lock-free reading

This commit is contained in:
Jörn-Michael Miehe 2024-03-15 12:37:55 +00:00
parent 23cf62e01f
commit 29e343b9c2

View file

@ -20,12 +20,13 @@ mod app {
#[shared]
struct Shared {
buffer: Option<&'static mut [u8; 512]>,
buffer: &'static mut [u8; 512],
}
#[local]
struct Local {
tx: Option<dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>>,
txbuffer: Option<&'static mut [u8; 512]>,
delay_us: timer::DelayUs<pac::TIM2>,
led: gpio::gpioc::PC13<gpio::Output>,
}
@ -71,10 +72,11 @@ mod app {
(
Shared {
buffer: Some(singleton!(: [u8; 512] = [0b01010101; 512]).unwrap()),
buffer: singleton!(: [u8; 512] = [0b01010101; 512]).unwrap(),
},
Local {
tx: Some(serial.tx.with_dma(dma1.4)),
txbuffer: Some(singleton!(: [u8; 512] = [0; 512]).unwrap()),
// Configure timer
delay_us: cx.device.TIM2.delay_us(&clocks),
@ -87,25 +89,24 @@ mod app {
)
}
#[idle(local = [tx, delay_us, led], shared = [buffer])]
fn idle(mut cx: idle::Context) -> ! {
let mut tx = cx.local.tx.take().unwrap();
#[idle(local = [tx, txbuffer, delay_us, led], shared = [&buffer])]
fn idle(cx: idle::Context) -> ! {
loop {
tx = (cx.shared.buffer).lock(|buffer| {
let buf = buffer.take().unwrap();
let xfer = tx.write(buf);
let mut tx = cx.local.tx.take().unwrap();
let mut txbuffer = cx.local.txbuffer.take().unwrap();
cx.local.delay_us.delay(1.secs());
cx.local.led.set_high();
txbuffer.copy_from_slice(*cx.shared.buffer);
let xfer = tx.write(txbuffer);
cx.local.delay_us.delay(1.secs());
cx.local.led.set_low();
cx.local.delay_us.delay(1.secs());
cx.local.led.set_high();
let (buf, tx) = xfer.wait();
buffer.replace(buf);
tx
});
cx.local.delay_us.delay(1.secs());
cx.local.led.set_low();
(txbuffer, tx) = xfer.wait();
cx.local.tx.replace(tx);
cx.local.txbuffer.replace(txbuffer);
}
}
}