1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
use std::{
collections::HashMap,
io::Result as IoResult,
sync::{
atomic::{AtomicUsize, Ordering},
mpsc::{channel, Receiver, Sender},
Arc, Mutex,
},
time::Duration,
};
use futures::{io::Error as FutIoError, task::AtomicWaker};
use mio::{
event::{Event, Events, Source},
Interest, Poll, Registry, Token as MioToken,
};
pub use mio;
type FutIoResult<T> = Result<T, FutIoError>;
mod logging;
pub mod tcp;
pub mod udp;
use crate::logging::*;
const INTEREST_RW: Interest = Interest::READABLE.add(Interest::WRITABLE);
pub struct PollDriver {
events: Events,
poll: mio::Poll,
timeout: Option<Duration>,
wakers: Arc<Mutex<HashMap<usize, SourceWaker>>>,
}
pub struct PollRegistry {
mio_registry: Registry,
token_counter: Arc<AtomicUsize>,
token_freed: Arc<Mutex<Receiver<usize>>>,
token_drop_box: Sender<usize>,
wakers: Arc<Mutex<HashMap<usize, SourceWaker>>>,
}
impl PollRegistry {
pub fn try_clone(&self) -> IoResult<Self> {
Ok(Self {
mio_registry: self.mio_registry.try_clone()?,
token_counter: self.token_counter.clone(),
token_freed: self.token_freed.clone(),
token_drop_box: self.token_drop_box.clone(),
wakers: self.wakers.clone(),
})
}
}
#[derive(Clone)]
pub struct SourceWaker {
pub(crate) read: Arc<AtomicWaker>,
pub(crate) write: Arc<AtomicWaker>,
}
impl SourceWaker {
pub fn wake(&self, event: &Event) {
if event.is_writable() | event.is_write_closed() | event.is_error() {
self.write.wake();
}
if event.is_readable() | event.is_read_closed() | event.is_error() {
self.read.wake();
}
}
pub fn new() -> Self {
let read = Arc::new(Default::default());
let write = Arc::new(Default::default());
SourceWaker { read, write }
}
pub fn get_read_waker(&self) -> Arc<AtomicWaker> {
self.read.clone()
}
pub fn get_write_waker(&self) -> Arc<AtomicWaker> {
self.write.clone()
}
}
pub struct Token {
val: usize,
drop_box: Sender<usize>,
registry: PollRegistry,
}
impl Token {
pub(crate) fn get_mio(&self) -> MioToken {
MioToken(self.val)
}
}
impl PartialEq<MioToken> for Token {
fn eq(&self, other: &MioToken) -> bool {
self.val == other.0
}
}
impl PartialEq<Token> for MioToken {
fn eq(&self, other: &Token) -> bool {
self.0 == other.val
}
}
impl Drop for Token {
fn drop(&mut self) {
let _ = self.registry.wakers.lock().map(|mut g| g.remove(&self.val));
let _ = self.drop_box.send(self.val);
}
}
impl PollDriver {
pub fn new(
timeout: impl Into<Option<Duration>>,
event_buf_size: usize,
) -> IoResult<(PollDriver, PollRegistry)> {
let poll = Poll::new()?;
let registry = poll.registry().try_clone()?;
let wakers = Arc::new(Mutex::new(Default::default()));
let (tx, rx) = channel();
let driver = PollDriver {
events: Events::with_capacity(event_buf_size),
poll,
timeout: timeout.into(),
wakers: wakers.clone(),
};
let registry = PollRegistry {
mio_registry: registry,
token_counter: Arc::new(AtomicUsize::new(1)),
token_freed: Arc::new(Mutex::new(rx)),
token_drop_box: tx,
wakers,
};
Ok((driver, registry))
}
pub fn iter(&mut self) -> IoResult<()> {
self.poll.poll(&mut self.events, self.timeout)?;
let wakers = self.wakers.lock().expect("Poisoned waker store");
for event in self.events.iter() {
if let Some(waker) = wakers.get(&event.token().0) {
waker.wake(event);
} else {
error!("Registered handler does not have a corresponding Waker. This is a bug.");
}
}
Ok(())
}
}
impl PollRegistry {
pub fn register<S: Source + ?Sized>(
&self,
handle: &mut S,
interest: Interest,
wakers: SourceWaker,
) -> IoResult<Token> {
let token = self.get_token()?;
self.mio_registry
.register(handle, token.get_mio(), interest)?;
self.wakers
.lock()
.expect("Poisoned PollRegistry")
.insert(token.val, wakers);
Ok(token)
}
fn get_token(&self) -> IoResult<Token> {
let val = match self
.token_freed
.lock()
.expect("Poisoned token channel")
.try_recv()
{
Err(_) => {
let val = self.token_counter.fetch_add(1, Ordering::AcqRel);
if val == 0 {
panic!("Token Counter overflow. Consider sharding your application");
}
val
}
Ok(val) => val,
};
Ok(Token {
val,
drop_box: self.token_drop_box.clone(),
registry: self.try_clone()?,
})
}
}
#[cfg(test)]
mod tests {
use std::io::Result as IoResult;
use crate::PollDriver;
#[cfg(feature = "use-log")]
pub fn init_test_log() {
let _ = env_logger::builder()
.filter_level(log::LevelFilter::Trace)
.is_test(true)
.try_init();
}
#[cfg(feature = "use-tracing")]
pub fn init_test_log() {
let sub = tracing_subscriber::FmtSubscriber::builder()
.with_max_level(tracing::Level::TRACE)
.finish();
let _ = tracing::subscriber::set_global_default(sub);
}
#[test]
fn recycle_token() -> IoResult<()> {
let (_driver, registry) = PollDriver::new(None, 0)?;
let t1 = registry.get_token()?;
let t2 = registry.get_token()?;
assert_eq!(t1.val, 1_usize, "First token was not 1");
assert_eq!(t2.val, 2_usize, "Second token was not 2");
drop(t1);
let t3 = registry.get_token()?;
assert_eq!(t3.val, 1_usize, "Third token was not 1");
Ok(())
}
}