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1 | // Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
85aaf69f | 11 | //! Multi-producer, single-consumer FIFO queue communication primitives. |
1a4d82fc JJ |
12 | //! |
13 | //! This module provides message-based communication over channels, concretely | |
14 | //! defined among three types: | |
15 | //! | |
16 | //! * `Sender` | |
17 | //! * `SyncSender` | |
18 | //! * `Receiver` | |
19 | //! | |
20 | //! A `Sender` or `SyncSender` is used to send data to a `Receiver`. Both | |
21 | //! senders are clone-able (multi-producer) such that many threads can send | |
22 | //! simultaneously to one receiver (single-consumer). | |
23 | //! | |
24 | //! These channels come in two flavors: | |
25 | //! | |
26 | //! 1. An asynchronous, infinitely buffered channel. The `channel()` function | |
27 | //! will return a `(Sender, Receiver)` tuple where all sends will be | |
28 | //! **asynchronous** (they never block). The channel conceptually has an | |
29 | //! infinite buffer. | |
30 | //! | |
31 | //! 2. A synchronous, bounded channel. The `sync_channel()` function will return | |
32 | //! a `(SyncSender, Receiver)` tuple where the storage for pending messages | |
33 | //! is a pre-allocated buffer of a fixed size. All sends will be | |
34 | //! **synchronous** by blocking until there is buffer space available. Note | |
35 | //! that a bound of 0 is allowed, causing the channel to become a | |
36 | //! "rendezvous" channel where each sender atomically hands off a message to | |
37 | //! a receiver. | |
38 | //! | |
39 | //! ## Disconnection | |
40 | //! | |
41 | //! The send and receive operations on channels will all return a `Result` | |
42 | //! indicating whether the operation succeeded or not. An unsuccessful operation | |
43 | //! is normally indicative of the other half of a channel having "hung up" by | |
44 | //! being dropped in its corresponding thread. | |
45 | //! | |
46 | //! Once half of a channel has been deallocated, most operations can no longer | |
47 | //! continue to make progress, so `Err` will be returned. Many applications will | |
48 | //! continue to `unwrap()` the results returned from this module, instigating a | |
49 | //! propagation of failure among threads if one unexpectedly dies. | |
50 | //! | |
51 | //! # Examples | |
52 | //! | |
53 | //! Simple usage: | |
54 | //! | |
55 | //! ``` | |
85aaf69f | 56 | //! use std::thread; |
1a4d82fc JJ |
57 | //! use std::sync::mpsc::channel; |
58 | //! | |
59 | //! // Create a simple streaming channel | |
60 | //! let (tx, rx) = channel(); | |
85aaf69f SL |
61 | //! thread::spawn(move|| { |
62 | //! tx.send(10).unwrap(); | |
1a4d82fc | 63 | //! }); |
85aaf69f | 64 | //! assert_eq!(rx.recv().unwrap(), 10); |
1a4d82fc JJ |
65 | //! ``` |
66 | //! | |
67 | //! Shared usage: | |
68 | //! | |
69 | //! ``` | |
85aaf69f | 70 | //! use std::thread; |
1a4d82fc JJ |
71 | //! use std::sync::mpsc::channel; |
72 | //! | |
73 | //! // Create a shared channel that can be sent along from many threads | |
74 | //! // where tx is the sending half (tx for transmission), and rx is the receiving | |
75 | //! // half (rx for receiving). | |
76 | //! let (tx, rx) = channel(); | |
85aaf69f | 77 | //! for i in 0..10 { |
1a4d82fc | 78 | //! let tx = tx.clone(); |
85aaf69f | 79 | //! thread::spawn(move|| { |
1a4d82fc JJ |
80 | //! tx.send(i).unwrap(); |
81 | //! }); | |
82 | //! } | |
83 | //! | |
85aaf69f | 84 | //! for _ in 0..10 { |
1a4d82fc JJ |
85 | //! let j = rx.recv().unwrap(); |
86 | //! assert!(0 <= j && j < 10); | |
87 | //! } | |
88 | //! ``` | |
89 | //! | |
90 | //! Propagating panics: | |
91 | //! | |
92 | //! ``` | |
93 | //! use std::sync::mpsc::channel; | |
94 | //! | |
95 | //! // The call to recv() will return an error because the channel has already | |
96 | //! // hung up (or been deallocated) | |
c34b1796 | 97 | //! let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
98 | //! drop(tx); |
99 | //! assert!(rx.recv().is_err()); | |
100 | //! ``` | |
101 | //! | |
102 | //! Synchronous channels: | |
103 | //! | |
104 | //! ``` | |
85aaf69f | 105 | //! use std::thread; |
1a4d82fc JJ |
106 | //! use std::sync::mpsc::sync_channel; |
107 | //! | |
c34b1796 | 108 | //! let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 109 | //! thread::spawn(move|| { |
bd371182 | 110 | //! // This will wait for the parent thread to start receiving |
1a4d82fc JJ |
111 | //! tx.send(53).unwrap(); |
112 | //! }); | |
113 | //! rx.recv().unwrap(); | |
114 | //! ``` | |
1a4d82fc | 115 | |
85aaf69f | 116 | #![stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
117 | |
118 | // A description of how Rust's channel implementation works | |
119 | // | |
120 | // Channels are supposed to be the basic building block for all other | |
121 | // concurrent primitives that are used in Rust. As a result, the channel type | |
122 | // needs to be highly optimized, flexible, and broad enough for use everywhere. | |
123 | // | |
124 | // The choice of implementation of all channels is to be built on lock-free data | |
125 | // structures. The channels themselves are then consequently also lock-free data | |
126 | // structures. As always with lock-free code, this is a very "here be dragons" | |
127 | // territory, especially because I'm unaware of any academic papers that have | |
128 | // gone into great length about channels of these flavors. | |
129 | // | |
130 | // ## Flavors of channels | |
131 | // | |
132 | // From the perspective of a consumer of this library, there is only one flavor | |
133 | // of channel. This channel can be used as a stream and cloned to allow multiple | |
134 | // senders. Under the hood, however, there are actually three flavors of | |
135 | // channels in play. | |
136 | // | |
3157f602 XL |
137 | // * Flavor::Oneshots - these channels are highly optimized for the one-send use |
138 | // case. They contain as few atomics as possible and | |
139 | // involve one and exactly one allocation. | |
1a4d82fc JJ |
140 | // * Streams - these channels are optimized for the non-shared use case. They |
141 | // use a different concurrent queue that is more tailored for this | |
142 | // use case. The initial allocation of this flavor of channel is not | |
143 | // optimized. | |
144 | // * Shared - this is the most general form of channel that this module offers, | |
145 | // a channel with multiple senders. This type is as optimized as it | |
146 | // can be, but the previous two types mentioned are much faster for | |
147 | // their use-cases. | |
148 | // | |
149 | // ## Concurrent queues | |
150 | // | |
3157f602 XL |
151 | // The basic idea of Rust's Sender/Receiver types is that send() never blocks, |
152 | // but recv() obviously blocks. This means that under the hood there must be | |
153 | // some shared and concurrent queue holding all of the actual data. | |
1a4d82fc JJ |
154 | // |
155 | // With two flavors of channels, two flavors of queues are also used. We have | |
156 | // chosen to use queues from a well-known author that are abbreviated as SPSC | |
157 | // and MPSC (single producer, single consumer and multiple producer, single | |
158 | // consumer). SPSC queues are used for streams while MPSC queues are used for | |
159 | // shared channels. | |
160 | // | |
161 | // ### SPSC optimizations | |
162 | // | |
163 | // The SPSC queue found online is essentially a linked list of nodes where one | |
164 | // half of the nodes are the "queue of data" and the other half of nodes are a | |
165 | // cache of unused nodes. The unused nodes are used such that an allocation is | |
166 | // not required on every push() and a free doesn't need to happen on every | |
167 | // pop(). | |
168 | // | |
169 | // As found online, however, the cache of nodes is of an infinite size. This | |
170 | // means that if a channel at one point in its life had 50k items in the queue, | |
171 | // then the queue will always have the capacity for 50k items. I believed that | |
172 | // this was an unnecessary limitation of the implementation, so I have altered | |
173 | // the queue to optionally have a bound on the cache size. | |
174 | // | |
175 | // By default, streams will have an unbounded SPSC queue with a small-ish cache | |
176 | // size. The hope is that the cache is still large enough to have very fast | |
177 | // send() operations while not too large such that millions of channels can | |
178 | // coexist at once. | |
179 | // | |
180 | // ### MPSC optimizations | |
181 | // | |
182 | // Right now the MPSC queue has not been optimized. Like the SPSC queue, it uses | |
183 | // a linked list under the hood to earn its unboundedness, but I have not put | |
184 | // forth much effort into having a cache of nodes similar to the SPSC queue. | |
185 | // | |
186 | // For now, I believe that this is "ok" because shared channels are not the most | |
187 | // common type, but soon we may wish to revisit this queue choice and determine | |
188 | // another candidate for backend storage of shared channels. | |
189 | // | |
190 | // ## Overview of the Implementation | |
191 | // | |
192 | // Now that there's a little background on the concurrent queues used, it's | |
193 | // worth going into much more detail about the channels themselves. The basic | |
194 | // pseudocode for a send/recv are: | |
195 | // | |
196 | // | |
197 | // send(t) recv() | |
198 | // queue.push(t) return if queue.pop() | |
199 | // if increment() == -1 deschedule { | |
200 | // wakeup() if decrement() > 0 | |
201 | // cancel_deschedule() | |
202 | // } | |
203 | // queue.pop() | |
204 | // | |
205 | // As mentioned before, there are no locks in this implementation, only atomic | |
206 | // instructions are used. | |
207 | // | |
208 | // ### The internal atomic counter | |
209 | // | |
210 | // Every channel has a shared counter with each half to keep track of the size | |
211 | // of the queue. This counter is used to abort descheduling by the receiver and | |
212 | // to know when to wake up on the sending side. | |
213 | // | |
214 | // As seen in the pseudocode, senders will increment this count and receivers | |
215 | // will decrement the count. The theory behind this is that if a sender sees a | |
216 | // -1 count, it will wake up the receiver, and if the receiver sees a 1+ count, | |
217 | // then it doesn't need to block. | |
218 | // | |
219 | // The recv() method has a beginning call to pop(), and if successful, it needs | |
220 | // to decrement the count. It is a crucial implementation detail that this | |
221 | // decrement does *not* happen to the shared counter. If this were the case, | |
222 | // then it would be possible for the counter to be very negative when there were | |
223 | // no receivers waiting, in which case the senders would have to determine when | |
224 | // it was actually appropriate to wake up a receiver. | |
225 | // | |
226 | // Instead, the "steal count" is kept track of separately (not atomically | |
227 | // because it's only used by receivers), and then the decrement() call when | |
228 | // descheduling will lump in all of the recent steals into one large decrement. | |
229 | // | |
230 | // The implication of this is that if a sender sees a -1 count, then there's | |
231 | // guaranteed to be a waiter waiting! | |
232 | // | |
233 | // ## Native Implementation | |
234 | // | |
235 | // A major goal of these channels is to work seamlessly on and off the runtime. | |
236 | // All of the previous race conditions have been worded in terms of | |
237 | // scheduler-isms (which is obviously not available without the runtime). | |
238 | // | |
239 | // For now, native usage of channels (off the runtime) will fall back onto | |
240 | // mutexes/cond vars for descheduling/atomic decisions. The no-contention path | |
241 | // is still entirely lock-free, the "deschedule" blocks above are surrounded by | |
242 | // a mutex and the "wakeup" blocks involve grabbing a mutex and signaling on a | |
243 | // condition variable. | |
244 | // | |
245 | // ## Select | |
246 | // | |
247 | // Being able to support selection over channels has greatly influenced this | |
248 | // design, and not only does selection need to work inside the runtime, but also | |
249 | // outside the runtime. | |
250 | // | |
251 | // The implementation is fairly straightforward. The goal of select() is not to | |
252 | // return some data, but only to return which channel can receive data without | |
253 | // blocking. The implementation is essentially the entire blocking procedure | |
254 | // followed by an increment as soon as its woken up. The cancellation procedure | |
255 | // involves an increment and swapping out of to_wake to acquire ownership of the | |
bd371182 | 256 | // thread to unblock. |
1a4d82fc JJ |
257 | // |
258 | // Sadly this current implementation requires multiple allocations, so I have | |
259 | // seen the throughput of select() be much worse than it should be. I do not | |
260 | // believe that there is anything fundamental that needs to change about these | |
261 | // channels, however, in order to support a more efficient select(). | |
262 | // | |
263 | // # Conclusion | |
264 | // | |
265 | // And now that you've seen all the races that I found and attempted to fix, | |
266 | // here's the code for you to find some more! | |
267 | ||
1a4d82fc | 268 | use sync::Arc; |
c34b1796 | 269 | use error; |
1a4d82fc | 270 | use fmt; |
1a4d82fc JJ |
271 | use mem; |
272 | use cell::UnsafeCell; | |
3157f602 | 273 | use time::{Duration, Instant}; |
1a4d82fc | 274 | |
92a42be0 | 275 | #[unstable(feature = "mpsc_select", issue = "27800")] |
1a4d82fc JJ |
276 | pub use self::select::{Select, Handle}; |
277 | use self::select::StartResult; | |
278 | use self::select::StartResult::*; | |
279 | use self::blocking::SignalToken; | |
280 | ||
281 | mod blocking; | |
282 | mod oneshot; | |
283 | mod select; | |
284 | mod shared; | |
285 | mod stream; | |
286 | mod sync; | |
287 | mod mpsc_queue; | |
288 | mod spsc_queue; | |
289 | ||
290 | /// The receiving-half of Rust's channel type. This half can only be owned by | |
bd371182 | 291 | /// one thread |
85aaf69f | 292 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
293 | pub struct Receiver<T> { |
294 | inner: UnsafeCell<Flavor<T>>, | |
295 | } | |
296 | ||
297 | // The receiver port can be sent from place to place, so long as it | |
298 | // is not used to receive non-sendable things. | |
92a42be0 | 299 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 300 | unsafe impl<T: Send> Send for Receiver<T> { } |
1a4d82fc | 301 | |
54a0048b SL |
302 | #[stable(feature = "rust1", since = "1.0.0")] |
303 | impl<T> !Sync for Receiver<T> { } | |
304 | ||
1a4d82fc JJ |
305 | /// An iterator over messages on a receiver, this iterator will block |
306 | /// whenever `next` is called, waiting for a new message, and `None` will be | |
307 | /// returned when the corresponding channel has hung up. | |
85aaf69f | 308 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 309 | pub struct Iter<'a, T: 'a> { |
1a4d82fc JJ |
310 | rx: &'a Receiver<T> |
311 | } | |
312 | ||
5bcae85e SL |
313 | /// An iterator that attempts to yield all pending values for a receiver. |
314 | /// `None` will be returned when there are no pending values remaining or | |
315 | /// if the corresponding channel has hung up. | |
316 | /// | |
317 | /// This Iterator will never block the caller in order to wait for data to | |
318 | /// become available. Instead, it will return `None`. | |
319 | #[unstable(feature = "receiver_try_iter", issue = "34931")] | |
320 | pub struct TryIter<'a, T: 'a> { | |
321 | rx: &'a Receiver<T> | |
322 | } | |
323 | ||
d9579d0f AL |
324 | /// An owning iterator over messages on a receiver, this iterator will block |
325 | /// whenever `next` is called, waiting for a new message, and `None` will be | |
326 | /// returned when the corresponding channel has hung up. | |
327 | #[stable(feature = "receiver_into_iter", since = "1.1.0")] | |
328 | pub struct IntoIter<T> { | |
329 | rx: Receiver<T> | |
330 | } | |
331 | ||
1a4d82fc | 332 | /// The sending-half of Rust's asynchronous channel type. This half can only be |
bd371182 | 333 | /// owned by one thread, but it can be cloned to send to other threads. |
85aaf69f | 334 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
335 | pub struct Sender<T> { |
336 | inner: UnsafeCell<Flavor<T>>, | |
337 | } | |
338 | ||
339 | // The send port can be sent from place to place, so long as it | |
340 | // is not used to send non-sendable things. | |
92a42be0 | 341 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 342 | unsafe impl<T: Send> Send for Sender<T> { } |
1a4d82fc | 343 | |
54a0048b SL |
344 | #[stable(feature = "rust1", since = "1.0.0")] |
345 | impl<T> !Sync for Sender<T> { } | |
346 | ||
1a4d82fc | 347 | /// The sending-half of Rust's synchronous channel type. This half can only be |
bd371182 | 348 | /// owned by one thread, but it can be cloned to send to other threads. |
85aaf69f | 349 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 350 | pub struct SyncSender<T> { |
85aaf69f | 351 | inner: Arc<UnsafeCell<sync::Packet<T>>>, |
1a4d82fc JJ |
352 | } |
353 | ||
92a42be0 | 354 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 355 | unsafe impl<T: Send> Send for SyncSender<T> {} |
85aaf69f | 356 | |
92a42be0 | 357 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
358 | impl<T> !Sync for SyncSender<T> {} |
359 | ||
1a4d82fc JJ |
360 | /// An error returned from the `send` function on channels. |
361 | /// | |
362 | /// A `send` operation can only fail if the receiving end of a channel is | |
363 | /// disconnected, implying that the data could never be received. The error | |
364 | /// contains the data being sent as a payload so it can be recovered. | |
85aaf69f SL |
365 | #[stable(feature = "rust1", since = "1.0.0")] |
366 | #[derive(PartialEq, Eq, Clone, Copy)] | |
c34b1796 | 367 | pub struct SendError<T>(#[stable(feature = "rust1", since = "1.0.0")] pub T); |
1a4d82fc JJ |
368 | |
369 | /// An error returned from the `recv` function on a `Receiver`. | |
370 | /// | |
371 | /// The `recv` operation can only fail if the sending half of a channel is | |
372 | /// disconnected, implying that no further messages will ever be received. | |
85aaf69f SL |
373 | #[derive(PartialEq, Eq, Clone, Copy, Debug)] |
374 | #[stable(feature = "rust1", since = "1.0.0")] | |
1a4d82fc JJ |
375 | pub struct RecvError; |
376 | ||
9346a6ac AL |
377 | /// This enumeration is the list of the possible reasons that `try_recv` could |
378 | /// not return data when called. | |
85aaf69f SL |
379 | #[derive(PartialEq, Eq, Clone, Copy, Debug)] |
380 | #[stable(feature = "rust1", since = "1.0.0")] | |
1a4d82fc JJ |
381 | pub enum TryRecvError { |
382 | /// This channel is currently empty, but the sender(s) have not yet | |
383 | /// disconnected, so data may yet become available. | |
85aaf69f | 384 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
385 | Empty, |
386 | ||
387 | /// This channel's sending half has become disconnected, and there will | |
388 | /// never be any more data received on this channel | |
85aaf69f | 389 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
390 | Disconnected, |
391 | } | |
392 | ||
3157f602 XL |
393 | /// This enumeration is the list of possible errors that `recv_timeout` could |
394 | /// not return data when called. | |
395 | #[derive(PartialEq, Eq, Clone, Copy, Debug)] | |
5bcae85e | 396 | #[stable(feature = "mpsc_recv_timeout", since = "1.12.0")] |
3157f602 XL |
397 | pub enum RecvTimeoutError { |
398 | /// This channel is currently empty, but the sender(s) have not yet | |
399 | /// disconnected, so data may yet become available. | |
5bcae85e | 400 | #[stable(feature = "mpsc_recv_timeout", since = "1.12.0")] |
3157f602 XL |
401 | Timeout, |
402 | /// This channel's sending half has become disconnected, and there will | |
403 | /// never be any more data received on this channel | |
5bcae85e | 404 | #[stable(feature = "mpsc_recv_timeout", since = "1.12.0")] |
3157f602 XL |
405 | Disconnected, |
406 | } | |
407 | ||
1a4d82fc JJ |
408 | /// This enumeration is the list of the possible error outcomes for the |
409 | /// `SyncSender::try_send` method. | |
85aaf69f SL |
410 | #[stable(feature = "rust1", since = "1.0.0")] |
411 | #[derive(PartialEq, Eq, Clone, Copy)] | |
1a4d82fc JJ |
412 | pub enum TrySendError<T> { |
413 | /// The data could not be sent on the channel because it would require that | |
414 | /// the callee block to send the data. | |
415 | /// | |
416 | /// If this is a buffered channel, then the buffer is full at this time. If | |
417 | /// this is not a buffered channel, then there is no receiver available to | |
418 | /// acquire the data. | |
85aaf69f | 419 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 420 | Full(#[stable(feature = "rust1", since = "1.0.0")] T), |
1a4d82fc JJ |
421 | |
422 | /// This channel's receiving half has disconnected, so the data could not be | |
423 | /// sent. The data is returned back to the callee in this case. | |
85aaf69f | 424 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 425 | Disconnected(#[stable(feature = "rust1", since = "1.0.0")] T), |
1a4d82fc JJ |
426 | } |
427 | ||
428 | enum Flavor<T> { | |
85aaf69f SL |
429 | Oneshot(Arc<UnsafeCell<oneshot::Packet<T>>>), |
430 | Stream(Arc<UnsafeCell<stream::Packet<T>>>), | |
431 | Shared(Arc<UnsafeCell<shared::Packet<T>>>), | |
432 | Sync(Arc<UnsafeCell<sync::Packet<T>>>), | |
1a4d82fc JJ |
433 | } |
434 | ||
435 | #[doc(hidden)] | |
436 | trait UnsafeFlavor<T> { | |
e9174d1e | 437 | fn inner_unsafe(&self) -> &UnsafeCell<Flavor<T>>; |
7453a54e | 438 | unsafe fn inner_mut(&self) -> &mut Flavor<T> { |
1a4d82fc JJ |
439 | &mut *self.inner_unsafe().get() |
440 | } | |
7453a54e | 441 | unsafe fn inner(&self) -> &Flavor<T> { |
1a4d82fc JJ |
442 | &*self.inner_unsafe().get() |
443 | } | |
444 | } | |
445 | impl<T> UnsafeFlavor<T> for Sender<T> { | |
e9174d1e | 446 | fn inner_unsafe(&self) -> &UnsafeCell<Flavor<T>> { |
1a4d82fc JJ |
447 | &self.inner |
448 | } | |
449 | } | |
450 | impl<T> UnsafeFlavor<T> for Receiver<T> { | |
e9174d1e | 451 | fn inner_unsafe(&self) -> &UnsafeCell<Flavor<T>> { |
1a4d82fc JJ |
452 | &self.inner |
453 | } | |
454 | } | |
455 | ||
456 | /// Creates a new asynchronous channel, returning the sender/receiver halves. | |
457 | /// | |
458 | /// All data sent on the sender will become available on the receiver, and no | |
bd371182 | 459 | /// send will block the calling thread (this channel has an "infinite buffer"). |
1a4d82fc | 460 | /// |
c34b1796 | 461 | /// # Examples |
1a4d82fc JJ |
462 | /// |
463 | /// ``` | |
464 | /// use std::sync::mpsc::channel; | |
85aaf69f | 465 | /// use std::thread; |
1a4d82fc | 466 | /// |
b039eaaf | 467 | /// // tx is the sending half (tx for transmission), and rx is the receiving |
1a4d82fc JJ |
468 | /// // half (rx for receiving). |
469 | /// let (tx, rx) = channel(); | |
470 | /// | |
471 | /// // Spawn off an expensive computation | |
85aaf69f | 472 | /// thread::spawn(move|| { |
1a4d82fc JJ |
473 | /// # fn expensive_computation() {} |
474 | /// tx.send(expensive_computation()).unwrap(); | |
475 | /// }); | |
476 | /// | |
477 | /// // Do some useful work for awhile | |
478 | /// | |
479 | /// // Let's see what that answer was | |
480 | /// println!("{:?}", rx.recv().unwrap()); | |
481 | /// ``` | |
85aaf69f | 482 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 483 | pub fn channel<T>() -> (Sender<T>, Receiver<T>) { |
85aaf69f | 484 | let a = Arc::new(UnsafeCell::new(oneshot::Packet::new())); |
1a4d82fc JJ |
485 | (Sender::new(Flavor::Oneshot(a.clone())), Receiver::new(Flavor::Oneshot(a))) |
486 | } | |
487 | ||
488 | /// Creates a new synchronous, bounded channel. | |
489 | /// | |
490 | /// Like asynchronous channels, the `Receiver` will block until a message | |
491 | /// becomes available. These channels differ greatly in the semantics of the | |
492 | /// sender from asynchronous channels, however. | |
493 | /// | |
494 | /// This channel has an internal buffer on which messages will be queued. When | |
495 | /// the internal buffer becomes full, future sends will *block* waiting for the | |
496 | /// buffer to open up. Note that a buffer size of 0 is valid, in which case this | |
497 | /// becomes "rendezvous channel" where each send will not return until a recv | |
498 | /// is paired with it. | |
499 | /// | |
500 | /// As with asynchronous channels, all senders will panic in `send` if the | |
501 | /// `Receiver` has been destroyed. | |
502 | /// | |
c34b1796 | 503 | /// # Examples |
1a4d82fc JJ |
504 | /// |
505 | /// ``` | |
506 | /// use std::sync::mpsc::sync_channel; | |
85aaf69f | 507 | /// use std::thread; |
1a4d82fc JJ |
508 | /// |
509 | /// let (tx, rx) = sync_channel(1); | |
510 | /// | |
511 | /// // this returns immediately | |
85aaf69f | 512 | /// tx.send(1).unwrap(); |
1a4d82fc | 513 | /// |
85aaf69f | 514 | /// thread::spawn(move|| { |
1a4d82fc | 515 | /// // this will block until the previous message has been received |
85aaf69f | 516 | /// tx.send(2).unwrap(); |
1a4d82fc JJ |
517 | /// }); |
518 | /// | |
85aaf69f SL |
519 | /// assert_eq!(rx.recv().unwrap(), 1); |
520 | /// assert_eq!(rx.recv().unwrap(), 2); | |
1a4d82fc | 521 | /// ``` |
85aaf69f | 522 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 523 | pub fn sync_channel<T>(bound: usize) -> (SyncSender<T>, Receiver<T>) { |
85aaf69f | 524 | let a = Arc::new(UnsafeCell::new(sync::Packet::new(bound))); |
1a4d82fc JJ |
525 | (SyncSender::new(a.clone()), Receiver::new(Flavor::Sync(a))) |
526 | } | |
527 | ||
528 | //////////////////////////////////////////////////////////////////////////////// | |
529 | // Sender | |
530 | //////////////////////////////////////////////////////////////////////////////// | |
531 | ||
c34b1796 | 532 | impl<T> Sender<T> { |
1a4d82fc JJ |
533 | fn new(inner: Flavor<T>) -> Sender<T> { |
534 | Sender { | |
535 | inner: UnsafeCell::new(inner), | |
536 | } | |
537 | } | |
538 | ||
539 | /// Attempts to send a value on this channel, returning it back if it could | |
540 | /// not be sent. | |
541 | /// | |
542 | /// A successful send occurs when it is determined that the other end of | |
543 | /// the channel has not hung up already. An unsuccessful send would be one | |
544 | /// where the corresponding receiver has already been deallocated. Note | |
545 | /// that a return value of `Err` means that the data will never be | |
546 | /// received, but a return value of `Ok` does *not* mean that the data | |
547 | /// will be received. It is possible for the corresponding receiver to | |
548 | /// hang up immediately after this function returns `Ok`. | |
549 | /// | |
550 | /// This method will never block the current thread. | |
551 | /// | |
c34b1796 | 552 | /// # Examples |
1a4d82fc JJ |
553 | /// |
554 | /// ``` | |
555 | /// use std::sync::mpsc::channel; | |
556 | /// | |
557 | /// let (tx, rx) = channel(); | |
558 | /// | |
559 | /// // This send is always successful | |
85aaf69f | 560 | /// tx.send(1).unwrap(); |
1a4d82fc JJ |
561 | /// |
562 | /// // This send will fail because the receiver is gone | |
563 | /// drop(rx); | |
a7813a04 | 564 | /// assert_eq!(tx.send(1).unwrap_err().0, 1); |
1a4d82fc | 565 | /// ``` |
85aaf69f | 566 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
567 | pub fn send(&self, t: T) -> Result<(), SendError<T>> { |
568 | let (new_inner, ret) = match *unsafe { self.inner() } { | |
569 | Flavor::Oneshot(ref p) => { | |
570 | unsafe { | |
571 | let p = p.get(); | |
572 | if !(*p).sent() { | |
573 | return (*p).send(t).map_err(SendError); | |
574 | } else { | |
575 | let a = | |
85aaf69f | 576 | Arc::new(UnsafeCell::new(stream::Packet::new())); |
1a4d82fc JJ |
577 | let rx = Receiver::new(Flavor::Stream(a.clone())); |
578 | match (*p).upgrade(rx) { | |
579 | oneshot::UpSuccess => { | |
580 | let ret = (*a.get()).send(t); | |
581 | (a, ret) | |
582 | } | |
583 | oneshot::UpDisconnected => (a, Err(t)), | |
584 | oneshot::UpWoke(token) => { | |
585 | // This send cannot panic because the thread is | |
586 | // asleep (we're looking at it), so the receiver | |
587 | // can't go away. | |
588 | (*a.get()).send(t).ok().unwrap(); | |
c34b1796 | 589 | token.signal(); |
1a4d82fc JJ |
590 | (a, Ok(())) |
591 | } | |
592 | } | |
593 | } | |
594 | } | |
595 | } | |
596 | Flavor::Stream(ref p) => return unsafe { | |
597 | (*p.get()).send(t).map_err(SendError) | |
598 | }, | |
599 | Flavor::Shared(ref p) => return unsafe { | |
600 | (*p.get()).send(t).map_err(SendError) | |
601 | }, | |
602 | Flavor::Sync(..) => unreachable!(), | |
603 | }; | |
604 | ||
605 | unsafe { | |
606 | let tmp = Sender::new(Flavor::Stream(new_inner)); | |
607 | mem::swap(self.inner_mut(), tmp.inner_mut()); | |
608 | } | |
609 | ret.map_err(SendError) | |
610 | } | |
611 | } | |
612 | ||
85aaf69f | 613 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 614 | impl<T> Clone for Sender<T> { |
1a4d82fc JJ |
615 | fn clone(&self) -> Sender<T> { |
616 | let (packet, sleeper, guard) = match *unsafe { self.inner() } { | |
617 | Flavor::Oneshot(ref p) => { | |
85aaf69f | 618 | let a = Arc::new(UnsafeCell::new(shared::Packet::new())); |
1a4d82fc JJ |
619 | unsafe { |
620 | let guard = (*a.get()).postinit_lock(); | |
621 | let rx = Receiver::new(Flavor::Shared(a.clone())); | |
622 | match (*p.get()).upgrade(rx) { | |
623 | oneshot::UpSuccess | | |
624 | oneshot::UpDisconnected => (a, None, guard), | |
625 | oneshot::UpWoke(task) => (a, Some(task), guard) | |
626 | } | |
627 | } | |
628 | } | |
629 | Flavor::Stream(ref p) => { | |
85aaf69f | 630 | let a = Arc::new(UnsafeCell::new(shared::Packet::new())); |
1a4d82fc JJ |
631 | unsafe { |
632 | let guard = (*a.get()).postinit_lock(); | |
633 | let rx = Receiver::new(Flavor::Shared(a.clone())); | |
634 | match (*p.get()).upgrade(rx) { | |
635 | stream::UpSuccess | | |
636 | stream::UpDisconnected => (a, None, guard), | |
637 | stream::UpWoke(task) => (a, Some(task), guard), | |
638 | } | |
639 | } | |
640 | } | |
641 | Flavor::Shared(ref p) => { | |
642 | unsafe { (*p.get()).clone_chan(); } | |
643 | return Sender::new(Flavor::Shared(p.clone())); | |
644 | } | |
645 | Flavor::Sync(..) => unreachable!(), | |
646 | }; | |
647 | ||
648 | unsafe { | |
649 | (*packet.get()).inherit_blocker(sleeper, guard); | |
650 | ||
651 | let tmp = Sender::new(Flavor::Shared(packet.clone())); | |
652 | mem::swap(self.inner_mut(), tmp.inner_mut()); | |
653 | } | |
654 | Sender::new(Flavor::Shared(packet)) | |
655 | } | |
656 | } | |
657 | ||
85aaf69f | 658 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 659 | impl<T> Drop for Sender<T> { |
1a4d82fc JJ |
660 | fn drop(&mut self) { |
661 | match *unsafe { self.inner_mut() } { | |
662 | Flavor::Oneshot(ref mut p) => unsafe { (*p.get()).drop_chan(); }, | |
663 | Flavor::Stream(ref mut p) => unsafe { (*p.get()).drop_chan(); }, | |
664 | Flavor::Shared(ref mut p) => unsafe { (*p.get()).drop_chan(); }, | |
665 | Flavor::Sync(..) => unreachable!(), | |
666 | } | |
667 | } | |
668 | } | |
669 | ||
7453a54e SL |
670 | #[stable(feature = "mpsc_debug", since = "1.7.0")] |
671 | impl<T> fmt::Debug for Sender<T> { | |
672 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
673 | write!(f, "Sender {{ .. }}") | |
674 | } | |
675 | } | |
676 | ||
1a4d82fc JJ |
677 | //////////////////////////////////////////////////////////////////////////////// |
678 | // SyncSender | |
679 | //////////////////////////////////////////////////////////////////////////////// | |
680 | ||
c34b1796 | 681 | impl<T> SyncSender<T> { |
85aaf69f SL |
682 | fn new(inner: Arc<UnsafeCell<sync::Packet<T>>>) -> SyncSender<T> { |
683 | SyncSender { inner: inner } | |
1a4d82fc JJ |
684 | } |
685 | ||
686 | /// Sends a value on this synchronous channel. | |
687 | /// | |
688 | /// This function will *block* until space in the internal buffer becomes | |
689 | /// available or a receiver is available to hand off the message to. | |
690 | /// | |
691 | /// Note that a successful send does *not* guarantee that the receiver will | |
692 | /// ever see the data if there is a buffer on this channel. Items may be | |
693 | /// enqueued in the internal buffer for the receiver to receive at a later | |
694 | /// time. If the buffer size is 0, however, it can be guaranteed that the | |
695 | /// receiver has indeed received the data if this function returns success. | |
696 | /// | |
697 | /// This function will never panic, but it may return `Err` if the | |
698 | /// `Receiver` has disconnected and is no longer able to receive | |
699 | /// information. | |
85aaf69f | 700 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
701 | pub fn send(&self, t: T) -> Result<(), SendError<T>> { |
702 | unsafe { (*self.inner.get()).send(t).map_err(SendError) } | |
703 | } | |
704 | ||
705 | /// Attempts to send a value on this channel without blocking. | |
706 | /// | |
707 | /// This method differs from `send` by returning immediately if the | |
708 | /// channel's buffer is full or no receiver is waiting to acquire some | |
709 | /// data. Compared with `send`, this function has two failure cases | |
710 | /// instead of one (one for disconnection, one for a full buffer). | |
711 | /// | |
712 | /// See `SyncSender::send` for notes about guarantees of whether the | |
713 | /// receiver has received the data or not if this function is successful. | |
85aaf69f | 714 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
715 | pub fn try_send(&self, t: T) -> Result<(), TrySendError<T>> { |
716 | unsafe { (*self.inner.get()).try_send(t) } | |
717 | } | |
718 | } | |
719 | ||
85aaf69f | 720 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 721 | impl<T> Clone for SyncSender<T> { |
1a4d82fc JJ |
722 | fn clone(&self) -> SyncSender<T> { |
723 | unsafe { (*self.inner.get()).clone_chan(); } | |
e9174d1e | 724 | SyncSender::new(self.inner.clone()) |
1a4d82fc JJ |
725 | } |
726 | } | |
727 | ||
85aaf69f | 728 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 729 | impl<T> Drop for SyncSender<T> { |
1a4d82fc JJ |
730 | fn drop(&mut self) { |
731 | unsafe { (*self.inner.get()).drop_chan(); } | |
732 | } | |
733 | } | |
734 | ||
7453a54e SL |
735 | #[stable(feature = "mpsc_debug", since = "1.7.0")] |
736 | impl<T> fmt::Debug for SyncSender<T> { | |
737 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
738 | write!(f, "SyncSender {{ .. }}") | |
739 | } | |
740 | } | |
741 | ||
1a4d82fc JJ |
742 | //////////////////////////////////////////////////////////////////////////////// |
743 | // Receiver | |
744 | //////////////////////////////////////////////////////////////////////////////// | |
745 | ||
c34b1796 | 746 | impl<T> Receiver<T> { |
1a4d82fc JJ |
747 | fn new(inner: Flavor<T>) -> Receiver<T> { |
748 | Receiver { inner: UnsafeCell::new(inner) } | |
749 | } | |
750 | ||
751 | /// Attempts to return a pending value on this receiver without blocking | |
752 | /// | |
753 | /// This method will never block the caller in order to wait for data to | |
754 | /// become available. Instead, this will always return immediately with a | |
755 | /// possible option of pending data on the channel. | |
756 | /// | |
757 | /// This is useful for a flavor of "optimistic check" before deciding to | |
758 | /// block on a receiver. | |
85aaf69f | 759 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
760 | pub fn try_recv(&self) -> Result<T, TryRecvError> { |
761 | loop { | |
762 | let new_port = match *unsafe { self.inner() } { | |
763 | Flavor::Oneshot(ref p) => { | |
764 | match unsafe { (*p.get()).try_recv() } { | |
765 | Ok(t) => return Ok(t), | |
766 | Err(oneshot::Empty) => return Err(TryRecvError::Empty), | |
767 | Err(oneshot::Disconnected) => { | |
768 | return Err(TryRecvError::Disconnected) | |
769 | } | |
770 | Err(oneshot::Upgraded(rx)) => rx, | |
771 | } | |
772 | } | |
773 | Flavor::Stream(ref p) => { | |
774 | match unsafe { (*p.get()).try_recv() } { | |
775 | Ok(t) => return Ok(t), | |
776 | Err(stream::Empty) => return Err(TryRecvError::Empty), | |
777 | Err(stream::Disconnected) => { | |
778 | return Err(TryRecvError::Disconnected) | |
779 | } | |
780 | Err(stream::Upgraded(rx)) => rx, | |
781 | } | |
782 | } | |
783 | Flavor::Shared(ref p) => { | |
784 | match unsafe { (*p.get()).try_recv() } { | |
785 | Ok(t) => return Ok(t), | |
786 | Err(shared::Empty) => return Err(TryRecvError::Empty), | |
787 | Err(shared::Disconnected) => { | |
788 | return Err(TryRecvError::Disconnected) | |
789 | } | |
790 | } | |
791 | } | |
792 | Flavor::Sync(ref p) => { | |
793 | match unsafe { (*p.get()).try_recv() } { | |
794 | Ok(t) => return Ok(t), | |
795 | Err(sync::Empty) => return Err(TryRecvError::Empty), | |
796 | Err(sync::Disconnected) => { | |
797 | return Err(TryRecvError::Disconnected) | |
798 | } | |
799 | } | |
800 | } | |
801 | }; | |
802 | unsafe { | |
803 | mem::swap(self.inner_mut(), | |
804 | new_port.inner_mut()); | |
805 | } | |
806 | } | |
807 | } | |
808 | ||
9346a6ac | 809 | /// Attempts to wait for a value on this receiver, returning an error if the |
1a4d82fc JJ |
810 | /// corresponding channel has hung up. |
811 | /// | |
812 | /// This function will always block the current thread if there is no data | |
813 | /// available and it's possible for more data to be sent. Once a message is | |
814 | /// sent to the corresponding `Sender`, then this receiver will wake up and | |
815 | /// return that message. | |
816 | /// | |
817 | /// If the corresponding `Sender` has disconnected, or it disconnects while | |
818 | /// this call is blocking, this call will wake up and return `Err` to | |
819 | /// indicate that no more messages can ever be received on this channel. | |
c1a9b12d SL |
820 | /// However, since channels are buffered, messages sent before the disconnect |
821 | /// will still be properly received. | |
822 | /// | |
823 | /// # Examples | |
824 | /// | |
825 | /// ``` | |
826 | /// use std::sync::mpsc; | |
827 | /// use std::thread; | |
828 | /// | |
829 | /// let (send, recv) = mpsc::channel(); | |
830 | /// let handle = thread::spawn(move || { | |
831 | /// send.send(1u8).unwrap(); | |
832 | /// }); | |
833 | /// | |
834 | /// handle.join().unwrap(); | |
835 | /// | |
836 | /// assert_eq!(Ok(1), recv.recv()); | |
837 | /// ``` | |
838 | /// | |
839 | /// Buffering behavior: | |
840 | /// | |
841 | /// ``` | |
842 | /// use std::sync::mpsc; | |
843 | /// use std::thread; | |
844 | /// use std::sync::mpsc::RecvError; | |
845 | /// | |
846 | /// let (send, recv) = mpsc::channel(); | |
847 | /// let handle = thread::spawn(move || { | |
848 | /// send.send(1u8).unwrap(); | |
849 | /// send.send(2).unwrap(); | |
850 | /// send.send(3).unwrap(); | |
851 | /// drop(send); | |
852 | /// }); | |
853 | /// | |
854 | /// // wait for the thread to join so we ensure the sender is dropped | |
855 | /// handle.join().unwrap(); | |
856 | /// | |
857 | /// assert_eq!(Ok(1), recv.recv()); | |
858 | /// assert_eq!(Ok(2), recv.recv()); | |
859 | /// assert_eq!(Ok(3), recv.recv()); | |
860 | /// assert_eq!(Err(RecvError), recv.recv()); | |
861 | /// ``` | |
85aaf69f | 862 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
863 | pub fn recv(&self) -> Result<T, RecvError> { |
864 | loop { | |
865 | let new_port = match *unsafe { self.inner() } { | |
866 | Flavor::Oneshot(ref p) => { | |
3157f602 | 867 | match unsafe { (*p.get()).recv(None) } { |
1a4d82fc | 868 | Ok(t) => return Ok(t), |
1a4d82fc JJ |
869 | Err(oneshot::Disconnected) => return Err(RecvError), |
870 | Err(oneshot::Upgraded(rx)) => rx, | |
3157f602 | 871 | Err(oneshot::Empty) => unreachable!(), |
1a4d82fc JJ |
872 | } |
873 | } | |
874 | Flavor::Stream(ref p) => { | |
3157f602 | 875 | match unsafe { (*p.get()).recv(None) } { |
1a4d82fc | 876 | Ok(t) => return Ok(t), |
1a4d82fc JJ |
877 | Err(stream::Disconnected) => return Err(RecvError), |
878 | Err(stream::Upgraded(rx)) => rx, | |
3157f602 | 879 | Err(stream::Empty) => unreachable!(), |
1a4d82fc JJ |
880 | } |
881 | } | |
882 | Flavor::Shared(ref p) => { | |
3157f602 | 883 | match unsafe { (*p.get()).recv(None) } { |
1a4d82fc | 884 | Ok(t) => return Ok(t), |
1a4d82fc | 885 | Err(shared::Disconnected) => return Err(RecvError), |
3157f602 | 886 | Err(shared::Empty) => unreachable!(), |
1a4d82fc JJ |
887 | } |
888 | } | |
889 | Flavor::Sync(ref p) => return unsafe { | |
3157f602 | 890 | (*p.get()).recv(None).map_err(|_| RecvError) |
1a4d82fc JJ |
891 | } |
892 | }; | |
893 | unsafe { | |
894 | mem::swap(self.inner_mut(), new_port.inner_mut()); | |
895 | } | |
896 | } | |
897 | } | |
898 | ||
3157f602 XL |
899 | /// Attempts to wait for a value on this receiver, returning an error if the |
900 | /// corresponding channel has hung up, or if it waits more than `timeout`. | |
901 | /// | |
902 | /// This function will always block the current thread if there is no data | |
903 | /// available and it's possible for more data to be sent. Once a message is | |
904 | /// sent to the corresponding `Sender`, then this receiver will wake up and | |
905 | /// return that message. | |
906 | /// | |
907 | /// If the corresponding `Sender` has disconnected, or it disconnects while | |
908 | /// this call is blocking, this call will wake up and return `Err` to | |
909 | /// indicate that no more messages can ever be received on this channel. | |
910 | /// However, since channels are buffered, messages sent before the disconnect | |
911 | /// will still be properly received. | |
912 | /// | |
913 | /// # Examples | |
914 | /// | |
915 | /// ```no_run | |
3157f602 XL |
916 | /// use std::sync::mpsc::{self, RecvTimeoutError}; |
917 | /// use std::time::Duration; | |
918 | /// | |
919 | /// let (send, recv) = mpsc::channel::<()>(); | |
920 | /// | |
921 | /// let timeout = Duration::from_millis(100); | |
922 | /// assert_eq!(Err(RecvTimeoutError::Timeout), recv.recv_timeout(timeout)); | |
923 | /// ``` | |
5bcae85e | 924 | #[stable(feature = "mpsc_recv_timeout", since = "1.12.0")] |
3157f602 XL |
925 | pub fn recv_timeout(&self, timeout: Duration) -> Result<T, RecvTimeoutError> { |
926 | // Do an optimistic try_recv to avoid the performance impact of | |
927 | // Instant::now() in the full-channel case. | |
928 | match self.try_recv() { | |
929 | Ok(result) | |
930 | => Ok(result), | |
931 | Err(TryRecvError::Disconnected) | |
932 | => Err(RecvTimeoutError::Disconnected), | |
933 | Err(TryRecvError::Empty) | |
934 | => self.recv_max_until(Instant::now() + timeout) | |
935 | } | |
936 | } | |
937 | ||
938 | fn recv_max_until(&self, deadline: Instant) -> Result<T, RecvTimeoutError> { | |
939 | use self::RecvTimeoutError::*; | |
940 | ||
941 | loop { | |
942 | let port_or_empty = match *unsafe { self.inner() } { | |
943 | Flavor::Oneshot(ref p) => { | |
944 | match unsafe { (*p.get()).recv(Some(deadline)) } { | |
945 | Ok(t) => return Ok(t), | |
946 | Err(oneshot::Disconnected) => return Err(Disconnected), | |
947 | Err(oneshot::Upgraded(rx)) => Some(rx), | |
948 | Err(oneshot::Empty) => None, | |
949 | } | |
950 | } | |
951 | Flavor::Stream(ref p) => { | |
952 | match unsafe { (*p.get()).recv(Some(deadline)) } { | |
953 | Ok(t) => return Ok(t), | |
954 | Err(stream::Disconnected) => return Err(Disconnected), | |
955 | Err(stream::Upgraded(rx)) => Some(rx), | |
956 | Err(stream::Empty) => None, | |
957 | } | |
958 | } | |
959 | Flavor::Shared(ref p) => { | |
960 | match unsafe { (*p.get()).recv(Some(deadline)) } { | |
961 | Ok(t) => return Ok(t), | |
962 | Err(shared::Disconnected) => return Err(Disconnected), | |
963 | Err(shared::Empty) => None, | |
964 | } | |
965 | } | |
966 | Flavor::Sync(ref p) => { | |
967 | match unsafe { (*p.get()).recv(Some(deadline)) } { | |
968 | Ok(t) => return Ok(t), | |
969 | Err(sync::Disconnected) => return Err(Disconnected), | |
970 | Err(sync::Empty) => None, | |
971 | } | |
972 | } | |
973 | }; | |
974 | ||
975 | if let Some(new_port) = port_or_empty { | |
976 | unsafe { | |
977 | mem::swap(self.inner_mut(), new_port.inner_mut()); | |
978 | } | |
979 | } | |
980 | ||
981 | // If we're already passed the deadline, and we're here without | |
982 | // data, return a timeout, else try again. | |
983 | if Instant::now() >= deadline { | |
984 | return Err(Timeout); | |
985 | } | |
986 | } | |
987 | } | |
988 | ||
1a4d82fc JJ |
989 | /// Returns an iterator that will block waiting for messages, but never |
990 | /// `panic!`. It will return `None` when the channel has hung up. | |
85aaf69f | 991 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
992 | pub fn iter(&self) -> Iter<T> { |
993 | Iter { rx: self } | |
994 | } | |
5bcae85e SL |
995 | |
996 | /// Returns an iterator that will attempt to yield all pending values. | |
997 | /// It will return `None` if there are no more pending values or if the | |
998 | /// channel has hung up. The iterator will never `panic!` or block the | |
999 | /// user by waiting for values. | |
1000 | #[unstable(feature = "receiver_try_iter", issue = "34931")] | |
1001 | pub fn try_iter(&self) -> TryIter<T> { | |
1002 | TryIter { rx: self } | |
1003 | } | |
1004 | ||
1a4d82fc JJ |
1005 | } |
1006 | ||
c34b1796 | 1007 | impl<T> select::Packet for Receiver<T> { |
1a4d82fc JJ |
1008 | fn can_recv(&self) -> bool { |
1009 | loop { | |
1010 | let new_port = match *unsafe { self.inner() } { | |
1011 | Flavor::Oneshot(ref p) => { | |
1012 | match unsafe { (*p.get()).can_recv() } { | |
1013 | Ok(ret) => return ret, | |
1014 | Err(upgrade) => upgrade, | |
1015 | } | |
1016 | } | |
1017 | Flavor::Stream(ref p) => { | |
1018 | match unsafe { (*p.get()).can_recv() } { | |
1019 | Ok(ret) => return ret, | |
1020 | Err(upgrade) => upgrade, | |
1021 | } | |
1022 | } | |
1023 | Flavor::Shared(ref p) => { | |
1024 | return unsafe { (*p.get()).can_recv() }; | |
1025 | } | |
1026 | Flavor::Sync(ref p) => { | |
1027 | return unsafe { (*p.get()).can_recv() }; | |
1028 | } | |
1029 | }; | |
1030 | unsafe { | |
1031 | mem::swap(self.inner_mut(), | |
1032 | new_port.inner_mut()); | |
1033 | } | |
1034 | } | |
1035 | } | |
1036 | ||
1037 | fn start_selection(&self, mut token: SignalToken) -> StartResult { | |
1038 | loop { | |
1039 | let (t, new_port) = match *unsafe { self.inner() } { | |
1040 | Flavor::Oneshot(ref p) => { | |
1041 | match unsafe { (*p.get()).start_selection(token) } { | |
1042 | oneshot::SelSuccess => return Installed, | |
1043 | oneshot::SelCanceled => return Abort, | |
1044 | oneshot::SelUpgraded(t, rx) => (t, rx), | |
1045 | } | |
1046 | } | |
1047 | Flavor::Stream(ref p) => { | |
1048 | match unsafe { (*p.get()).start_selection(token) } { | |
1049 | stream::SelSuccess => return Installed, | |
1050 | stream::SelCanceled => return Abort, | |
1051 | stream::SelUpgraded(t, rx) => (t, rx), | |
1052 | } | |
1053 | } | |
1054 | Flavor::Shared(ref p) => { | |
1055 | return unsafe { (*p.get()).start_selection(token) }; | |
1056 | } | |
1057 | Flavor::Sync(ref p) => { | |
1058 | return unsafe { (*p.get()).start_selection(token) }; | |
1059 | } | |
1060 | }; | |
1061 | token = t; | |
1062 | unsafe { | |
1063 | mem::swap(self.inner_mut(), new_port.inner_mut()); | |
1064 | } | |
1065 | } | |
1066 | } | |
1067 | ||
1068 | fn abort_selection(&self) -> bool { | |
1069 | let mut was_upgrade = false; | |
1070 | loop { | |
1071 | let result = match *unsafe { self.inner() } { | |
1072 | Flavor::Oneshot(ref p) => unsafe { (*p.get()).abort_selection() }, | |
1073 | Flavor::Stream(ref p) => unsafe { | |
1074 | (*p.get()).abort_selection(was_upgrade) | |
1075 | }, | |
1076 | Flavor::Shared(ref p) => return unsafe { | |
1077 | (*p.get()).abort_selection(was_upgrade) | |
1078 | }, | |
1079 | Flavor::Sync(ref p) => return unsafe { | |
1080 | (*p.get()).abort_selection() | |
1081 | }, | |
1082 | }; | |
1083 | let new_port = match result { Ok(b) => return b, Err(p) => p }; | |
1084 | was_upgrade = true; | |
1085 | unsafe { | |
1086 | mem::swap(self.inner_mut(), | |
1087 | new_port.inner_mut()); | |
1088 | } | |
1089 | } | |
1090 | } | |
1091 | } | |
1092 | ||
85aaf69f | 1093 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 1094 | impl<'a, T> Iterator for Iter<'a, T> { |
1a4d82fc JJ |
1095 | type Item = T; |
1096 | ||
1097 | fn next(&mut self) -> Option<T> { self.rx.recv().ok() } | |
1098 | } | |
1099 | ||
5bcae85e SL |
1100 | #[unstable(feature = "receiver_try_iter", issue = "34931")] |
1101 | impl<'a, T> Iterator for TryIter<'a, T> { | |
1102 | type Item = T; | |
1103 | ||
1104 | fn next(&mut self) -> Option<T> { self.rx.try_recv().ok() } | |
1105 | } | |
1106 | ||
d9579d0f AL |
1107 | #[stable(feature = "receiver_into_iter", since = "1.1.0")] |
1108 | impl<'a, T> IntoIterator for &'a Receiver<T> { | |
1109 | type Item = T; | |
1110 | type IntoIter = Iter<'a, T>; | |
1111 | ||
1112 | fn into_iter(self) -> Iter<'a, T> { self.iter() } | |
1113 | } | |
1114 | ||
92a42be0 | 1115 | #[stable(feature = "receiver_into_iter", since = "1.1.0")] |
d9579d0f AL |
1116 | impl<T> Iterator for IntoIter<T> { |
1117 | type Item = T; | |
1118 | fn next(&mut self) -> Option<T> { self.rx.recv().ok() } | |
1119 | } | |
1120 | ||
1121 | #[stable(feature = "receiver_into_iter", since = "1.1.0")] | |
1122 | impl <T> IntoIterator for Receiver<T> { | |
1123 | type Item = T; | |
1124 | type IntoIter = IntoIter<T>; | |
1125 | ||
1126 | fn into_iter(self) -> IntoIter<T> { | |
1127 | IntoIter { rx: self } | |
1128 | } | |
1129 | } | |
1130 | ||
85aaf69f | 1131 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 1132 | impl<T> Drop for Receiver<T> { |
1a4d82fc JJ |
1133 | fn drop(&mut self) { |
1134 | match *unsafe { self.inner_mut() } { | |
1135 | Flavor::Oneshot(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
1136 | Flavor::Stream(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
1137 | Flavor::Shared(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
1138 | Flavor::Sync(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
1139 | } | |
1140 | } | |
1141 | } | |
1142 | ||
7453a54e SL |
1143 | #[stable(feature = "mpsc_debug", since = "1.7.0")] |
1144 | impl<T> fmt::Debug for Receiver<T> { | |
1145 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
1146 | write!(f, "Receiver {{ .. }}") | |
1147 | } | |
1148 | } | |
1149 | ||
85aaf69f SL |
1150 | #[stable(feature = "rust1", since = "1.0.0")] |
1151 | impl<T> fmt::Debug for SendError<T> { | |
1152 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
1153 | "SendError(..)".fmt(f) | |
1a4d82fc | 1154 | } |
85aaf69f | 1155 | } |
1a4d82fc | 1156 | |
85aaf69f SL |
1157 | #[stable(feature = "rust1", since = "1.0.0")] |
1158 | impl<T> fmt::Display for SendError<T> { | |
1159 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
1160 | "sending on a closed channel".fmt(f) | |
1a4d82fc | 1161 | } |
1a4d82fc JJ |
1162 | } |
1163 | ||
c34b1796 | 1164 | #[stable(feature = "rust1", since = "1.0.0")] |
9e0c209e | 1165 | impl<T: Send> error::Error for SendError<T> { |
c34b1796 AL |
1166 | fn description(&self) -> &str { |
1167 | "sending on a closed channel" | |
1168 | } | |
1169 | ||
1170 | fn cause(&self) -> Option<&error::Error> { | |
1171 | None | |
1172 | } | |
1173 | } | |
1174 | ||
85aaf69f SL |
1175 | #[stable(feature = "rust1", since = "1.0.0")] |
1176 | impl<T> fmt::Debug for TrySendError<T> { | |
1a4d82fc | 1177 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
85aaf69f SL |
1178 | match *self { |
1179 | TrySendError::Full(..) => "Full(..)".fmt(f), | |
1180 | TrySendError::Disconnected(..) => "Disconnected(..)".fmt(f), | |
1181 | } | |
1a4d82fc JJ |
1182 | } |
1183 | } | |
1184 | ||
85aaf69f SL |
1185 | #[stable(feature = "rust1", since = "1.0.0")] |
1186 | impl<T> fmt::Display for TrySendError<T> { | |
1a4d82fc JJ |
1187 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
1188 | match *self { | |
1189 | TrySendError::Full(..) => { | |
1190 | "sending on a full channel".fmt(f) | |
1191 | } | |
1192 | TrySendError::Disconnected(..) => { | |
1193 | "sending on a closed channel".fmt(f) | |
1194 | } | |
1195 | } | |
1196 | } | |
1197 | } | |
1198 | ||
c34b1796 | 1199 | #[stable(feature = "rust1", since = "1.0.0")] |
9e0c209e | 1200 | impl<T: Send> error::Error for TrySendError<T> { |
c34b1796 AL |
1201 | |
1202 | fn description(&self) -> &str { | |
1203 | match *self { | |
1204 | TrySendError::Full(..) => { | |
1205 | "sending on a full channel" | |
1206 | } | |
1207 | TrySendError::Disconnected(..) => { | |
1208 | "sending on a closed channel" | |
1209 | } | |
1210 | } | |
1211 | } | |
1212 | ||
1213 | fn cause(&self) -> Option<&error::Error> { | |
1214 | None | |
1215 | } | |
1216 | } | |
1217 | ||
85aaf69f SL |
1218 | #[stable(feature = "rust1", since = "1.0.0")] |
1219 | impl fmt::Display for RecvError { | |
1a4d82fc JJ |
1220 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
1221 | "receiving on a closed channel".fmt(f) | |
1222 | } | |
1223 | } | |
1224 | ||
c34b1796 AL |
1225 | #[stable(feature = "rust1", since = "1.0.0")] |
1226 | impl error::Error for RecvError { | |
1227 | ||
1228 | fn description(&self) -> &str { | |
1229 | "receiving on a closed channel" | |
1230 | } | |
1231 | ||
1232 | fn cause(&self) -> Option<&error::Error> { | |
1233 | None | |
1234 | } | |
1235 | } | |
1236 | ||
85aaf69f SL |
1237 | #[stable(feature = "rust1", since = "1.0.0")] |
1238 | impl fmt::Display for TryRecvError { | |
1a4d82fc JJ |
1239 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
1240 | match *self { | |
1241 | TryRecvError::Empty => { | |
1242 | "receiving on an empty channel".fmt(f) | |
1243 | } | |
1244 | TryRecvError::Disconnected => { | |
1245 | "receiving on a closed channel".fmt(f) | |
1246 | } | |
1247 | } | |
1248 | } | |
1249 | } | |
1250 | ||
c34b1796 AL |
1251 | #[stable(feature = "rust1", since = "1.0.0")] |
1252 | impl error::Error for TryRecvError { | |
1253 | ||
1254 | fn description(&self) -> &str { | |
1255 | match *self { | |
1256 | TryRecvError::Empty => { | |
1257 | "receiving on an empty channel" | |
1258 | } | |
1259 | TryRecvError::Disconnected => { | |
1260 | "receiving on a closed channel" | |
1261 | } | |
1262 | } | |
1263 | } | |
1264 | ||
1265 | fn cause(&self) -> Option<&error::Error> { | |
1266 | None | |
1267 | } | |
1268 | } | |
1269 | ||
1a4d82fc | 1270 | #[cfg(test)] |
d9579d0f | 1271 | mod tests { |
c1a9b12d | 1272 | use env; |
1a4d82fc | 1273 | use super::*; |
85aaf69f | 1274 | use thread; |
3157f602 | 1275 | use time::{Duration, Instant}; |
1a4d82fc | 1276 | |
c34b1796 | 1277 | pub fn stress_factor() -> usize { |
85aaf69f SL |
1278 | match env::var("RUST_TEST_STRESS") { |
1279 | Ok(val) => val.parse().unwrap(), | |
1280 | Err(..) => 1, | |
1a4d82fc JJ |
1281 | } |
1282 | } | |
1283 | ||
1284 | #[test] | |
1285 | fn smoke() { | |
c34b1796 | 1286 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1287 | tx.send(1).unwrap(); |
1288 | assert_eq!(rx.recv().unwrap(), 1); | |
1289 | } | |
1290 | ||
1291 | #[test] | |
1292 | fn drop_full() { | |
c34b1796 | 1293 | let (tx, _rx) = channel::<Box<isize>>(); |
85aaf69f | 1294 | tx.send(box 1).unwrap(); |
1a4d82fc JJ |
1295 | } |
1296 | ||
1297 | #[test] | |
1298 | fn drop_full_shared() { | |
c34b1796 | 1299 | let (tx, _rx) = channel::<Box<isize>>(); |
1a4d82fc JJ |
1300 | drop(tx.clone()); |
1301 | drop(tx.clone()); | |
85aaf69f | 1302 | tx.send(box 1).unwrap(); |
1a4d82fc JJ |
1303 | } |
1304 | ||
1305 | #[test] | |
1306 | fn smoke_shared() { | |
c34b1796 | 1307 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1308 | tx.send(1).unwrap(); |
1309 | assert_eq!(rx.recv().unwrap(), 1); | |
1310 | let tx = tx.clone(); | |
1311 | tx.send(1).unwrap(); | |
1312 | assert_eq!(rx.recv().unwrap(), 1); | |
1313 | } | |
1314 | ||
1315 | #[test] | |
1316 | fn smoke_threads() { | |
c34b1796 | 1317 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1318 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1319 | tx.send(1).unwrap(); |
1320 | }); | |
1321 | assert_eq!(rx.recv().unwrap(), 1); | |
1322 | } | |
1323 | ||
1324 | #[test] | |
1325 | fn smoke_port_gone() { | |
c34b1796 | 1326 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1327 | drop(rx); |
1328 | assert!(tx.send(1).is_err()); | |
1329 | } | |
1330 | ||
1331 | #[test] | |
1332 | fn smoke_shared_port_gone() { | |
c34b1796 | 1333 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1334 | drop(rx); |
1335 | assert!(tx.send(1).is_err()) | |
1336 | } | |
1337 | ||
1338 | #[test] | |
1339 | fn smoke_shared_port_gone2() { | |
c34b1796 | 1340 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1341 | drop(rx); |
1342 | let tx2 = tx.clone(); | |
1343 | drop(tx); | |
1344 | assert!(tx2.send(1).is_err()); | |
1345 | } | |
1346 | ||
1347 | #[test] | |
1348 | fn port_gone_concurrent() { | |
c34b1796 | 1349 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1350 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1351 | rx.recv().unwrap(); |
1352 | }); | |
1353 | while tx.send(1).is_ok() {} | |
1354 | } | |
1355 | ||
1356 | #[test] | |
1357 | fn port_gone_concurrent_shared() { | |
c34b1796 | 1358 | let (tx, rx) = channel::<i32>(); |
1a4d82fc | 1359 | let tx2 = tx.clone(); |
85aaf69f | 1360 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1361 | rx.recv().unwrap(); |
1362 | }); | |
1363 | while tx.send(1).is_ok() && tx2.send(1).is_ok() {} | |
1364 | } | |
1365 | ||
1366 | #[test] | |
1367 | fn smoke_chan_gone() { | |
c34b1796 | 1368 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1369 | drop(tx); |
1370 | assert!(rx.recv().is_err()); | |
1371 | } | |
1372 | ||
1373 | #[test] | |
1374 | fn smoke_chan_gone_shared() { | |
1375 | let (tx, rx) = channel::<()>(); | |
1376 | let tx2 = tx.clone(); | |
1377 | drop(tx); | |
1378 | drop(tx2); | |
1379 | assert!(rx.recv().is_err()); | |
1380 | } | |
1381 | ||
1382 | #[test] | |
1383 | fn chan_gone_concurrent() { | |
c34b1796 | 1384 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1385 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1386 | tx.send(1).unwrap(); |
1387 | tx.send(1).unwrap(); | |
1388 | }); | |
1389 | while rx.recv().is_ok() {} | |
1390 | } | |
1391 | ||
1392 | #[test] | |
1393 | fn stress() { | |
c34b1796 | 1394 | let (tx, rx) = channel::<i32>(); |
85aaf69f SL |
1395 | let t = thread::spawn(move|| { |
1396 | for _ in 0..10000 { tx.send(1).unwrap(); } | |
1a4d82fc | 1397 | }); |
85aaf69f | 1398 | for _ in 0..10000 { |
1a4d82fc JJ |
1399 | assert_eq!(rx.recv().unwrap(), 1); |
1400 | } | |
1401 | t.join().ok().unwrap(); | |
1402 | } | |
1403 | ||
1404 | #[test] | |
1405 | fn stress_shared() { | |
c34b1796 AL |
1406 | const AMT: u32 = 10000; |
1407 | const NTHREADS: u32 = 8; | |
1408 | let (tx, rx) = channel::<i32>(); | |
1a4d82fc | 1409 | |
85aaf69f SL |
1410 | let t = thread::spawn(move|| { |
1411 | for _ in 0..AMT * NTHREADS { | |
1a4d82fc JJ |
1412 | assert_eq!(rx.recv().unwrap(), 1); |
1413 | } | |
1414 | match rx.try_recv() { | |
1415 | Ok(..) => panic!(), | |
1416 | _ => {} | |
1417 | } | |
1418 | }); | |
1419 | ||
85aaf69f | 1420 | for _ in 0..NTHREADS { |
1a4d82fc | 1421 | let tx = tx.clone(); |
85aaf69f SL |
1422 | thread::spawn(move|| { |
1423 | for _ in 0..AMT { tx.send(1).unwrap(); } | |
1a4d82fc JJ |
1424 | }); |
1425 | } | |
1426 | drop(tx); | |
1427 | t.join().ok().unwrap(); | |
1428 | } | |
1429 | ||
1430 | #[test] | |
1431 | fn send_from_outside_runtime() { | |
1432 | let (tx1, rx1) = channel::<()>(); | |
c34b1796 | 1433 | let (tx2, rx2) = channel::<i32>(); |
85aaf69f | 1434 | let t1 = thread::spawn(move|| { |
1a4d82fc | 1435 | tx1.send(()).unwrap(); |
85aaf69f | 1436 | for _ in 0..40 { |
1a4d82fc JJ |
1437 | assert_eq!(rx2.recv().unwrap(), 1); |
1438 | } | |
1439 | }); | |
1440 | rx1.recv().unwrap(); | |
85aaf69f SL |
1441 | let t2 = thread::spawn(move|| { |
1442 | for _ in 0..40 { | |
1a4d82fc JJ |
1443 | tx2.send(1).unwrap(); |
1444 | } | |
1445 | }); | |
1446 | t1.join().ok().unwrap(); | |
1447 | t2.join().ok().unwrap(); | |
1448 | } | |
1449 | ||
1450 | #[test] | |
1451 | fn recv_from_outside_runtime() { | |
c34b1796 | 1452 | let (tx, rx) = channel::<i32>(); |
85aaf69f SL |
1453 | let t = thread::spawn(move|| { |
1454 | for _ in 0..40 { | |
1a4d82fc JJ |
1455 | assert_eq!(rx.recv().unwrap(), 1); |
1456 | } | |
1457 | }); | |
85aaf69f | 1458 | for _ in 0..40 { |
1a4d82fc JJ |
1459 | tx.send(1).unwrap(); |
1460 | } | |
1461 | t.join().ok().unwrap(); | |
1462 | } | |
1463 | ||
1464 | #[test] | |
1465 | fn no_runtime() { | |
c34b1796 AL |
1466 | let (tx1, rx1) = channel::<i32>(); |
1467 | let (tx2, rx2) = channel::<i32>(); | |
85aaf69f | 1468 | let t1 = thread::spawn(move|| { |
1a4d82fc JJ |
1469 | assert_eq!(rx1.recv().unwrap(), 1); |
1470 | tx2.send(2).unwrap(); | |
1471 | }); | |
85aaf69f | 1472 | let t2 = thread::spawn(move|| { |
1a4d82fc JJ |
1473 | tx1.send(1).unwrap(); |
1474 | assert_eq!(rx2.recv().unwrap(), 2); | |
1475 | }); | |
1476 | t1.join().ok().unwrap(); | |
1477 | t2.join().ok().unwrap(); | |
1478 | } | |
1479 | ||
1480 | #[test] | |
1481 | fn oneshot_single_thread_close_port_first() { | |
1482 | // Simple test of closing without sending | |
c34b1796 | 1483 | let (_tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1484 | drop(rx); |
1485 | } | |
1486 | ||
1487 | #[test] | |
1488 | fn oneshot_single_thread_close_chan_first() { | |
1489 | // Simple test of closing without sending | |
c34b1796 | 1490 | let (tx, _rx) = channel::<i32>(); |
1a4d82fc JJ |
1491 | drop(tx); |
1492 | } | |
1493 | ||
1494 | #[test] | |
1495 | fn oneshot_single_thread_send_port_close() { | |
1496 | // Testing that the sender cleans up the payload if receiver is closed | |
c34b1796 | 1497 | let (tx, rx) = channel::<Box<i32>>(); |
1a4d82fc JJ |
1498 | drop(rx); |
1499 | assert!(tx.send(box 0).is_err()); | |
1500 | } | |
1501 | ||
1502 | #[test] | |
1503 | fn oneshot_single_thread_recv_chan_close() { | |
1504 | // Receiving on a closed chan will panic | |
85aaf69f | 1505 | let res = thread::spawn(move|| { |
c34b1796 | 1506 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1507 | drop(tx); |
1508 | rx.recv().unwrap(); | |
1509 | }).join(); | |
1510 | // What is our res? | |
1511 | assert!(res.is_err()); | |
1512 | } | |
1513 | ||
1514 | #[test] | |
1515 | fn oneshot_single_thread_send_then_recv() { | |
c34b1796 | 1516 | let (tx, rx) = channel::<Box<i32>>(); |
1a4d82fc JJ |
1517 | tx.send(box 10).unwrap(); |
1518 | assert!(rx.recv().unwrap() == box 10); | |
1519 | } | |
1520 | ||
1521 | #[test] | |
1522 | fn oneshot_single_thread_try_send_open() { | |
c34b1796 | 1523 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1524 | assert!(tx.send(10).is_ok()); |
1525 | assert!(rx.recv().unwrap() == 10); | |
1526 | } | |
1527 | ||
1528 | #[test] | |
1529 | fn oneshot_single_thread_try_send_closed() { | |
c34b1796 | 1530 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1531 | drop(rx); |
1532 | assert!(tx.send(10).is_err()); | |
1533 | } | |
1534 | ||
1535 | #[test] | |
1536 | fn oneshot_single_thread_try_recv_open() { | |
c34b1796 | 1537 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1538 | tx.send(10).unwrap(); |
1539 | assert!(rx.recv() == Ok(10)); | |
1540 | } | |
1541 | ||
1542 | #[test] | |
1543 | fn oneshot_single_thread_try_recv_closed() { | |
c34b1796 | 1544 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1545 | drop(tx); |
1546 | assert!(rx.recv().is_err()); | |
1547 | } | |
1548 | ||
1549 | #[test] | |
1550 | fn oneshot_single_thread_peek_data() { | |
c34b1796 | 1551 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1552 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
1553 | tx.send(10).unwrap(); | |
1554 | assert_eq!(rx.try_recv(), Ok(10)); | |
1555 | } | |
1556 | ||
1557 | #[test] | |
1558 | fn oneshot_single_thread_peek_close() { | |
c34b1796 | 1559 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1560 | drop(tx); |
1561 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
1562 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
1563 | } | |
1564 | ||
1565 | #[test] | |
1566 | fn oneshot_single_thread_peek_open() { | |
c34b1796 | 1567 | let (_tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1568 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
1569 | } | |
1570 | ||
1571 | #[test] | |
1572 | fn oneshot_multi_task_recv_then_send() { | |
c34b1796 | 1573 | let (tx, rx) = channel::<Box<i32>>(); |
85aaf69f | 1574 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1575 | assert!(rx.recv().unwrap() == box 10); |
1576 | }); | |
1577 | ||
1578 | tx.send(box 10).unwrap(); | |
1579 | } | |
1580 | ||
1581 | #[test] | |
1582 | fn oneshot_multi_task_recv_then_close() { | |
c34b1796 | 1583 | let (tx, rx) = channel::<Box<i32>>(); |
85aaf69f | 1584 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1585 | drop(tx); |
1586 | }); | |
85aaf69f | 1587 | let res = thread::spawn(move|| { |
1a4d82fc JJ |
1588 | assert!(rx.recv().unwrap() == box 10); |
1589 | }).join(); | |
1590 | assert!(res.is_err()); | |
1591 | } | |
1592 | ||
1593 | #[test] | |
1594 | fn oneshot_multi_thread_close_stress() { | |
85aaf69f | 1595 | for _ in 0..stress_factor() { |
c34b1796 | 1596 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1597 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1598 | drop(rx); |
1599 | }); | |
1600 | drop(tx); | |
1601 | } | |
1602 | } | |
1603 | ||
1604 | #[test] | |
1605 | fn oneshot_multi_thread_send_close_stress() { | |
85aaf69f | 1606 | for _ in 0..stress_factor() { |
c34b1796 | 1607 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1608 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1609 | drop(rx); |
1610 | }); | |
85aaf69f | 1611 | let _ = thread::spawn(move|| { |
1a4d82fc JJ |
1612 | tx.send(1).unwrap(); |
1613 | }).join(); | |
1614 | } | |
1615 | } | |
1616 | ||
1617 | #[test] | |
1618 | fn oneshot_multi_thread_recv_close_stress() { | |
85aaf69f | 1619 | for _ in 0..stress_factor() { |
c34b1796 | 1620 | let (tx, rx) = channel::<i32>(); |
85aaf69f SL |
1621 | thread::spawn(move|| { |
1622 | let res = thread::spawn(move|| { | |
1a4d82fc JJ |
1623 | rx.recv().unwrap(); |
1624 | }).join(); | |
1625 | assert!(res.is_err()); | |
1626 | }); | |
85aaf69f SL |
1627 | let _t = thread::spawn(move|| { |
1628 | thread::spawn(move|| { | |
1a4d82fc JJ |
1629 | drop(tx); |
1630 | }); | |
1631 | }); | |
1632 | } | |
1633 | } | |
1634 | ||
1635 | #[test] | |
1636 | fn oneshot_multi_thread_send_recv_stress() { | |
85aaf69f | 1637 | for _ in 0..stress_factor() { |
c34b1796 | 1638 | let (tx, rx) = channel::<Box<isize>>(); |
85aaf69f SL |
1639 | let _t = thread::spawn(move|| { |
1640 | tx.send(box 10).unwrap(); | |
1a4d82fc | 1641 | }); |
85aaf69f | 1642 | assert!(rx.recv().unwrap() == box 10); |
1a4d82fc JJ |
1643 | } |
1644 | } | |
1645 | ||
1646 | #[test] | |
1647 | fn stream_send_recv_stress() { | |
85aaf69f | 1648 | for _ in 0..stress_factor() { |
1a4d82fc JJ |
1649 | let (tx, rx) = channel(); |
1650 | ||
1651 | send(tx, 0); | |
1652 | recv(rx, 0); | |
1653 | ||
c34b1796 | 1654 | fn send(tx: Sender<Box<i32>>, i: i32) { |
1a4d82fc JJ |
1655 | if i == 10 { return } |
1656 | ||
85aaf69f | 1657 | thread::spawn(move|| { |
1a4d82fc JJ |
1658 | tx.send(box i).unwrap(); |
1659 | send(tx, i + 1); | |
1660 | }); | |
1661 | } | |
1662 | ||
c34b1796 | 1663 | fn recv(rx: Receiver<Box<i32>>, i: i32) { |
1a4d82fc JJ |
1664 | if i == 10 { return } |
1665 | ||
85aaf69f | 1666 | thread::spawn(move|| { |
1a4d82fc JJ |
1667 | assert!(rx.recv().unwrap() == box i); |
1668 | recv(rx, i + 1); | |
1669 | }); | |
1670 | } | |
1671 | } | |
1672 | } | |
1673 | ||
3157f602 XL |
1674 | #[test] |
1675 | fn oneshot_single_thread_recv_timeout() { | |
1676 | let (tx, rx) = channel(); | |
1677 | tx.send(()).unwrap(); | |
1678 | assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(())); | |
1679 | assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Err(RecvTimeoutError::Timeout)); | |
1680 | tx.send(()).unwrap(); | |
1681 | assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(())); | |
1682 | } | |
1683 | ||
1684 | #[test] | |
1685 | fn stress_recv_timeout_two_threads() { | |
1686 | let (tx, rx) = channel(); | |
1687 | let stress = stress_factor() + 100; | |
1688 | let timeout = Duration::from_millis(100); | |
1689 | ||
1690 | thread::spawn(move || { | |
1691 | for i in 0..stress { | |
1692 | if i % 2 == 0 { | |
1693 | thread::sleep(timeout * 2); | |
1694 | } | |
1695 | tx.send(1usize).unwrap(); | |
1696 | } | |
1697 | }); | |
1698 | ||
1699 | let mut recv_count = 0; | |
1700 | loop { | |
1701 | match rx.recv_timeout(timeout) { | |
1702 | Ok(n) => { | |
1703 | assert_eq!(n, 1usize); | |
1704 | recv_count += 1; | |
1705 | } | |
1706 | Err(RecvTimeoutError::Timeout) => continue, | |
1707 | Err(RecvTimeoutError::Disconnected) => break, | |
1708 | } | |
1709 | } | |
1710 | ||
1711 | assert_eq!(recv_count, stress); | |
1712 | } | |
1713 | ||
1714 | #[test] | |
1715 | fn recv_timeout_upgrade() { | |
1716 | let (tx, rx) = channel::<()>(); | |
1717 | let timeout = Duration::from_millis(1); | |
1718 | let _tx_clone = tx.clone(); | |
1719 | ||
1720 | let start = Instant::now(); | |
1721 | assert_eq!(rx.recv_timeout(timeout), Err(RecvTimeoutError::Timeout)); | |
1722 | assert!(Instant::now() >= start + timeout); | |
1723 | } | |
1724 | ||
1725 | #[test] | |
1726 | fn stress_recv_timeout_shared() { | |
1727 | let (tx, rx) = channel(); | |
1728 | let stress = stress_factor() + 100; | |
1729 | ||
1730 | for i in 0..stress { | |
1731 | let tx = tx.clone(); | |
1732 | thread::spawn(move || { | |
1733 | thread::sleep(Duration::from_millis(i as u64 * 10)); | |
1734 | tx.send(1usize).unwrap(); | |
1735 | }); | |
1736 | } | |
1737 | ||
1738 | drop(tx); | |
1739 | ||
1740 | let mut recv_count = 0; | |
1741 | loop { | |
1742 | match rx.recv_timeout(Duration::from_millis(10)) { | |
1743 | Ok(n) => { | |
1744 | assert_eq!(n, 1usize); | |
1745 | recv_count += 1; | |
1746 | } | |
1747 | Err(RecvTimeoutError::Timeout) => continue, | |
1748 | Err(RecvTimeoutError::Disconnected) => break, | |
1749 | } | |
1750 | } | |
1751 | ||
1752 | assert_eq!(recv_count, stress); | |
1753 | } | |
1754 | ||
1a4d82fc JJ |
1755 | #[test] |
1756 | fn recv_a_lot() { | |
1757 | // Regression test that we don't run out of stack in scheduler context | |
1758 | let (tx, rx) = channel(); | |
85aaf69f SL |
1759 | for _ in 0..10000 { tx.send(()).unwrap(); } |
1760 | for _ in 0..10000 { rx.recv().unwrap(); } | |
1a4d82fc JJ |
1761 | } |
1762 | ||
3157f602 XL |
1763 | #[test] |
1764 | fn shared_recv_timeout() { | |
1765 | let (tx, rx) = channel(); | |
1766 | let total = 5; | |
1767 | for _ in 0..total { | |
1768 | let tx = tx.clone(); | |
1769 | thread::spawn(move|| { | |
1770 | tx.send(()).unwrap(); | |
1771 | }); | |
1772 | } | |
1773 | ||
1774 | for _ in 0..total { rx.recv().unwrap(); } | |
1775 | ||
1776 | assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Err(RecvTimeoutError::Timeout)); | |
1777 | tx.send(()).unwrap(); | |
1778 | assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(())); | |
1779 | } | |
1780 | ||
1a4d82fc JJ |
1781 | #[test] |
1782 | fn shared_chan_stress() { | |
1783 | let (tx, rx) = channel(); | |
1784 | let total = stress_factor() + 100; | |
85aaf69f | 1785 | for _ in 0..total { |
1a4d82fc | 1786 | let tx = tx.clone(); |
85aaf69f | 1787 | thread::spawn(move|| { |
1a4d82fc JJ |
1788 | tx.send(()).unwrap(); |
1789 | }); | |
1790 | } | |
1791 | ||
85aaf69f | 1792 | for _ in 0..total { |
1a4d82fc JJ |
1793 | rx.recv().unwrap(); |
1794 | } | |
1795 | } | |
1796 | ||
1797 | #[test] | |
1798 | fn test_nested_recv_iter() { | |
c34b1796 AL |
1799 | let (tx, rx) = channel::<i32>(); |
1800 | let (total_tx, total_rx) = channel::<i32>(); | |
1a4d82fc | 1801 | |
85aaf69f | 1802 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1803 | let mut acc = 0; |
1804 | for x in rx.iter() { | |
1805 | acc += x; | |
1806 | } | |
1807 | total_tx.send(acc).unwrap(); | |
1808 | }); | |
1809 | ||
1810 | tx.send(3).unwrap(); | |
1811 | tx.send(1).unwrap(); | |
1812 | tx.send(2).unwrap(); | |
1813 | drop(tx); | |
1814 | assert_eq!(total_rx.recv().unwrap(), 6); | |
1815 | } | |
1816 | ||
1817 | #[test] | |
1818 | fn test_recv_iter_break() { | |
c34b1796 | 1819 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1820 | let (count_tx, count_rx) = channel(); |
1821 | ||
85aaf69f | 1822 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1823 | let mut count = 0; |
1824 | for x in rx.iter() { | |
1825 | if count >= 3 { | |
1826 | break; | |
1827 | } else { | |
1828 | count += x; | |
1829 | } | |
1830 | } | |
1831 | count_tx.send(count).unwrap(); | |
1832 | }); | |
1833 | ||
1834 | tx.send(2).unwrap(); | |
1835 | tx.send(2).unwrap(); | |
1836 | tx.send(2).unwrap(); | |
1837 | let _ = tx.send(2); | |
1838 | drop(tx); | |
1839 | assert_eq!(count_rx.recv().unwrap(), 4); | |
1840 | } | |
1841 | ||
5bcae85e SL |
1842 | #[test] |
1843 | fn test_recv_try_iter() { | |
1844 | let (request_tx, request_rx) = channel(); | |
1845 | let (response_tx, response_rx) = channel(); | |
1846 | ||
1847 | // Request `x`s until we have `6`. | |
1848 | let t = thread::spawn(move|| { | |
1849 | let mut count = 0; | |
1850 | loop { | |
1851 | for x in response_rx.try_iter() { | |
1852 | count += x; | |
1853 | if count == 6 { | |
1854 | return count; | |
1855 | } | |
1856 | } | |
1857 | request_tx.send(()).unwrap(); | |
1858 | } | |
1859 | }); | |
1860 | ||
1861 | for _ in request_rx.iter() { | |
1862 | if response_tx.send(2).is_err() { | |
1863 | break; | |
1864 | } | |
1865 | } | |
1866 | ||
1867 | assert_eq!(t.join().unwrap(), 6); | |
1868 | } | |
1869 | ||
d9579d0f AL |
1870 | #[test] |
1871 | fn test_recv_into_iter_owned() { | |
1872 | let mut iter = { | |
1873 | let (tx, rx) = channel::<i32>(); | |
1874 | tx.send(1).unwrap(); | |
1875 | tx.send(2).unwrap(); | |
1876 | ||
1877 | rx.into_iter() | |
1878 | }; | |
1879 | assert_eq!(iter.next().unwrap(), 1); | |
1880 | assert_eq!(iter.next().unwrap(), 2); | |
1881 | assert_eq!(iter.next().is_none(), true); | |
1882 | } | |
1883 | ||
1884 | #[test] | |
1885 | fn test_recv_into_iter_borrowed() { | |
1886 | let (tx, rx) = channel::<i32>(); | |
1887 | tx.send(1).unwrap(); | |
1888 | tx.send(2).unwrap(); | |
1889 | drop(tx); | |
1890 | let mut iter = (&rx).into_iter(); | |
1891 | assert_eq!(iter.next().unwrap(), 1); | |
1892 | assert_eq!(iter.next().unwrap(), 2); | |
1893 | assert_eq!(iter.next().is_none(), true); | |
1894 | } | |
1895 | ||
1a4d82fc JJ |
1896 | #[test] |
1897 | fn try_recv_states() { | |
c34b1796 | 1898 | let (tx1, rx1) = channel::<i32>(); |
1a4d82fc JJ |
1899 | let (tx2, rx2) = channel::<()>(); |
1900 | let (tx3, rx3) = channel::<()>(); | |
85aaf69f | 1901 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1902 | rx2.recv().unwrap(); |
1903 | tx1.send(1).unwrap(); | |
1904 | tx3.send(()).unwrap(); | |
1905 | rx2.recv().unwrap(); | |
1906 | drop(tx1); | |
1907 | tx3.send(()).unwrap(); | |
1908 | }); | |
1909 | ||
1910 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
1911 | tx2.send(()).unwrap(); | |
1912 | rx3.recv().unwrap(); | |
1913 | assert_eq!(rx1.try_recv(), Ok(1)); | |
1914 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
1915 | tx2.send(()).unwrap(); | |
1916 | rx3.recv().unwrap(); | |
1917 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Disconnected)); | |
1918 | } | |
1919 | ||
1920 | // This bug used to end up in a livelock inside of the Receiver destructor | |
1921 | // because the internal state of the Shared packet was corrupted | |
1922 | #[test] | |
1923 | fn destroy_upgraded_shared_port_when_sender_still_active() { | |
1924 | let (tx, rx) = channel(); | |
1925 | let (tx2, rx2) = channel(); | |
85aaf69f | 1926 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1927 | rx.recv().unwrap(); // wait on a oneshot |
1928 | drop(rx); // destroy a shared | |
1929 | tx2.send(()).unwrap(); | |
1930 | }); | |
bd371182 | 1931 | // make sure the other thread has gone to sleep |
85aaf69f | 1932 | for _ in 0..5000 { thread::yield_now(); } |
1a4d82fc JJ |
1933 | |
1934 | // upgrade to a shared chan and send a message | |
1935 | let t = tx.clone(); | |
1936 | drop(tx); | |
1937 | t.send(()).unwrap(); | |
1938 | ||
bd371182 | 1939 | // wait for the child thread to exit before we exit |
1a4d82fc JJ |
1940 | rx2.recv().unwrap(); |
1941 | } | |
1942 | } | |
1943 | ||
1944 | #[cfg(test)] | |
1945 | mod sync_tests { | |
c1a9b12d | 1946 | use env; |
85aaf69f | 1947 | use thread; |
1a4d82fc | 1948 | use super::*; |
3157f602 | 1949 | use time::Duration; |
1a4d82fc | 1950 | |
c34b1796 | 1951 | pub fn stress_factor() -> usize { |
85aaf69f SL |
1952 | match env::var("RUST_TEST_STRESS") { |
1953 | Ok(val) => val.parse().unwrap(), | |
1954 | Err(..) => 1, | |
1a4d82fc JJ |
1955 | } |
1956 | } | |
1957 | ||
1958 | #[test] | |
1959 | fn smoke() { | |
c34b1796 | 1960 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
1961 | tx.send(1).unwrap(); |
1962 | assert_eq!(rx.recv().unwrap(), 1); | |
1963 | } | |
1964 | ||
1965 | #[test] | |
1966 | fn drop_full() { | |
c34b1796 | 1967 | let (tx, _rx) = sync_channel::<Box<isize>>(1); |
85aaf69f | 1968 | tx.send(box 1).unwrap(); |
1a4d82fc JJ |
1969 | } |
1970 | ||
1971 | #[test] | |
1972 | fn smoke_shared() { | |
c34b1796 | 1973 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
1974 | tx.send(1).unwrap(); |
1975 | assert_eq!(rx.recv().unwrap(), 1); | |
1976 | let tx = tx.clone(); | |
1977 | tx.send(1).unwrap(); | |
1978 | assert_eq!(rx.recv().unwrap(), 1); | |
1979 | } | |
1980 | ||
3157f602 XL |
1981 | #[test] |
1982 | fn recv_timeout() { | |
1983 | let (tx, rx) = sync_channel::<i32>(1); | |
1984 | assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Err(RecvTimeoutError::Timeout)); | |
1985 | tx.send(1).unwrap(); | |
1986 | assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(1)); | |
1987 | } | |
1988 | ||
1a4d82fc JJ |
1989 | #[test] |
1990 | fn smoke_threads() { | |
c34b1796 | 1991 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 1992 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1993 | tx.send(1).unwrap(); |
1994 | }); | |
1995 | assert_eq!(rx.recv().unwrap(), 1); | |
1996 | } | |
1997 | ||
1998 | #[test] | |
1999 | fn smoke_port_gone() { | |
c34b1796 | 2000 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2001 | drop(rx); |
2002 | assert!(tx.send(1).is_err()); | |
2003 | } | |
2004 | ||
2005 | #[test] | |
2006 | fn smoke_shared_port_gone2() { | |
c34b1796 | 2007 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2008 | drop(rx); |
2009 | let tx2 = tx.clone(); | |
2010 | drop(tx); | |
2011 | assert!(tx2.send(1).is_err()); | |
2012 | } | |
2013 | ||
2014 | #[test] | |
2015 | fn port_gone_concurrent() { | |
c34b1796 | 2016 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2017 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2018 | rx.recv().unwrap(); |
2019 | }); | |
2020 | while tx.send(1).is_ok() {} | |
2021 | } | |
2022 | ||
2023 | #[test] | |
2024 | fn port_gone_concurrent_shared() { | |
c34b1796 | 2025 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc | 2026 | let tx2 = tx.clone(); |
85aaf69f | 2027 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2028 | rx.recv().unwrap(); |
2029 | }); | |
2030 | while tx.send(1).is_ok() && tx2.send(1).is_ok() {} | |
2031 | } | |
2032 | ||
2033 | #[test] | |
2034 | fn smoke_chan_gone() { | |
c34b1796 | 2035 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2036 | drop(tx); |
2037 | assert!(rx.recv().is_err()); | |
2038 | } | |
2039 | ||
2040 | #[test] | |
2041 | fn smoke_chan_gone_shared() { | |
2042 | let (tx, rx) = sync_channel::<()>(0); | |
2043 | let tx2 = tx.clone(); | |
2044 | drop(tx); | |
2045 | drop(tx2); | |
2046 | assert!(rx.recv().is_err()); | |
2047 | } | |
2048 | ||
2049 | #[test] | |
2050 | fn chan_gone_concurrent() { | |
c34b1796 | 2051 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2052 | thread::spawn(move|| { |
1a4d82fc JJ |
2053 | tx.send(1).unwrap(); |
2054 | tx.send(1).unwrap(); | |
2055 | }); | |
2056 | while rx.recv().is_ok() {} | |
2057 | } | |
2058 | ||
2059 | #[test] | |
2060 | fn stress() { | |
c34b1796 | 2061 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f SL |
2062 | thread::spawn(move|| { |
2063 | for _ in 0..10000 { tx.send(1).unwrap(); } | |
1a4d82fc | 2064 | }); |
85aaf69f | 2065 | for _ in 0..10000 { |
1a4d82fc JJ |
2066 | assert_eq!(rx.recv().unwrap(), 1); |
2067 | } | |
2068 | } | |
2069 | ||
2070 | #[test] | |
3157f602 XL |
2071 | fn stress_recv_timeout_two_threads() { |
2072 | let (tx, rx) = sync_channel::<i32>(0); | |
2073 | ||
2074 | thread::spawn(move|| { | |
2075 | for _ in 0..10000 { tx.send(1).unwrap(); } | |
2076 | }); | |
2077 | ||
2078 | let mut recv_count = 0; | |
2079 | loop { | |
2080 | match rx.recv_timeout(Duration::from_millis(1)) { | |
2081 | Ok(v) => { | |
2082 | assert_eq!(v, 1); | |
2083 | recv_count += 1; | |
2084 | }, | |
2085 | Err(RecvTimeoutError::Timeout) => continue, | |
2086 | Err(RecvTimeoutError::Disconnected) => break, | |
2087 | } | |
2088 | } | |
2089 | ||
2090 | assert_eq!(recv_count, 10000); | |
2091 | } | |
2092 | ||
2093 | #[test] | |
2094 | fn stress_recv_timeout_shared() { | |
2095 | const AMT: u32 = 1000; | |
2096 | const NTHREADS: u32 = 8; | |
2097 | let (tx, rx) = sync_channel::<i32>(0); | |
2098 | let (dtx, drx) = sync_channel::<()>(0); | |
2099 | ||
2100 | thread::spawn(move|| { | |
2101 | let mut recv_count = 0; | |
2102 | loop { | |
2103 | match rx.recv_timeout(Duration::from_millis(10)) { | |
2104 | Ok(v) => { | |
2105 | assert_eq!(v, 1); | |
2106 | recv_count += 1; | |
2107 | }, | |
2108 | Err(RecvTimeoutError::Timeout) => continue, | |
2109 | Err(RecvTimeoutError::Disconnected) => break, | |
2110 | } | |
2111 | } | |
2112 | ||
2113 | assert_eq!(recv_count, AMT * NTHREADS); | |
2114 | assert!(rx.try_recv().is_err()); | |
2115 | ||
2116 | dtx.send(()).unwrap(); | |
2117 | }); | |
2118 | ||
2119 | for _ in 0..NTHREADS { | |
2120 | let tx = tx.clone(); | |
2121 | thread::spawn(move|| { | |
2122 | for _ in 0..AMT { tx.send(1).unwrap(); } | |
2123 | }); | |
2124 | } | |
2125 | ||
2126 | drop(tx); | |
2127 | ||
2128 | drx.recv().unwrap(); | |
2129 | } | |
2130 | ||
2131 | #[test] | |
1a4d82fc | 2132 | fn stress_shared() { |
c34b1796 AL |
2133 | const AMT: u32 = 1000; |
2134 | const NTHREADS: u32 = 8; | |
2135 | let (tx, rx) = sync_channel::<i32>(0); | |
1a4d82fc JJ |
2136 | let (dtx, drx) = sync_channel::<()>(0); |
2137 | ||
85aaf69f SL |
2138 | thread::spawn(move|| { |
2139 | for _ in 0..AMT * NTHREADS { | |
1a4d82fc JJ |
2140 | assert_eq!(rx.recv().unwrap(), 1); |
2141 | } | |
2142 | match rx.try_recv() { | |
2143 | Ok(..) => panic!(), | |
2144 | _ => {} | |
2145 | } | |
2146 | dtx.send(()).unwrap(); | |
2147 | }); | |
2148 | ||
85aaf69f | 2149 | for _ in 0..NTHREADS { |
1a4d82fc | 2150 | let tx = tx.clone(); |
85aaf69f SL |
2151 | thread::spawn(move|| { |
2152 | for _ in 0..AMT { tx.send(1).unwrap(); } | |
1a4d82fc JJ |
2153 | }); |
2154 | } | |
2155 | drop(tx); | |
2156 | drx.recv().unwrap(); | |
2157 | } | |
2158 | ||
2159 | #[test] | |
2160 | fn oneshot_single_thread_close_port_first() { | |
2161 | // Simple test of closing without sending | |
c34b1796 | 2162 | let (_tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2163 | drop(rx); |
2164 | } | |
2165 | ||
2166 | #[test] | |
2167 | fn oneshot_single_thread_close_chan_first() { | |
2168 | // Simple test of closing without sending | |
c34b1796 | 2169 | let (tx, _rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2170 | drop(tx); |
2171 | } | |
2172 | ||
2173 | #[test] | |
2174 | fn oneshot_single_thread_send_port_close() { | |
2175 | // Testing that the sender cleans up the payload if receiver is closed | |
c34b1796 | 2176 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
1a4d82fc JJ |
2177 | drop(rx); |
2178 | assert!(tx.send(box 0).is_err()); | |
2179 | } | |
2180 | ||
2181 | #[test] | |
2182 | fn oneshot_single_thread_recv_chan_close() { | |
2183 | // Receiving on a closed chan will panic | |
85aaf69f | 2184 | let res = thread::spawn(move|| { |
c34b1796 | 2185 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2186 | drop(tx); |
2187 | rx.recv().unwrap(); | |
2188 | }).join(); | |
2189 | // What is our res? | |
2190 | assert!(res.is_err()); | |
2191 | } | |
2192 | ||
2193 | #[test] | |
2194 | fn oneshot_single_thread_send_then_recv() { | |
c34b1796 | 2195 | let (tx, rx) = sync_channel::<Box<i32>>(1); |
1a4d82fc JJ |
2196 | tx.send(box 10).unwrap(); |
2197 | assert!(rx.recv().unwrap() == box 10); | |
2198 | } | |
2199 | ||
2200 | #[test] | |
2201 | fn oneshot_single_thread_try_send_open() { | |
c34b1796 | 2202 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2203 | assert_eq!(tx.try_send(10), Ok(())); |
2204 | assert!(rx.recv().unwrap() == 10); | |
2205 | } | |
2206 | ||
2207 | #[test] | |
2208 | fn oneshot_single_thread_try_send_closed() { | |
c34b1796 | 2209 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2210 | drop(rx); |
2211 | assert_eq!(tx.try_send(10), Err(TrySendError::Disconnected(10))); | |
2212 | } | |
2213 | ||
2214 | #[test] | |
2215 | fn oneshot_single_thread_try_send_closed2() { | |
c34b1796 | 2216 | let (tx, _rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2217 | assert_eq!(tx.try_send(10), Err(TrySendError::Full(10))); |
2218 | } | |
2219 | ||
2220 | #[test] | |
2221 | fn oneshot_single_thread_try_recv_open() { | |
c34b1796 | 2222 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2223 | tx.send(10).unwrap(); |
2224 | assert!(rx.recv() == Ok(10)); | |
2225 | } | |
2226 | ||
2227 | #[test] | |
2228 | fn oneshot_single_thread_try_recv_closed() { | |
c34b1796 | 2229 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2230 | drop(tx); |
2231 | assert!(rx.recv().is_err()); | |
2232 | } | |
2233 | ||
5bcae85e SL |
2234 | #[test] |
2235 | fn oneshot_single_thread_try_recv_closed_with_data() { | |
2236 | let (tx, rx) = sync_channel::<i32>(1); | |
2237 | tx.send(10).unwrap(); | |
2238 | drop(tx); | |
2239 | assert_eq!(rx.try_recv(), Ok(10)); | |
2240 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
2241 | } | |
2242 | ||
1a4d82fc JJ |
2243 | #[test] |
2244 | fn oneshot_single_thread_peek_data() { | |
c34b1796 | 2245 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2246 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
2247 | tx.send(10).unwrap(); | |
2248 | assert_eq!(rx.try_recv(), Ok(10)); | |
2249 | } | |
2250 | ||
2251 | #[test] | |
2252 | fn oneshot_single_thread_peek_close() { | |
c34b1796 | 2253 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2254 | drop(tx); |
2255 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
2256 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
2257 | } | |
2258 | ||
2259 | #[test] | |
2260 | fn oneshot_single_thread_peek_open() { | |
c34b1796 | 2261 | let (_tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2262 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
2263 | } | |
2264 | ||
2265 | #[test] | |
2266 | fn oneshot_multi_task_recv_then_send() { | |
c34b1796 | 2267 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
85aaf69f | 2268 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2269 | assert!(rx.recv().unwrap() == box 10); |
2270 | }); | |
2271 | ||
2272 | tx.send(box 10).unwrap(); | |
2273 | } | |
2274 | ||
2275 | #[test] | |
2276 | fn oneshot_multi_task_recv_then_close() { | |
c34b1796 | 2277 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
85aaf69f | 2278 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2279 | drop(tx); |
2280 | }); | |
85aaf69f | 2281 | let res = thread::spawn(move|| { |
1a4d82fc JJ |
2282 | assert!(rx.recv().unwrap() == box 10); |
2283 | }).join(); | |
2284 | assert!(res.is_err()); | |
2285 | } | |
2286 | ||
2287 | #[test] | |
2288 | fn oneshot_multi_thread_close_stress() { | |
85aaf69f | 2289 | for _ in 0..stress_factor() { |
c34b1796 | 2290 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2291 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2292 | drop(rx); |
2293 | }); | |
2294 | drop(tx); | |
2295 | } | |
2296 | } | |
2297 | ||
2298 | #[test] | |
2299 | fn oneshot_multi_thread_send_close_stress() { | |
85aaf69f | 2300 | for _ in 0..stress_factor() { |
c34b1796 | 2301 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2302 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2303 | drop(rx); |
2304 | }); | |
85aaf69f | 2305 | let _ = thread::spawn(move || { |
1a4d82fc JJ |
2306 | tx.send(1).unwrap(); |
2307 | }).join(); | |
2308 | } | |
2309 | } | |
2310 | ||
2311 | #[test] | |
2312 | fn oneshot_multi_thread_recv_close_stress() { | |
85aaf69f | 2313 | for _ in 0..stress_factor() { |
c34b1796 | 2314 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f SL |
2315 | let _t = thread::spawn(move|| { |
2316 | let res = thread::spawn(move|| { | |
1a4d82fc JJ |
2317 | rx.recv().unwrap(); |
2318 | }).join(); | |
2319 | assert!(res.is_err()); | |
2320 | }); | |
85aaf69f SL |
2321 | let _t = thread::spawn(move|| { |
2322 | thread::spawn(move|| { | |
1a4d82fc JJ |
2323 | drop(tx); |
2324 | }); | |
2325 | }); | |
2326 | } | |
2327 | } | |
2328 | ||
2329 | #[test] | |
2330 | fn oneshot_multi_thread_send_recv_stress() { | |
85aaf69f | 2331 | for _ in 0..stress_factor() { |
c34b1796 | 2332 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
85aaf69f SL |
2333 | let _t = thread::spawn(move|| { |
2334 | tx.send(box 10).unwrap(); | |
1a4d82fc | 2335 | }); |
85aaf69f | 2336 | assert!(rx.recv().unwrap() == box 10); |
1a4d82fc JJ |
2337 | } |
2338 | } | |
2339 | ||
2340 | #[test] | |
2341 | fn stream_send_recv_stress() { | |
85aaf69f | 2342 | for _ in 0..stress_factor() { |
c34b1796 | 2343 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
1a4d82fc JJ |
2344 | |
2345 | send(tx, 0); | |
2346 | recv(rx, 0); | |
2347 | ||
c34b1796 | 2348 | fn send(tx: SyncSender<Box<i32>>, i: i32) { |
1a4d82fc JJ |
2349 | if i == 10 { return } |
2350 | ||
85aaf69f | 2351 | thread::spawn(move|| { |
1a4d82fc JJ |
2352 | tx.send(box i).unwrap(); |
2353 | send(tx, i + 1); | |
2354 | }); | |
2355 | } | |
2356 | ||
c34b1796 | 2357 | fn recv(rx: Receiver<Box<i32>>, i: i32) { |
1a4d82fc JJ |
2358 | if i == 10 { return } |
2359 | ||
85aaf69f | 2360 | thread::spawn(move|| { |
1a4d82fc JJ |
2361 | assert!(rx.recv().unwrap() == box i); |
2362 | recv(rx, i + 1); | |
2363 | }); | |
2364 | } | |
2365 | } | |
2366 | } | |
2367 | ||
2368 | #[test] | |
2369 | fn recv_a_lot() { | |
2370 | // Regression test that we don't run out of stack in scheduler context | |
2371 | let (tx, rx) = sync_channel(10000); | |
85aaf69f SL |
2372 | for _ in 0..10000 { tx.send(()).unwrap(); } |
2373 | for _ in 0..10000 { rx.recv().unwrap(); } | |
1a4d82fc JJ |
2374 | } |
2375 | ||
2376 | #[test] | |
2377 | fn shared_chan_stress() { | |
2378 | let (tx, rx) = sync_channel(0); | |
2379 | let total = stress_factor() + 100; | |
85aaf69f | 2380 | for _ in 0..total { |
1a4d82fc | 2381 | let tx = tx.clone(); |
85aaf69f | 2382 | thread::spawn(move|| { |
1a4d82fc JJ |
2383 | tx.send(()).unwrap(); |
2384 | }); | |
2385 | } | |
2386 | ||
85aaf69f | 2387 | for _ in 0..total { |
1a4d82fc JJ |
2388 | rx.recv().unwrap(); |
2389 | } | |
2390 | } | |
2391 | ||
2392 | #[test] | |
2393 | fn test_nested_recv_iter() { | |
c34b1796 AL |
2394 | let (tx, rx) = sync_channel::<i32>(0); |
2395 | let (total_tx, total_rx) = sync_channel::<i32>(0); | |
1a4d82fc | 2396 | |
85aaf69f | 2397 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2398 | let mut acc = 0; |
2399 | for x in rx.iter() { | |
2400 | acc += x; | |
2401 | } | |
2402 | total_tx.send(acc).unwrap(); | |
2403 | }); | |
2404 | ||
2405 | tx.send(3).unwrap(); | |
2406 | tx.send(1).unwrap(); | |
2407 | tx.send(2).unwrap(); | |
2408 | drop(tx); | |
2409 | assert_eq!(total_rx.recv().unwrap(), 6); | |
2410 | } | |
2411 | ||
2412 | #[test] | |
2413 | fn test_recv_iter_break() { | |
c34b1796 | 2414 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2415 | let (count_tx, count_rx) = sync_channel(0); |
2416 | ||
85aaf69f | 2417 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2418 | let mut count = 0; |
2419 | for x in rx.iter() { | |
2420 | if count >= 3 { | |
2421 | break; | |
2422 | } else { | |
2423 | count += x; | |
2424 | } | |
2425 | } | |
2426 | count_tx.send(count).unwrap(); | |
2427 | }); | |
2428 | ||
2429 | tx.send(2).unwrap(); | |
2430 | tx.send(2).unwrap(); | |
2431 | tx.send(2).unwrap(); | |
2432 | let _ = tx.try_send(2); | |
2433 | drop(tx); | |
2434 | assert_eq!(count_rx.recv().unwrap(), 4); | |
2435 | } | |
2436 | ||
2437 | #[test] | |
2438 | fn try_recv_states() { | |
c34b1796 | 2439 | let (tx1, rx1) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2440 | let (tx2, rx2) = sync_channel::<()>(1); |
2441 | let (tx3, rx3) = sync_channel::<()>(1); | |
85aaf69f | 2442 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2443 | rx2.recv().unwrap(); |
2444 | tx1.send(1).unwrap(); | |
2445 | tx3.send(()).unwrap(); | |
2446 | rx2.recv().unwrap(); | |
2447 | drop(tx1); | |
2448 | tx3.send(()).unwrap(); | |
2449 | }); | |
2450 | ||
2451 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
2452 | tx2.send(()).unwrap(); | |
2453 | rx3.recv().unwrap(); | |
2454 | assert_eq!(rx1.try_recv(), Ok(1)); | |
2455 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
2456 | tx2.send(()).unwrap(); | |
2457 | rx3.recv().unwrap(); | |
2458 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Disconnected)); | |
2459 | } | |
2460 | ||
2461 | // This bug used to end up in a livelock inside of the Receiver destructor | |
2462 | // because the internal state of the Shared packet was corrupted | |
2463 | #[test] | |
2464 | fn destroy_upgraded_shared_port_when_sender_still_active() { | |
2465 | let (tx, rx) = sync_channel::<()>(0); | |
2466 | let (tx2, rx2) = sync_channel::<()>(0); | |
85aaf69f | 2467 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2468 | rx.recv().unwrap(); // wait on a oneshot |
2469 | drop(rx); // destroy a shared | |
2470 | tx2.send(()).unwrap(); | |
2471 | }); | |
bd371182 | 2472 | // make sure the other thread has gone to sleep |
85aaf69f | 2473 | for _ in 0..5000 { thread::yield_now(); } |
1a4d82fc JJ |
2474 | |
2475 | // upgrade to a shared chan and send a message | |
2476 | let t = tx.clone(); | |
2477 | drop(tx); | |
2478 | t.send(()).unwrap(); | |
2479 | ||
bd371182 | 2480 | // wait for the child thread to exit before we exit |
1a4d82fc JJ |
2481 | rx2.recv().unwrap(); |
2482 | } | |
2483 | ||
2484 | #[test] | |
2485 | fn send1() { | |
c34b1796 | 2486 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2487 | let _t = thread::spawn(move|| { rx.recv().unwrap(); }); |
1a4d82fc JJ |
2488 | assert_eq!(tx.send(1), Ok(())); |
2489 | } | |
2490 | ||
2491 | #[test] | |
2492 | fn send2() { | |
c34b1796 | 2493 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2494 | let _t = thread::spawn(move|| { drop(rx); }); |
1a4d82fc JJ |
2495 | assert!(tx.send(1).is_err()); |
2496 | } | |
2497 | ||
2498 | #[test] | |
2499 | fn send3() { | |
c34b1796 | 2500 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc | 2501 | assert_eq!(tx.send(1), Ok(())); |
85aaf69f | 2502 | let _t =thread::spawn(move|| { drop(rx); }); |
1a4d82fc JJ |
2503 | assert!(tx.send(1).is_err()); |
2504 | } | |
2505 | ||
2506 | #[test] | |
2507 | fn send4() { | |
c34b1796 | 2508 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2509 | let tx2 = tx.clone(); |
2510 | let (done, donerx) = channel(); | |
2511 | let done2 = done.clone(); | |
85aaf69f | 2512 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2513 | assert!(tx.send(1).is_err()); |
2514 | done.send(()).unwrap(); | |
2515 | }); | |
85aaf69f | 2516 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2517 | assert!(tx2.send(2).is_err()); |
2518 | done2.send(()).unwrap(); | |
2519 | }); | |
2520 | drop(rx); | |
2521 | donerx.recv().unwrap(); | |
2522 | donerx.recv().unwrap(); | |
2523 | } | |
2524 | ||
2525 | #[test] | |
2526 | fn try_send1() { | |
c34b1796 | 2527 | let (tx, _rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2528 | assert_eq!(tx.try_send(1), Err(TrySendError::Full(1))); |
2529 | } | |
2530 | ||
2531 | #[test] | |
2532 | fn try_send2() { | |
c34b1796 | 2533 | let (tx, _rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2534 | assert_eq!(tx.try_send(1), Ok(())); |
2535 | assert_eq!(tx.try_send(1), Err(TrySendError::Full(1))); | |
2536 | } | |
2537 | ||
2538 | #[test] | |
2539 | fn try_send3() { | |
c34b1796 | 2540 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2541 | assert_eq!(tx.try_send(1), Ok(())); |
2542 | drop(rx); | |
2543 | assert_eq!(tx.try_send(1), Err(TrySendError::Disconnected(1))); | |
2544 | } | |
2545 | ||
2546 | #[test] | |
2547 | fn issue_15761() { | |
2548 | fn repro() { | |
2549 | let (tx1, rx1) = sync_channel::<()>(3); | |
2550 | let (tx2, rx2) = sync_channel::<()>(3); | |
2551 | ||
85aaf69f | 2552 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2553 | rx1.recv().unwrap(); |
2554 | tx2.try_send(()).unwrap(); | |
2555 | }); | |
2556 | ||
2557 | tx1.try_send(()).unwrap(); | |
2558 | rx2.recv().unwrap(); | |
2559 | } | |
2560 | ||
85aaf69f | 2561 | for _ in 0..100 { |
1a4d82fc JJ |
2562 | repro() |
2563 | } | |
2564 | } | |
7453a54e SL |
2565 | |
2566 | #[test] | |
2567 | fn fmt_debug_sender() { | |
2568 | let (tx, _) = channel::<i32>(); | |
2569 | assert_eq!(format!("{:?}", tx), "Sender { .. }"); | |
2570 | } | |
2571 | ||
2572 | #[test] | |
2573 | fn fmt_debug_recv() { | |
2574 | let (_, rx) = channel::<i32>(); | |
2575 | assert_eq!(format!("{:?}", rx), "Receiver { .. }"); | |
2576 | } | |
2577 | ||
2578 | #[test] | |
2579 | fn fmt_debug_sync_sender() { | |
2580 | let (tx, _) = sync_channel::<i32>(1); | |
2581 | assert_eq!(format!("{:?}", tx), "SyncSender { .. }"); | |
2582 | } | |
1a4d82fc | 2583 | } |