time: remove dependency on embassy-sync.

embassy-time/Cargo.toml

@@ -156,7 +156,6 @@ embedded-hal-1 = { package = "embedded-hal", version = "=1.0.0-alpha.10", option
 embedded-hal-async = { version = "=0.2.0-alpha.1", optional = true}
 
 futures-util = { version = "0.3.17", default-features = false }
-embassy-sync = { version = "0.2.0", path = "../embassy-sync" }
 atomic-polyfill = "1.0.1"
 critical-section = "1.1"
 cfg-if = "1.0.0"

embassy-time/src/driver_std.rs

@@ -5,8 +5,7 @@ use std::time::{Duration as StdDuration, Instant as StdInstant};
 use std::{mem, ptr, thread};
 
 use atomic_polyfill::{AtomicU8, Ordering};
-use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
+use critical_section::Mutex as CsMutex;
-use embassy_sync::blocking_mutex::Mutex as EmbassyMutex;
 
 use crate::driver::{AlarmHandle, Driver};
 
@@ -40,7 +39,7 @@ struct TimeDriver {
     // The STD Driver implementation requires the alarms' mutex to be reentrant, which the STD Mutex isn't
     // Fortunately, mutexes based on the `critical-section` crate are reentrant, because the critical sections
     // themselves are reentrant
-    alarms: UninitCell<EmbassyMutex<CriticalSectionRawMutex, RefCell<[AlarmState; ALARM_COUNT]>>>,
+    alarms: UninitCell<CsMutex<RefCell<[AlarmState; ALARM_COUNT]>>>,
     zero_instant: UninitCell<StdInstant>,
     signaler: UninitCell<Signaler>,
 }
@@ -58,8 +57,7 @@ crate::time_driver_impl!(static DRIVER: TimeDriver = TimeDriver {
 impl TimeDriver {
     fn init(&self) {
         self.once.call_once(|| unsafe {
-            self.alarms
+            self.alarms.write(CsMutex::new(RefCell::new([ALARM_NEW; ALARM_COUNT])));
-                .write(EmbassyMutex::new(RefCell::new([ALARM_NEW; ALARM_COUNT])));
             self.zero_instant.write(StdInstant::now());
             self.signaler.write(Signaler::new());
 
@@ -72,7 +70,8 @@ impl TimeDriver {
         loop {
             let now = DRIVER.now();
 
-            let next_alarm = unsafe { DRIVER.alarms.as_ref() }.lock(|alarms| {
+            let next_alarm = critical_section::with(|cs| {
+                let alarms = unsafe { DRIVER.alarms.as_ref() }.borrow(cs);
                 loop {
                     let pending = alarms
                         .borrow_mut()
@@ -139,8 +138,8 @@ impl Driver for TimeDriver {
 
     fn set_alarm_callback(&self, alarm: AlarmHandle, callback: fn(*mut ()), ctx: *mut ()) {
         self.init();
-        unsafe { self.alarms.as_ref() }.lock(|alarms| {
+        critical_section::with(|cs| {
-            let mut alarms = alarms.borrow_mut();
+            let mut alarms = unsafe { self.alarms.as_ref() }.borrow_ref_mut(cs);
             let alarm = &mut alarms[alarm.id() as usize];
             alarm.callback = callback as *const ();
             alarm.ctx = ctx;
@@ -149,9 +148,8 @@ impl Driver for TimeDriver {
 
     fn set_alarm(&self, alarm: AlarmHandle, timestamp: u64) -> bool {
         self.init();
-        unsafe { self.alarms.as_ref() }.lock(|alarms| {
+        critical_section::with(|cs| {
-            let mut alarms = alarms.borrow_mut();
+            let mut alarms = unsafe { self.alarms.as_ref() }.borrow_ref_mut(cs);
-
             let alarm = &mut alarms[alarm.id() as usize];
             alarm.timestamp = timestamp;
             unsafe { self.signaler.as_ref() }.signal();

embassy-time/src/queue_generic.rs

@@ -2,8 +2,7 @@ use core::cell::RefCell;
 use core::cmp::{min, Ordering};
 use core::task::Waker;
 
-use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
+use critical_section::Mutex;
-use embassy_sync::blocking_mutex::Mutex;
 use heapless::Vec;
 
 use crate::driver::{allocate_alarm, set_alarm, set_alarm_callback, AlarmHandle};
@@ -129,7 +128,7 @@ impl InnerQueue {
 }
 
 struct Queue {
-    inner: Mutex<CriticalSectionRawMutex, RefCell<Option<InnerQueue>>>,
+    inner: Mutex<RefCell<Option<InnerQueue>>>,
 }
 
 impl Queue {
@@ -140,8 +139,8 @@ impl Queue {
     }
 
     fn schedule_wake(&'static self, at: Instant, waker: &Waker) {
-        self.inner.lock(|inner| {
+        critical_section::with(|cs| {
-            let mut inner = inner.borrow_mut();
+            let mut inner = self.inner.borrow_ref_mut(cs);
 
             if inner.is_none() {}
 
@@ -159,8 +158,7 @@ impl Queue {
     }
 
     fn handle_alarm(&self) {
-        self.inner
+        critical_section::with(|cs| self.inner.borrow_ref_mut(cs).as_mut().unwrap().handle_alarm())
-            .lock(|inner| inner.borrow_mut().as_mut().unwrap().handle_alarm());
     }
 
     fn handle_alarm_callback(ctx: *mut ()) {