Line data Source code
1 : use std::{
2 : cmp::Ordering,
3 : collections::{BinaryHeap, VecDeque},
4 : fmt::{self, Debug},
5 : ops::DerefMut,
6 : sync::{mpsc, Arc},
7 : };
8 :
9 : use parking_lot::{
10 : lock_api::{MappedMutexGuard, MutexGuard},
11 : Mutex, RawMutex,
12 : };
13 : use rand::rngs::StdRng;
14 : use tracing::debug;
15 :
16 : use crate::{
17 : executor::{self, ThreadContext},
18 : options::NetworkOptions,
19 : proto::NetEvent,
20 : proto::NodeEvent,
21 : };
22 :
23 : use super::{chan::Chan, proto::AnyMessage};
24 :
25 : pub struct NetworkTask {
26 : options: Arc<NetworkOptions>,
27 : connections: Mutex<Vec<VirtualConnection>>,
28 : /// min-heap of connections having something to deliver.
29 : events: Mutex<BinaryHeap<Event>>,
30 : task_context: Arc<ThreadContext>,
31 : }
32 :
33 : impl NetworkTask {
34 528 : pub fn start_new(options: Arc<NetworkOptions>, tx: mpsc::Sender<Arc<NetworkTask>>) {
35 528 : let ctx = executor::get_thread_ctx();
36 528 : let task = Arc::new(Self {
37 528 : options,
38 528 : connections: Mutex::new(Vec::new()),
39 528 : events: Mutex::new(BinaryHeap::new()),
40 528 : task_context: ctx,
41 528 : });
42 528 :
43 528 : // send the task upstream
44 528 : tx.send(task.clone()).unwrap();
45 528 :
46 528 : // start the task
47 528 : task.start();
48 528 : }
49 :
50 34492 : pub fn start_new_connection(self: &Arc<Self>, rng: StdRng, dst_accept: Chan<NodeEvent>) -> TCP {
51 34492 : let now = executor::now();
52 34492 : let connection_id = self.connections.lock().len();
53 34492 :
54 34492 : let vc = VirtualConnection {
55 34492 : connection_id,
56 34492 : dst_accept,
57 34492 : dst_sockets: [Chan::new(), Chan::new()],
58 34492 : state: Mutex::new(ConnectionState {
59 34492 : buffers: [NetworkBuffer::new(None), NetworkBuffer::new(Some(now))],
60 34492 : rng,
61 34492 : }),
62 34492 : };
63 34492 : vc.schedule_timeout(self);
64 34492 : vc.send_connect(self);
65 34492 :
66 34492 : let recv_chan = vc.dst_sockets[0].clone();
67 34492 : self.connections.lock().push(vc);
68 34492 :
69 34492 : TCP {
70 34492 : net: self.clone(),
71 34492 : conn_id: connection_id,
72 34492 : dir: 0,
73 34492 : recv_chan,
74 34492 : }
75 34492 : }
76 : }
77 :
78 : // private functions
79 : impl NetworkTask {
80 : /// Schedule to wakeup network task (self) `after_ms` later to deliver
81 : /// messages of connection `id`.
82 176981 : fn schedule(&self, id: usize, after_ms: u64) {
83 176981 : self.events.lock().push(Event {
84 176981 : time: executor::now() + after_ms,
85 176981 : conn_id: id,
86 176981 : });
87 176981 : self.task_context.schedule_wakeup(after_ms);
88 176981 : }
89 :
90 : /// Get locked connection `id`.
91 235087 : fn get(&self, id: usize) -> MappedMutexGuard<'_, RawMutex, VirtualConnection> {
92 235087 : MutexGuard::map(self.connections.lock(), |connections| {
93 235087 : connections.get_mut(id).unwrap()
94 235087 : })
95 235087 : }
96 :
97 165201 : fn collect_pending_events(&self, now: u64, vec: &mut Vec<Event>) {
98 165201 : vec.clear();
99 165201 : let mut events = self.events.lock();
100 329875 : while let Some(event) = events.peek() {
101 327357 : if event.time > now {
102 162683 : break;
103 164674 : }
104 164674 : let event = events.pop().unwrap();
105 164674 : vec.push(event);
106 : }
107 165201 : }
108 :
109 528 : fn start(self: &Arc<Self>) {
110 528 : debug!("started network task");
111 :
112 528 : let mut events = Vec::new();
113 : loop {
114 165729 : let now = executor::now();
115 165729 : self.collect_pending_events(now, &mut events);
116 :
117 165729 : for event in events.drain(..) {
118 164674 : let conn = self.get(event.conn_id);
119 164674 : conn.process(self);
120 164674 : }
121 :
122 : // block until wakeup
123 165201 : executor::yield_me(-1);
124 : }
125 : }
126 : }
127 :
128 : // 0 - from node(0) to node(1)
129 : // 1 - from node(1) to node(0)
130 : type MessageDirection = u8;
131 :
132 1285 : fn sender_str(dir: MessageDirection) -> &'static str {
133 1285 : match dir {
134 211 : 0 => "client",
135 1074 : 1 => "server",
136 0 : _ => unreachable!(),
137 : }
138 1285 : }
139 :
140 347 : fn receiver_str(dir: MessageDirection) -> &'static str {
141 347 : match dir {
142 158 : 0 => "server",
143 189 : 1 => "client",
144 0 : _ => unreachable!(),
145 : }
146 347 : }
147 :
148 : /// Virtual connection between two nodes.
149 : /// Node 0 is the creator of the connection (client),
150 : /// and node 1 is the acceptor (server).
151 : struct VirtualConnection {
152 : connection_id: usize,
153 : /// one-off chan, used to deliver Accept message to dst
154 : dst_accept: Chan<NodeEvent>,
155 : /// message sinks
156 : dst_sockets: [Chan<NetEvent>; 2],
157 : state: Mutex<ConnectionState>,
158 : }
159 :
160 : struct ConnectionState {
161 : buffers: [NetworkBuffer; 2],
162 : rng: StdRng,
163 : }
164 :
165 : impl VirtualConnection {
166 : /// Notify the future about the possible timeout.
167 101848 : fn schedule_timeout(&self, net: &NetworkTask) {
168 101848 : if let Some(timeout) = net.options.keepalive_timeout {
169 101848 : net.schedule(self.connection_id, timeout);
170 101848 : }
171 101848 : }
172 :
173 : /// Send the handshake (Accept) to the server.
174 34492 : fn send_connect(&self, net: &NetworkTask) {
175 34492 : let now = executor::now();
176 34492 : let mut state = self.state.lock();
177 34492 : let delay = net.options.connect_delay.delay(&mut state.rng);
178 34492 : let buffer = &mut state.buffers[0];
179 34492 : assert!(buffer.buf.is_empty());
180 34492 : assert!(!buffer.recv_closed);
181 34492 : assert!(!buffer.send_closed);
182 34492 : assert!(buffer.last_recv.is_none());
183 :
184 34492 : let delay = if let Some(ms) = delay {
185 26591 : ms
186 : } else {
187 7901 : debug!("NET: TCP #{} dropped connect", self.connection_id);
188 7901 : buffer.send_closed = true;
189 7901 : return;
190 : };
191 :
192 : // Send a message into the future.
193 26591 : buffer
194 26591 : .buf
195 26591 : .push_back((now + delay, AnyMessage::InternalConnect));
196 26591 : net.schedule(self.connection_id, delay);
197 34492 : }
198 :
199 : /// Transmit some of the messages from the buffer to the nodes.
200 164674 : fn process(&self, net: &Arc<NetworkTask>) {
201 164674 : let now = executor::now();
202 164674 :
203 164674 : let mut state = self.state.lock();
204 :
205 494022 : for direction in 0..2 {
206 329348 : self.process_direction(
207 329348 : net,
208 329348 : state.deref_mut(),
209 329348 : now,
210 329348 : direction as MessageDirection,
211 329348 : &self.dst_sockets[direction ^ 1],
212 329348 : );
213 329348 : }
214 :
215 : // Close the one side of the connection by timeout if the node
216 : // has not received any messages for a long time.
217 164674 : if let Some(timeout) = net.options.keepalive_timeout {
218 164674 : let mut to_close = [false, false];
219 494022 : for direction in 0..2 {
220 329348 : let buffer = &mut state.buffers[direction];
221 329348 : if buffer.recv_closed {
222 66012 : continue;
223 263336 : }
224 263336 : if let Some(last_recv) = buffer.last_recv {
225 239123 : if now - last_recv >= timeout {
226 51207 : debug!(
227 0 : "NET: connection {} timed out at {}",
228 0 : self.connection_id,
229 0 : receiver_str(direction as MessageDirection)
230 : );
231 51207 : let node_idx = direction ^ 1;
232 51207 : to_close[node_idx] = true;
233 187916 : }
234 24213 : }
235 : }
236 164674 : drop(state);
237 :
238 329348 : for (node_idx, should_close) in to_close.iter().enumerate() {
239 329348 : if *should_close {
240 51207 : self.close(node_idx);
241 278141 : }
242 : }
243 0 : }
244 164674 : }
245 :
246 : /// Process messages in the buffer in the given direction.
247 329348 : fn process_direction(
248 329348 : &self,
249 329348 : net: &Arc<NetworkTask>,
250 329348 : state: &mut ConnectionState,
251 329348 : now: u64,
252 329348 : direction: MessageDirection,
253 329348 : to_socket: &Chan<NetEvent>,
254 329348 : ) {
255 329348 : let buffer = &mut state.buffers[direction as usize];
256 329348 : if buffer.recv_closed {
257 66012 : assert!(buffer.buf.is_empty());
258 263336 : }
259 :
260 396704 : while !buffer.buf.is_empty() && buffer.buf.front().unwrap().0 <= now {
261 67356 : let msg = buffer.buf.pop_front().unwrap().1;
262 67356 :
263 67356 : buffer.last_recv = Some(now);
264 67356 : self.schedule_timeout(net);
265 67356 :
266 67356 : if let AnyMessage::InternalConnect = msg {
267 25202 : // TODO: assert to_socket is the server
268 25202 : let server_to_client = TCP {
269 25202 : net: net.clone(),
270 25202 : conn_id: self.connection_id,
271 25202 : dir: direction ^ 1,
272 25202 : recv_chan: to_socket.clone(),
273 25202 : };
274 25202 : // special case, we need to deliver new connection to a separate channel
275 25202 : self.dst_accept.send(NodeEvent::Accept(server_to_client));
276 42154 : } else {
277 42154 : to_socket.send(NetEvent::Message(msg));
278 42154 : }
279 : }
280 329348 : }
281 :
282 : /// Try to send a message to the buffer, optionally dropping it and
283 : /// determining delivery timestamp.
284 66569 : fn send(&self, net: &NetworkTask, direction: MessageDirection, msg: AnyMessage) {
285 66569 : let now = executor::now();
286 66569 : let mut state = self.state.lock();
287 :
288 66569 : let (delay, close) = if let Some(ms) = net.options.send_delay.delay(&mut state.rng) {
289 60316 : (ms, false)
290 : } else {
291 6253 : (0, true)
292 : };
293 :
294 66569 : let buffer = &mut state.buffers[direction as usize];
295 66569 : if buffer.send_closed {
296 7487 : debug!(
297 0 : "NET: TCP #{} dropped message {:?} (broken pipe)",
298 : self.connection_id, msg
299 : );
300 7487 : return;
301 59082 : }
302 59082 :
303 59082 : if close {
304 4631 : debug!(
305 0 : "NET: TCP #{} dropped message {:?} (pipe just broke)",
306 : self.connection_id, msg
307 : );
308 4631 : buffer.send_closed = true;
309 4631 : return;
310 54451 : }
311 54451 :
312 54451 : if buffer.recv_closed {
313 5909 : debug!(
314 0 : "NET: TCP #{} dropped message {:?} (recv closed)",
315 : self.connection_id, msg
316 : );
317 5909 : return;
318 48542 : }
319 48542 :
320 48542 : // Send a message into the future.
321 48542 : buffer.buf.push_back((now + delay, msg));
322 48542 : net.schedule(self.connection_id, delay);
323 66569 : }
324 :
325 : /// Close the connection. Only one side of the connection will be closed,
326 : /// and no further messages will be delivered. The other side will not be notified.
327 55051 : fn close(&self, node_idx: usize) {
328 55051 : let mut state = self.state.lock();
329 55051 : let recv_buffer = &mut state.buffers[1 ^ node_idx];
330 55051 : if recv_buffer.recv_closed {
331 313 : debug!(
332 0 : "NET: TCP #{} closed twice at {}",
333 0 : self.connection_id,
334 0 : sender_str(node_idx as MessageDirection),
335 : );
336 313 : return;
337 54738 : }
338 54738 :
339 54738 : debug!(
340 0 : "NET: TCP #{} closed at {}",
341 0 : self.connection_id,
342 0 : sender_str(node_idx as MessageDirection),
343 : );
344 54738 : recv_buffer.recv_closed = true;
345 54738 : for msg in recv_buffer.buf.drain(..) {
346 4829 : debug!(
347 0 : "NET: TCP #{} dropped message {:?} (closed)",
348 : self.connection_id, msg
349 : );
350 : }
351 :
352 54738 : let send_buffer = &mut state.buffers[node_idx];
353 54738 : send_buffer.send_closed = true;
354 54738 : drop(state);
355 54738 :
356 54738 : // TODO: notify the other side?
357 54738 :
358 54738 : self.dst_sockets[node_idx].send(NetEvent::Closed);
359 55051 : }
360 : }
361 :
362 : struct NetworkBuffer {
363 : /// Messages paired with time of delivery
364 : buf: VecDeque<(u64, AnyMessage)>,
365 : /// True if the connection is closed on the receiving side,
366 : /// i.e. no more messages from the buffer will be delivered.
367 : recv_closed: bool,
368 : /// True if the connection is closed on the sending side,
369 : /// i.e. no more messages will be added to the buffer.
370 : send_closed: bool,
371 : /// Last time a message was delivered from the buffer.
372 : /// If None, it means that the server is the receiver and
373 : /// it has not yet aware of this connection (i.e. has not
374 : /// received the Accept).
375 : last_recv: Option<u64>,
376 : }
377 :
378 : impl NetworkBuffer {
379 68984 : fn new(last_recv: Option<u64>) -> Self {
380 68984 : Self {
381 68984 : buf: VecDeque::new(),
382 68984 : recv_closed: false,
383 68984 : send_closed: false,
384 68984 : last_recv,
385 68984 : }
386 68984 : }
387 : }
388 :
389 : /// Single end of a bidirectional network stream without reordering (TCP-like).
390 : /// Reads are implemented using channels, writes go to the buffer inside VirtualConnection.
391 : pub struct TCP {
392 : net: Arc<NetworkTask>,
393 : conn_id: usize,
394 : dir: MessageDirection,
395 : recv_chan: Chan<NetEvent>,
396 : }
397 :
398 : impl Debug for TCP {
399 901 : fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
400 901 : write!(f, "TCP #{} ({})", self.conn_id, sender_str(self.dir),)
401 901 : }
402 : }
403 :
404 : impl TCP {
405 : /// Send a message to the other side. It's guaranteed that it will not arrive
406 : /// before the arrival of all messages sent earlier.
407 66569 : pub fn send(&self, msg: AnyMessage) {
408 66569 : let conn = self.net.get(self.conn_id);
409 66569 : conn.send(&self.net, self.dir, msg);
410 66569 : }
411 :
412 : /// Get a channel to receive incoming messages.
413 425936 : pub fn recv_chan(&self) -> Chan<NetEvent> {
414 425936 : self.recv_chan.clone()
415 425936 : }
416 :
417 289471 : pub fn connection_id(&self) -> usize {
418 289471 : self.conn_id
419 289471 : }
420 :
421 3844 : pub fn close(&self) {
422 3844 : let conn = self.net.get(self.conn_id);
423 3844 : conn.close(self.dir as usize);
424 3844 : }
425 : }
426 : struct Event {
427 : time: u64,
428 : conn_id: usize,
429 : }
430 :
431 : // BinaryHeap is a max-heap, and we want a min-heap. Reverse the ordering here
432 : // to get that.
433 : impl PartialOrd for Event {
434 1017397 : fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
435 1017397 : Some(self.cmp(other))
436 1017397 : }
437 : }
438 :
439 : impl Ord for Event {
440 1017397 : fn cmp(&self, other: &Self) -> Ordering {
441 1017397 : (other.time, other.conn_id).cmp(&(self.time, self.conn_id))
442 1017397 : }
443 : }
444 :
445 : impl PartialEq for Event {
446 0 : fn eq(&self, other: &Self) -> bool {
447 0 : (other.time, other.conn_id) == (self.time, self.conn_id)
448 0 : }
449 : }
450 :
451 : impl Eq for Event {}
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