Trait IoDriver 

pub trait IoDriver: Send + Sync {
    // Required methods
    fn set_process_callback(&self, cb: Box<dyn FnMut(&ClockTick)>);
    fn run(&self, running: Arc<AtomicBool>) -> IoResult<()>;
    fn stop(&self) -> IoResult<()>;

    // Provided methods
    fn set_input_process_callback(&self, _cb: Box<dyn FnMut(&ClockTick)>) { ... }
    fn as_control(&self) -> Option<&dyn IoControl> { ... }
}

A backend that can be the clock driver for the signal graph.

The driver owns the timing loop: it registers a process callback and fires it on every I/O tick. Only one driver is active per rack.

A single backend struct may implement IoDriver together with IoCapture and/or IoPlayback — capturing and playing are orthogonal capabilities on top of the driver role.

Required Methods

fn set_process_callback(&self, cb: Box<dyn FnMut(&ClockTick)>)

Register the process callback that the driver calls each tick.

The callback receives a ClockTick with timing metadata (sample position, rate, speed_ratio, etc.).

fn run(&self, running: Arc<AtomicBool>) -> IoResult<()>

Enter the I/O lifecycle. Called on the pre-created signal thread.

For poll-driven backends (ALSA, PipeWire) this blocks inside the I/O loop and returns only after running becomes false. For callback-driven backends (JACK, PortAudio) it sets up the stream and returns immediately — the process callback fires on the I/O API’s own thread.

fn stop(&self) -> IoResult<()>

Signal the driver to shut down. Called from the control thread. After this returns the driver must be safe to drop.

Provided Methods

fn set_input_process_callback(&self, _cb: Box<dyn FnMut(&ClockTick)>)

Register an optional input-stream callback for split-chain backends (e.g. PipeWire full-duplex).

When both input and output streams exist, the recording chain (Source → WriteHead) is driven from this callback, while the playback chain (ReadHeads → Sink) is driven from [set_process_callback]. Default no-op for single-stream backends.

fn as_control(&self) -> Option<&dyn IoControl>

Returns a control interface if this driver supports runtime register/data writes. Returns None by default.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors