Refactor Condvar.

library/std/src/sys/unix/condvar.rs

@@ -30,7 +30,6 @@ impl Condvar {
  target_os = "ios",
  target_os = "l4re",
  target_os = "android",
- target_os = "freertos",
  target_os = "redox"
  ))]
  pub unsafe fn init(&mut self) {}
@@ -40,7 +39,6 @@ impl Condvar {
  target_os = "ios",
  target_os = "l4re",
  target_os = "android",
- target_os = "freertos",
  target_os = "redox"
  )))]
  pub unsafe fn init(&mut self) {

library/std/src/sys/unix/freertos/condvar.rs

@@ -17,32 +17,27 @@ unsafe impl Sync for Condvar {}
 
 impl Condvar {
  pub const fn new() -> Condvar {
- // Might be moved and address is changing it is better to avoid
- // initialization of potentially opaque OS data before it landed
  Condvar {
  lock: unsafe { ReentrantMutex::uninitialized() },
  waiter_list: UnsafeCell::new(None),
  }
  }
 
  #[inline]
- pub unsafe fn init(&mut self) {}
-
- #[inline]
- unsafe fn init_waiter_list(&self) {
- if (*self.waiter_list.get()).is_none() {
- (*self.waiter_list.get()) = Some(VecDeque::new());
- }
+ pub unsafe fn init(&mut self) {
+ self.waiter_list.get_mut().replace(VecDeque::new());
  }
 
  #[inline]
  pub unsafe fn notify_one(&self) {
  self.lock.lock();
 
- self.init_waiter_list();
- let waiter_list = (&*self.waiter_list.get()).as_ref().unwrap();
- if let Some(&waiter) = waiter_list.front() {
- xSemaphoreGive(waiter);
+ if let Some(waiter_list) = (&*self.waiter_list.get()).as_ref() {
+ if let Some(&waiter) = waiter_list.front() {
+ xSemaphoreGive(waiter);
+ }
+ } else {
+ core::hint::unreachable_unchecked();
  }
 
  self.lock.unlock();
@@ -52,10 +47,12 @@ impl Condvar {
  pub unsafe fn notify_all(&self) {
  self.lock.lock();
 
- self.init_waiter_list();
- let waiter_list = (&*self.waiter_list.get()).as_ref().unwrap();
- for &waiter in waiter_list {
- xSemaphoreGive(waiter);
+ if let Some(waiter_list) = (&*self.waiter_list.get()).as_ref() {
+ for &waiter in waiter_list {
+ xSemaphoreGive(waiter);
+ }
+ } else {
+ core::hint::unreachable_unchecked();
  }
 
  self.lock.unlock();
@@ -88,9 +85,11 @@ impl Condvar {
 
  self.lock.lock();
 
- self.init_waiter_list();
- let waiter_list = (&mut *self.waiter_list.get()).as_mut().unwrap();
- waiter_list.push_back(waiter);
+ if let Some(waiter_list) = (&mut *self.waiter_list.get()).as_mut() {
+ waiter_list.push_back(waiter);
+ } else {
+ core::hint::unreachable_unchecked();
+ }
 
  self.lock.unlock();
 
@@ -104,18 +103,19 @@ impl Condvar {
 
  self.lock.lock();
 
- let waiter_list = (&mut *self.waiter_list.get()).as_mut().unwrap();
- let deleted_waiter = if let Some(index) = waiter_list.iter().position(|&w| w == waiter) {
- waiter_list.remove(index)
+ if let Some(waiter_list) = (&mut *self.waiter_list.get()).as_mut() {
+ if let Some(index) = waiter_list.iter().position(|&w| w == waiter) {
+ waiter_list.remove(index);
+ } else {
+ core::hint::unreachable_unchecked();
+ }
  } else {
- None
- };
+ core::hint::unreachable_unchecked();
+ }
 
  self.lock.unlock();
 
- if let Some(deleted_waiter) = deleted_waiter {
- vSemaphoreDelete(deleted_waiter);
- }
+ vSemaphoreDelete(waiter);
 
  mutex.lock();
 
@@ -128,12 +128,17 @@ impl Condvar {
 
  #[inline]
  pub unsafe fn destroy(&self) {
+ #[cfg(debug)]
+ {
  self.lock.lock();
 
- if let Some(waiter_list) = (&*self.waiter_list.get()).as_ref() {
- assert!(waiter_list.is_empty());
+ if let Some(waiter_list) = (&*self.waiter_list.get()).as_mut() {
+ debug_assert!(waiter_list.is_empty());
+ } else {
+ core::hint::unreachable_unchecked();
  }
 
  self.lock.unlock();
+ }
  }
 }