1 use crate::ffi::c_void;
3 use crate::sync::atomic::{AtomicUsize, Ordering::SeqCst};
4 use crate::sys::hermit::abi;
5 use crate::sys::locks::Mutex;
6 use crate::time::Duration;
8 // The implementation is inspired by Andrew D. Birrell's paper
9 // "Implementing Condition Variables with Semaphores"
17 pub type MovableCondvar = Condvar;
19 unsafe impl Send for Condvar {}
20 unsafe impl Sync for Condvar {}
23 pub const fn new() -> Condvar {
24 Condvar { counter: AtomicUsize::new(0), sem1: ptr::null(), sem2: ptr::null() }
27 pub unsafe fn init(&mut self) {
28 let _ = abi::sem_init(&mut self.sem1 as *mut *const c_void, 0);
29 let _ = abi::sem_init(&mut self.sem2 as *mut *const c_void, 0);
32 pub unsafe fn notify_one(&self) {
33 if self.counter.load(SeqCst) > 0 {
34 self.counter.fetch_sub(1, SeqCst);
35 abi::sem_post(self.sem1);
36 abi::sem_timedwait(self.sem2, 0);
40 pub unsafe fn notify_all(&self) {
41 let counter = self.counter.swap(0, SeqCst);
43 abi::sem_post(self.sem1);
46 abi::sem_timedwait(self.sem2, 0);
50 pub unsafe fn wait(&self, mutex: &Mutex) {
51 self.counter.fetch_add(1, SeqCst);
53 abi::sem_timedwait(self.sem1, 0);
54 abi::sem_post(self.sem2);
58 pub unsafe fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool {
59 self.counter.fetch_add(1, SeqCst);
61 let millis = dur.as_millis().min(u32::MAX as u128) as u32;
63 let res = if millis > 0 {
64 abi::sem_timedwait(self.sem1, millis)
66 abi::sem_trywait(self.sem1)
69 abi::sem_post(self.sem2);
74 pub unsafe fn destroy(&self) {
75 let _ = abi::sem_destroy(self.sem1);
76 let _ = abi::sem_destroy(self.sem2);