Avoid allocation in the benchmarks

benches/bench.rs

@@ -1,22 +1,31 @@
+use std::pin::Pin;
+
 use criterion::{criterion_group, criterion_main, Criterion};
-use event_listener::Event;
+use event_listener::{Event, EventListener};
 
 const COUNT: usize = 8000;
 
 fn bench_events(c: &mut Criterion) {
     c.bench_function("notify_and_wait", |b| {
         let ev = Event::new();
-        b.iter(|| {
-            let mut handles = Vec::with_capacity(COUNT);
+        let mut handles = Vec::with_capacity(COUNT);
+        for _ in 0..COUNT {
+            handles.push(EventListener::new(&ev));
+        }
 
-            for _ in 0..COUNT {
-                handles.push(ev.listen());
+        b.iter(|| {
+            for handle in &mut handles {
+                // SAFETY: The handle is not moved out.
+                let listener = unsafe { Pin::new_unchecked(handle) };
+                listener.listen();
             }
 
             ev.notify(COUNT);
 
-            for mut handle in handles {
-                handle.as_mut().wait();
+            for handle in &mut handles {
+                // SAFETY: The handle is not moved out.
+                let listener = unsafe { Pin::new_unchecked(handle) };
+                listener.wait();
             }
         });
     });