ethercat-linux/vendor/ethercrab/examples/performance.rs

//! Demonstrate running the TX/RX loop in a separate realtime thread.
//!
//! Please note that this example is currently quite unstable on my (@jamwaffles) test system so
//! YMMV!

#[cfg(not(target_os = "linux"))]
fn main() {
    eprintln!("This example is only supported on Linux systems");
}

#[cfg(target_os = "linux")]
#[tokio::main]
async fn main() -> Result<(), ethercrab::error::Error> {
    use env_logger::Env;
    use ethercrab::{
        MainDevice, MainDeviceConfig, PduStorage, SubDeviceGroup, Timeouts,
        error::Error,
        std::{ethercat_now, tx_rx_task},
    };
    use smol::LocalExecutor;
    use std::{
        sync::Arc,
        time::{Duration, Instant},
    };
    use thread_priority::{
        RealtimeThreadSchedulePolicy, ThreadPriority, ThreadPriorityValue, ThreadSchedulePolicy,
    };
    use tokio::time::MissedTickBehavior;

    /// Maximum number of SubDevices that can be stored. This must be a power of 2 greater than 1.
    const MAX_SUBDEVICES: usize = 16;
    /// Maximum PDU data payload size - set this to the max PDI size or higher.
    const MAX_PDU_DATA: usize = PduStorage::element_size(1100);
    /// Maximum number of EtherCAT frames that can be in flight at any one time.
    const MAX_FRAMES: usize = 16;

    static PDU_STORAGE: PduStorage<MAX_FRAMES, MAX_PDU_DATA> = PduStorage::new();

    #[derive(Default)]
    struct Groups {
        /// EL2889 and EK1100/EK1501. For EK1100, 2 items, 2 bytes of PDI for 16 output bits. The EK1501
        /// has 2 bytes of its own PDI so we'll use an upper bound of 4.
        ///
        /// We'll keep the EK1100/EK1501 in here as it has no useful PDI but still needs to live
        /// somewhere.
        slow_outputs: SubDeviceGroup<2, 4>,
        /// EL2828. 1 item, 1 byte of PDI for 8 output bits.
        fast_outputs: SubDeviceGroup<1, 1>,
    }

    env_logger::Builder::from_env(Env::default().default_filter_or("info")).init();

    let interface = std::env::args()
        .nth(1)
        .expect("Provide network interface as first argument.");

    log::info!("Starting multiple groups demo...");
    log::info!(
        "Ensure an EK1100/EK1501 is the first SubDevice, with an EL2828 and EL2889 following it"
    );
    log::info!("Run with RUST_LOG=ethercrab=debug or =trace for debug information");

    let (tx, rx, pdu_loop) = PDU_STORAGE.try_split().expect("can only split once");

    let maindevice = MainDevice::new(
        pdu_loop,
        Timeouts {
            wait_loop_delay: Duration::from_millis(2),
            mailbox_response: Duration::from_millis(1000),
            ..Default::default()
        },
        MainDeviceConfig::default(),
    );

    thread_priority::ThreadBuilder::default()
        .name("tx-rx-task")
        // Might need to set `<user> hard rtprio 99` and `<user> soft rtprio 99` in `/etc/security/limits.conf`
        // Check limits with `ulimit -Hr` or `ulimit -Sr`
        .priority(ThreadPriority::Crossplatform(
            ThreadPriorityValue::try_from(99u8).unwrap(),
        ))
        // NOTE: Requires a realtime kernel
        .policy(ThreadSchedulePolicy::Realtime(
            RealtimeThreadSchedulePolicy::Fifo,
        ))
        .spawn(move |_| {
            core_affinity::set_for_current(core_affinity::CoreId { id: 0 })
                .then_some(())
                .expect("Set TX/RX thread core");

            let ex = LocalExecutor::new();

            futures_lite::future::block_on(
                ex.run(tx_rx_task(&interface, tx, rx).expect("spawn TX/RX task")),
            )
            .expect("TX/RX task exited");
        })
        .unwrap();

    let maindevice = Arc::new(maindevice);

    // Read configurations from SubDevice EEPROMs and configure devices.
    let groups = maindevice
        .init::<MAX_SUBDEVICES, _>(
            ethercat_now,
            Groups::default(),
            |groups: &Groups, subdevice| match subdevice.name() {
                "EL2889" | "EK1100" | "EK1501" => Ok(&groups.slow_outputs),
                "EL2828" => Ok(&groups.fast_outputs),
                _ => Err(Error::UnknownSubDevice),
            },
        )
        .await
        .expect("Init");

    let Groups {
        slow_outputs,
        fast_outputs,
    } = groups;

    let maindevice_slow = maindevice.clone();

    let slow_task = tokio::spawn(async move {
        let slow_outputs = slow_outputs
            .into_op(&maindevice_slow)
            .await
            .expect("PRE-OP -> OP");

        let mut slow_cycle_time = tokio::time::interval(Duration::from_millis(3));
        slow_cycle_time.set_missed_tick_behavior(MissedTickBehavior::Skip);

        let slow_duration = Duration::from_millis(250);

        // Only update "slow" outputs every 250ms using this instant
        let mut tick = Instant::now();

        // EK1100 is first SubDevice, EL2889 is second
        let el2889 = slow_outputs
            .subdevice(&maindevice_slow, 1)
            .expect("EL2889 not present!");

        // Set initial output state
        el2889.outputs_raw_mut()[0] = 0x01;
        el2889.outputs_raw_mut()[1] = 0x80;

        loop {
            let Ok(_) = slow_outputs.tx_rx(&maindevice_slow).await else {
                break;
            };

            // Increment every output byte for every SubDevice by one
            if tick.elapsed() > slow_duration {
                tick = Instant::now();

                let el2889 = slow_outputs
                    .subdevice(&maindevice_slow, 1)
                    .expect("EL2889 not present!");

                let mut o = el2889.outputs_raw_mut();

                // Make a nice pattern on EL2889 LEDs
                o[0] = o[0].rotate_left(1);
                o[1] = o[1].rotate_right(1);
            }

            slow_cycle_time.tick().await;
        }
    });

    let fast_task = tokio::spawn(async move {
        let fast_outputs = fast_outputs
            .into_op(&maindevice)
            .await
            .expect("PRE-OP -> OP");

        let mut fast_cycle_time = tokio::time::interval(Duration::from_millis(5));
        fast_cycle_time.set_missed_tick_behavior(MissedTickBehavior::Skip);

        loop {
            let Ok(_) = fast_outputs.tx_rx(&maindevice).await else {
                break;
            };

            // Increment every output byte for every SubDevice by one
            for subdevice in fast_outputs.iter(&maindevice) {
                let mut o = subdevice.outputs_raw_mut();

                for byte in o.iter_mut() {
                    *byte = byte.wrapping_add(1);
                }
            }

            fast_cycle_time.tick().await;
        }
    });

    let (slow, fast) = tokio::join!(slow_task, fast_task);

    slow.expect("slow task failed");
    fast.expect("fast task failed");

    Ok(())
}