1435: Added example for multi priority executors rp2040 r=Dirbaio a=fakusb

I added an example for multiple priorities of tasks on rp2040 by adjusting [examples/nrf52840/src/bin/multiprio.rs](https://github.com/embassy-rs/embassy/blob/master/examples/nrf52840/src/bin/multiprio.rs) .

This needs https://github.com/embassy-rs/rp-pac/pull/2 , and this commit also adds the 6 new interrupt handlers for software interrupts to embassy-rs.

We might need to change the git path for rp-pac in [embassy-rp/Cargo.toml](https://github.com/embassy-rs/embassy/compare/master...fakusb:rp2040-multiprio-executor?expand=1#diff-47463ea358745927ecdb686f52feab816fde5d402a9628a136c116f34a802ab0)

Closes #1413

Co-authored-by: Fabian Kunze <fkunze@fkunze.de>
This commit is contained in:
bors[bot] 2023-05-08 16:59:07 +00:00 committed by GitHub
commit d0703f83db
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4 changed files with 160 additions and 2 deletions

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@ -61,7 +61,7 @@ embedded-storage = { version = "0.3" }
rand_core = "0.6.4"
fixed = "1.23.1"
rp-pac = { version = "2", features = ["rt"] }
rp-pac = { version = "3", features = ["rt"] }
embedded-hal-02 = { package = "embedded-hal", version = "0.2.6", features = ["unproven"] }
embedded-hal-1 = { package = "embedded-hal", version = "=1.0.0-alpha.10", optional = true}

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@ -34,3 +34,9 @@ declare!(ADC_IRQ_FIFO);
declare!(I2C0_IRQ);
declare!(I2C1_IRQ);
declare!(RTC_IRQ);
declare!(SWI_IRQ_0);
declare!(SWI_IRQ_1);
declare!(SWI_IRQ_2);
declare!(SWI_IRQ_3);
declare!(SWI_IRQ_4);
declare!(SWI_IRQ_5);

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@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
[dependencies]
embassy-embedded-hal = { version = "0.1.0", path = "../../embassy-embedded-hal", features = ["defmt"] }
embassy-sync = { version = "0.2.0", path = "../../embassy-sync", features = ["defmt"] }
embassy-executor = { version = "0.2.0", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
embassy-executor = { version = "0.2.0", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "executor-interrupt", "defmt", "integrated-timers"] }
embassy-time = { version = "0.1.0", path = "../../embassy-time", features = ["nightly", "unstable-traits", "defmt", "defmt-timestamp-uptime"] }
embassy-rp = { version = "0.1.0", path = "../../embassy-rp", features = ["defmt", "unstable-traits", "nightly", "unstable-pac", "time-driver", "critical-section-impl"] }
embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }

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@ -0,0 +1,152 @@
//! This example showcases how to create multiple Executor instances to run tasks at
//! different priority levels.
//!
//! Low priority executor runs in thread mode (not interrupt), and uses `sev` for signaling
//! there's work in the queue, and `wfe` for waiting for work.
//!
//! Medium and high priority executors run in two interrupts with different priorities.
//! Signaling work is done by pending the interrupt. No "waiting" needs to be done explicitly, since
//! when there's work the interrupt will trigger and run the executor.
//!
//! Sample output below. Note that high priority ticks can interrupt everything else, and
//! medium priority computations can interrupt low priority computations, making them to appear
//! to take significantly longer time.
//!
//! ```not_rust
//! [med] Starting long computation
//! [med] done in 992 ms
//! [high] tick!
//! [low] Starting long computation
//! [med] Starting long computation
//! [high] tick!
//! [high] tick!
//! [med] done in 993 ms
//! [med] Starting long computation
//! [high] tick!
//! [high] tick!
//! [med] done in 993 ms
//! [low] done in 3972 ms
//! [med] Starting long computation
//! [high] tick!
//! [high] tick!
//! [med] done in 993 ms
//! ```
//!
//! For comparison, try changing the code so all 3 tasks get spawned on the low priority executor.
//! You will get an output like the following. Note that no computation is ever interrupted.
//!
//! ```not_rust
//! [high] tick!
//! [med] Starting long computation
//! [med] done in 496 ms
//! [low] Starting long computation
//! [low] done in 992 ms
//! [med] Starting long computation
//! [med] done in 496 ms
//! [high] tick!
//! [low] Starting long computation
//! [low] done in 992 ms
//! [high] tick!
//! [med] Starting long computation
//! [med] done in 496 ms
//! [high] tick!
//! ```
//!
#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]
use core::mem;
use cortex_m::peripheral::NVIC;
use cortex_m_rt::entry;
use defmt::{info, unwrap};
use embassy_rp::executor::{Executor, InterruptExecutor};
use embassy_rp::interrupt;
use embassy_rp::pac::Interrupt;
use embassy_time::{Duration, Instant, Timer, TICK_HZ};
use static_cell::StaticCell;
use {defmt_rtt as _, panic_probe as _};
#[embassy_executor::task]
async fn run_high() {
loop {
info!(" [high] tick!");
Timer::after(Duration::from_ticks(673740)).await;
}
}
#[embassy_executor::task]
async fn run_med() {
loop {
let start = Instant::now();
info!(" [med] Starting long computation");
// Spin-wait to simulate a long CPU computation
cortex_m::asm::delay(125_000_000); // ~1 second
let end = Instant::now();
let ms = end.duration_since(start).as_ticks() * 1000 / TICK_HZ;
info!(" [med] done in {} ms", ms);
Timer::after(Duration::from_ticks(53421)).await;
}
}
#[embassy_executor::task]
async fn run_low() {
loop {
let start = Instant::now();
info!("[low] Starting long computation");
// Spin-wait to simulate a long CPU computation
cortex_m::asm::delay(250_000_000); // ~2 seconds
let end = Instant::now();
let ms = end.duration_since(start).as_ticks() * 1000 / TICK_HZ;
info!("[low] done in {} ms", ms);
Timer::after(Duration::from_ticks(82983)).await;
}
}
static EXECUTOR_HIGH: InterruptExecutor = InterruptExecutor::new();
static EXECUTOR_MED: InterruptExecutor = InterruptExecutor::new();
static EXECUTOR_LOW: StaticCell<Executor> = StaticCell::new();
#[interrupt]
unsafe fn SWI_IRQ_1() {
EXECUTOR_HIGH.on_interrupt()
}
#[interrupt]
unsafe fn SWI_IRQ_0() {
EXECUTOR_MED.on_interrupt()
}
#[entry]
fn main() -> ! {
info!("Hello World!");
let _p = embassy_rp::init(Default::default());
let mut nvic: NVIC = unsafe { mem::transmute(()) };
// High-priority executor: SWI_IRQ_1, priority level 2
unsafe { nvic.set_priority(Interrupt::SWI_IRQ_1, 2 << 6) };
info!("bla: {}", NVIC::get_priority(Interrupt::SWI_IRQ_1));
let spawner = EXECUTOR_HIGH.start(Interrupt::SWI_IRQ_1);
unwrap!(spawner.spawn(run_high()));
// Medium-priority executor: SWI_IRQ_0, priority level 3
unsafe { nvic.set_priority(Interrupt::SWI_IRQ_0, 3 << 6) };
info!("bla: {}", NVIC::get_priority(Interrupt::SWI_IRQ_0));
let spawner = EXECUTOR_MED.start(Interrupt::SWI_IRQ_0);
unwrap!(spawner.spawn(run_med()));
// Low priority executor: runs in thread mode, using WFE/SEV
let executor = EXECUTOR_LOW.init(Executor::new());
executor.run(|spawner| {
unwrap!(spawner.spawn(run_low()));
});
}