1 files changed, 130 insertions, 0 deletions
diff --git a/benches/sync_semaphore.rs b/benches/sync_semaphore.rs
new file mode 100644
index 00000000..c43311c0
--- /dev/null
+++ b/benches/sync_semaphore.rs
@@ -0,0 +1,130 @@
+use bencher::Bencher;
+use std::sync::Arc;
+use tokio::{sync::Semaphore, task};
+
+fn uncontended(b: &mut Bencher) {
+    let mut rt = tokio::runtime::Builder::new()
+        .core_threads(6)
+        .threaded_scheduler()
+        .build()
+        .unwrap();
+
+    let s = Arc::new(Semaphore::new(10));
+    b.iter(|| {
+        let s = s.clone();
+        rt.block_on(async move {
+            for _ in 0..6 {
+                let permit = s.acquire().await;
+                drop(permit);
+            }
+        })
+    });
+}
+
+async fn task(s: Arc<Semaphore>) {
+    let permit = s.acquire().await;
+    drop(permit);
+}
+
+fn uncontended_concurrent_multi(b: &mut Bencher) {
+    let mut rt = tokio::runtime::Builder::new()
+        .core_threads(6)
+        .threaded_scheduler()
+        .build()
+        .unwrap();
+
+    let s = Arc::new(Semaphore::new(10));
+    b.iter(|| {
+        let s = s.clone();
+        rt.block_on(async move {
+            let j = tokio::try_join! {
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone()))
+            };
+            j.unwrap();
+        })
+    });
+}
+
+fn uncontended_concurrent_single(b: &mut Bencher) {
+    let mut rt = tokio::runtime::Builder::new()
+        .basic_scheduler()
+        .build()
+        .unwrap();
+
+    let s = Arc::new(Semaphore::new(10));
+    b.iter(|| {
+        let s = s.clone();
+        rt.block_on(async move {
+            tokio::join! {
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone())
+            };
+        })
+    });
+}
+
+fn contended_concurrent_multi(b: &mut Bencher) {
+    let mut rt = tokio::runtime::Builder::new()
+        .core_threads(6)
+        .threaded_scheduler()
+        .build()
+        .unwrap();
+
+    let s = Arc::new(Semaphore::new(5));
+    b.iter(|| {
+        let s = s.clone();
+        rt.block_on(async move {
+            let j = tokio::try_join! {
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone())),
+                task::spawn(task(s.clone()))
+            };
+            j.unwrap();
+        })
+    });
+}
+
+fn contended_concurrent_single(b: &mut Bencher) {
+    let mut rt = tokio::runtime::Builder::new()
+        .basic_scheduler()
+        .build()
+        .unwrap();
+
+    let s = Arc::new(Semaphore::new(5));
+    b.iter(|| {
+        let s = s.clone();
+        rt.block_on(async move {
+            tokio::join! {
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone()),
+                task(s.clone())
+            };
+        })
+    });
+}
+
+bencher::benchmark_group!(
+    sync_semaphore,
+    uncontended,
+    uncontended_concurrent_multi,
+    uncontended_concurrent_single,
+    contended_concurrent_multi,
+    contended_concurrent_single
+);
+
+bencher::benchmark_main!(sync_semaphore);