feat: dagrunner, initial version

benches/patterns/breakdown.rs

@@ -0,0 +1,58 @@
+//! 10,000 task breakdown benchmarks - construction vs execution
+
+use criterion::Criterion;
+use dagx::{task_fn, DagRunner};
+
+pub fn bench_10k_breakdown(c: &mut Criterion) {
+    let rt = tokio::runtime::Runtime::new().unwrap();
+    let mut group = c.benchmark_group("10k_tasks");
+    group.measurement_time(std::time::Duration::from_secs(10));
+
+    // a) Adding 10k tasks (construction only)
+    group.bench_function("construction", |b| {
+        b.iter(|| {
+            let dag = DagRunner::new();
+            for i in 0..10_000 {
+                dag.add_task(task_fn(move |_: ()| async move { i }));
+            }
+        });
+    });
+
+    // b) Full lifecycle: add 10k tasks + run them
+    group.bench_function("full_execution", |b| {
+        b.iter(|| {
+            rt.block_on(async {
+                let dag = DagRunner::new();
+                for i in 0..10_000 {
+                    dag.add_task(task_fn(move |_: ()| async move { i }));
+                }
+                dag.run(|fut| {
+                    tokio::spawn(fut);
+                })
+                .await
+                .unwrap();
+            })
+        });
+    });
+
+    // c) Execution only (pre-built DAG, just run)
+    group.bench_function("execution_only", |b| {
+        // Pre-build the DAG outside the measurement
+        let dag = DagRunner::new();
+        for i in 0..10_000 {
+            dag.add_task(task_fn(move |_: ()| async move { i }));
+        }
+
+        b.iter(|| {
+            rt.block_on(async {
+                dag.run(|fut| {
+                    tokio::spawn(fut);
+                })
+                .await
+                .unwrap();
+            })
+        });
+    });
+
+    group.finish();
+}