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|
use mio::{Ready,Token,Event};
use mio::tcp::TcpListener;
use std::net::SocketAddr;
use std::io::{Result,ErrorKind};
use std::time::Duration;
use std::sync::{Arc,Mutex};
use eventloop::{Machine,Context,EventLoop,TToken,Action};
use config;
use itf_http;
struct ConnCount {
max: u32,
cnt: Mutex<u32>,
}
impl ConnCount {
fn new(max: u32) -> ConnCount {
ConnCount { max: max, cnt: Mutex::new(0) }
}
// Increases count and returns true if there is a slot free
fn acquire(&self) -> bool {
let mut cnt = self.cnt.lock().unwrap();
if *cnt >= self.max {
false
} else {
*cnt += 1;
true
}
}
fn release(&self) {
let mut cnt = self.cnt.lock().unwrap();
*cnt -= 1;
}
}
pub struct Interface {
connections: ConnCount,
global_connections: Arc<ConnCount>,
pub cfg: config::Interface,
}
impl Interface {
pub fn acquire(&self) -> bool {
if self.connections.acquire() {
if self.global_connections.acquire() {
return true;
} else {
self.connections.release();
}
}
false
}
// TODO: Using a guard object is much less error-prone than this manual release(), but needs
// either yet-another-Arc or unsafe code.
pub fn release(&self) {
self.connections.release();
self.global_connections.release();
}
}
struct Listener {
sock: TcpListener,
addr: SocketAddr,
io: Token,
timeout: TToken,
itf: Arc<Interface>,
}
impl Listener {
fn new(ctx: &mut Context, itf: Arc<Interface>, sock: TcpListener, addr: SocketAddr) -> Listener {
info!("Listening on {}", addr);
let io = ctx.register(&sock, Ready::readable());
Listener {
sock: sock,
addr: addr,
io: io,
timeout: ctx.alloc_timeout(),
itf: itf,
}
}
}
impl Machine for Listener {
fn handle(&mut self, ctx: &mut Context, _: Event) -> Option<Action> {
match self.sock.accept() {
Err(err) => {
match err.kind() {
ErrorKind::WouldBlock |
ErrorKind::Interrupted |
ErrorKind::TimedOut => { /* Uninteresting temporary errors */ },
_ => {
error!("Error accepting on {}: {}", self.addr, err);
// Stop listening for short time. If this error is not persistent (like
// EMFILE), it will solve itself by just waiting. Not much else we can do.
ctx.deregister(&self.sock, self.io);
ctx.reset_timeout(self.timeout, Duration::from_millis(500));
}
}
},
Ok((sock, addr)) => {
debug!("{}: New connection", addr);
if self.itf.acquire() {
let itf = self.itf.clone();
ctx.spawn(move|ctx| { Box::new(itf_http::ItfHttp::new(ctx, itf.clone(), sock, addr)) });
} else {
// TODO: Specify which connection limit
warn!("Connection limit reached, consider increasing max-connections.");
}
}
}
None
}
fn timeout(&mut self, ctx: &mut Context, _: TToken) -> Option<Action> {
self.io = ctx.register(&self.sock, Ready::readable());
None
}
}
pub fn setup(ev: &mut EventLoop, cfg: &config::Config) -> Result<()> {
// XXX: All this ARC stuff is silly, listeners stay alive forever so none of this memory is
// ever deallocated.
let global_connections = Arc::new(ConnCount::new(cfg.max_connections));
for itf in &cfg.itf {
let interface = Arc::new(Interface {
connections: ConnCount::new(itf.max_connections),
global_connections: global_connections.clone(),
cfg: itf.clone(), // Silly, config is never deallocated.
});
for &addr in &itf.addr {
trace!("Binding {}", addr);
let sock = try!(TcpListener::bind(&addr));
let itf = interface.clone();
ev.spawn(move|ctx| { Box::new(Listener::new(ctx, itf, sock, addr)) });
}
}
Ok(())
}
|
