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|
use std::{
sync::Weak,
time::{Duration, Instant},
};
use tokio::sync::Mutex;
use crate::TunnelType;
use super::check::{Cancellable, Check};
use super::error::Error;
/// Sleep time used when checking if an established connection is still working.
const REGULAR_LOOP_SLEEP: Duration = Duration::from_secs(1);
pub struct Monitor {
connectivity_check: Check<Cancellable>,
}
impl Monitor {
pub fn init(connectivity_check: Check<Cancellable>) -> Self {
Self { connectivity_check }
}
pub fn run(self, tunnel_handle: Weak<Mutex<Option<TunnelType>>>) -> Result<(), Error> {
self.wait_loop(REGULAR_LOOP_SLEEP, tunnel_handle)
}
fn wait_loop(
mut self,
iter_delay: Duration,
tunnel_handle: Weak<Mutex<Option<TunnelType>>>,
) -> Result<(), Error> {
let mut last_iteration = Instant::now();
while !self.connectivity_check.should_shut_down(iter_delay) {
let mut current_iteration = Instant::now();
let time_slept = current_iteration - last_iteration;
if time_slept < (iter_delay * 2) {
let Some(tunnel) = tunnel_handle.upgrade() else {
return Ok(());
};
let lock = tunnel.blocking_lock();
let Some(tunnel) = lock.as_ref() else {
return Ok(());
};
if !self
.connectivity_check
.check_connectivity(Instant::now(), tunnel)?
{
return Ok(());
}
drop(lock);
let end = Instant::now();
if end - current_iteration > Duration::from_secs(1) {
current_iteration = end;
}
} else {
// Loop was suspended for too long, so it's safer to assume that the host still has
// connectivity.
self.connectivity_check.reset(current_iteration);
}
last_iteration = current_iteration;
}
Ok(())
}
}
#[cfg(test)]
mod test {
use super::*;
// TODO: Port to async + tokio to reduce cost of testing?
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::mpsc;
use std::sync::Arc;
use std::time::Duration;
use std::time::Instant;
use tokio::sync::Mutex;
use crate::connectivity::constants::*;
use crate::connectivity::mock::*;
#[test]
/// Verify that the connectivity monitor doesn't fail if the tunnel constantly sends traffic,
/// and it shuts down properly.
fn test_wait_loop() {
use std::sync::mpsc;
let (result_tx, result_rx) = mpsc::channel();
let tunnel = MockTunnel::always_incrementing().boxed();
let pinger = MockPinger::default();
let (mut checker, stop_tx) = {
let now = Instant::now();
let start = now.checked_sub(Duration::from_secs(1)).unwrap();
mock_checker(start, Box::new(pinger)).with_cancellation()
};
std::thread::spawn(move || {
let start_result = checker.establish_connectivity(&tunnel);
result_tx.send(start_result).unwrap();
// Pointer dance
let tunnel = Arc::new(Mutex::new(Some(tunnel)));
let _tunnel = Arc::downgrade(&tunnel);
let result = Monitor::init(checker).run(_tunnel).map(|_| true);
result_tx.send(result).unwrap();
});
std::thread::sleep(Duration::from_secs(1));
assert!(result_rx.try_recv().unwrap().unwrap());
stop_tx.send(()).unwrap();
std::thread::sleep(Duration::from_secs(1));
assert!(result_rx.try_recv().unwrap().is_ok());
}
#[test]
/// Verify that the connectivity monitor detects the tunnel timing out after no longer than
/// `BYTES_RX_TIMEOUT` and `PING_TIMEOUT` combined.
fn test_wait_loop_timeout() {
let should_stop = Arc::new(AtomicBool::new(false));
let should_stop_inner = should_stop.clone();
let mut map = StatsMap::new();
map.insert(
[0u8; 32],
Stats {
tx_bytes: 0,
rx_bytes: 0,
},
);
let tunnel_stats = std::sync::Mutex::new(map);
let pinger = MockPinger::default();
let tunnel = MockTunnel::new(move || {
let mut tunnel_stats = tunnel_stats.lock().unwrap();
if !should_stop_inner.load(Ordering::SeqCst) {
for traffic in tunnel_stats.values_mut() {
traffic.rx_bytes += 1;
}
}
for traffic in tunnel_stats.values_mut() {
traffic.tx_bytes += 1;
}
Ok(tunnel_stats.clone())
})
.boxed();
let (result_tx, result_rx) = mpsc::channel();
std::thread::spawn(move || {
let (mut checker, _cancellation_token) = {
let now = Instant::now();
let start = now.checked_sub(Duration::from_secs(1)).unwrap();
mock_checker(start, Box::new(pinger)).with_cancellation()
};
let start_result = checker.establish_connectivity(&tunnel);
result_tx.send(start_result).unwrap();
// Pointer dance
let _tunnel = Arc::new(Mutex::new(Some(tunnel)));
let tunnel = Arc::downgrade(&_tunnel);
let end_result = Monitor::init(checker).run(tunnel).map(|_| true);
result_tx.send(end_result).expect("Failed to send result");
});
assert!(result_rx
.recv_timeout(Duration::from_secs(1))
.unwrap()
.unwrap());
should_stop.store(true, Ordering::SeqCst);
assert!(result_rx
.recv_timeout(BYTES_RX_TIMEOUT + PING_TIMEOUT + Duration::from_secs(2))
.unwrap()
.is_ok());
}
}
|
