feat: dagrunner, initial version

benches/patterns/diamond.rs

@@ -0,0 +1,36 @@
+//! Diamond pattern benchmarks (fan-out then fan-in)
+
+use criterion::Criterion;
+use dagx::{task_fn, DagRunner};
+
+pub fn bench_diamond(c: &mut Criterion) {
+    let rt = tokio::runtime::Runtime::new().unwrap();
+
+    c.bench_function("diamond_pattern_50", |b| {
+        b.iter(|| {
+            rt.block_on(async {
+                let dag = DagRunner::new();
+
+                for i in 0..50 {
+                    let source = dag.add_task(task_fn(move |_: ()| async move { i }));
+
+                    let left = dag
+                        .add_task(task_fn(|x: i32| async move { x * 2 }))
+                        .depends_on(&source);
+                    let right = dag
+                        .add_task(task_fn(|x: i32| async move { x * 3 }))
+                        .depends_on(&source);
+
+                    dag.add_task(task_fn(|(l, r): (i32, i32)| async move { l + r }))
+                        .depends_on((&left, &right));
+                }
+
+                dag.run(|fut| {
+                    tokio::spawn(fut);
+                })
+                .await
+                .unwrap();
+            })
+        });
+    });
+}