4lDO2
108 lines
2.9 KiB
Rust
108 lines
2.9 KiB
Rust
use alloc::collections::VecDeque;
|
|
use spin::Mutex;
|
|
use syscall::{EAGAIN, EINTR};
|
|
|
|
use crate::{
|
|
sync::WaitCondition,
|
|
syscall::{
|
|
error::{Error, Result, EINVAL},
|
|
usercopy::UserSliceWo,
|
|
},
|
|
};
|
|
|
|
#[derive(Debug)]
|
|
pub struct WaitQueue<T> {
|
|
pub inner: Mutex<VecDeque<T>>,
|
|
pub condition: WaitCondition,
|
|
}
|
|
|
|
impl<T> WaitQueue<T> {
|
|
pub const fn new() -> WaitQueue<T> {
|
|
WaitQueue {
|
|
inner: Mutex::new(VecDeque::new()),
|
|
condition: WaitCondition::new(),
|
|
}
|
|
}
|
|
pub fn is_currently_empty(&self) -> bool {
|
|
self.inner.lock().is_empty()
|
|
}
|
|
|
|
pub fn receive(&self, block: bool, reason: &'static str) -> Result<T> {
|
|
loop {
|
|
let mut inner = self.inner.lock();
|
|
|
|
if let Some(t) = inner.pop_front() {
|
|
return Ok(t);
|
|
} else if block {
|
|
if !self.condition.wait(inner, reason) {
|
|
return Err(Error::new(EINTR));
|
|
}
|
|
continue;
|
|
} else {
|
|
return Err(Error::new(EAGAIN));
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn receive_into_user(
|
|
&self,
|
|
buf: UserSliceWo,
|
|
block: bool,
|
|
reason: &'static str,
|
|
) -> Result<usize> {
|
|
loop {
|
|
let mut inner = self.inner.lock();
|
|
|
|
if inner.is_empty() {
|
|
if block {
|
|
if !self.condition.wait(inner, reason) {
|
|
return Err(Error::new(EINTR));
|
|
}
|
|
continue;
|
|
} else if buf.is_empty() {
|
|
return Ok(0);
|
|
} else if buf.len() < core::mem::size_of::<T>() {
|
|
return Err(Error::new(EINVAL));
|
|
} else {
|
|
// TODO: EWOULDBLOCK?
|
|
return Err(Error::new(EAGAIN));
|
|
}
|
|
}
|
|
|
|
let (s1, s2) = inner.as_slices();
|
|
let s1_bytes = unsafe {
|
|
core::slice::from_raw_parts(
|
|
s1.as_ptr().cast::<u8>(),
|
|
s1.len() * core::mem::size_of::<T>(),
|
|
)
|
|
};
|
|
let s2_bytes = unsafe {
|
|
core::slice::from_raw_parts(
|
|
s2.as_ptr().cast::<u8>(),
|
|
s2.len() * core::mem::size_of::<T>(),
|
|
)
|
|
};
|
|
|
|
let mut bytes_copied = buf.copy_common_bytes_from_slice(s1_bytes)?;
|
|
|
|
if let Some(buf_for_s2) = buf.advance(s1_bytes.len()) {
|
|
bytes_copied += buf_for_s2.copy_common_bytes_from_slice(s2_bytes)?;
|
|
}
|
|
|
|
let _ = inner.drain(..bytes_copied / core::mem::size_of::<T>());
|
|
|
|
return Ok(bytes_copied);
|
|
}
|
|
}
|
|
|
|
pub fn send(&self, value: T) -> usize {
|
|
let len = {
|
|
let mut inner = self.inner.lock();
|
|
inner.push_back(value);
|
|
inner.len()
|
|
};
|
|
self.condition.notify();
|
|
len
|
|
}
|
|
}
|