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use std::{
io::{Read, Write},
marker::PhantomData,
time::Duration,
};
use rmp_serde::decode;
use serde::{de::DeserializeOwned, Serialize};
use thiserror::Error;
use crate::{
host_api::{message, process},
tag::Tag,
};
const SIGNAL: u32 = 1;
const TIMEOUT: u32 = 9027;
#[derive(Debug)]
pub struct Mailbox<T: Serialize + DeserializeOwned> {
_phantom: PhantomData<T>,
}
impl<T: Serialize + DeserializeOwned> Mailbox<T> {
pub unsafe fn new() -> Self {
Self {
_phantom: PhantomData {},
}
}
pub fn receive(&self) -> Result<T, ReceiveError> {
self.receive_(None, None)
}
pub fn receive_timeout(&self, timeout: Duration) -> Result<T, ReceiveError> {
self.receive_(None, Some(timeout))
}
pub fn receive_with_tag(&self) -> Result<(T, Tag), ReceiveError> {
let message = self.receive_(None, None)?;
let tag = unsafe { message::get_tag() };
Ok((message, Tag::from(tag)))
}
pub fn tag_receive(&self, tag: Tag) -> Result<T, ReceiveError> {
self.receive_(Some(tag.id()), None)
}
pub fn tag_receive_timeout(&self, tag: Tag, timeout: Duration) -> Result<T, ReceiveError> {
self.receive_(Some(tag.id()), Some(timeout))
}
fn receive_(&self, tag: Option<i64>, timeout: Option<Duration>) -> Result<T, ReceiveError> {
let tag = tag.unwrap_or(0);
let timeout_ms = match timeout {
Some(timeout) => match timeout.as_millis() {
0 => 1,
other => other as u32,
},
None => 0,
};
let message_type = unsafe { message::receive(tag, timeout_ms) };
assert_ne!(message_type, SIGNAL);
if message_type == TIMEOUT {
return Err(ReceiveError::Timeout);
}
match rmp_serde::from_read(MessageRw {}) {
Ok(result) => Ok(result),
Err(decode_error) => Err(ReceiveError::DeserializationFailed(decode_error)),
}
}
}
impl<T: Serialize + DeserializeOwned> TransformMailbox<T> for Mailbox<T> {
fn catch_link_panic(self) -> LinkMailbox<T> {
unsafe { process::die_when_link_dies(0) };
LinkMailbox::new()
}
fn panic_if_link_panics(self) -> Mailbox<T> {
self
}
}
#[derive(Debug)]
pub struct LinkMailbox<T: Serialize + DeserializeOwned> {
_phantom: PhantomData<T>,
}
impl<T: Serialize + DeserializeOwned> LinkMailbox<T> {
pub(crate) fn new() -> Self {
Self {
_phantom: PhantomData {},
}
}
pub fn receive(&self) -> Message<T> {
self.receive_(None, None)
}
pub fn receive_timeout(&self, timeout: Duration) -> Message<T> {
self.receive_(None, Some(timeout))
}
pub fn tag_receive(&self, tag: Tag) -> Message<T> {
self.receive_(Some(tag.id()), None)
}
pub fn tag_receive_timeout(&self, tag: Tag, timeout: Duration) -> Message<T> {
self.receive_(Some(tag.id()), Some(timeout))
}
fn receive_(&self, tag: Option<i64>, timeout: Option<Duration>) -> Message<T> {
let tag = tag.unwrap_or(0);
let timeout_ms = match timeout {
Some(timeout) => match timeout.as_millis() {
0 => 1,
other => other as u32,
},
None => 0,
};
let message_type = unsafe { message::receive(tag, timeout_ms) };
if message_type == SIGNAL {
let tag = unsafe { message::get_tag() };
return Message::Signal(Tag::from(tag));
}
else if message_type == TIMEOUT {
return Message::Normal(Err(ReceiveError::Timeout));
}
let message = match rmp_serde::from_read(MessageRw {}) {
Ok(result) => Ok(result),
Err(decode_error) => Err(ReceiveError::DeserializationFailed(decode_error)),
};
Message::Normal(message)
}
}
impl<T: Serialize + DeserializeOwned> TransformMailbox<T> for LinkMailbox<T> {
fn catch_link_panic(self) -> LinkMailbox<T> {
self
}
fn panic_if_link_panics(self) -> Mailbox<T> {
unsafe { process::die_when_link_dies(1) };
unsafe { Mailbox::new() }
}
}
#[derive(Error, Debug)]
pub enum ReceiveError {
#[error("Deserialization failed")]
DeserializationFailed(#[from] decode::Error),
#[error("Timed out while waiting for message")]
Timeout,
}
#[derive(Debug)]
pub enum Message<T> {
Normal(Result<T, ReceiveError>),
Signal(Tag),
}
impl<T> Message<T> {
pub fn is_signal(&self) -> bool {
match self {
Message::Normal(_) => false,
Message::Signal(_) => true,
}
}
pub fn normal_or_unwrap(self) -> Result<T, ReceiveError> {
match self {
Message::Normal(message) => message,
Message::Signal(_) => panic!("Message is of type Signal"),
}
}
}
#[derive(Debug, Clone, Copy)]
pub struct Signal {}
pub trait TransformMailbox<T: Serialize + DeserializeOwned> {
fn catch_link_panic(self) -> LinkMailbox<T>;
fn panic_if_link_panics(self) -> Mailbox<T>;
}
pub(crate) struct MessageRw {}
impl Read for MessageRw {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
Ok(unsafe { message::read_data(buf.as_mut_ptr(), buf.len()) })
}
}
impl Write for MessageRw {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
Ok(unsafe { message::write_data(buf.as_ptr(), buf.len()) })
}
fn flush(&mut self) -> std::io::Result<()> {
Ok(())
}
}