1 #![deny(unsafe_op_in_unsafe_fn)]
3 use crate::ffi::c_void;
5 use crate::sync::atomic::{AtomicUsize, Ordering::SeqCst};
6 use crate::sys::hermit::abi;
7 use crate::sys::mutex::Mutex;
8 use crate::time::Duration;
10 // The implementation is inspired by Andrew D. Birrell's paper
11 // "Implementing Condition Variables with Semaphores"
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) {
29 let _ = abi::sem_init(&mut self.sem1 as *mut *const c_void, 0);
30 let _ = abi::sem_init(&mut self.sem2 as *mut *const c_void, 0);
34 pub unsafe fn notify_one(&self) {
35 if self.counter.load(SeqCst) > 0 {
36 self.counter.fetch_sub(1, SeqCst);
38 abi::sem_post(self.sem1);
39 abi::sem_timedwait(self.sem2, 0);
44 pub unsafe fn notify_all(&self) {
45 let counter = self.counter.swap(0, SeqCst);
48 abi::sem_post(self.sem1);
53 abi::sem_timedwait(self.sem2, 0);
58 pub unsafe fn wait(&self, mutex: &Mutex) {
59 self.counter.fetch_add(1, SeqCst);
62 abi::sem_timedwait(self.sem1, 0);
63 abi::sem_post(self.sem2);
68 pub unsafe fn wait_timeout(&self, _mutex: &Mutex, _dur: Duration) -> bool {
69 panic!("wait_timeout not supported on hermit");
72 pub unsafe fn destroy(&self) {
74 let _ = abi::sem_destroy(self.sem1);
75 let _ = abi::sem_destroy(self.sem2);