Trait Dispatcher 

pub trait Dispatcher:
    Send
    + Sync
    + 'static {
    // Required methods
    fn dispatch_on_main_thread(&self, task: Runnable);
    fn dispatch_background(&self, task: Runnable, priority: DispatchPriority);
    fn dispatch_after(&self, delay: Duration, task: Runnable);
    fn wake(&self, window: Option<AppWindowId>);
    fn exec_capabilities(&self) -> ExecCapabilities;
}

Portable execution surface provided by the runner.

This is a semantic contract (ADR 0175). Implementations live in platform runners and must:

• Preserve the main-thread mutation invariant (UI/runtime state is main-thread only).
• Keep the servicing thread/queue mapping stable for the lifetime of the process.
• Provide a wake() that advances the runner to the next driver boundary.

Required Methods

fn dispatch_on_main_thread(&self, task: Runnable)

Schedule work to run on the UI/main thread.

fn dispatch_background(&self, task: Runnable, priority: DispatchPriority)

Schedule work to run off the UI thread where available.

On constrained platforms (e.g. wasm without threads) this may be implemented as best-effort cooperative execution, but must still preserve the main-thread mutation invariant.

fn dispatch_after(&self, delay: Duration, task: Runnable)

Schedule delayed work.

Implementations must share the same timer substrate/time base as effect timers to avoid split-brain scheduling (ADR 0175 / ADR 0034).

fn wake(&self, window: Option<AppWindowId>)

Request that the runner reaches the next driver boundary promptly.

Runners should coalesce repeated calls and may use window as a hint for multi-window implementations.

fn exec_capabilities(&self) -> ExecCapabilities

Execution capabilities exposed by this dispatcher implementation.

Implementors