Remove Forever, switch to static_cell.

examples/nrf/Cargo.toml

@@ -22,6 +22,7 @@ embedded-io = "0.3.0"
 defmt = "0.3"
 defmt-rtt = "0.3"
 
+static_cell = "1.0"
 cortex-m = { version = "0.7.6", features = ["critical-section-single-core"] }
 cortex-m-rt = "0.7.0"
 panic-probe = { version = "0.3", features = ["print-defmt"] }

examples/nrf/src/bin/channel_sender_receiver.rs

@@ -8,7 +8,7 @@ use embassy_nrf::gpio::{AnyPin, Level, Output, OutputDrive, Pin};
 use embassy_time::{Duration, Timer};
 use embassy_util::blocking_mutex::raw::NoopRawMutex;
 use embassy_util::channel::mpmc::{Channel, Receiver, Sender};
-use embassy_util::Forever;
+use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
 
 enum LedState {
@@ -16,7 +16,7 @@ enum LedState {
     Off,
 }
 
-static CHANNEL: Forever<Channel<NoopRawMutex, LedState, 1>> = Forever::new();
+static CHANNEL: StaticCell<Channel<NoopRawMutex, LedState, 1>> = StaticCell::new();
 
 #[embassy_executor::task]
 async fn send_task(sender: Sender<'static, NoopRawMutex, LedState, 1>) {
@@ -43,7 +43,7 @@ async fn recv_task(led: AnyPin, receiver: Receiver<'static, NoopRawMutex, LedSta
 #[embassy_executor::main]
 async fn main(spawner: Spawner) {
     let p = embassy_nrf::init(Default::default());
-    let channel = CHANNEL.put(Channel::new());
+    let channel = CHANNEL.init(Channel::new());
 
     unwrap!(spawner.spawn(send_task(channel.sender())));
     unwrap!(spawner.spawn(recv_task(p.P0_13.degrade(), channel.receiver())));

examples/nrf/src/bin/multiprio.rs

@@ -63,7 +63,7 @@ use embassy_nrf::executor::{Executor, InterruptExecutor};
 use embassy_nrf::interrupt;
 use embassy_nrf::interrupt::InterruptExt;
 use embassy_time::{Duration, Instant, Timer};
-use embassy_util::Forever;
+use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
 
 #[embassy_executor::task]
@@ -108,9 +108,9 @@ async fn run_low() {
     }
 }
 
-static EXECUTOR_HIGH: Forever<InterruptExecutor<interrupt::SWI1_EGU1>> = Forever::new();
-static EXECUTOR_MED: Forever<InterruptExecutor<interrupt::SWI0_EGU0>> = Forever::new();
-static EXECUTOR_LOW: Forever<Executor> = Forever::new();
+static EXECUTOR_HIGH: StaticCell<InterruptExecutor<interrupt::SWI1_EGU1>> = StaticCell::new();
+static EXECUTOR_MED: StaticCell<InterruptExecutor<interrupt::SWI0_EGU0>> = StaticCell::new();
+static EXECUTOR_LOW: StaticCell<Executor> = StaticCell::new();
 
 #[entry]
 fn main() -> ! {
@@ -121,19 +121,19 @@ fn main() -> ! {
     // High-priority executor: SWI1_EGU1, priority level 6
     let irq = interrupt::take!(SWI1_EGU1);
     irq.set_priority(interrupt::Priority::P6);
-    let executor = EXECUTOR_HIGH.put(InterruptExecutor::new(irq));
+    let executor = EXECUTOR_HIGH.init(InterruptExecutor::new(irq));
     let spawner = executor.start();
     unwrap!(spawner.spawn(run_high()));
 
     // Medium-priority executor: SWI0_EGU0, priority level 7
     let irq = interrupt::take!(SWI0_EGU0);
     irq.set_priority(interrupt::Priority::P7);
-    let executor = EXECUTOR_MED.put(InterruptExecutor::new(irq));
+    let executor = EXECUTOR_MED.init(InterruptExecutor::new(irq));
     let spawner = executor.start();
     unwrap!(spawner.spawn(run_med()));
 
     // Low priority executor: runs in thread mode, using WFE/SEV
-    let executor = EXECUTOR_LOW.put(Executor::new());
+    let executor = EXECUTOR_LOW.init(Executor::new());
     executor.run(|spawner| {
         unwrap!(spawner.spawn(run_low()));
     });

examples/nrf/src/bin/raw_spawn.rs

@@ -8,7 +8,7 @@ use defmt::{info, unwrap};
 use embassy_executor::raw::TaskStorage;
 use embassy_executor::Executor;
 use embassy_time::{Duration, Timer};
-use embassy_util::Forever;
+use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
 
 async fn run1() {
@@ -25,14 +25,14 @@ async fn run2() {
     }
 }
 
-static EXECUTOR: Forever<Executor> = Forever::new();
+static EXECUTOR: StaticCell<Executor> = StaticCell::new();
 
 #[entry]
 fn main() -> ! {
     info!("Hello World!");
 
     let _p = embassy_nrf::init(Default::default());
-    let executor = EXECUTOR.put(Executor::new());
+    let executor = EXECUTOR.init(Executor::new());
 
     let run1_task = TaskStorage::new();
     let run2_task = TaskStorage::new();

examples/nrf/src/bin/usb_ethernet.rs

@@ -18,17 +18,17 @@ use embassy_usb::{Builder, Config, UsbDevice};
 use embassy_usb_ncm::{CdcNcmClass, Receiver, Sender, State};
 use embassy_util::blocking_mutex::raw::ThreadModeRawMutex;
 use embassy_util::channel::mpmc::Channel;
-use embassy_util::Forever;
 use embedded_io::asynch::{Read, Write};
+use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
 
 type MyDriver = Driver<'static, peripherals::USBD, PowerUsb>;
 
-macro_rules! forever {
+macro_rules! singleton {
     ($val:expr) => {{
         type T = impl Sized;
-        static FOREVER: Forever<T> = Forever::new();
-        FOREVER.put_with(move || $val)
+        static STATIC_CELL: StaticCell<T> = StaticCell::new();
+        STATIC_CELL.init_with(move || $val)
     }};
 }
 
@@ -116,7 +116,7 @@ async fn main(spawner: Spawner) {
         control_buf: [u8; 128],
         serial_state: State<'static>,
     }
-    let res: &mut Resources = forever!(Resources {
+    let res: &mut Resources = singleton!(Resources {
         device_descriptor: [0; 256],
         config_descriptor: [0; 256],
         bos_descriptor: [0; 256],
@@ -174,10 +174,10 @@ async fn main(spawner: Spawner) {
 
     // Init network stack
     let device = Device { mac_addr: our_mac_addr };
-    let stack = &*forever!(Stack::new(
+    let stack = &*singleton!(Stack::new(
         device,
         config,
-        forever!(StackResources::<1, 2, 8>::new()),
+        singleton!(StackResources::<1, 2, 8>::new()),
         seed
     ));
 

examples/nrf/src/bin/usb_serial_multitask.rs

@@ -12,7 +12,7 @@ use embassy_nrf::{interrupt, pac, peripherals};
 use embassy_usb::driver::EndpointError;
 use embassy_usb::{Builder, Config, UsbDevice};
 use embassy_usb_serial::{CdcAcmClass, State};
-use embassy_util::Forever;
+use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
 
 type MyDriver = Driver<'static, peripherals::USBD, PowerUsb>;
@@ -67,8 +67,8 @@ async fn main(spawner: Spawner) {
         control_buf: [u8; 64],
         serial_state: State<'static>,
     }
-    static RESOURCES: Forever<Resources> = Forever::new();
-    let res = RESOURCES.put(Resources {
+    static RESOURCES: StaticCell<Resources> = StaticCell::new();
+    let res = RESOURCES.init(Resources {
         device_descriptor: [0; 256],
         config_descriptor: [0; 256],
         bos_descriptor: [0; 256],