1 files changed, 135 insertions, 0 deletions
diff --git a/vendor/futures-channel/benches/sync_mpsc.rs b/vendor/futures-channel/benches/sync_mpsc.rs
new file mode 100644
index 000000000..7c3c3d3a8
--- /dev/null
+++ b/vendor/futures-channel/benches/sync_mpsc.rs
@@ -0,0 +1,135 @@
+#![feature(test)]
+
+extern crate test;
+use crate::test::Bencher;
+
+use {
+    futures::{
+        channel::mpsc::{self, Sender, UnboundedSender},
+        ready,
+        sink::Sink,
+        stream::{Stream, StreamExt},
+        task::{Context, Poll},
+    },
+    futures_test::task::noop_context,
+    std::pin::Pin,
+};
+
+/// Single producer, single consumer
+#[bench]
+fn unbounded_1_tx(b: &mut Bencher) {
+    let mut cx = noop_context();
+    b.iter(|| {
+        let (tx, mut rx) = mpsc::unbounded();
+
+        // 1000 iterations to avoid measuring overhead of initialization
+        // Result should be divided by 1000
+        for i in 0..1000 {
+            // Poll, not ready, park
+            assert_eq!(Poll::Pending, rx.poll_next_unpin(&mut cx));
+
+            UnboundedSender::unbounded_send(&tx, i).unwrap();
+
+            // Now poll ready
+            assert_eq!(Poll::Ready(Some(i)), rx.poll_next_unpin(&mut cx));
+        }
+    })
+}
+
+/// 100 producers, single consumer
+#[bench]
+fn unbounded_100_tx(b: &mut Bencher) {
+    let mut cx = noop_context();
+    b.iter(|| {
+        let (tx, mut rx) = mpsc::unbounded();
+
+        let tx: Vec<_> = (0..100).map(|_| tx.clone()).collect();
+
+        // 1000 send/recv operations total, result should be divided by 1000
+        for _ in 0..10 {
+            for (i, x) in tx.iter().enumerate() {
+                assert_eq!(Poll::Pending, rx.poll_next_unpin(&mut cx));
+
+                UnboundedSender::unbounded_send(x, i).unwrap();
+
+                assert_eq!(Poll::Ready(Some(i)), rx.poll_next_unpin(&mut cx));
+            }
+        }
+    })
+}
+
+#[bench]
+fn unbounded_uncontended(b: &mut Bencher) {
+    let mut cx = noop_context();
+    b.iter(|| {
+        let (tx, mut rx) = mpsc::unbounded();
+
+        for i in 0..1000 {
+            UnboundedSender::unbounded_send(&tx, i).expect("send");
+            // No need to create a task, because poll is not going to park.
+            assert_eq!(Poll::Ready(Some(i)), rx.poll_next_unpin(&mut cx));
+        }
+    })
+}
+
+/// A Stream that continuously sends incrementing number of the queue
+struct TestSender {
+    tx: Sender<u32>,
+    last: u32, // Last number sent
+}
+
+// Could be a Future, it doesn't matter
+impl Stream for TestSender {
+    type Item = u32;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let this = &mut *self;
+        let mut tx = Pin::new(&mut this.tx);
+
+        ready!(tx.as_mut().poll_ready(cx)).unwrap();
+        tx.as_mut().start_send(this.last + 1).unwrap();
+        this.last += 1;
+        assert_eq!(Poll::Pending, tx.as_mut().poll_flush(cx));
+        Poll::Ready(Some(this.last))
+    }
+}
+
+/// Single producers, single consumer
+#[bench]
+fn bounded_1_tx(b: &mut Bencher) {
+    let mut cx = noop_context();
+    b.iter(|| {
+        let (tx, mut rx) = mpsc::channel(0);
+
+        let mut tx = TestSender { tx, last: 0 };
+
+        for i in 0..1000 {
+            assert_eq!(Poll::Ready(Some(i + 1)), tx.poll_next_unpin(&mut cx));
+            assert_eq!(Poll::Pending, tx.poll_next_unpin(&mut cx));
+            assert_eq!(Poll::Ready(Some(i + 1)), rx.poll_next_unpin(&mut cx));
+        }
+    })
+}
+
+/// 100 producers, single consumer
+#[bench]
+fn bounded_100_tx(b: &mut Bencher) {
+    let mut cx = noop_context();
+    b.iter(|| {
+        // Each sender can send one item after specified capacity
+        let (tx, mut rx) = mpsc::channel(0);
+
+        let mut tx: Vec<_> = (0..100).map(|_| TestSender { tx: tx.clone(), last: 0 }).collect();
+
+        for i in 0..10 {
+            for x in &mut tx {
+                // Send an item
+                assert_eq!(Poll::Ready(Some(i + 1)), x.poll_next_unpin(&mut cx));
+                // Then block
+                assert_eq!(Poll::Pending, x.poll_next_unpin(&mut cx));
+                // Recv the item
+                assert_eq!(Poll::Ready(Some(i + 1)), rx.poll_next_unpin(&mut cx));
+            }
+        }
+    })
+}