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use crate::execute_delay;
use crate::options::Options;
use crate::response::build_response;
use crate::PORT_COUNTERS;
use crate::REQUESTS;
use crate::REQUEST_BYTES;
use crate::RESPONSES;
use crate::RESPONSE_BYTES;
use crate::ServerConfig;
use crate::create_listener;
use anyhow::Result;
use compio::io::{AsyncRead, AsyncWriteExt};
use compio::net::TcpListener;
use futures::stream::{select_all, unfold, StreamExt};
use std::mem::MaybeUninit;
use std::net::SocketAddr;
use std::sync::Arc;
use std::time::Duration;
use tracing::error;
pub fn run_thread(
id: usize,
addrs: Vec<SocketAddr>,
config: Arc<ServerConfig>,
opts: &Options,
) -> Result<()> {
use tracing::info;
let delay = opts.delay;
let meter = opts.meter;
let tcp_nodelay = opts.tcp_nodelay;
let rt = compio::runtime::Runtime::new()?;
rt.block_on(async move {
// Create compio listeners from std listeners (SO_REUSEPORT already configured)
let mut listeners = Vec::new();
for addr in &addrs {
let std_listener = match create_listener(*addr, opts) {
Ok(l) => l,
Err(e) => {
error!("Failed to create listener for {}: {}", addr, e);
return;
}
};
let listener = match TcpListener::from_std(std_listener) {
Ok(l) => l,
Err(e) => {
error!("Failed to create compio listener: {}", e);
return;
}
};
listeners.push(listener);
}
info!("Thread {} listening on {:?} (compio)", id, addrs);
// Convert each listener into a stream using unfold
// compio's TcpListener is !Send, but that's fine since everything stays
// on this thread's single-threaded runtime.
let streams: Vec<_> = listeners
.into_iter()
.map(|listener| {
let port = listener.local_addr().unwrap().port();
Box::pin(unfold(listener, move |l| async move {
match l.accept().await {
Ok((stream, _addr)) => Some((Ok((stream, port)), l)),
Err(e) => Some((Err(e), l)),
}
}))
})
.collect();
// Fan-in all listener streams into one
let mut all_listeners = select_all(streams);
loop {
let (stream, port) = match all_listeners.next().await {
Some(Ok(s)) => s,
Some(Err(e)) => {
error!("Thread {} accept error: {}", id, e);
continue;
}
None => {
error!("Thread {} all listeners closed", id);
break;
}
};
// Apply TCP_NODELAY for lower latency if requested
if tcp_nodelay {
if let Err(e) = stream.set_nodelay(true) {
error!("Failed to set TCP_NODELAY: {}", e);
}
}
let config = config.clone();
// Spawn a local task to handle the connection.
// compio's spawn() only requires F: Future + 'static (not Send),
// so !Send types like TcpStream are perfectly fine here.
// Task::detach() lets the task run to completion independently.
compio::runtime::spawn(async move {
if let Err(e) =
handle_connection_compio(stream, port, config, meter, delay).await
{
error!("Error handling compio connection: {}", e);
}
})
.detach();
}
});
Ok(())
}
async fn handle_connection_compio(
mut stream: compio::net::TcpStream,
port: u16,
config: Arc<ServerConfig>,
meter: bool,
delay: Option<Duration>,
) -> Result<usize> {
use http_wire::WireDecode;
let mut response_buf = build_response(&config)?;
// Single buffer strategy for maximum performance:
// - In the common case (complete request in one read), we parse directly with zero copies
// - Only compact when we have leftover data from incomplete requests (rare case)
let mut buf: Vec<u8> = Vec::with_capacity(8192);
let mut parsed = 0; // Number of bytes already parsed/consumed
let mut requests_served = 0;
loop {
// FAST PATH: If we've consumed all data, reset the buffer (zero-cost operation)
if parsed == buf.len() && parsed > 0 {
unsafe {
buf.set_len(0);
}
parsed = 0;
}
// SLOW PATH: If we have many dead bytes at the beginning, compact the buffer.
// This only happens when requests are split across multiple reads (rare).
else if parsed > 4096 {
buf.copy_within(parsed.., 0);
unsafe {
buf.set_len(buf.len() - parsed);
}
parsed = 0;
}
// Ensure we have enough spare capacity for reading.
// Only reserve if needed to avoid unnecessary allocations in the common case.
let current_len = buf.len();
if buf.capacity() - current_len < 4096 {
buf.reserve(4096);
}
// TRICK: Create a temporary Vec from the spare capacity for compio's ownership-based API.
//
// Compio, like monoio, is a completion-based runtime (hence the name): buffers are
// handed off to io_uring by value and returned together with the result.
// This means we cannot pass a raw &mut slice — we must pass an owned buffer implementing IoBufMut.
//
// We create a zero-length Vec that *points into* our main buffer's spare capacity.
// IoBufMut for Vec<u8> will read/write starting at buf.as_mut_ptr() + buf.len(),
// which is exactly where we want new data to land. After the await:
// - we mem::forget to avoid a double-free (it aliases buf's memory)
// - we manually advance buf's length by the number of bytes read
let spare_cap = buf.capacity() - current_len;
let temp_buf =
unsafe { Vec::from_raw_parts(buf.as_mut_ptr().add(current_len), 0, spare_cap) };
let compio::BufResult(result, temp_buf) = stream.read(temp_buf).await;
// Forget the alias to avoid double-free; buf retains ownership of the memory
std::mem::forget(temp_buf);
let n = match result {
Ok(0) => break, // EOF — remote closed the connection
Ok(n) => n,
Err(e) => return Err(anyhow::Error::new(e)),
};
// Extend the main buffer to include the newly read bytes
unsafe {
buf.set_len(current_len + n);
}
// Parse all complete requests present in the buffer.
// This handles HTTP pipelining: multiple requests arriving in a single read.
let mut headers = [const { MaybeUninit::uninit() }; 128];
loop {
match http_wire::request::FullRequest::decode_uninit(&buf[parsed..], &mut headers) {
Ok((_, req_len)) => {
requests_served += 1;
parsed += req_len;
if meter {
REQUESTS.add(1);
REQUEST_BYTES.add(req_len);
let entry = PORT_COUNTERS.entry(port).or_default();
entry.requests.add(1);
entry.request_bytes.add(req_len);
}
if let Some(d) = delay {
execute_delay(d).await;
}
// write_all transfers ownership of response_buf to io_uring, then returns
// it back in the BufResult — identical ownership dance to monoio.
let compio::BufResult(res, buf_back) = stream.write_all(response_buf).await;
response_buf = buf_back;
res?;
if meter {
RESPONSES.add(1);
RESPONSE_BYTES.add(response_buf.len());
let entry = PORT_COUNTERS.entry(port).or_default();
entry.responses.add(1);
entry.response_bytes.add(response_buf.len());
}
}
Err(_) => break, // Incomplete request — wait for more data
}
}
}
Ok(requests_served)
}