Merge branch 'no-wq-exec' into tasks-pre

Author: d3zd3z

samples/work-philosophers/CMakeLists.txt renamed to samples/async-philosophers/CMakeLists.txt

@@ -3,6 +3,6 @@
 cmake_minimum_required(VERSION 3.20.0)
 
 find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(work_philosophers)
+project(async_philosophers)
 
 rust_cargo_application()

samples/async-philosophers/Cargo.toml

@@ -0,0 +1,36 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+[package]
+# This must be rustapp for now.
+name = "rustapp"
+version = "0.1.0"
+edition = "2021"
+description = "A sample hello world application in Rust"
+license = "Apache-2.0 or MIT"
+
+[lib]
+crate-type = ["staticlib"]
+
+[dependencies]
+zephyr = { version = "0.1.0", features = ["time-driver", "executor-zephyr"] }
+static_cell = "2.1"
+
+embassy-executor = { version = "0.7.0", features = ["log", "task-arena-size-2048"] }
+embassy-sync = "0.6.2"
+
+# For real builds, you should figure out your target's tick rate and set the appropriate feature,
+# like in these examples.  Without this, embassy-time will assume a 1Mhz tick rate, and every time
+# operation will involve a conversion.
+embassy-time = "0.4.0"
+# embassy-time = { version = "0.4.0", features = ["tick-hz-10_000"] }
+# embassy-time = { version = "0.4.0", features = ["tick-hz-100"] }
+
+# Dependencies that are used by build.rs.
+[build-dependencies]
+zephyr-build = "0.1.0"
+
+[profile.release]
+debug-assertions = true
+overflow-checks = true
+debug = true

samples/work-philosophers/Kconfig renamed to samples/async-philosophers/Kconfig

@@ -7,6 +7,7 @@ CONFIG_MAIN_STACK_SIZE=8192
 CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096
 
 CONFIG_POLL=y
+CONFIG_STACK_CANARIES=y
 
 # CONFIG_DEBUG=y
 

samples/work-philosophers/boards/rpi_pico.conf renamed to samples/async-philosophers/boards/rpi_pico.conf

@@ -1,6 +1,6 @@
 sample:
-  description: Philosphers, in Rust
-  name: workq philosophers rust
+  description: Async Philosphers, in Rust
+  name: async philosophers rust
 common:
   harness: console
   harness_config:

samples/work-philosophers/build.rs renamed to samples/async-philosophers/build.rs

@@ -0,0 +1,98 @@
+//! Async Semaphore based demo
+//!
+//! This implementation on the dining philosopher problem uses Zephyr semaphores to represent the
+//! forks.  Each philosopher dines as per the algorithm a number of times, and when the are all
+//! finished, the test is considered successful.  Deadlock will result in the primary thread not
+//! completing.
+//!
+//! Notably, this uses Rc and RefCell along with spawn_local to demonstrate that multiple async
+//! tasks run on the same worker do not need Send.  It is just important that write operations on
+//! the RefCell do not `.await` or a panic is likely.
+
+use embassy_executor::Spawner;
+use embassy_sync::{
+    blocking_mutex::raw::CriticalSectionRawMutex,
+    mutex::Mutex,
+    semaphore::{FairSemaphore, Semaphore},
+};
+use embassy_time::Timer;
+use zephyr::{printkln, sync::Arc};
+
+use crate::{get_random_delay, ResultSignal, Stats, NUM_PHIL};
+
+type ESemaphore = FairSemaphore<CriticalSectionRawMutex, NUM_PHIL>;
+
+/// The semaphores for the forks.
+static FORKS: [ESemaphore; NUM_PHIL] = [const { ESemaphore::new(1) }; NUM_PHIL];
+
+/// The semaphore to wait for them all to finish.
+static DONE_SEM: ESemaphore = ESemaphore::new(0);
+
+/// Number of iterations of each philospher.
+///
+/// Should be long enough to exercise the test, but too
+/// long and the test will timeout.  The delay calculated will randomly be between 25 and 775, and
+/// there are two waits, so typically, each "eat" will take about a second.
+const EAT_COUNT: usize = 10;
+
+#[embassy_executor::task]
+pub async fn phil(spawner: Spawner, stats_sig: &'static ResultSignal) {
+    // Our overall stats.
+    let stats = Arc::new(Mutex::new(Stats::default()));
+
+    // Spawn off each philosopher.
+    for i in 0..NUM_PHIL {
+        let forks = if i == NUM_PHIL - 1 {
+            [&FORKS[0], &FORKS[i]]
+        } else {
+            [&FORKS[i], &FORKS[i + 1]]
+        };
+
+        spawner.spawn(one_phil(forks, i, stats.clone())).unwrap();
+    }
+
+    // Wait for them all to finish.
+    DONE_SEM.acquire(NUM_PHIL).await.unwrap();
+
+    // Send the stats back.
+    stats_sig.signal(stats);
+}
+
+/// Simulate a single philospher.
+///
+/// The forks must be ordered with the first fork having th lowest number, otherwise this will
+/// likely deadlock.
+///
+/// This will run for EAT_COUNT times, and then return.
+#[embassy_executor::task(pool_size = NUM_PHIL)]
+async fn one_phil(
+    forks: [&'static ESemaphore; 2],
+    n: usize,
+    stats: Arc<Mutex<CriticalSectionRawMutex, Stats>>,
+) {
+    for i in 0..EAT_COUNT {
+        // Acquire the forks.
+        // printkln!("Child {n} take left fork");
+        forks[0].acquire(1).await.unwrap().disarm();
+        // printkln!("Child {n} take right fork");
+        forks[1].acquire(1).await.unwrap().disarm();
+
+        // printkln!("Child {n} eating");
+        let delay = get_random_delay(n, 25);
+        Timer::after(delay).await;
+        stats.lock().await.record_eat(n, delay);
+
+        // Release the forks.
+        // printkln!("Child {n} giving up forks");
+        forks[1].release(1);
+        forks[0].release(1);
+
+        let delay = get_random_delay(n, 25);
+        Timer::after(delay).await;
+        stats.lock().await.record_think(n, delay);
+
+        printkln!("Philospher {n} finished eating time {i}");
+    }
+
+    DONE_SEM.release(1);
+}

samples/work-philosophers/prj.conf renamed to samples/async-philosophers/prj.conf

@@ -9,76 +9,59 @@
 
 extern crate alloc;
 
-use zephyr::{
-    kio::spawn,
-    kobj_define, printkln,
-    sync::Arc,
-    sys::uptime_get,
-    time::{Duration, Tick},
-    work::WorkQueueBuilder,
-};
+use embassy_executor::Spawner;
+use embassy_sync::{blocking_mutex::raw::CriticalSectionRawMutex, mutex::Mutex, signal::Signal};
+use embassy_time::Duration;
+use static_cell::StaticCell;
+use zephyr::{embassy::Executor, printkln, sync::Arc, sys::uptime_get};
 
 mod async_sem;
 
 /// How many philosophers.  There will be the same number of forks.
 const NUM_PHIL: usize = 6;
 
-/// Size of the stack for the work queue.
-const WORK_STACK_SIZE: usize = 2048;
-
 // The dining philosophers problem is a simple example of cooperation between multiple threads.
 // This implementation demonstrates a few ways that Zephyr's work-queues can be used to simulate
 // this problem.
 
 #[no_mangle]
 extern "C" fn rust_main() {
-    printkln!(
-        "Async/work-queue dining philosophers{}",
-        zephyr::kconfig::CONFIG_BOARD
-    );
+    printkln!("Async dining philosophers{}", zephyr::kconfig::CONFIG_BOARD);
     printkln!("Time tick: {}", zephyr::time::SYS_FREQUENCY);
 
-    // Create the work queue to run this.
-    let worker = Arc::new(
-        WorkQueueBuilder::new()
-            .set_priority(1)
-            .start(WORK_STACK.init_once(()).unwrap()),
-    );
-
-    // In addition, create a lower priority worker.
-    let lower_worker = Arc::new(
-        WorkQueueBuilder::new()
-            .set_priority(5)
-            .start(LOWER_WORK_STACK.init_once(()).unwrap()),
-    );
-
-    // It is important that work queues are not dropped, as they are persistent objects in the
-    // Zephyr world.
-    let _ = Arc::into_raw(lower_worker.clone());
-    let _ = Arc::into_raw(worker.clone());
+    let executor = EXECUTOR.init(Executor::new());
+    executor.run(|spawner| {
+        spawner.spawn(main(spawner)).unwrap();
+    })
+}
+
+static EXECUTOR: StaticCell<Executor> = StaticCell::new();
+
+type ResultSignal = Signal<CriticalSectionRawMutex, Arc<Mutex<CriticalSectionRawMutex, Stats>>>;
+static RESULT_SIGNAL: ResultSignal = Signal::new();
 
+#[embassy_executor::task]
+async fn main(spawner: Spawner) -> () {
     // First run the async semaphore based one.
     printkln!("Running 'async-sem' test");
-    let handle = spawn(async_sem::phil(), &worker, c"async-sem");
-    let stats = handle.join();
+    spawner
+        .spawn(async_sem::phil(spawner, &RESULT_SIGNAL))
+        .unwrap();
+
+    let stats = RESULT_SIGNAL.wait().await;
     printkln!("Done with 'async-sem' test");
-    stats.show();
+    stats.lock().await.show();
 
     printkln!("All threads done");
 }
 
-kobj_define! {
-    static WORK_STACK: ThreadStack<WORK_STACK_SIZE>;
-    static LOWER_WORK_STACK: ThreadStack<WORK_STACK_SIZE>;
-}
-
 /// Get a random delay, based on the ID of this user, and the current uptime.
 fn get_random_delay(id: usize, period: usize) -> Duration {
-    let tick = (uptime_get() & (usize::MAX as i64)) as usize;
-    let delay = (tick / 100 * (id + 1)) & 0x1f;
+    let tick = (uptime_get() & (usize::MAX as i64)) as u64;
+    let delay = (tick / 100 * (id as u64 + 1)) & 0x1f;
 
     // Use one greater to be sure to never get a delay of zero.
-    Duration::millis_at_least(((delay + 1) * period) as Tick)
+    Duration::from_millis((delay + 1) * (period as u64))
 }
 
 /// Instead of just printint out so much information that the data just scolls by, gather
@@ -95,11 +78,11 @@ struct Stats {
 
 impl Stats {
     fn record_eat(&mut self, index: usize, time: Duration) {
-        self.eating[index] += time.to_millis();
+        self.eating[index] += time.as_millis();
     }
 
     fn record_think(&mut self, index: usize, time: Duration) {
-        self.thinking[index] += time.to_millis();
+        self.thinking[index] += time.as_millis();
         self.count[index] += 1;
     }
 

samples/work-philosophers/sample.yaml renamed to samples/async-philosophers/sample.yaml

@@ -13,11 +13,18 @@ license = "Apache-2.0 or MIT"
 crate-type = ["staticlib"]
 
 [dependencies]
-zephyr = "0.1.0"
+zephyr = { version = "0.1.0", features = ["time-driver", "executor-zephyr"] }
 critical-section = "1.1.2"
 heapless = "0.8"
 static_cell = "2.1"
 
+embassy-executor = { version = "0.7.0", features = ["log", "task-arena-size-2048"] }
+embassy-sync = "0.6.2"
+embassy-futures = "0.1.1"
+
+# Hard code the tick rate.
+embassy-time = { version = "0.4.0", features = ["tick-hz-10_000"] }
+
 # Dependencies that are used by build.rs.
 [build-dependencies]
 zephyr-build = "0.1.0"