+                    let tx = tx.clone();
+
+                    tokio::spawn(future::lazy(move || {
+                        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();
+
+                        tokio::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);
+                                }
+                            }
+                        }));
+
+                        Ok(())
+                    }));
+                }
+
+                Ok(())
+            })).unwrap();
+
+            for _ in 0..tasks {
+                rx.recv().unwrap();
+            }
+        })
+    }
 }

tokio-threadpool/src/pool/mod.rs

@@ -317,6 +317,16 @@ impl Pool {
 
         // All workers are active, so pick a random worker and submit the
         // task to it.
+        self.submit_to_random(task, inner);
+    }
+
+    /// Submit a task to a random worker
+    ///
+    /// Called from outside of the scheduler, this function is how new tasks
+    /// enter the system.
+    pub fn submit_to_random(&self, task: Arc<Task>, inner: &Arc<Pool>) {
+        debug_assert_eq!(*self, **inner);
+
         let len = self.workers.len();
         let idx = self.rand_usize() % len;
 

tokio-threadpool/src/sender.rs

@@ -161,7 +161,7 @@ impl<'a> tokio_executor::Executor for &'a Sender {
         // Create a new task for the future
         let task = Arc::new(Task::new(future));
 
-        self.inner.submit(task, &self.inner);
+        self.inner.submit_to_random(task, &self.inner);
 
         Ok(())
     }