| use crate::sys::condvar as imp; |
| use crate::sys_common::mutex::{self, Mutex}; |
| use crate::time::Duration; |
| |
| /// An OS-based condition variable. |
| /// |
| /// This structure is the lowest layer possible on top of the OS-provided |
| /// condition variables. It is consequently entirely unsafe to use. It is |
| /// recommended to use the safer types at the top level of this crate instead of |
| /// this type. |
| pub struct Condvar(imp::Condvar); |
| |
| impl Condvar { |
| /// Creates a new condition variable for use. |
| /// |
| /// Behavior is undefined if the condition variable is moved after it is |
| /// first used with any of the functions below. |
| pub const fn new() -> Condvar { |
| Condvar(imp::Condvar::new()) |
| } |
| |
| /// Prepares the condition variable for use. |
| /// |
| /// This should be called once the condition variable is at a stable memory |
| /// address. |
| #[inline] |
| pub unsafe fn init(&mut self) { |
| self.0.init() |
| } |
| |
| /// Signals one waiter on this condition variable to wake up. |
| #[inline] |
| pub unsafe fn notify_one(&self) { |
| self.0.notify_one() |
| } |
| |
| /// Awakens all current waiters on this condition variable. |
| #[inline] |
| pub unsafe fn notify_all(&self) { |
| self.0.notify_all() |
| } |
| |
| /// Waits for a signal on the specified mutex. |
| /// |
| /// Behavior is undefined if the mutex is not locked by the current thread. |
| /// Behavior is also undefined if more than one mutex is used concurrently |
| /// on this condition variable. |
| #[inline] |
| pub unsafe fn wait(&self, mutex: &Mutex) { |
| self.0.wait(mutex::raw(mutex)) |
| } |
| |
| /// Waits for a signal on the specified mutex with a timeout duration |
| /// specified by `dur` (a relative time into the future). |
| /// |
| /// Behavior is undefined if the mutex is not locked by the current thread. |
| /// Behavior is also undefined if more than one mutex is used concurrently |
| /// on this condition variable. |
| #[inline] |
| pub unsafe fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool { |
| self.0.wait_timeout(mutex::raw(mutex), dur) |
| } |
| |
| /// Deallocates all resources associated with this condition variable. |
| /// |
| /// Behavior is undefined if there are current or will be future users of |
| /// this condition variable. |
| #[inline] |
| pub unsafe fn destroy(&self) { |
| self.0.destroy() |
| } |
| } |