Implement a new algorithm to make this crate no_std

.github/workflows/ci.yml

@@ -29,6 +29,10 @@ jobs:
         if: startsWith(matrix.rust, 'nightly')
         run: cargo check -Z features=dev_dep
       - run: cargo test
+      - name: Install cargo-hack
+        uses: taiki-e/install-action@cargo-hack
+      - run: rustup target add thumbv7m-none-eabi
+      - run: cargo hack build --target thumbv7m-none-eabi --no-default-features --no-dev-deps
 
   msrv:
     runs-on: ubuntu-latest

Cargo.toml

@@ -15,7 +15,19 @@ categories = ["asynchronous", "concurrency"]
 exclude = ["/.*"]
 
 [dependencies]
-parking = "2.0.0"
+concurrent-queue = { git = "https://github.com/smol-rs/concurrent-queue.git", branch = "loom", default-features = false }
+parking = { version = "2", optional = true }
+portable-atomic = { version = "0.3", default-features = false, optional = true }
+
+# Enables loom testing. This feature is permanently unstable and the API may
+# change at any time.
+[target.'cfg(loom)'.dependencies]
+loom = { version = "0.5", optional = true }
+concurrent-queue = { git = "https://github.com/smol-rs/concurrent-queue.git", branch = "loom", default-features = false, features = ["loom"] }
+
+[features]
+default = ["std"]
+std = ["parking", "concurrent-queue/std"]
 
 [dev-dependencies]
 criterion = "0.3.4"

benches/bench.rs

@@ -20,6 +20,18 @@ fn bench_events(c: &mut Criterion) {
             }
         });
     });
+
+    c.bench_function("notify_single", |b| {
+        let ev = Event::new();
+
+        b.iter(|| {
+            for _ in 0..COUNT {
+                let handle = ev.listen();
+                ev.notify(1);
+                handle.wait();
+            }
+        });
+    });
 }
 
 criterion_group!(benches, bench_events);