Provides a cleaner construction of the channel with the common "new" naming

This commit is contained in:
huntc 2021-07-15 12:08:35 +10:00
parent 6f78527aeb
commit 3778f55d80
3 changed files with 51 additions and 88 deletions

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@ -581,75 +581,27 @@ where
pub type WithCriticalSections = CriticalSectionMutex<()>; pub type WithCriticalSections = CriticalSectionMutex<()>;
impl<T, const N: usize> Channel<WithCriticalSections, T, N> {
/// Establish a new bounded channel using critical sections. Critical sections
/// should be used only single core targets where communication is required
/// from exception mode e.g. interrupt handlers. To create one:
///
/// ```
/// use embassy::util::mpsc;
/// use embassy::util::mpsc::{Channel, WithCriticalSections};
///
/// // Declare a bounded channel of 3 u32s.
/// let mut channel = Channel::<WithCriticalSections, u32, 3>::with_critical_sections();
/// // once we have a channel, obtain its sender and receiver
/// let (sender, receiver) = mpsc::split(&mut channel);
/// ```
pub const fn with_critical_sections() -> Self {
let mutex = CriticalSectionMutex::new(());
let state = ChannelState::new();
let channel_cell = ChannelCell { mutex, state };
Channel {
channel_cell: UnsafeCell::new(channel_cell),
receiver_consumed: PhantomData,
}
}
}
pub type WithThreadModeOnly = ThreadModeMutex<()>; pub type WithThreadModeOnly = ThreadModeMutex<()>;
impl<T, const N: usize> Channel<WithThreadModeOnly, T, N> {
/// Establish a new bounded channel for use in Cortex-M thread mode. Thread
/// mode is intended for application threads on a single core, not interrupts.
/// As such, only one task at a time can acquire a resource and so this
/// channel avoids all locks. To create one:
///
/// ``` no_run
/// use embassy::util::mpsc;
/// use embassy::util::mpsc::{Channel, WithThreadModeOnly};
///
/// // Declare a bounded channel of 3 u32s.
/// let mut channel = Channel::<WithThreadModeOnly, u32, 3>::with_thread_mode_only();
/// // once we have a channel, obtain its sender and receiver
/// let (sender, receiver) = mpsc::split(&mut channel);
/// ```
pub const fn with_thread_mode_only() -> Self {
let mutex = ThreadModeMutex::new(());
let state = ChannelState::new();
let channel_cell = ChannelCell { mutex, state };
Channel {
channel_cell: UnsafeCell::new(channel_cell),
receiver_consumed: PhantomData,
}
}
}
pub type WithNoThreads = NoopMutex<()>; pub type WithNoThreads = NoopMutex<()>;
impl<T, const N: usize> Channel<WithNoThreads, T, N> { impl<M, T, const N: usize> Channel<M, T, N>
/// Establish a new bounded channel for within a single thread. To create one: where
M: Mutex<Data = ()>,
{
/// Establish a new bounded channel. For example, to create one with a NoopMutex:
/// ///
/// ``` /// ```
/// use embassy::util::mpsc; /// use embassy::util::mpsc;
/// use embassy::util::mpsc::{Channel, WithNoThreads}; /// use embassy::util::mpsc::{Channel, WithNoThreads};
/// ///
/// // Declare a bounded channel of 3 u32s. /// // Declare a bounded channel of 3 u32s.
/// let mut channel = Channel::<WithNoThreads, u32, 3>::with_no_threads(); /// let mut channel = Channel::<WithNoThreads, u32, 3>::new();
/// // once we have a channel, obtain its sender and receiver /// // once we have a channel, obtain its sender and receiver
/// let (sender, receiver) = mpsc::split(&mut channel); /// let (sender, receiver) = mpsc::split(&mut channel);
/// ``` /// ```
pub const fn with_no_threads() -> Self { pub fn new() -> Self {
let mutex = NoopMutex::new(()); let mutex = M::new(());
let state = ChannelState::new(); let state = ChannelState::new();
let channel_cell = ChannelCell { mutex, state }; let channel_cell = ChannelCell { mutex, state };
Channel { Channel {
@ -657,12 +609,7 @@ impl<T, const N: usize> Channel<WithNoThreads, T, N> {
receiver_consumed: PhantomData, receiver_consumed: PhantomData,
} }
} }
}
impl<M, T, const N: usize> Channel<M, T, N>
where
M: Mutex<Data = ()>,
{
fn lock<R>( fn lock<R>(
channel_cell: &UnsafeCell<ChannelCell<M, T, N>>, channel_cell: &UnsafeCell<ChannelCell<M, T, N>>,
f: impl FnOnce(&mut ChannelState<T, N>) -> R, f: impl FnOnce(&mut ChannelState<T, N>) -> R,
@ -684,6 +631,8 @@ mod tests {
use futures_executor::ThreadPool; use futures_executor::ThreadPool;
use futures_timer::Delay; use futures_timer::Delay;
use crate::util::Forever;
use super::*; use super::*;
fn capacity<T, const N: usize>(c: &ChannelState<T, N>) -> usize { fn capacity<T, const N: usize>(c: &ChannelState<T, N>) -> usize {
@ -758,7 +707,7 @@ mod tests {
#[test] #[test]
fn simple_send_and_receive() { fn simple_send_and_receive() {
let mut c = Channel::<WithNoThreads, u32, 3>::with_no_threads(); let mut c = Channel::<WithNoThreads, u32, 3>::new();
let (s, r) = split(&mut c); let (s, r) = split(&mut c);
assert!(s.clone().try_send(1).is_ok()); assert!(s.clone().try_send(1).is_ok());
assert_eq!(r.try_recv().unwrap(), 1); assert_eq!(r.try_recv().unwrap(), 1);
@ -766,7 +715,7 @@ mod tests {
#[test] #[test]
fn should_close_without_sender() { fn should_close_without_sender() {
let mut c = Channel::<WithNoThreads, u32, 3>::with_no_threads(); let mut c = Channel::<WithNoThreads, u32, 3>::new();
let (s, r) = split(&mut c); let (s, r) = split(&mut c);
drop(s); drop(s);
match r.try_recv() { match r.try_recv() {
@ -777,7 +726,7 @@ mod tests {
#[test] #[test]
fn should_close_once_drained() { fn should_close_once_drained() {
let mut c = Channel::<WithNoThreads, u32, 3>::with_no_threads(); let mut c = Channel::<WithNoThreads, u32, 3>::new();
let (s, r) = split(&mut c); let (s, r) = split(&mut c);
assert!(s.try_send(1).is_ok()); assert!(s.try_send(1).is_ok());
drop(s); drop(s);
@ -790,7 +739,7 @@ mod tests {
#[test] #[test]
fn should_reject_send_when_receiver_dropped() { fn should_reject_send_when_receiver_dropped() {
let mut c = Channel::<WithNoThreads, u32, 3>::with_no_threads(); let mut c = Channel::<WithNoThreads, u32, 3>::new();
let (s, r) = split(&mut c); let (s, r) = split(&mut c);
drop(r); drop(r);
match s.try_send(1) { match s.try_send(1) {
@ -801,7 +750,7 @@ mod tests {
#[test] #[test]
fn should_reject_send_when_channel_closed() { fn should_reject_send_when_channel_closed() {
let mut c = Channel::<WithNoThreads, u32, 3>::with_no_threads(); let mut c = Channel::<WithNoThreads, u32, 3>::new();
let (s, mut r) = split(&mut c); let (s, mut r) = split(&mut c);
assert!(s.try_send(1).is_ok()); assert!(s.try_send(1).is_ok());
r.close(); r.close();
@ -817,9 +766,9 @@ mod tests {
async fn receiver_closes_when_sender_dropped_async() { async fn receiver_closes_when_sender_dropped_async() {
let executor = ThreadPool::new().unwrap(); let executor = ThreadPool::new().unwrap();
static mut CHANNEL: Channel<WithCriticalSections, u32, 3> = static CHANNEL: Forever<Channel<WithCriticalSections, u32, 3>> = Forever::new();
Channel::with_critical_sections(); let c = CHANNEL.put(Channel::new());
let (s, mut r) = split(unsafe { &mut CHANNEL }); let (s, mut r) = split(c);
assert!(executor assert!(executor
.spawn(async move { .spawn(async move {
drop(s); drop(s);
@ -832,9 +781,9 @@ mod tests {
async fn receiver_receives_given_try_send_async() { async fn receiver_receives_given_try_send_async() {
let executor = ThreadPool::new().unwrap(); let executor = ThreadPool::new().unwrap();
static mut CHANNEL: Channel<WithCriticalSections, u32, 3> = static CHANNEL: Forever<Channel<WithCriticalSections, u32, 3>> = Forever::new();
Channel::with_critical_sections(); let c = CHANNEL.put(Channel::new());
let (s, mut r) = split(unsafe { &mut CHANNEL }); let (s, mut r) = split(c);
assert!(executor assert!(executor
.spawn(async move { .spawn(async move {
assert!(s.try_send(1).is_ok()); assert!(s.try_send(1).is_ok());
@ -845,18 +794,17 @@ mod tests {
#[futures_test::test] #[futures_test::test]
async fn sender_send_completes_if_capacity() { async fn sender_send_completes_if_capacity() {
static mut CHANNEL: Channel<WithCriticalSections, u32, 1> = let mut c = Channel::<WithCriticalSections, u32, 1>::new();
Channel::with_critical_sections(); let (s, mut r) = split(&mut c);
let (s, mut r) = split(unsafe { &mut CHANNEL });
assert!(s.send(1).await.is_ok()); assert!(s.send(1).await.is_ok());
assert_eq!(r.recv().await, Some(1)); assert_eq!(r.recv().await, Some(1));
} }
#[futures_test::test] #[futures_test::test]
async fn sender_send_completes_if_closed() { async fn sender_send_completes_if_closed() {
static mut CHANNEL: Channel<WithCriticalSections, u32, 1> = static CHANNEL: Forever<Channel<WithCriticalSections, u32, 1>> = Forever::new();
Channel::with_critical_sections(); let c = CHANNEL.put(Channel::new());
let (s, r) = split(unsafe { &mut CHANNEL }); let (s, r) = split(c);
drop(r); drop(r);
match s.send(1).await { match s.send(1).await {
Err(SendError(1)) => assert!(true), Err(SendError(1)) => assert!(true),
@ -868,9 +816,9 @@ mod tests {
async fn senders_sends_wait_until_capacity() { async fn senders_sends_wait_until_capacity() {
let executor = ThreadPool::new().unwrap(); let executor = ThreadPool::new().unwrap();
static mut CHANNEL: Channel<WithCriticalSections, u32, 1> = static CHANNEL: Forever<Channel<WithCriticalSections, u32, 1>> = Forever::new();
Channel::with_critical_sections(); let c = CHANNEL.put(Channel::new());
let (s0, mut r) = split(unsafe { &mut CHANNEL }); let (s0, mut r) = split(c);
assert!(s0.try_send(1).is_ok()); assert!(s0.try_send(1).is_ok());
let s1 = s0.clone(); let s1 = s0.clone();
let send_task_1 = executor.spawn_with_handle(async move { s0.send(2).await }); let send_task_1 = executor.spawn_with_handle(async move { s0.send(2).await });
@ -888,18 +836,18 @@ mod tests {
#[futures_test::test] #[futures_test::test]
async fn sender_close_completes_if_closing() { async fn sender_close_completes_if_closing() {
static mut CHANNEL: Channel<WithCriticalSections, u32, 1> = static CHANNEL: Forever<Channel<WithCriticalSections, u32, 1>> = Forever::new();
Channel::with_critical_sections(); let c = CHANNEL.put(Channel::new());
let (s, mut r) = split(unsafe { &mut CHANNEL }); let (s, mut r) = split(c);
r.close(); r.close();
s.closed().await; s.closed().await;
} }
#[futures_test::test] #[futures_test::test]
async fn sender_close_completes_if_closed() { async fn sender_close_completes_if_closed() {
static mut CHANNEL: Channel<WithCriticalSections, u32, 1> = static CHANNEL: Forever<Channel<WithCriticalSections, u32, 1>> = Forever::new();
Channel::with_critical_sections(); let c = CHANNEL.put(Channel::new());
let (s, r) = split(unsafe { &mut CHANNEL }); let (s, r) = split(c);
drop(r); drop(r);
s.closed().await; s.closed().await;
} }

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@ -8,6 +8,8 @@ pub trait Mutex {
/// Data protected by the mutex. /// Data protected by the mutex.
type Data; type Data;
fn new(data: Self::Data) -> Self;
/// Creates a critical section and grants temporary access to the protected data. /// Creates a critical section and grants temporary access to the protected data.
fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R; fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R;
} }
@ -47,6 +49,10 @@ impl<T> CriticalSectionMutex<T> {
impl<T> Mutex for CriticalSectionMutex<T> { impl<T> Mutex for CriticalSectionMutex<T> {
type Data = T; type Data = T;
fn new(data: T) -> Self {
Self::new(data)
}
fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R { fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R {
critical_section::with(|cs| f(self.borrow(cs))) critical_section::with(|cs| f(self.borrow(cs)))
} }
@ -92,6 +98,10 @@ impl<T> ThreadModeMutex<T> {
impl<T> Mutex for ThreadModeMutex<T> { impl<T> Mutex for ThreadModeMutex<T> {
type Data = T; type Data = T;
fn new(data: T) -> Self {
Self::new(data)
}
fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R { fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R {
f(self.borrow()) f(self.borrow())
} }
@ -126,6 +136,10 @@ impl<T> NoopMutex<T> {
impl<T> Mutex for NoopMutex<T> { impl<T> Mutex for NoopMutex<T> {
type Data = T; type Data = T;
fn new(data: T) -> Self {
Self::new(data)
}
fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R { fn lock<R>(&mut self, f: impl FnOnce(&Self::Data) -> R) -> R {
f(self.borrow()) f(self.borrow())
} }

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@ -37,9 +37,10 @@ async fn my_task(sender: Sender<'static, WithNoThreads, LedState, 1>) {
#[embassy::main] #[embassy::main]
async fn main(spawner: Spawner, p: Peripherals) { async fn main(spawner: Spawner, p: Peripherals) {
let mut led = Output::new(p.P0_13, Level::Low, OutputDrive::Standard); let mut led = Output::new(p.P0_13, Level::Low, OutputDrive::Standard);
let channel = CHANNEL.put(Channel::with_no_threads()); let channel = CHANNEL.put(Channel::new());
let (sender, mut receiver) = mpsc::split(channel); let (sender, mut receiver) = mpsc::split(channel);
spawner.spawn(my_task(sender)).unwrap(); spawner.spawn(my_task(sender)).unwrap();