How to stop my tokio thread from blocking - rust

Question

I am writing a client for a Unix Domain Socket, which should listen for messages from a server, I got it to work after hours of researching (it shows 1-2 messages), but after that tokio crashes with the error: Error: Kind(WouldBlock), here is my code:
use std::env::{var, VarError};
use std::io::{self, Write};
use tokio::net::UnixStream;
#[tokio::main]
async fn main() -> io::Result<()> {
let hypr_instance_sig = match var("HYPRLAND_INSTANCE_SIGNATURE") {
Ok(var) => var,
Err(VarError::NotPresent) => panic!("Is hyprland running?"),
Err(VarError::NotUnicode(_)) => panic!("wtf no unicode?"),
};
let socket_path = format!("/tmp/hypr/{hypr_instance_sig}/.socket2.sock");
let stream = UnixStream::connect(socket_path).await?;
loop {
stream.readable().await?;
let mut buf = [0; 4096];
stream.try_read(&mut buf)?;
io::stdout().lock().write_all(&buf)?;
}
}
Could someone please help me?

Answer 1

I fully agree with #Caesar's comment.
don't use try_read, use read instead
slice the buffer to the correct size after reading
check for 0 bytes read, which indicates that the end of the stream was reached
use std::env::{var, VarError};
use std::io::{self, Write};
use tokio::io::AsyncReadExt;
use tokio::net::UnixStream;
#[tokio::main]
async fn main() -> io::Result<()> {
let hypr_instance_sig = match var("HYPRLAND_INSTANCE_SIGNATURE") {
Ok(var) => var,
Err(VarError::NotPresent) => panic!("Is hyprland running?"),
Err(VarError::NotUnicode(_)) => panic!("wtf no unicode?"),
};
let socket_path = format!("/tmp/hypr/{hypr_instance_sig}/.socket2.sock");
let mut stream = UnixStream::connect(socket_path).await?;
let mut buf = [0; 4096];
loop {
let num_read = stream.read(&mut buf).await?;
if num_read == 0 {
break;
}
let buf = &buf[..num_read];
io::stdout().lock().write_all(buf)?;
}
Ok(())
}
Disclaimer: I didn't test the code because I don't have the required socket file. It compiles, though.