Function init_flush_scheduler 

pub fn init_flush_scheduler(sched: Rc<dyn ScheduleFlush>)

Set the platform flush scheduler and install the signal deferred- callback hook.

Idempotent — subsequent calls are no-ops (the hook is installed via std::sync::OnceLock, so it fires exactly once per process).

Threading constraint

The hook is per-process and routes signal notifications to the executor that is “current” when the notification fires (see with_executor). For single-threaded use (Wasm, CLI) this is transparent. For multi-threaded SSR, enable the ssr-tokio feature and call init_scope_store_tokio. See with_executor for the full routing contract.

Examples found in repository

examples/scope_bench.rs (line 21)

fn init() {
    init_flush_scheduler(Rc::new(BenchScheduleFlush));
}

// ---------------------------------------------------------------------------
// Batched scheduler
// ---------------------------------------------------------------------------

struct BatchedFlush {
    callbacks: RefCell<Vec<Box<dyn FnOnce()>>>,
}
impl BatchedFlush {
    fn new() -> Rc<Self> {
        Rc::new(Self {
            callbacks: RefCell::new(Vec::new()),
        })
    }
    fn drain(&self) {
        while let Some(cb) = self.callbacks.borrow_mut().pop() {
            cb();
        }
    }
}
impl ScheduleFlush for BatchedFlush {
    fn schedule(&self, callback: Box<dyn FnOnce()>) {
        self.callbacks.borrow_mut().push(callback);
    }
}

// ---------------------------------------------------------------------------
// Timer helper
// ---------------------------------------------------------------------------

fn time<R>(label: &str, iterations: u64, mut f: impl FnMut() -> R) {
    // Warm-up
    for _ in 0..(iterations / 10).max(1) {
        f();
    }
    let start = Instant::now();
    for _ in 0..iterations {
        f();
    }
    let elapsed = start.elapsed().as_secs_f64() * 1_000_000.0 / iterations as f64;
    println!("  {:<42} {:>8.2} µs/iter", label, elapsed);
}

// ---------------------------------------------------------------------------

fn main() {
    println!("=== Auralis Task Scope Benchmarks ===\n");

    // 1. Scope create + destroy (100 tasks)
    let iterations = 50_000;
    init();
    time("scope_100_tasks_create_destroy", iterations, || {
        let scope = TaskScope::new();
        for _ in 0..100 {
            scope.spawn(async {});
        }
        drop(scope);
    });

    // 2. Deep nesting drop (200 levels)
    init();
    time("scope_200_levels_deep_drop", 5_000, || {
        let root = TaskScope::new();
        {
            let mut current = TaskScope::new_child(&root);
            for _ in 0..199 {
                current.spawn(async {});
                current = TaskScope::new_child(&current);
            }
        }
        drop(root);
    });

    // 3. Priority ordering (batched flush)
    {
        let order: Rc<RefCell<Vec<String>>> = Rc::new(RefCell::new(Vec::new()));
        let min_iterations = 5_000;
        // Warm-up
        for _ in 0..500 {
            let sched = BatchedFlush::new();
            init_flush_scheduler(Rc::clone(&sched) as Rc<dyn ScheduleFlush>);
            order.borrow_mut().clear();
            for i in 0..1000 {
                let o = Rc::clone(&order);
                auralis_task::spawn_global_with_priority(Priority::Low, async move {
                    o.borrow_mut().push(format!("low_{i}"));
                });
            }
            for i in 0..10 {
                let o = Rc::clone(&order);
                auralis_task::spawn_global_with_priority(Priority::High, async move {
                    o.borrow_mut().push(format!("high_{i}"));
                });
            }
            sched.drain();
        }

        let start = Instant::now();
        for _ in 0..min_iterations {
            let sched = BatchedFlush::new();
            init_flush_scheduler(Rc::clone(&sched) as Rc<dyn ScheduleFlush>);
            order.borrow_mut().clear();
            for i in 0..1000 {
                let o = Rc::clone(&order);
                auralis_task::spawn_global_with_priority(Priority::Low, async move {
                    o.borrow_mut().push(format!("low_{i}"));
                });
            }
            for i in 0..10 {
                let o = Rc::clone(&order);
                auralis_task::spawn_global_with_priority(Priority::High, async move {
                    o.borrow_mut().push(format!("high_{i}"));
                });
            }
            sched.drain();
            // Verify correctness.
            let result = order.borrow().clone();
            debug_assert_eq!(result.len(), 1010);
        }
        let elapsed = start.elapsed().as_secs_f64() * 1_000_000.0 / min_iterations as f64;
        println!(
            "  {:<42} {:>8.2} µs/iter",
            "priority_1000_low_10_high", elapsed
        );
        init(); // restore sync scheduler
    }

    // 4. Scope churn (100 scopes x 10 tasks, batch drop)
    init();
    time("scope_churn_100x10_batch_drop", 5_000, || {
        let scopes: Vec<TaskScope> = (0..100)
            .map(|_| {
                let s = TaskScope::new();
                for _ in 0..10 {
                    s.spawn(async {});
                }
                s
            })
            .collect();
        drop(scopes);
    });

    // 5. Scope suspend + resume (1000 tasks)
    init();
    let scope = TaskScope::new();
    for _ in 0..1000 {
        scope.spawn(async {});
    }
    time("scope_suspend_resume_1000_tasks", 500_000, || {
        scope.suspend();
        scope.resume();
    });

    // 6. Wide shallow tree drop (50x50, ~2550 tasks)
    init();
    time("scope_wide_tree_50x3_drop", 500, || {
        let root = TaskScope::new();
        for _ in 0..50 {
            let child = TaskScope::new_child(&root);
            child.spawn(async {});
            for _ in 0..50 {
                let grandchild = TaskScope::new_child(&child);
                grandchild.spawn(async {});
            }
        }
        drop(root);
    });

    println!("\n=== Done ===");
}

examples/counter.rs (line 39)

fn main() {
    // One-time executor setup.
    init_flush_scheduler(Rc::new(CliScheduler));
    init_time_source(Rc::new(CliClock::new()));

    // ---- Signal basics ----
    println!("=== Signal basics ===");
    let count = Signal::new(0);
    println!("count = {}", count.read());
    count.set(42);
    println!("count = {}", count.read());

    // ---- Memo (auto-tracking computed value) ----
    println!("\n=== Memo ===");
    let a = Signal::new(2);
    let b = Signal::new(3);
    let a2 = a.clone();
    let b2 = b.clone();
    let sum = Memo::new(move || a2.read() + b2.read());
    println!("2 + 3 = {}", sum.read());
    a.set(10);
    println!("10 + 3 = {}", sum.read());

    // ---- TaskScope: spawn a task that watches a signal ----
    println!("\n=== TaskScope (scoped signal watcher) ===");
    let messages = Signal::new(vec!["hello".to_string()]);

    {
        let scope = TaskScope::new();
        let msgs = messages.clone();
        scope.spawn(async move {
            loop {
                let val = msgs.changed().await;
                println!("  task observed: {:?}", val);
            }
        });

        messages.set(vec!["hello".to_string(), "world".to_string()]);
        messages.set(vec![
            "hello".to_string(),
            "world".to_string(),
            "!".to_string(),
        ]);

        // Explicit drop — cancels the task and cleans up resources.
        drop(scope);
    }
    println!("(scope dropped — task and subscriptions cleaned up)");

    // ---- Batch: multiple sets, one notification ----
    println!("\n=== Batch ===");
    let x = Signal::new(0);
    let notifications = Rc::new(Cell::new(0u32));
    let n = Rc::clone(&notifications);
    let x2 = x.clone();

    let scope = TaskScope::new();
    scope.spawn(async move {
        loop {
            x2.changed().await;
            n.set(n.get() + 1);
        }
    });

    batch(|| {
        x.set(1);
        x.set(2);
        x.set(3);
    });
    println!(
        "After 3 sets in a batch: {} notification(s)",
        notifications.get()
    );
    // Should be 1 — not 3.

    println!("\nDone.");
}