Question on periodic timer event_loop message

[enelson1001]

I am new to rust. I am trying to retrieve the event_loop_message data outside the subscribe closure. Is there a way to do this? I can't use view_manager inside the closure as it take ownership and I need to use view_manger later.

This is what I have so far in main.rs. The "????" is how do I get the Bme280ReadMessage data outside the bme280_read_event_loop.subscribe closure.

info!("About to start a bme280 read event loop");
    let mut bme280_read_event_loop = EspBackgroundEventLoop::new(&Default::default()).unwrap();

    info!("About to subscribe to the background event loop");
    let bme280_read_subscription =
        bme280_read_event_loop.subscribe(move |message: &Bme280ReadMessage| {
            info!("Got bme280 read message");
        });

    let bme280_read_subscription = match bme280_read_subscription {
        Ok(EspSubscription) => {
            let bme280_values = ??????????????????????????????????????????????????????????????
            view_manager
                .set_temperature_text((bme280_values.0 * 1.8) as i16 + 32)
                .unwrap();
            view_manager.set_humidity_text(bme280_values.1 as u8).unwrap();
            view_manager
                .set_pressure_text(bme280_values.2 * 0.00029529983071445)
                .unwrap();
        }
        Err(e) => panic!("Error {}", e),
    };

    info!("About to schedule a bme280 read periodic timer every one seconds");
    let mut bme280_read_periodic_timer = EspTimerService::new()
        .unwrap()
        .timer(move || {
            info!("Tick from periodic timer");
            let measurements = i2c_bme280.measure(&mut delay).unwrap();
            bme280_read_event_loop
                .post(
                    &Bme280ReadMessage::new(
                        measurements.temperature,
                        measurements.humidity,
                        measurements.pressure,
                    ),
                    None,
                )
                .unwrap();
        })
        .unwrap();

    bme280_read_periodic_timer
        .every(Duration::from_secs(5))
        .unwrap();

#[derive(Copy, Clone, Debug)]
pub struct Bme280ReadMessage(pub f32, pub f32, pub f32);

impl Bme280ReadMessage {
    pub fn new(temperature: f32, humidity: f32, pressure: f32) -> Self {
        Self(temperature, humidity, pressure)
    }
}

impl EspTypedEventSource for Bme280ReadMessage {
    fn source() -> *const c_types::c_char {
        b"BME280 READ TIMER SERVICE\0".as_ptr() as *const _
    }
}

impl EspTypedEventSerializer<Bme280ReadMessage> for Bme280ReadMessage {
    fn serialize<R>(
        event: &Bme280ReadMessage,
        f: impl for<'a> FnOnce(&'a EspEventPostData) -> R,
    ) -> R {
        f(&unsafe { EspEventPostData::new(Self::source(), Self::event_id(), event) })
    }
}

impl EspTypedEventDeserializer<Bme280ReadMessage> for Bme280ReadMessage {
    fn deserialize<R>(
        data: &EspEventFetchData,
        f: &mut impl for<'a> FnMut(&'a Bme280ReadMessage) -> R,
    ) -> R {
        f(unsafe { data.as_payload() })
    }
}

[ivmarkov]

You have to wrap your view manager in a STD Arc<Mutex<ViewManager>>. Once you do this, you can clone it and then send the clones to other threads, where you can safely lock the manager due to the mutex and then call methods on the manager. Alternatively, you should make the view manager itself Sync Send and Clone but thats more complex for a beginner. Regardless, it would be beneficial for you if you read about Send and Sync in Rust, as these concepts are key for the language.

If it is not clear, both the timer closure and the event loop closure are executed in separate threads.

Other points:

• the event loop machinery you are using seems unnecessary. You can do everything from the timer closure itself
• even the timer is a bit of a overkill for sleep periods > than a few tens of milliseconds. You can use a regular Rust thread instead, that sleeps for every 5 seconds in a loop. You still need the arc mutex thing of course

These questions btw beling to the Matrix channel. Youll get faster reaction there from many contributors. :)