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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|| { |
1a4d82fc JJ |
110 | //! // This will wait for the parent task to start receiving |
111 | //! tx.send(53).unwrap(); | |
112 | //! }); | |
113 | //! rx.recv().unwrap(); | |
114 | //! ``` | |
115 | //! | |
116 | //! Reading from a channel with a timeout requires to use a Timer together | |
c34b1796 | 117 | //! with the channel. You can use the `select!` macro to select either and |
1a4d82fc JJ |
118 | //! handle the timeout case. This first example will break out of the loop |
119 | //! after 10 seconds no matter what: | |
120 | //! | |
121 | //! ```no_run | |
c34b1796 | 122 | //! # #![feature(std_misc, old_io)] |
1a4d82fc | 123 | //! use std::sync::mpsc::channel; |
85aaf69f | 124 | //! use std::old_io::timer::Timer; |
1a4d82fc JJ |
125 | //! use std::time::Duration; |
126 | //! | |
c34b1796 | 127 | //! let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
128 | //! let mut timer = Timer::new().unwrap(); |
129 | //! let timeout = timer.oneshot(Duration::seconds(10)); | |
130 | //! | |
131 | //! loop { | |
132 | //! select! { | |
133 | //! val = rx.recv() => println!("Received {}", val.unwrap()), | |
134 | //! _ = timeout.recv() => { | |
135 | //! println!("timed out, total time was more than 10 seconds"); | |
136 | //! break; | |
137 | //! } | |
138 | //! } | |
139 | //! } | |
140 | //! ``` | |
141 | //! | |
142 | //! This second example is more costly since it allocates a new timer every | |
143 | //! time a message is received, but it allows you to timeout after the channel | |
144 | //! has been inactive for 5 seconds: | |
145 | //! | |
146 | //! ```no_run | |
c34b1796 | 147 | //! # #![feature(std_misc, old_io)] |
1a4d82fc | 148 | //! use std::sync::mpsc::channel; |
85aaf69f | 149 | //! use std::old_io::timer::Timer; |
1a4d82fc JJ |
150 | //! use std::time::Duration; |
151 | //! | |
c34b1796 | 152 | //! let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
153 | //! let mut timer = Timer::new().unwrap(); |
154 | //! | |
155 | //! loop { | |
156 | //! let timeout = timer.oneshot(Duration::seconds(5)); | |
157 | //! | |
158 | //! select! { | |
159 | //! val = rx.recv() => println!("Received {}", val.unwrap()), | |
160 | //! _ = timeout.recv() => { | |
161 | //! println!("timed out, no message received in 5 seconds"); | |
162 | //! break; | |
163 | //! } | |
164 | //! } | |
165 | //! } | |
166 | //! ``` | |
167 | ||
85aaf69f | 168 | #![stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
169 | |
170 | // A description of how Rust's channel implementation works | |
171 | // | |
172 | // Channels are supposed to be the basic building block for all other | |
173 | // concurrent primitives that are used in Rust. As a result, the channel type | |
174 | // needs to be highly optimized, flexible, and broad enough for use everywhere. | |
175 | // | |
176 | // The choice of implementation of all channels is to be built on lock-free data | |
177 | // structures. The channels themselves are then consequently also lock-free data | |
178 | // structures. As always with lock-free code, this is a very "here be dragons" | |
179 | // territory, especially because I'm unaware of any academic papers that have | |
180 | // gone into great length about channels of these flavors. | |
181 | // | |
182 | // ## Flavors of channels | |
183 | // | |
184 | // From the perspective of a consumer of this library, there is only one flavor | |
185 | // of channel. This channel can be used as a stream and cloned to allow multiple | |
186 | // senders. Under the hood, however, there are actually three flavors of | |
187 | // channels in play. | |
188 | // | |
189 | // * Flavor::Oneshots - these channels are highly optimized for the one-send use case. | |
190 | // They contain as few atomics as possible and involve one and | |
191 | // exactly one allocation. | |
192 | // * Streams - these channels are optimized for the non-shared use case. They | |
193 | // use a different concurrent queue that is more tailored for this | |
194 | // use case. The initial allocation of this flavor of channel is not | |
195 | // optimized. | |
196 | // * Shared - this is the most general form of channel that this module offers, | |
197 | // a channel with multiple senders. This type is as optimized as it | |
198 | // can be, but the previous two types mentioned are much faster for | |
199 | // their use-cases. | |
200 | // | |
201 | // ## Concurrent queues | |
202 | // | |
203 | // The basic idea of Rust's Sender/Receiver types is that send() never blocks, but | |
204 | // recv() obviously blocks. This means that under the hood there must be some | |
205 | // shared and concurrent queue holding all of the actual data. | |
206 | // | |
207 | // With two flavors of channels, two flavors of queues are also used. We have | |
208 | // chosen to use queues from a well-known author that are abbreviated as SPSC | |
209 | // and MPSC (single producer, single consumer and multiple producer, single | |
210 | // consumer). SPSC queues are used for streams while MPSC queues are used for | |
211 | // shared channels. | |
212 | // | |
213 | // ### SPSC optimizations | |
214 | // | |
215 | // The SPSC queue found online is essentially a linked list of nodes where one | |
216 | // half of the nodes are the "queue of data" and the other half of nodes are a | |
217 | // cache of unused nodes. The unused nodes are used such that an allocation is | |
218 | // not required on every push() and a free doesn't need to happen on every | |
219 | // pop(). | |
220 | // | |
221 | // As found online, however, the cache of nodes is of an infinite size. This | |
222 | // means that if a channel at one point in its life had 50k items in the queue, | |
223 | // then the queue will always have the capacity for 50k items. I believed that | |
224 | // this was an unnecessary limitation of the implementation, so I have altered | |
225 | // the queue to optionally have a bound on the cache size. | |
226 | // | |
227 | // By default, streams will have an unbounded SPSC queue with a small-ish cache | |
228 | // size. The hope is that the cache is still large enough to have very fast | |
229 | // send() operations while not too large such that millions of channels can | |
230 | // coexist at once. | |
231 | // | |
232 | // ### MPSC optimizations | |
233 | // | |
234 | // Right now the MPSC queue has not been optimized. Like the SPSC queue, it uses | |
235 | // a linked list under the hood to earn its unboundedness, but I have not put | |
236 | // forth much effort into having a cache of nodes similar to the SPSC queue. | |
237 | // | |
238 | // For now, I believe that this is "ok" because shared channels are not the most | |
239 | // common type, but soon we may wish to revisit this queue choice and determine | |
240 | // another candidate for backend storage of shared channels. | |
241 | // | |
242 | // ## Overview of the Implementation | |
243 | // | |
244 | // Now that there's a little background on the concurrent queues used, it's | |
245 | // worth going into much more detail about the channels themselves. The basic | |
246 | // pseudocode for a send/recv are: | |
247 | // | |
248 | // | |
249 | // send(t) recv() | |
250 | // queue.push(t) return if queue.pop() | |
251 | // if increment() == -1 deschedule { | |
252 | // wakeup() if decrement() > 0 | |
253 | // cancel_deschedule() | |
254 | // } | |
255 | // queue.pop() | |
256 | // | |
257 | // As mentioned before, there are no locks in this implementation, only atomic | |
258 | // instructions are used. | |
259 | // | |
260 | // ### The internal atomic counter | |
261 | // | |
262 | // Every channel has a shared counter with each half to keep track of the size | |
263 | // of the queue. This counter is used to abort descheduling by the receiver and | |
264 | // to know when to wake up on the sending side. | |
265 | // | |
266 | // As seen in the pseudocode, senders will increment this count and receivers | |
267 | // will decrement the count. The theory behind this is that if a sender sees a | |
268 | // -1 count, it will wake up the receiver, and if the receiver sees a 1+ count, | |
269 | // then it doesn't need to block. | |
270 | // | |
271 | // The recv() method has a beginning call to pop(), and if successful, it needs | |
272 | // to decrement the count. It is a crucial implementation detail that this | |
273 | // decrement does *not* happen to the shared counter. If this were the case, | |
274 | // then it would be possible for the counter to be very negative when there were | |
275 | // no receivers waiting, in which case the senders would have to determine when | |
276 | // it was actually appropriate to wake up a receiver. | |
277 | // | |
278 | // Instead, the "steal count" is kept track of separately (not atomically | |
279 | // because it's only used by receivers), and then the decrement() call when | |
280 | // descheduling will lump in all of the recent steals into one large decrement. | |
281 | // | |
282 | // The implication of this is that if a sender sees a -1 count, then there's | |
283 | // guaranteed to be a waiter waiting! | |
284 | // | |
285 | // ## Native Implementation | |
286 | // | |
287 | // A major goal of these channels is to work seamlessly on and off the runtime. | |
288 | // All of the previous race conditions have been worded in terms of | |
289 | // scheduler-isms (which is obviously not available without the runtime). | |
290 | // | |
291 | // For now, native usage of channels (off the runtime) will fall back onto | |
292 | // mutexes/cond vars for descheduling/atomic decisions. The no-contention path | |
293 | // is still entirely lock-free, the "deschedule" blocks above are surrounded by | |
294 | // a mutex and the "wakeup" blocks involve grabbing a mutex and signaling on a | |
295 | // condition variable. | |
296 | // | |
297 | // ## Select | |
298 | // | |
299 | // Being able to support selection over channels has greatly influenced this | |
300 | // design, and not only does selection need to work inside the runtime, but also | |
301 | // outside the runtime. | |
302 | // | |
303 | // The implementation is fairly straightforward. The goal of select() is not to | |
304 | // return some data, but only to return which channel can receive data without | |
305 | // blocking. The implementation is essentially the entire blocking procedure | |
306 | // followed by an increment as soon as its woken up. The cancellation procedure | |
307 | // involves an increment and swapping out of to_wake to acquire ownership of the | |
308 | // task to unblock. | |
309 | // | |
310 | // Sadly this current implementation requires multiple allocations, so I have | |
311 | // seen the throughput of select() be much worse than it should be. I do not | |
312 | // believe that there is anything fundamental that needs to change about these | |
313 | // channels, however, in order to support a more efficient select(). | |
314 | // | |
315 | // # Conclusion | |
316 | // | |
317 | // And now that you've seen all the races that I found and attempted to fix, | |
318 | // here's the code for you to find some more! | |
319 | ||
320 | use prelude::v1::*; | |
321 | ||
322 | use sync::Arc; | |
c34b1796 | 323 | use error; |
1a4d82fc | 324 | use fmt; |
1a4d82fc JJ |
325 | use mem; |
326 | use cell::UnsafeCell; | |
327 | ||
328 | pub use self::select::{Select, Handle}; | |
329 | use self::select::StartResult; | |
330 | use self::select::StartResult::*; | |
331 | use self::blocking::SignalToken; | |
332 | ||
333 | mod blocking; | |
334 | mod oneshot; | |
335 | mod select; | |
336 | mod shared; | |
337 | mod stream; | |
338 | mod sync; | |
339 | mod mpsc_queue; | |
340 | mod spsc_queue; | |
341 | ||
342 | /// The receiving-half of Rust's channel type. This half can only be owned by | |
343 | /// one task | |
85aaf69f | 344 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
345 | pub struct Receiver<T> { |
346 | inner: UnsafeCell<Flavor<T>>, | |
347 | } | |
348 | ||
349 | // The receiver port can be sent from place to place, so long as it | |
350 | // is not used to receive non-sendable things. | |
c34b1796 | 351 | unsafe impl<T: Send> Send for Receiver<T> { } |
1a4d82fc JJ |
352 | |
353 | /// An iterator over messages on a receiver, this iterator will block | |
354 | /// whenever `next` is called, waiting for a new message, and `None` will be | |
355 | /// returned when the corresponding channel has hung up. | |
85aaf69f | 356 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 357 | pub struct Iter<'a, T: 'a> { |
1a4d82fc JJ |
358 | rx: &'a Receiver<T> |
359 | } | |
360 | ||
361 | /// The sending-half of Rust's asynchronous channel type. This half can only be | |
362 | /// owned by one task, but it can be cloned to send to other tasks. | |
85aaf69f | 363 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
364 | pub struct Sender<T> { |
365 | inner: UnsafeCell<Flavor<T>>, | |
366 | } | |
367 | ||
368 | // The send port can be sent from place to place, so long as it | |
369 | // is not used to send non-sendable things. | |
c34b1796 | 370 | unsafe impl<T: Send> Send for Sender<T> { } |
1a4d82fc JJ |
371 | |
372 | /// The sending-half of Rust's synchronous channel type. This half can only be | |
373 | /// owned by one task, but it can be cloned to send to other tasks. | |
85aaf69f | 374 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 375 | pub struct SyncSender<T> { |
85aaf69f | 376 | inner: Arc<UnsafeCell<sync::Packet<T>>>, |
1a4d82fc JJ |
377 | } |
378 | ||
c34b1796 | 379 | unsafe impl<T: Send> Send for SyncSender<T> {} |
85aaf69f SL |
380 | |
381 | impl<T> !Sync for SyncSender<T> {} | |
382 | ||
1a4d82fc JJ |
383 | /// An error returned from the `send` function on channels. |
384 | /// | |
385 | /// A `send` operation can only fail if the receiving end of a channel is | |
386 | /// disconnected, implying that the data could never be received. The error | |
387 | /// contains the data being sent as a payload so it can be recovered. | |
85aaf69f SL |
388 | #[stable(feature = "rust1", since = "1.0.0")] |
389 | #[derive(PartialEq, Eq, Clone, Copy)] | |
c34b1796 | 390 | pub struct SendError<T>(#[stable(feature = "rust1", since = "1.0.0")] pub T); |
1a4d82fc JJ |
391 | |
392 | /// An error returned from the `recv` function on a `Receiver`. | |
393 | /// | |
394 | /// The `recv` operation can only fail if the sending half of a channel is | |
395 | /// disconnected, implying that no further messages will ever be received. | |
85aaf69f SL |
396 | #[derive(PartialEq, Eq, Clone, Copy, Debug)] |
397 | #[stable(feature = "rust1", since = "1.0.0")] | |
1a4d82fc JJ |
398 | pub struct RecvError; |
399 | ||
400 | /// This enumeration is the list of the possible reasons that try_recv could not | |
401 | /// return data when called. | |
85aaf69f SL |
402 | #[derive(PartialEq, Eq, Clone, Copy, Debug)] |
403 | #[stable(feature = "rust1", since = "1.0.0")] | |
1a4d82fc JJ |
404 | pub enum TryRecvError { |
405 | /// This channel is currently empty, but the sender(s) have not yet | |
406 | /// disconnected, so data may yet become available. | |
85aaf69f | 407 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
408 | Empty, |
409 | ||
410 | /// This channel's sending half has become disconnected, and there will | |
411 | /// never be any more data received on this channel | |
85aaf69f | 412 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
413 | Disconnected, |
414 | } | |
415 | ||
416 | /// This enumeration is the list of the possible error outcomes for the | |
417 | /// `SyncSender::try_send` method. | |
85aaf69f SL |
418 | #[stable(feature = "rust1", since = "1.0.0")] |
419 | #[derive(PartialEq, Eq, Clone, Copy)] | |
1a4d82fc JJ |
420 | pub enum TrySendError<T> { |
421 | /// The data could not be sent on the channel because it would require that | |
422 | /// the callee block to send the data. | |
423 | /// | |
424 | /// If this is a buffered channel, then the buffer is full at this time. If | |
425 | /// this is not a buffered channel, then there is no receiver available to | |
426 | /// acquire the data. | |
85aaf69f | 427 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
428 | Full(T), |
429 | ||
430 | /// This channel's receiving half has disconnected, so the data could not be | |
431 | /// sent. The data is returned back to the callee in this case. | |
85aaf69f | 432 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
433 | Disconnected(T), |
434 | } | |
435 | ||
436 | enum Flavor<T> { | |
85aaf69f SL |
437 | Oneshot(Arc<UnsafeCell<oneshot::Packet<T>>>), |
438 | Stream(Arc<UnsafeCell<stream::Packet<T>>>), | |
439 | Shared(Arc<UnsafeCell<shared::Packet<T>>>), | |
440 | Sync(Arc<UnsafeCell<sync::Packet<T>>>), | |
1a4d82fc JJ |
441 | } |
442 | ||
443 | #[doc(hidden)] | |
444 | trait UnsafeFlavor<T> { | |
445 | fn inner_unsafe<'a>(&'a self) -> &'a UnsafeCell<Flavor<T>>; | |
446 | unsafe fn inner_mut<'a>(&'a self) -> &'a mut Flavor<T> { | |
447 | &mut *self.inner_unsafe().get() | |
448 | } | |
449 | unsafe fn inner<'a>(&'a self) -> &'a Flavor<T> { | |
450 | &*self.inner_unsafe().get() | |
451 | } | |
452 | } | |
453 | impl<T> UnsafeFlavor<T> for Sender<T> { | |
454 | fn inner_unsafe<'a>(&'a self) -> &'a UnsafeCell<Flavor<T>> { | |
455 | &self.inner | |
456 | } | |
457 | } | |
458 | impl<T> UnsafeFlavor<T> for Receiver<T> { | |
459 | fn inner_unsafe<'a>(&'a self) -> &'a UnsafeCell<Flavor<T>> { | |
460 | &self.inner | |
461 | } | |
462 | } | |
463 | ||
464 | /// Creates a new asynchronous channel, returning the sender/receiver halves. | |
465 | /// | |
466 | /// All data sent on the sender will become available on the receiver, and no | |
467 | /// send will block the calling task (this channel has an "infinite buffer"). | |
468 | /// | |
c34b1796 | 469 | /// # Examples |
1a4d82fc JJ |
470 | /// |
471 | /// ``` | |
472 | /// use std::sync::mpsc::channel; | |
85aaf69f | 473 | /// use std::thread; |
1a4d82fc JJ |
474 | /// |
475 | /// // tx is is the sending half (tx for transmission), and rx is the receiving | |
476 | /// // half (rx for receiving). | |
477 | /// let (tx, rx) = channel(); | |
478 | /// | |
479 | /// // Spawn off an expensive computation | |
85aaf69f | 480 | /// thread::spawn(move|| { |
1a4d82fc JJ |
481 | /// # fn expensive_computation() {} |
482 | /// tx.send(expensive_computation()).unwrap(); | |
483 | /// }); | |
484 | /// | |
485 | /// // Do some useful work for awhile | |
486 | /// | |
487 | /// // Let's see what that answer was | |
488 | /// println!("{:?}", rx.recv().unwrap()); | |
489 | /// ``` | |
85aaf69f | 490 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 491 | pub fn channel<T>() -> (Sender<T>, Receiver<T>) { |
85aaf69f | 492 | let a = Arc::new(UnsafeCell::new(oneshot::Packet::new())); |
1a4d82fc JJ |
493 | (Sender::new(Flavor::Oneshot(a.clone())), Receiver::new(Flavor::Oneshot(a))) |
494 | } | |
495 | ||
496 | /// Creates a new synchronous, bounded channel. | |
497 | /// | |
498 | /// Like asynchronous channels, the `Receiver` will block until a message | |
499 | /// becomes available. These channels differ greatly in the semantics of the | |
500 | /// sender from asynchronous channels, however. | |
501 | /// | |
502 | /// This channel has an internal buffer on which messages will be queued. When | |
503 | /// the internal buffer becomes full, future sends will *block* waiting for the | |
504 | /// buffer to open up. Note that a buffer size of 0 is valid, in which case this | |
505 | /// becomes "rendezvous channel" where each send will not return until a recv | |
506 | /// is paired with it. | |
507 | /// | |
508 | /// As with asynchronous channels, all senders will panic in `send` if the | |
509 | /// `Receiver` has been destroyed. | |
510 | /// | |
c34b1796 | 511 | /// # Examples |
1a4d82fc JJ |
512 | /// |
513 | /// ``` | |
514 | /// use std::sync::mpsc::sync_channel; | |
85aaf69f | 515 | /// use std::thread; |
1a4d82fc JJ |
516 | /// |
517 | /// let (tx, rx) = sync_channel(1); | |
518 | /// | |
519 | /// // this returns immediately | |
85aaf69f | 520 | /// tx.send(1).unwrap(); |
1a4d82fc | 521 | /// |
85aaf69f | 522 | /// thread::spawn(move|| { |
1a4d82fc | 523 | /// // this will block until the previous message has been received |
85aaf69f | 524 | /// tx.send(2).unwrap(); |
1a4d82fc JJ |
525 | /// }); |
526 | /// | |
85aaf69f SL |
527 | /// assert_eq!(rx.recv().unwrap(), 1); |
528 | /// assert_eq!(rx.recv().unwrap(), 2); | |
1a4d82fc | 529 | /// ``` |
85aaf69f | 530 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 531 | pub fn sync_channel<T>(bound: usize) -> (SyncSender<T>, Receiver<T>) { |
85aaf69f | 532 | let a = Arc::new(UnsafeCell::new(sync::Packet::new(bound))); |
1a4d82fc JJ |
533 | (SyncSender::new(a.clone()), Receiver::new(Flavor::Sync(a))) |
534 | } | |
535 | ||
536 | //////////////////////////////////////////////////////////////////////////////// | |
537 | // Sender | |
538 | //////////////////////////////////////////////////////////////////////////////// | |
539 | ||
c34b1796 | 540 | impl<T> Sender<T> { |
1a4d82fc JJ |
541 | fn new(inner: Flavor<T>) -> Sender<T> { |
542 | Sender { | |
543 | inner: UnsafeCell::new(inner), | |
544 | } | |
545 | } | |
546 | ||
547 | /// Attempts to send a value on this channel, returning it back if it could | |
548 | /// not be sent. | |
549 | /// | |
550 | /// A successful send occurs when it is determined that the other end of | |
551 | /// the channel has not hung up already. An unsuccessful send would be one | |
552 | /// where the corresponding receiver has already been deallocated. Note | |
553 | /// that a return value of `Err` means that the data will never be | |
554 | /// received, but a return value of `Ok` does *not* mean that the data | |
555 | /// will be received. It is possible for the corresponding receiver to | |
556 | /// hang up immediately after this function returns `Ok`. | |
557 | /// | |
558 | /// This method will never block the current thread. | |
559 | /// | |
c34b1796 | 560 | /// # Examples |
1a4d82fc JJ |
561 | /// |
562 | /// ``` | |
563 | /// use std::sync::mpsc::channel; | |
564 | /// | |
565 | /// let (tx, rx) = channel(); | |
566 | /// | |
567 | /// // This send is always successful | |
85aaf69f | 568 | /// tx.send(1).unwrap(); |
1a4d82fc JJ |
569 | /// |
570 | /// // This send will fail because the receiver is gone | |
571 | /// drop(rx); | |
85aaf69f | 572 | /// assert_eq!(tx.send(1).err().unwrap().0, 1); |
1a4d82fc | 573 | /// ``` |
85aaf69f | 574 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
575 | pub fn send(&self, t: T) -> Result<(), SendError<T>> { |
576 | let (new_inner, ret) = match *unsafe { self.inner() } { | |
577 | Flavor::Oneshot(ref p) => { | |
578 | unsafe { | |
579 | let p = p.get(); | |
580 | if !(*p).sent() { | |
581 | return (*p).send(t).map_err(SendError); | |
582 | } else { | |
583 | let a = | |
85aaf69f | 584 | Arc::new(UnsafeCell::new(stream::Packet::new())); |
1a4d82fc JJ |
585 | let rx = Receiver::new(Flavor::Stream(a.clone())); |
586 | match (*p).upgrade(rx) { | |
587 | oneshot::UpSuccess => { | |
588 | let ret = (*a.get()).send(t); | |
589 | (a, ret) | |
590 | } | |
591 | oneshot::UpDisconnected => (a, Err(t)), | |
592 | oneshot::UpWoke(token) => { | |
593 | // This send cannot panic because the thread is | |
594 | // asleep (we're looking at it), so the receiver | |
595 | // can't go away. | |
596 | (*a.get()).send(t).ok().unwrap(); | |
c34b1796 | 597 | token.signal(); |
1a4d82fc JJ |
598 | (a, Ok(())) |
599 | } | |
600 | } | |
601 | } | |
602 | } | |
603 | } | |
604 | Flavor::Stream(ref p) => return unsafe { | |
605 | (*p.get()).send(t).map_err(SendError) | |
606 | }, | |
607 | Flavor::Shared(ref p) => return unsafe { | |
608 | (*p.get()).send(t).map_err(SendError) | |
609 | }, | |
610 | Flavor::Sync(..) => unreachable!(), | |
611 | }; | |
612 | ||
613 | unsafe { | |
614 | let tmp = Sender::new(Flavor::Stream(new_inner)); | |
615 | mem::swap(self.inner_mut(), tmp.inner_mut()); | |
616 | } | |
617 | ret.map_err(SendError) | |
618 | } | |
619 | } | |
620 | ||
85aaf69f | 621 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 622 | impl<T> Clone for Sender<T> { |
1a4d82fc JJ |
623 | fn clone(&self) -> Sender<T> { |
624 | let (packet, sleeper, guard) = match *unsafe { self.inner() } { | |
625 | Flavor::Oneshot(ref p) => { | |
85aaf69f | 626 | let a = Arc::new(UnsafeCell::new(shared::Packet::new())); |
1a4d82fc JJ |
627 | unsafe { |
628 | let guard = (*a.get()).postinit_lock(); | |
629 | let rx = Receiver::new(Flavor::Shared(a.clone())); | |
630 | match (*p.get()).upgrade(rx) { | |
631 | oneshot::UpSuccess | | |
632 | oneshot::UpDisconnected => (a, None, guard), | |
633 | oneshot::UpWoke(task) => (a, Some(task), guard) | |
634 | } | |
635 | } | |
636 | } | |
637 | Flavor::Stream(ref p) => { | |
85aaf69f | 638 | let a = Arc::new(UnsafeCell::new(shared::Packet::new())); |
1a4d82fc JJ |
639 | unsafe { |
640 | let guard = (*a.get()).postinit_lock(); | |
641 | let rx = Receiver::new(Flavor::Shared(a.clone())); | |
642 | match (*p.get()).upgrade(rx) { | |
643 | stream::UpSuccess | | |
644 | stream::UpDisconnected => (a, None, guard), | |
645 | stream::UpWoke(task) => (a, Some(task), guard), | |
646 | } | |
647 | } | |
648 | } | |
649 | Flavor::Shared(ref p) => { | |
650 | unsafe { (*p.get()).clone_chan(); } | |
651 | return Sender::new(Flavor::Shared(p.clone())); | |
652 | } | |
653 | Flavor::Sync(..) => unreachable!(), | |
654 | }; | |
655 | ||
656 | unsafe { | |
657 | (*packet.get()).inherit_blocker(sleeper, guard); | |
658 | ||
659 | let tmp = Sender::new(Flavor::Shared(packet.clone())); | |
660 | mem::swap(self.inner_mut(), tmp.inner_mut()); | |
661 | } | |
662 | Sender::new(Flavor::Shared(packet)) | |
663 | } | |
664 | } | |
665 | ||
666 | #[unsafe_destructor] | |
85aaf69f | 667 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 668 | impl<T> Drop for Sender<T> { |
1a4d82fc JJ |
669 | fn drop(&mut self) { |
670 | match *unsafe { self.inner_mut() } { | |
671 | Flavor::Oneshot(ref mut p) => unsafe { (*p.get()).drop_chan(); }, | |
672 | Flavor::Stream(ref mut p) => unsafe { (*p.get()).drop_chan(); }, | |
673 | Flavor::Shared(ref mut p) => unsafe { (*p.get()).drop_chan(); }, | |
674 | Flavor::Sync(..) => unreachable!(), | |
675 | } | |
676 | } | |
677 | } | |
678 | ||
679 | //////////////////////////////////////////////////////////////////////////////// | |
680 | // SyncSender | |
681 | //////////////////////////////////////////////////////////////////////////////// | |
682 | ||
c34b1796 | 683 | impl<T> SyncSender<T> { |
85aaf69f SL |
684 | fn new(inner: Arc<UnsafeCell<sync::Packet<T>>>) -> SyncSender<T> { |
685 | SyncSender { inner: inner } | |
1a4d82fc JJ |
686 | } |
687 | ||
688 | /// Sends a value on this synchronous channel. | |
689 | /// | |
690 | /// This function will *block* until space in the internal buffer becomes | |
691 | /// available or a receiver is available to hand off the message to. | |
692 | /// | |
693 | /// Note that a successful send does *not* guarantee that the receiver will | |
694 | /// ever see the data if there is a buffer on this channel. Items may be | |
695 | /// enqueued in the internal buffer for the receiver to receive at a later | |
696 | /// time. If the buffer size is 0, however, it can be guaranteed that the | |
697 | /// receiver has indeed received the data if this function returns success. | |
698 | /// | |
699 | /// This function will never panic, but it may return `Err` if the | |
700 | /// `Receiver` has disconnected and is no longer able to receive | |
701 | /// information. | |
85aaf69f | 702 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
703 | pub fn send(&self, t: T) -> Result<(), SendError<T>> { |
704 | unsafe { (*self.inner.get()).send(t).map_err(SendError) } | |
705 | } | |
706 | ||
707 | /// Attempts to send a value on this channel without blocking. | |
708 | /// | |
709 | /// This method differs from `send` by returning immediately if the | |
710 | /// channel's buffer is full or no receiver is waiting to acquire some | |
711 | /// data. Compared with `send`, this function has two failure cases | |
712 | /// instead of one (one for disconnection, one for a full buffer). | |
713 | /// | |
714 | /// See `SyncSender::send` for notes about guarantees of whether the | |
715 | /// receiver has received the data or not if this function is successful. | |
85aaf69f | 716 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
717 | pub fn try_send(&self, t: T) -> Result<(), TrySendError<T>> { |
718 | unsafe { (*self.inner.get()).try_send(t) } | |
719 | } | |
720 | } | |
721 | ||
85aaf69f | 722 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 723 | impl<T> Clone for SyncSender<T> { |
1a4d82fc JJ |
724 | fn clone(&self) -> SyncSender<T> { |
725 | unsafe { (*self.inner.get()).clone_chan(); } | |
726 | return SyncSender::new(self.inner.clone()); | |
727 | } | |
728 | } | |
729 | ||
730 | #[unsafe_destructor] | |
85aaf69f | 731 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 732 | impl<T> Drop for SyncSender<T> { |
1a4d82fc JJ |
733 | fn drop(&mut self) { |
734 | unsafe { (*self.inner.get()).drop_chan(); } | |
735 | } | |
736 | } | |
737 | ||
738 | //////////////////////////////////////////////////////////////////////////////// | |
739 | // Receiver | |
740 | //////////////////////////////////////////////////////////////////////////////// | |
741 | ||
c34b1796 | 742 | impl<T> Receiver<T> { |
1a4d82fc JJ |
743 | fn new(inner: Flavor<T>) -> Receiver<T> { |
744 | Receiver { inner: UnsafeCell::new(inner) } | |
745 | } | |
746 | ||
747 | /// Attempts to return a pending value on this receiver without blocking | |
748 | /// | |
749 | /// This method will never block the caller in order to wait for data to | |
750 | /// become available. Instead, this will always return immediately with a | |
751 | /// possible option of pending data on the channel. | |
752 | /// | |
753 | /// This is useful for a flavor of "optimistic check" before deciding to | |
754 | /// block on a receiver. | |
85aaf69f | 755 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
756 | pub fn try_recv(&self) -> Result<T, TryRecvError> { |
757 | loop { | |
758 | let new_port = match *unsafe { self.inner() } { | |
759 | Flavor::Oneshot(ref p) => { | |
760 | match unsafe { (*p.get()).try_recv() } { | |
761 | Ok(t) => return Ok(t), | |
762 | Err(oneshot::Empty) => return Err(TryRecvError::Empty), | |
763 | Err(oneshot::Disconnected) => { | |
764 | return Err(TryRecvError::Disconnected) | |
765 | } | |
766 | Err(oneshot::Upgraded(rx)) => rx, | |
767 | } | |
768 | } | |
769 | Flavor::Stream(ref p) => { | |
770 | match unsafe { (*p.get()).try_recv() } { | |
771 | Ok(t) => return Ok(t), | |
772 | Err(stream::Empty) => return Err(TryRecvError::Empty), | |
773 | Err(stream::Disconnected) => { | |
774 | return Err(TryRecvError::Disconnected) | |
775 | } | |
776 | Err(stream::Upgraded(rx)) => rx, | |
777 | } | |
778 | } | |
779 | Flavor::Shared(ref p) => { | |
780 | match unsafe { (*p.get()).try_recv() } { | |
781 | Ok(t) => return Ok(t), | |
782 | Err(shared::Empty) => return Err(TryRecvError::Empty), | |
783 | Err(shared::Disconnected) => { | |
784 | return Err(TryRecvError::Disconnected) | |
785 | } | |
786 | } | |
787 | } | |
788 | Flavor::Sync(ref p) => { | |
789 | match unsafe { (*p.get()).try_recv() } { | |
790 | Ok(t) => return Ok(t), | |
791 | Err(sync::Empty) => return Err(TryRecvError::Empty), | |
792 | Err(sync::Disconnected) => { | |
793 | return Err(TryRecvError::Disconnected) | |
794 | } | |
795 | } | |
796 | } | |
797 | }; | |
798 | unsafe { | |
799 | mem::swap(self.inner_mut(), | |
800 | new_port.inner_mut()); | |
801 | } | |
802 | } | |
803 | } | |
804 | ||
805 | /// Attempt to wait for a value on this receiver, returning an error if the | |
806 | /// corresponding channel has hung up. | |
807 | /// | |
808 | /// This function will always block the current thread if there is no data | |
809 | /// available and it's possible for more data to be sent. Once a message is | |
810 | /// sent to the corresponding `Sender`, then this receiver will wake up and | |
811 | /// return that message. | |
812 | /// | |
813 | /// If the corresponding `Sender` has disconnected, or it disconnects while | |
814 | /// this call is blocking, this call will wake up and return `Err` to | |
815 | /// indicate that no more messages can ever be received on this channel. | |
85aaf69f | 816 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
817 | pub fn recv(&self) -> Result<T, RecvError> { |
818 | loop { | |
819 | let new_port = match *unsafe { self.inner() } { | |
820 | Flavor::Oneshot(ref p) => { | |
821 | match unsafe { (*p.get()).recv() } { | |
822 | Ok(t) => return Ok(t), | |
823 | Err(oneshot::Empty) => return unreachable!(), | |
824 | Err(oneshot::Disconnected) => return Err(RecvError), | |
825 | Err(oneshot::Upgraded(rx)) => rx, | |
826 | } | |
827 | } | |
828 | Flavor::Stream(ref p) => { | |
829 | match unsafe { (*p.get()).recv() } { | |
830 | Ok(t) => return Ok(t), | |
831 | Err(stream::Empty) => return unreachable!(), | |
832 | Err(stream::Disconnected) => return Err(RecvError), | |
833 | Err(stream::Upgraded(rx)) => rx, | |
834 | } | |
835 | } | |
836 | Flavor::Shared(ref p) => { | |
837 | match unsafe { (*p.get()).recv() } { | |
838 | Ok(t) => return Ok(t), | |
839 | Err(shared::Empty) => return unreachable!(), | |
840 | Err(shared::Disconnected) => return Err(RecvError), | |
841 | } | |
842 | } | |
843 | Flavor::Sync(ref p) => return unsafe { | |
844 | (*p.get()).recv().map_err(|()| RecvError) | |
845 | } | |
846 | }; | |
847 | unsafe { | |
848 | mem::swap(self.inner_mut(), new_port.inner_mut()); | |
849 | } | |
850 | } | |
851 | } | |
852 | ||
853 | /// Returns an iterator that will block waiting for messages, but never | |
854 | /// `panic!`. It will return `None` when the channel has hung up. | |
85aaf69f | 855 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
856 | pub fn iter(&self) -> Iter<T> { |
857 | Iter { rx: self } | |
858 | } | |
859 | } | |
860 | ||
c34b1796 | 861 | impl<T> select::Packet for Receiver<T> { |
1a4d82fc JJ |
862 | fn can_recv(&self) -> bool { |
863 | loop { | |
864 | let new_port = match *unsafe { self.inner() } { | |
865 | Flavor::Oneshot(ref p) => { | |
866 | match unsafe { (*p.get()).can_recv() } { | |
867 | Ok(ret) => return ret, | |
868 | Err(upgrade) => upgrade, | |
869 | } | |
870 | } | |
871 | Flavor::Stream(ref p) => { | |
872 | match unsafe { (*p.get()).can_recv() } { | |
873 | Ok(ret) => return ret, | |
874 | Err(upgrade) => upgrade, | |
875 | } | |
876 | } | |
877 | Flavor::Shared(ref p) => { | |
878 | return unsafe { (*p.get()).can_recv() }; | |
879 | } | |
880 | Flavor::Sync(ref p) => { | |
881 | return unsafe { (*p.get()).can_recv() }; | |
882 | } | |
883 | }; | |
884 | unsafe { | |
885 | mem::swap(self.inner_mut(), | |
886 | new_port.inner_mut()); | |
887 | } | |
888 | } | |
889 | } | |
890 | ||
891 | fn start_selection(&self, mut token: SignalToken) -> StartResult { | |
892 | loop { | |
893 | let (t, new_port) = match *unsafe { self.inner() } { | |
894 | Flavor::Oneshot(ref p) => { | |
895 | match unsafe { (*p.get()).start_selection(token) } { | |
896 | oneshot::SelSuccess => return Installed, | |
897 | oneshot::SelCanceled => return Abort, | |
898 | oneshot::SelUpgraded(t, rx) => (t, rx), | |
899 | } | |
900 | } | |
901 | Flavor::Stream(ref p) => { | |
902 | match unsafe { (*p.get()).start_selection(token) } { | |
903 | stream::SelSuccess => return Installed, | |
904 | stream::SelCanceled => return Abort, | |
905 | stream::SelUpgraded(t, rx) => (t, rx), | |
906 | } | |
907 | } | |
908 | Flavor::Shared(ref p) => { | |
909 | return unsafe { (*p.get()).start_selection(token) }; | |
910 | } | |
911 | Flavor::Sync(ref p) => { | |
912 | return unsafe { (*p.get()).start_selection(token) }; | |
913 | } | |
914 | }; | |
915 | token = t; | |
916 | unsafe { | |
917 | mem::swap(self.inner_mut(), new_port.inner_mut()); | |
918 | } | |
919 | } | |
920 | } | |
921 | ||
922 | fn abort_selection(&self) -> bool { | |
923 | let mut was_upgrade = false; | |
924 | loop { | |
925 | let result = match *unsafe { self.inner() } { | |
926 | Flavor::Oneshot(ref p) => unsafe { (*p.get()).abort_selection() }, | |
927 | Flavor::Stream(ref p) => unsafe { | |
928 | (*p.get()).abort_selection(was_upgrade) | |
929 | }, | |
930 | Flavor::Shared(ref p) => return unsafe { | |
931 | (*p.get()).abort_selection(was_upgrade) | |
932 | }, | |
933 | Flavor::Sync(ref p) => return unsafe { | |
934 | (*p.get()).abort_selection() | |
935 | }, | |
936 | }; | |
937 | let new_port = match result { Ok(b) => return b, Err(p) => p }; | |
938 | was_upgrade = true; | |
939 | unsafe { | |
940 | mem::swap(self.inner_mut(), | |
941 | new_port.inner_mut()); | |
942 | } | |
943 | } | |
944 | } | |
945 | } | |
946 | ||
85aaf69f | 947 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 948 | impl<'a, T> Iterator for Iter<'a, T> { |
1a4d82fc JJ |
949 | type Item = T; |
950 | ||
951 | fn next(&mut self) -> Option<T> { self.rx.recv().ok() } | |
952 | } | |
953 | ||
954 | #[unsafe_destructor] | |
85aaf69f | 955 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 956 | impl<T> Drop for Receiver<T> { |
1a4d82fc JJ |
957 | fn drop(&mut self) { |
958 | match *unsafe { self.inner_mut() } { | |
959 | Flavor::Oneshot(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
960 | Flavor::Stream(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
961 | Flavor::Shared(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
962 | Flavor::Sync(ref mut p) => unsafe { (*p.get()).drop_port(); }, | |
963 | } | |
964 | } | |
965 | } | |
966 | ||
85aaf69f SL |
967 | #[stable(feature = "rust1", since = "1.0.0")] |
968 | impl<T> fmt::Debug for SendError<T> { | |
969 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
970 | "SendError(..)".fmt(f) | |
1a4d82fc | 971 | } |
85aaf69f | 972 | } |
1a4d82fc | 973 | |
85aaf69f SL |
974 | #[stable(feature = "rust1", since = "1.0.0")] |
975 | impl<T> fmt::Display for SendError<T> { | |
976 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
977 | "sending on a closed channel".fmt(f) | |
1a4d82fc | 978 | } |
1a4d82fc JJ |
979 | } |
980 | ||
c34b1796 AL |
981 | #[stable(feature = "rust1", since = "1.0.0")] |
982 | impl<T: Send> error::Error for SendError<T> { | |
983 | ||
984 | fn description(&self) -> &str { | |
985 | "sending on a closed channel" | |
986 | } | |
987 | ||
988 | fn cause(&self) -> Option<&error::Error> { | |
989 | None | |
990 | } | |
991 | } | |
992 | ||
85aaf69f SL |
993 | #[stable(feature = "rust1", since = "1.0.0")] |
994 | impl<T> fmt::Debug for TrySendError<T> { | |
1a4d82fc | 995 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
85aaf69f SL |
996 | match *self { |
997 | TrySendError::Full(..) => "Full(..)".fmt(f), | |
998 | TrySendError::Disconnected(..) => "Disconnected(..)".fmt(f), | |
999 | } | |
1a4d82fc JJ |
1000 | } |
1001 | } | |
1002 | ||
85aaf69f SL |
1003 | #[stable(feature = "rust1", since = "1.0.0")] |
1004 | impl<T> fmt::Display for TrySendError<T> { | |
1a4d82fc JJ |
1005 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
1006 | match *self { | |
1007 | TrySendError::Full(..) => { | |
1008 | "sending on a full channel".fmt(f) | |
1009 | } | |
1010 | TrySendError::Disconnected(..) => { | |
1011 | "sending on a closed channel".fmt(f) | |
1012 | } | |
1013 | } | |
1014 | } | |
1015 | } | |
1016 | ||
c34b1796 AL |
1017 | #[stable(feature = "rust1", since = "1.0.0")] |
1018 | impl<T: Send> error::Error for TrySendError<T> { | |
1019 | ||
1020 | fn description(&self) -> &str { | |
1021 | match *self { | |
1022 | TrySendError::Full(..) => { | |
1023 | "sending on a full channel" | |
1024 | } | |
1025 | TrySendError::Disconnected(..) => { | |
1026 | "sending on a closed channel" | |
1027 | } | |
1028 | } | |
1029 | } | |
1030 | ||
1031 | fn cause(&self) -> Option<&error::Error> { | |
1032 | None | |
1033 | } | |
1034 | } | |
1035 | ||
85aaf69f SL |
1036 | #[stable(feature = "rust1", since = "1.0.0")] |
1037 | impl fmt::Display for RecvError { | |
1a4d82fc JJ |
1038 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
1039 | "receiving on a closed channel".fmt(f) | |
1040 | } | |
1041 | } | |
1042 | ||
c34b1796 AL |
1043 | #[stable(feature = "rust1", since = "1.0.0")] |
1044 | impl error::Error for RecvError { | |
1045 | ||
1046 | fn description(&self) -> &str { | |
1047 | "receiving on a closed channel" | |
1048 | } | |
1049 | ||
1050 | fn cause(&self) -> Option<&error::Error> { | |
1051 | None | |
1052 | } | |
1053 | } | |
1054 | ||
85aaf69f SL |
1055 | #[stable(feature = "rust1", since = "1.0.0")] |
1056 | impl fmt::Display for TryRecvError { | |
1a4d82fc JJ |
1057 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
1058 | match *self { | |
1059 | TryRecvError::Empty => { | |
1060 | "receiving on an empty channel".fmt(f) | |
1061 | } | |
1062 | TryRecvError::Disconnected => { | |
1063 | "receiving on a closed channel".fmt(f) | |
1064 | } | |
1065 | } | |
1066 | } | |
1067 | } | |
1068 | ||
c34b1796 AL |
1069 | #[stable(feature = "rust1", since = "1.0.0")] |
1070 | impl error::Error for TryRecvError { | |
1071 | ||
1072 | fn description(&self) -> &str { | |
1073 | match *self { | |
1074 | TryRecvError::Empty => { | |
1075 | "receiving on an empty channel" | |
1076 | } | |
1077 | TryRecvError::Disconnected => { | |
1078 | "receiving on a closed channel" | |
1079 | } | |
1080 | } | |
1081 | } | |
1082 | ||
1083 | fn cause(&self) -> Option<&error::Error> { | |
1084 | None | |
1085 | } | |
1086 | } | |
1087 | ||
1a4d82fc JJ |
1088 | #[cfg(test)] |
1089 | mod test { | |
1090 | use prelude::v1::*; | |
1091 | ||
85aaf69f | 1092 | use std::env; |
1a4d82fc | 1093 | use super::*; |
85aaf69f | 1094 | use thread; |
1a4d82fc | 1095 | |
c34b1796 | 1096 | pub fn stress_factor() -> usize { |
85aaf69f SL |
1097 | match env::var("RUST_TEST_STRESS") { |
1098 | Ok(val) => val.parse().unwrap(), | |
1099 | Err(..) => 1, | |
1a4d82fc JJ |
1100 | } |
1101 | } | |
1102 | ||
1103 | #[test] | |
1104 | fn smoke() { | |
c34b1796 | 1105 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1106 | tx.send(1).unwrap(); |
1107 | assert_eq!(rx.recv().unwrap(), 1); | |
1108 | } | |
1109 | ||
1110 | #[test] | |
1111 | fn drop_full() { | |
c34b1796 | 1112 | let (tx, _rx) = channel::<Box<isize>>(); |
85aaf69f | 1113 | tx.send(box 1).unwrap(); |
1a4d82fc JJ |
1114 | } |
1115 | ||
1116 | #[test] | |
1117 | fn drop_full_shared() { | |
c34b1796 | 1118 | let (tx, _rx) = channel::<Box<isize>>(); |
1a4d82fc JJ |
1119 | drop(tx.clone()); |
1120 | drop(tx.clone()); | |
85aaf69f | 1121 | tx.send(box 1).unwrap(); |
1a4d82fc JJ |
1122 | } |
1123 | ||
1124 | #[test] | |
1125 | fn smoke_shared() { | |
c34b1796 | 1126 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1127 | tx.send(1).unwrap(); |
1128 | assert_eq!(rx.recv().unwrap(), 1); | |
1129 | let tx = tx.clone(); | |
1130 | tx.send(1).unwrap(); | |
1131 | assert_eq!(rx.recv().unwrap(), 1); | |
1132 | } | |
1133 | ||
1134 | #[test] | |
1135 | fn smoke_threads() { | |
c34b1796 | 1136 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1137 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1138 | tx.send(1).unwrap(); |
1139 | }); | |
1140 | assert_eq!(rx.recv().unwrap(), 1); | |
1141 | } | |
1142 | ||
1143 | #[test] | |
1144 | fn smoke_port_gone() { | |
c34b1796 | 1145 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1146 | drop(rx); |
1147 | assert!(tx.send(1).is_err()); | |
1148 | } | |
1149 | ||
1150 | #[test] | |
1151 | fn smoke_shared_port_gone() { | |
c34b1796 | 1152 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1153 | drop(rx); |
1154 | assert!(tx.send(1).is_err()) | |
1155 | } | |
1156 | ||
1157 | #[test] | |
1158 | fn smoke_shared_port_gone2() { | |
c34b1796 | 1159 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1160 | drop(rx); |
1161 | let tx2 = tx.clone(); | |
1162 | drop(tx); | |
1163 | assert!(tx2.send(1).is_err()); | |
1164 | } | |
1165 | ||
1166 | #[test] | |
1167 | fn port_gone_concurrent() { | |
c34b1796 | 1168 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1169 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1170 | rx.recv().unwrap(); |
1171 | }); | |
1172 | while tx.send(1).is_ok() {} | |
1173 | } | |
1174 | ||
1175 | #[test] | |
1176 | fn port_gone_concurrent_shared() { | |
c34b1796 | 1177 | let (tx, rx) = channel::<i32>(); |
1a4d82fc | 1178 | let tx2 = tx.clone(); |
85aaf69f | 1179 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1180 | rx.recv().unwrap(); |
1181 | }); | |
1182 | while tx.send(1).is_ok() && tx2.send(1).is_ok() {} | |
1183 | } | |
1184 | ||
1185 | #[test] | |
1186 | fn smoke_chan_gone() { | |
c34b1796 | 1187 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1188 | drop(tx); |
1189 | assert!(rx.recv().is_err()); | |
1190 | } | |
1191 | ||
1192 | #[test] | |
1193 | fn smoke_chan_gone_shared() { | |
1194 | let (tx, rx) = channel::<()>(); | |
1195 | let tx2 = tx.clone(); | |
1196 | drop(tx); | |
1197 | drop(tx2); | |
1198 | assert!(rx.recv().is_err()); | |
1199 | } | |
1200 | ||
1201 | #[test] | |
1202 | fn chan_gone_concurrent() { | |
c34b1796 | 1203 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1204 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1205 | tx.send(1).unwrap(); |
1206 | tx.send(1).unwrap(); | |
1207 | }); | |
1208 | while rx.recv().is_ok() {} | |
1209 | } | |
1210 | ||
1211 | #[test] | |
1212 | fn stress() { | |
c34b1796 | 1213 | let (tx, rx) = channel::<i32>(); |
85aaf69f SL |
1214 | let t = thread::spawn(move|| { |
1215 | for _ in 0..10000 { tx.send(1).unwrap(); } | |
1a4d82fc | 1216 | }); |
85aaf69f | 1217 | for _ in 0..10000 { |
1a4d82fc JJ |
1218 | assert_eq!(rx.recv().unwrap(), 1); |
1219 | } | |
1220 | t.join().ok().unwrap(); | |
1221 | } | |
1222 | ||
1223 | #[test] | |
1224 | fn stress_shared() { | |
c34b1796 AL |
1225 | const AMT: u32 = 10000; |
1226 | const NTHREADS: u32 = 8; | |
1227 | let (tx, rx) = channel::<i32>(); | |
1a4d82fc | 1228 | |
85aaf69f SL |
1229 | let t = thread::spawn(move|| { |
1230 | for _ in 0..AMT * NTHREADS { | |
1a4d82fc JJ |
1231 | assert_eq!(rx.recv().unwrap(), 1); |
1232 | } | |
1233 | match rx.try_recv() { | |
1234 | Ok(..) => panic!(), | |
1235 | _ => {} | |
1236 | } | |
1237 | }); | |
1238 | ||
85aaf69f | 1239 | for _ in 0..NTHREADS { |
1a4d82fc | 1240 | let tx = tx.clone(); |
85aaf69f SL |
1241 | thread::spawn(move|| { |
1242 | for _ in 0..AMT { tx.send(1).unwrap(); } | |
1a4d82fc JJ |
1243 | }); |
1244 | } | |
1245 | drop(tx); | |
1246 | t.join().ok().unwrap(); | |
1247 | } | |
1248 | ||
1249 | #[test] | |
1250 | fn send_from_outside_runtime() { | |
1251 | let (tx1, rx1) = channel::<()>(); | |
c34b1796 | 1252 | let (tx2, rx2) = channel::<i32>(); |
85aaf69f | 1253 | let t1 = thread::spawn(move|| { |
1a4d82fc | 1254 | tx1.send(()).unwrap(); |
85aaf69f | 1255 | for _ in 0..40 { |
1a4d82fc JJ |
1256 | assert_eq!(rx2.recv().unwrap(), 1); |
1257 | } | |
1258 | }); | |
1259 | rx1.recv().unwrap(); | |
85aaf69f SL |
1260 | let t2 = thread::spawn(move|| { |
1261 | for _ in 0..40 { | |
1a4d82fc JJ |
1262 | tx2.send(1).unwrap(); |
1263 | } | |
1264 | }); | |
1265 | t1.join().ok().unwrap(); | |
1266 | t2.join().ok().unwrap(); | |
1267 | } | |
1268 | ||
1269 | #[test] | |
1270 | fn recv_from_outside_runtime() { | |
c34b1796 | 1271 | let (tx, rx) = channel::<i32>(); |
85aaf69f SL |
1272 | let t = thread::spawn(move|| { |
1273 | for _ in 0..40 { | |
1a4d82fc JJ |
1274 | assert_eq!(rx.recv().unwrap(), 1); |
1275 | } | |
1276 | }); | |
85aaf69f | 1277 | for _ in 0..40 { |
1a4d82fc JJ |
1278 | tx.send(1).unwrap(); |
1279 | } | |
1280 | t.join().ok().unwrap(); | |
1281 | } | |
1282 | ||
1283 | #[test] | |
1284 | fn no_runtime() { | |
c34b1796 AL |
1285 | let (tx1, rx1) = channel::<i32>(); |
1286 | let (tx2, rx2) = channel::<i32>(); | |
85aaf69f | 1287 | let t1 = thread::spawn(move|| { |
1a4d82fc JJ |
1288 | assert_eq!(rx1.recv().unwrap(), 1); |
1289 | tx2.send(2).unwrap(); | |
1290 | }); | |
85aaf69f | 1291 | let t2 = thread::spawn(move|| { |
1a4d82fc JJ |
1292 | tx1.send(1).unwrap(); |
1293 | assert_eq!(rx2.recv().unwrap(), 2); | |
1294 | }); | |
1295 | t1.join().ok().unwrap(); | |
1296 | t2.join().ok().unwrap(); | |
1297 | } | |
1298 | ||
1299 | #[test] | |
1300 | fn oneshot_single_thread_close_port_first() { | |
1301 | // Simple test of closing without sending | |
c34b1796 | 1302 | let (_tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1303 | drop(rx); |
1304 | } | |
1305 | ||
1306 | #[test] | |
1307 | fn oneshot_single_thread_close_chan_first() { | |
1308 | // Simple test of closing without sending | |
c34b1796 | 1309 | let (tx, _rx) = channel::<i32>(); |
1a4d82fc JJ |
1310 | drop(tx); |
1311 | } | |
1312 | ||
1313 | #[test] | |
1314 | fn oneshot_single_thread_send_port_close() { | |
1315 | // Testing that the sender cleans up the payload if receiver is closed | |
c34b1796 | 1316 | let (tx, rx) = channel::<Box<i32>>(); |
1a4d82fc JJ |
1317 | drop(rx); |
1318 | assert!(tx.send(box 0).is_err()); | |
1319 | } | |
1320 | ||
1321 | #[test] | |
1322 | fn oneshot_single_thread_recv_chan_close() { | |
1323 | // Receiving on a closed chan will panic | |
85aaf69f | 1324 | let res = thread::spawn(move|| { |
c34b1796 | 1325 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1326 | drop(tx); |
1327 | rx.recv().unwrap(); | |
1328 | }).join(); | |
1329 | // What is our res? | |
1330 | assert!(res.is_err()); | |
1331 | } | |
1332 | ||
1333 | #[test] | |
1334 | fn oneshot_single_thread_send_then_recv() { | |
c34b1796 | 1335 | let (tx, rx) = channel::<Box<i32>>(); |
1a4d82fc JJ |
1336 | tx.send(box 10).unwrap(); |
1337 | assert!(rx.recv().unwrap() == box 10); | |
1338 | } | |
1339 | ||
1340 | #[test] | |
1341 | fn oneshot_single_thread_try_send_open() { | |
c34b1796 | 1342 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1343 | assert!(tx.send(10).is_ok()); |
1344 | assert!(rx.recv().unwrap() == 10); | |
1345 | } | |
1346 | ||
1347 | #[test] | |
1348 | fn oneshot_single_thread_try_send_closed() { | |
c34b1796 | 1349 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1350 | drop(rx); |
1351 | assert!(tx.send(10).is_err()); | |
1352 | } | |
1353 | ||
1354 | #[test] | |
1355 | fn oneshot_single_thread_try_recv_open() { | |
c34b1796 | 1356 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1357 | tx.send(10).unwrap(); |
1358 | assert!(rx.recv() == Ok(10)); | |
1359 | } | |
1360 | ||
1361 | #[test] | |
1362 | fn oneshot_single_thread_try_recv_closed() { | |
c34b1796 | 1363 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1364 | drop(tx); |
1365 | assert!(rx.recv().is_err()); | |
1366 | } | |
1367 | ||
1368 | #[test] | |
1369 | fn oneshot_single_thread_peek_data() { | |
c34b1796 | 1370 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1371 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
1372 | tx.send(10).unwrap(); | |
1373 | assert_eq!(rx.try_recv(), Ok(10)); | |
1374 | } | |
1375 | ||
1376 | #[test] | |
1377 | fn oneshot_single_thread_peek_close() { | |
c34b1796 | 1378 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1379 | drop(tx); |
1380 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
1381 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
1382 | } | |
1383 | ||
1384 | #[test] | |
1385 | fn oneshot_single_thread_peek_open() { | |
c34b1796 | 1386 | let (_tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1387 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
1388 | } | |
1389 | ||
1390 | #[test] | |
1391 | fn oneshot_multi_task_recv_then_send() { | |
c34b1796 | 1392 | let (tx, rx) = channel::<Box<i32>>(); |
85aaf69f | 1393 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1394 | assert!(rx.recv().unwrap() == box 10); |
1395 | }); | |
1396 | ||
1397 | tx.send(box 10).unwrap(); | |
1398 | } | |
1399 | ||
1400 | #[test] | |
1401 | fn oneshot_multi_task_recv_then_close() { | |
c34b1796 | 1402 | let (tx, rx) = channel::<Box<i32>>(); |
85aaf69f | 1403 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1404 | drop(tx); |
1405 | }); | |
85aaf69f | 1406 | let res = thread::spawn(move|| { |
1a4d82fc JJ |
1407 | assert!(rx.recv().unwrap() == box 10); |
1408 | }).join(); | |
1409 | assert!(res.is_err()); | |
1410 | } | |
1411 | ||
1412 | #[test] | |
1413 | fn oneshot_multi_thread_close_stress() { | |
85aaf69f | 1414 | for _ in 0..stress_factor() { |
c34b1796 | 1415 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1416 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1417 | drop(rx); |
1418 | }); | |
1419 | drop(tx); | |
1420 | } | |
1421 | } | |
1422 | ||
1423 | #[test] | |
1424 | fn oneshot_multi_thread_send_close_stress() { | |
85aaf69f | 1425 | for _ in 0..stress_factor() { |
c34b1796 | 1426 | let (tx, rx) = channel::<i32>(); |
85aaf69f | 1427 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1428 | drop(rx); |
1429 | }); | |
85aaf69f | 1430 | let _ = thread::spawn(move|| { |
1a4d82fc JJ |
1431 | tx.send(1).unwrap(); |
1432 | }).join(); | |
1433 | } | |
1434 | } | |
1435 | ||
1436 | #[test] | |
1437 | fn oneshot_multi_thread_recv_close_stress() { | |
85aaf69f | 1438 | for _ in 0..stress_factor() { |
c34b1796 | 1439 | let (tx, rx) = channel::<i32>(); |
85aaf69f SL |
1440 | thread::spawn(move|| { |
1441 | let res = thread::spawn(move|| { | |
1a4d82fc JJ |
1442 | rx.recv().unwrap(); |
1443 | }).join(); | |
1444 | assert!(res.is_err()); | |
1445 | }); | |
85aaf69f SL |
1446 | let _t = thread::spawn(move|| { |
1447 | thread::spawn(move|| { | |
1a4d82fc JJ |
1448 | drop(tx); |
1449 | }); | |
1450 | }); | |
1451 | } | |
1452 | } | |
1453 | ||
1454 | #[test] | |
1455 | fn oneshot_multi_thread_send_recv_stress() { | |
85aaf69f | 1456 | for _ in 0..stress_factor() { |
c34b1796 | 1457 | let (tx, rx) = channel::<Box<isize>>(); |
85aaf69f SL |
1458 | let _t = thread::spawn(move|| { |
1459 | tx.send(box 10).unwrap(); | |
1a4d82fc | 1460 | }); |
85aaf69f | 1461 | assert!(rx.recv().unwrap() == box 10); |
1a4d82fc JJ |
1462 | } |
1463 | } | |
1464 | ||
1465 | #[test] | |
1466 | fn stream_send_recv_stress() { | |
85aaf69f | 1467 | for _ in 0..stress_factor() { |
1a4d82fc JJ |
1468 | let (tx, rx) = channel(); |
1469 | ||
1470 | send(tx, 0); | |
1471 | recv(rx, 0); | |
1472 | ||
c34b1796 | 1473 | fn send(tx: Sender<Box<i32>>, i: i32) { |
1a4d82fc JJ |
1474 | if i == 10 { return } |
1475 | ||
85aaf69f | 1476 | thread::spawn(move|| { |
1a4d82fc JJ |
1477 | tx.send(box i).unwrap(); |
1478 | send(tx, i + 1); | |
1479 | }); | |
1480 | } | |
1481 | ||
c34b1796 | 1482 | fn recv(rx: Receiver<Box<i32>>, i: i32) { |
1a4d82fc JJ |
1483 | if i == 10 { return } |
1484 | ||
85aaf69f | 1485 | thread::spawn(move|| { |
1a4d82fc JJ |
1486 | assert!(rx.recv().unwrap() == box i); |
1487 | recv(rx, i + 1); | |
1488 | }); | |
1489 | } | |
1490 | } | |
1491 | } | |
1492 | ||
1493 | #[test] | |
1494 | fn recv_a_lot() { | |
1495 | // Regression test that we don't run out of stack in scheduler context | |
1496 | let (tx, rx) = channel(); | |
85aaf69f SL |
1497 | for _ in 0..10000 { tx.send(()).unwrap(); } |
1498 | for _ in 0..10000 { rx.recv().unwrap(); } | |
1a4d82fc JJ |
1499 | } |
1500 | ||
1501 | #[test] | |
1502 | fn shared_chan_stress() { | |
1503 | let (tx, rx) = channel(); | |
1504 | let total = stress_factor() + 100; | |
85aaf69f | 1505 | for _ in 0..total { |
1a4d82fc | 1506 | let tx = tx.clone(); |
85aaf69f | 1507 | thread::spawn(move|| { |
1a4d82fc JJ |
1508 | tx.send(()).unwrap(); |
1509 | }); | |
1510 | } | |
1511 | ||
85aaf69f | 1512 | for _ in 0..total { |
1a4d82fc JJ |
1513 | rx.recv().unwrap(); |
1514 | } | |
1515 | } | |
1516 | ||
1517 | #[test] | |
1518 | fn test_nested_recv_iter() { | |
c34b1796 AL |
1519 | let (tx, rx) = channel::<i32>(); |
1520 | let (total_tx, total_rx) = channel::<i32>(); | |
1a4d82fc | 1521 | |
85aaf69f | 1522 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1523 | let mut acc = 0; |
1524 | for x in rx.iter() { | |
1525 | acc += x; | |
1526 | } | |
1527 | total_tx.send(acc).unwrap(); | |
1528 | }); | |
1529 | ||
1530 | tx.send(3).unwrap(); | |
1531 | tx.send(1).unwrap(); | |
1532 | tx.send(2).unwrap(); | |
1533 | drop(tx); | |
1534 | assert_eq!(total_rx.recv().unwrap(), 6); | |
1535 | } | |
1536 | ||
1537 | #[test] | |
1538 | fn test_recv_iter_break() { | |
c34b1796 | 1539 | let (tx, rx) = channel::<i32>(); |
1a4d82fc JJ |
1540 | let (count_tx, count_rx) = channel(); |
1541 | ||
85aaf69f | 1542 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1543 | let mut count = 0; |
1544 | for x in rx.iter() { | |
1545 | if count >= 3 { | |
1546 | break; | |
1547 | } else { | |
1548 | count += x; | |
1549 | } | |
1550 | } | |
1551 | count_tx.send(count).unwrap(); | |
1552 | }); | |
1553 | ||
1554 | tx.send(2).unwrap(); | |
1555 | tx.send(2).unwrap(); | |
1556 | tx.send(2).unwrap(); | |
1557 | let _ = tx.send(2); | |
1558 | drop(tx); | |
1559 | assert_eq!(count_rx.recv().unwrap(), 4); | |
1560 | } | |
1561 | ||
1562 | #[test] | |
1563 | fn try_recv_states() { | |
c34b1796 | 1564 | let (tx1, rx1) = channel::<i32>(); |
1a4d82fc JJ |
1565 | let (tx2, rx2) = channel::<()>(); |
1566 | let (tx3, rx3) = channel::<()>(); | |
85aaf69f | 1567 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1568 | rx2.recv().unwrap(); |
1569 | tx1.send(1).unwrap(); | |
1570 | tx3.send(()).unwrap(); | |
1571 | rx2.recv().unwrap(); | |
1572 | drop(tx1); | |
1573 | tx3.send(()).unwrap(); | |
1574 | }); | |
1575 | ||
1576 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
1577 | tx2.send(()).unwrap(); | |
1578 | rx3.recv().unwrap(); | |
1579 | assert_eq!(rx1.try_recv(), Ok(1)); | |
1580 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
1581 | tx2.send(()).unwrap(); | |
1582 | rx3.recv().unwrap(); | |
1583 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Disconnected)); | |
1584 | } | |
1585 | ||
1586 | // This bug used to end up in a livelock inside of the Receiver destructor | |
1587 | // because the internal state of the Shared packet was corrupted | |
1588 | #[test] | |
1589 | fn destroy_upgraded_shared_port_when_sender_still_active() { | |
1590 | let (tx, rx) = channel(); | |
1591 | let (tx2, rx2) = channel(); | |
85aaf69f | 1592 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1593 | rx.recv().unwrap(); // wait on a oneshot |
1594 | drop(rx); // destroy a shared | |
1595 | tx2.send(()).unwrap(); | |
1596 | }); | |
1597 | // make sure the other task has gone to sleep | |
85aaf69f | 1598 | for _ in 0..5000 { thread::yield_now(); } |
1a4d82fc JJ |
1599 | |
1600 | // upgrade to a shared chan and send a message | |
1601 | let t = tx.clone(); | |
1602 | drop(tx); | |
1603 | t.send(()).unwrap(); | |
1604 | ||
1605 | // wait for the child task to exit before we exit | |
1606 | rx2.recv().unwrap(); | |
1607 | } | |
1608 | } | |
1609 | ||
1610 | #[cfg(test)] | |
1611 | mod sync_tests { | |
1612 | use prelude::v1::*; | |
1613 | ||
85aaf69f SL |
1614 | use std::env; |
1615 | use thread; | |
1a4d82fc JJ |
1616 | use super::*; |
1617 | ||
c34b1796 | 1618 | pub fn stress_factor() -> usize { |
85aaf69f SL |
1619 | match env::var("RUST_TEST_STRESS") { |
1620 | Ok(val) => val.parse().unwrap(), | |
1621 | Err(..) => 1, | |
1a4d82fc JJ |
1622 | } |
1623 | } | |
1624 | ||
1625 | #[test] | |
1626 | fn smoke() { | |
c34b1796 | 1627 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
1628 | tx.send(1).unwrap(); |
1629 | assert_eq!(rx.recv().unwrap(), 1); | |
1630 | } | |
1631 | ||
1632 | #[test] | |
1633 | fn drop_full() { | |
c34b1796 | 1634 | let (tx, _rx) = sync_channel::<Box<isize>>(1); |
85aaf69f | 1635 | tx.send(box 1).unwrap(); |
1a4d82fc JJ |
1636 | } |
1637 | ||
1638 | #[test] | |
1639 | fn smoke_shared() { | |
c34b1796 | 1640 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
1641 | tx.send(1).unwrap(); |
1642 | assert_eq!(rx.recv().unwrap(), 1); | |
1643 | let tx = tx.clone(); | |
1644 | tx.send(1).unwrap(); | |
1645 | assert_eq!(rx.recv().unwrap(), 1); | |
1646 | } | |
1647 | ||
1648 | #[test] | |
1649 | fn smoke_threads() { | |
c34b1796 | 1650 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 1651 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1652 | tx.send(1).unwrap(); |
1653 | }); | |
1654 | assert_eq!(rx.recv().unwrap(), 1); | |
1655 | } | |
1656 | ||
1657 | #[test] | |
1658 | fn smoke_port_gone() { | |
c34b1796 | 1659 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1660 | drop(rx); |
1661 | assert!(tx.send(1).is_err()); | |
1662 | } | |
1663 | ||
1664 | #[test] | |
1665 | fn smoke_shared_port_gone2() { | |
c34b1796 | 1666 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1667 | drop(rx); |
1668 | let tx2 = tx.clone(); | |
1669 | drop(tx); | |
1670 | assert!(tx2.send(1).is_err()); | |
1671 | } | |
1672 | ||
1673 | #[test] | |
1674 | fn port_gone_concurrent() { | |
c34b1796 | 1675 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 1676 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1677 | rx.recv().unwrap(); |
1678 | }); | |
1679 | while tx.send(1).is_ok() {} | |
1680 | } | |
1681 | ||
1682 | #[test] | |
1683 | fn port_gone_concurrent_shared() { | |
c34b1796 | 1684 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc | 1685 | let tx2 = tx.clone(); |
85aaf69f | 1686 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1687 | rx.recv().unwrap(); |
1688 | }); | |
1689 | while tx.send(1).is_ok() && tx2.send(1).is_ok() {} | |
1690 | } | |
1691 | ||
1692 | #[test] | |
1693 | fn smoke_chan_gone() { | |
c34b1796 | 1694 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1695 | drop(tx); |
1696 | assert!(rx.recv().is_err()); | |
1697 | } | |
1698 | ||
1699 | #[test] | |
1700 | fn smoke_chan_gone_shared() { | |
1701 | let (tx, rx) = sync_channel::<()>(0); | |
1702 | let tx2 = tx.clone(); | |
1703 | drop(tx); | |
1704 | drop(tx2); | |
1705 | assert!(rx.recv().is_err()); | |
1706 | } | |
1707 | ||
1708 | #[test] | |
1709 | fn chan_gone_concurrent() { | |
c34b1796 | 1710 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 1711 | thread::spawn(move|| { |
1a4d82fc JJ |
1712 | tx.send(1).unwrap(); |
1713 | tx.send(1).unwrap(); | |
1714 | }); | |
1715 | while rx.recv().is_ok() {} | |
1716 | } | |
1717 | ||
1718 | #[test] | |
1719 | fn stress() { | |
c34b1796 | 1720 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f SL |
1721 | thread::spawn(move|| { |
1722 | for _ in 0..10000 { tx.send(1).unwrap(); } | |
1a4d82fc | 1723 | }); |
85aaf69f | 1724 | for _ in 0..10000 { |
1a4d82fc JJ |
1725 | assert_eq!(rx.recv().unwrap(), 1); |
1726 | } | |
1727 | } | |
1728 | ||
1729 | #[test] | |
1730 | fn stress_shared() { | |
c34b1796 AL |
1731 | const AMT: u32 = 1000; |
1732 | const NTHREADS: u32 = 8; | |
1733 | let (tx, rx) = sync_channel::<i32>(0); | |
1a4d82fc JJ |
1734 | let (dtx, drx) = sync_channel::<()>(0); |
1735 | ||
85aaf69f SL |
1736 | thread::spawn(move|| { |
1737 | for _ in 0..AMT * NTHREADS { | |
1a4d82fc JJ |
1738 | assert_eq!(rx.recv().unwrap(), 1); |
1739 | } | |
1740 | match rx.try_recv() { | |
1741 | Ok(..) => panic!(), | |
1742 | _ => {} | |
1743 | } | |
1744 | dtx.send(()).unwrap(); | |
1745 | }); | |
1746 | ||
85aaf69f | 1747 | for _ in 0..NTHREADS { |
1a4d82fc | 1748 | let tx = tx.clone(); |
85aaf69f SL |
1749 | thread::spawn(move|| { |
1750 | for _ in 0..AMT { tx.send(1).unwrap(); } | |
1a4d82fc JJ |
1751 | }); |
1752 | } | |
1753 | drop(tx); | |
1754 | drx.recv().unwrap(); | |
1755 | } | |
1756 | ||
1757 | #[test] | |
1758 | fn oneshot_single_thread_close_port_first() { | |
1759 | // Simple test of closing without sending | |
c34b1796 | 1760 | let (_tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1761 | drop(rx); |
1762 | } | |
1763 | ||
1764 | #[test] | |
1765 | fn oneshot_single_thread_close_chan_first() { | |
1766 | // Simple test of closing without sending | |
c34b1796 | 1767 | let (tx, _rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1768 | drop(tx); |
1769 | } | |
1770 | ||
1771 | #[test] | |
1772 | fn oneshot_single_thread_send_port_close() { | |
1773 | // Testing that the sender cleans up the payload if receiver is closed | |
c34b1796 | 1774 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
1a4d82fc JJ |
1775 | drop(rx); |
1776 | assert!(tx.send(box 0).is_err()); | |
1777 | } | |
1778 | ||
1779 | #[test] | |
1780 | fn oneshot_single_thread_recv_chan_close() { | |
1781 | // Receiving on a closed chan will panic | |
85aaf69f | 1782 | let res = thread::spawn(move|| { |
c34b1796 | 1783 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1784 | drop(tx); |
1785 | rx.recv().unwrap(); | |
1786 | }).join(); | |
1787 | // What is our res? | |
1788 | assert!(res.is_err()); | |
1789 | } | |
1790 | ||
1791 | #[test] | |
1792 | fn oneshot_single_thread_send_then_recv() { | |
c34b1796 | 1793 | let (tx, rx) = sync_channel::<Box<i32>>(1); |
1a4d82fc JJ |
1794 | tx.send(box 10).unwrap(); |
1795 | assert!(rx.recv().unwrap() == box 10); | |
1796 | } | |
1797 | ||
1798 | #[test] | |
1799 | fn oneshot_single_thread_try_send_open() { | |
c34b1796 | 1800 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
1801 | assert_eq!(tx.try_send(10), Ok(())); |
1802 | assert!(rx.recv().unwrap() == 10); | |
1803 | } | |
1804 | ||
1805 | #[test] | |
1806 | fn oneshot_single_thread_try_send_closed() { | |
c34b1796 | 1807 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1808 | drop(rx); |
1809 | assert_eq!(tx.try_send(10), Err(TrySendError::Disconnected(10))); | |
1810 | } | |
1811 | ||
1812 | #[test] | |
1813 | fn oneshot_single_thread_try_send_closed2() { | |
c34b1796 | 1814 | let (tx, _rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1815 | assert_eq!(tx.try_send(10), Err(TrySendError::Full(10))); |
1816 | } | |
1817 | ||
1818 | #[test] | |
1819 | fn oneshot_single_thread_try_recv_open() { | |
c34b1796 | 1820 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
1821 | tx.send(10).unwrap(); |
1822 | assert!(rx.recv() == Ok(10)); | |
1823 | } | |
1824 | ||
1825 | #[test] | |
1826 | fn oneshot_single_thread_try_recv_closed() { | |
c34b1796 | 1827 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1828 | drop(tx); |
1829 | assert!(rx.recv().is_err()); | |
1830 | } | |
1831 | ||
1832 | #[test] | |
1833 | fn oneshot_single_thread_peek_data() { | |
c34b1796 | 1834 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
1835 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
1836 | tx.send(10).unwrap(); | |
1837 | assert_eq!(rx.try_recv(), Ok(10)); | |
1838 | } | |
1839 | ||
1840 | #[test] | |
1841 | fn oneshot_single_thread_peek_close() { | |
c34b1796 | 1842 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1843 | drop(tx); |
1844 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
1845 | assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected)); | |
1846 | } | |
1847 | ||
1848 | #[test] | |
1849 | fn oneshot_single_thread_peek_open() { | |
c34b1796 | 1850 | let (_tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
1851 | assert_eq!(rx.try_recv(), Err(TryRecvError::Empty)); |
1852 | } | |
1853 | ||
1854 | #[test] | |
1855 | fn oneshot_multi_task_recv_then_send() { | |
c34b1796 | 1856 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
85aaf69f | 1857 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1858 | assert!(rx.recv().unwrap() == box 10); |
1859 | }); | |
1860 | ||
1861 | tx.send(box 10).unwrap(); | |
1862 | } | |
1863 | ||
1864 | #[test] | |
1865 | fn oneshot_multi_task_recv_then_close() { | |
c34b1796 | 1866 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
85aaf69f | 1867 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1868 | drop(tx); |
1869 | }); | |
85aaf69f | 1870 | let res = thread::spawn(move|| { |
1a4d82fc JJ |
1871 | assert!(rx.recv().unwrap() == box 10); |
1872 | }).join(); | |
1873 | assert!(res.is_err()); | |
1874 | } | |
1875 | ||
1876 | #[test] | |
1877 | fn oneshot_multi_thread_close_stress() { | |
85aaf69f | 1878 | for _ in 0..stress_factor() { |
c34b1796 | 1879 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 1880 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1881 | drop(rx); |
1882 | }); | |
1883 | drop(tx); | |
1884 | } | |
1885 | } | |
1886 | ||
1887 | #[test] | |
1888 | fn oneshot_multi_thread_send_close_stress() { | |
85aaf69f | 1889 | for _ in 0..stress_factor() { |
c34b1796 | 1890 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 1891 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1892 | drop(rx); |
1893 | }); | |
85aaf69f | 1894 | let _ = thread::spawn(move || { |
1a4d82fc JJ |
1895 | tx.send(1).unwrap(); |
1896 | }).join(); | |
1897 | } | |
1898 | } | |
1899 | ||
1900 | #[test] | |
1901 | fn oneshot_multi_thread_recv_close_stress() { | |
85aaf69f | 1902 | for _ in 0..stress_factor() { |
c34b1796 | 1903 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f SL |
1904 | let _t = thread::spawn(move|| { |
1905 | let res = thread::spawn(move|| { | |
1a4d82fc JJ |
1906 | rx.recv().unwrap(); |
1907 | }).join(); | |
1908 | assert!(res.is_err()); | |
1909 | }); | |
85aaf69f SL |
1910 | let _t = thread::spawn(move|| { |
1911 | thread::spawn(move|| { | |
1a4d82fc JJ |
1912 | drop(tx); |
1913 | }); | |
1914 | }); | |
1915 | } | |
1916 | } | |
1917 | ||
1918 | #[test] | |
1919 | fn oneshot_multi_thread_send_recv_stress() { | |
85aaf69f | 1920 | for _ in 0..stress_factor() { |
c34b1796 | 1921 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
85aaf69f SL |
1922 | let _t = thread::spawn(move|| { |
1923 | tx.send(box 10).unwrap(); | |
1a4d82fc | 1924 | }); |
85aaf69f | 1925 | assert!(rx.recv().unwrap() == box 10); |
1a4d82fc JJ |
1926 | } |
1927 | } | |
1928 | ||
1929 | #[test] | |
1930 | fn stream_send_recv_stress() { | |
85aaf69f | 1931 | for _ in 0..stress_factor() { |
c34b1796 | 1932 | let (tx, rx) = sync_channel::<Box<i32>>(0); |
1a4d82fc JJ |
1933 | |
1934 | send(tx, 0); | |
1935 | recv(rx, 0); | |
1936 | ||
c34b1796 | 1937 | fn send(tx: SyncSender<Box<i32>>, i: i32) { |
1a4d82fc JJ |
1938 | if i == 10 { return } |
1939 | ||
85aaf69f | 1940 | thread::spawn(move|| { |
1a4d82fc JJ |
1941 | tx.send(box i).unwrap(); |
1942 | send(tx, i + 1); | |
1943 | }); | |
1944 | } | |
1945 | ||
c34b1796 | 1946 | fn recv(rx: Receiver<Box<i32>>, i: i32) { |
1a4d82fc JJ |
1947 | if i == 10 { return } |
1948 | ||
85aaf69f | 1949 | thread::spawn(move|| { |
1a4d82fc JJ |
1950 | assert!(rx.recv().unwrap() == box i); |
1951 | recv(rx, i + 1); | |
1952 | }); | |
1953 | } | |
1954 | } | |
1955 | } | |
1956 | ||
1957 | #[test] | |
1958 | fn recv_a_lot() { | |
1959 | // Regression test that we don't run out of stack in scheduler context | |
1960 | let (tx, rx) = sync_channel(10000); | |
85aaf69f SL |
1961 | for _ in 0..10000 { tx.send(()).unwrap(); } |
1962 | for _ in 0..10000 { rx.recv().unwrap(); } | |
1a4d82fc JJ |
1963 | } |
1964 | ||
1965 | #[test] | |
1966 | fn shared_chan_stress() { | |
1967 | let (tx, rx) = sync_channel(0); | |
1968 | let total = stress_factor() + 100; | |
85aaf69f | 1969 | for _ in 0..total { |
1a4d82fc | 1970 | let tx = tx.clone(); |
85aaf69f | 1971 | thread::spawn(move|| { |
1a4d82fc JJ |
1972 | tx.send(()).unwrap(); |
1973 | }); | |
1974 | } | |
1975 | ||
85aaf69f | 1976 | for _ in 0..total { |
1a4d82fc JJ |
1977 | rx.recv().unwrap(); |
1978 | } | |
1979 | } | |
1980 | ||
1981 | #[test] | |
1982 | fn test_nested_recv_iter() { | |
c34b1796 AL |
1983 | let (tx, rx) = sync_channel::<i32>(0); |
1984 | let (total_tx, total_rx) = sync_channel::<i32>(0); | |
1a4d82fc | 1985 | |
85aaf69f | 1986 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
1987 | let mut acc = 0; |
1988 | for x in rx.iter() { | |
1989 | acc += x; | |
1990 | } | |
1991 | total_tx.send(acc).unwrap(); | |
1992 | }); | |
1993 | ||
1994 | tx.send(3).unwrap(); | |
1995 | tx.send(1).unwrap(); | |
1996 | tx.send(2).unwrap(); | |
1997 | drop(tx); | |
1998 | assert_eq!(total_rx.recv().unwrap(), 6); | |
1999 | } | |
2000 | ||
2001 | #[test] | |
2002 | fn test_recv_iter_break() { | |
c34b1796 | 2003 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2004 | let (count_tx, count_rx) = sync_channel(0); |
2005 | ||
85aaf69f | 2006 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2007 | let mut count = 0; |
2008 | for x in rx.iter() { | |
2009 | if count >= 3 { | |
2010 | break; | |
2011 | } else { | |
2012 | count += x; | |
2013 | } | |
2014 | } | |
2015 | count_tx.send(count).unwrap(); | |
2016 | }); | |
2017 | ||
2018 | tx.send(2).unwrap(); | |
2019 | tx.send(2).unwrap(); | |
2020 | tx.send(2).unwrap(); | |
2021 | let _ = tx.try_send(2); | |
2022 | drop(tx); | |
2023 | assert_eq!(count_rx.recv().unwrap(), 4); | |
2024 | } | |
2025 | ||
2026 | #[test] | |
2027 | fn try_recv_states() { | |
c34b1796 | 2028 | let (tx1, rx1) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2029 | let (tx2, rx2) = sync_channel::<()>(1); |
2030 | let (tx3, rx3) = sync_channel::<()>(1); | |
85aaf69f | 2031 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2032 | rx2.recv().unwrap(); |
2033 | tx1.send(1).unwrap(); | |
2034 | tx3.send(()).unwrap(); | |
2035 | rx2.recv().unwrap(); | |
2036 | drop(tx1); | |
2037 | tx3.send(()).unwrap(); | |
2038 | }); | |
2039 | ||
2040 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
2041 | tx2.send(()).unwrap(); | |
2042 | rx3.recv().unwrap(); | |
2043 | assert_eq!(rx1.try_recv(), Ok(1)); | |
2044 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty)); | |
2045 | tx2.send(()).unwrap(); | |
2046 | rx3.recv().unwrap(); | |
2047 | assert_eq!(rx1.try_recv(), Err(TryRecvError::Disconnected)); | |
2048 | } | |
2049 | ||
2050 | // This bug used to end up in a livelock inside of the Receiver destructor | |
2051 | // because the internal state of the Shared packet was corrupted | |
2052 | #[test] | |
2053 | fn destroy_upgraded_shared_port_when_sender_still_active() { | |
2054 | let (tx, rx) = sync_channel::<()>(0); | |
2055 | let (tx2, rx2) = sync_channel::<()>(0); | |
85aaf69f | 2056 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2057 | rx.recv().unwrap(); // wait on a oneshot |
2058 | drop(rx); // destroy a shared | |
2059 | tx2.send(()).unwrap(); | |
2060 | }); | |
2061 | // make sure the other task has gone to sleep | |
85aaf69f | 2062 | for _ in 0..5000 { thread::yield_now(); } |
1a4d82fc JJ |
2063 | |
2064 | // upgrade to a shared chan and send a message | |
2065 | let t = tx.clone(); | |
2066 | drop(tx); | |
2067 | t.send(()).unwrap(); | |
2068 | ||
2069 | // wait for the child task to exit before we exit | |
2070 | rx2.recv().unwrap(); | |
2071 | } | |
2072 | ||
2073 | #[test] | |
2074 | fn send1() { | |
c34b1796 | 2075 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2076 | let _t = thread::spawn(move|| { rx.recv().unwrap(); }); |
1a4d82fc JJ |
2077 | assert_eq!(tx.send(1), Ok(())); |
2078 | } | |
2079 | ||
2080 | #[test] | |
2081 | fn send2() { | |
c34b1796 | 2082 | let (tx, rx) = sync_channel::<i32>(0); |
85aaf69f | 2083 | let _t = thread::spawn(move|| { drop(rx); }); |
1a4d82fc JJ |
2084 | assert!(tx.send(1).is_err()); |
2085 | } | |
2086 | ||
2087 | #[test] | |
2088 | fn send3() { | |
c34b1796 | 2089 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc | 2090 | assert_eq!(tx.send(1), Ok(())); |
85aaf69f | 2091 | let _t =thread::spawn(move|| { drop(rx); }); |
1a4d82fc JJ |
2092 | assert!(tx.send(1).is_err()); |
2093 | } | |
2094 | ||
2095 | #[test] | |
2096 | fn send4() { | |
c34b1796 | 2097 | let (tx, rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2098 | let tx2 = tx.clone(); |
2099 | let (done, donerx) = channel(); | |
2100 | let done2 = done.clone(); | |
85aaf69f | 2101 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2102 | assert!(tx.send(1).is_err()); |
2103 | done.send(()).unwrap(); | |
2104 | }); | |
85aaf69f | 2105 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2106 | assert!(tx2.send(2).is_err()); |
2107 | done2.send(()).unwrap(); | |
2108 | }); | |
2109 | drop(rx); | |
2110 | donerx.recv().unwrap(); | |
2111 | donerx.recv().unwrap(); | |
2112 | } | |
2113 | ||
2114 | #[test] | |
2115 | fn try_send1() { | |
c34b1796 | 2116 | let (tx, _rx) = sync_channel::<i32>(0); |
1a4d82fc JJ |
2117 | assert_eq!(tx.try_send(1), Err(TrySendError::Full(1))); |
2118 | } | |
2119 | ||
2120 | #[test] | |
2121 | fn try_send2() { | |
c34b1796 | 2122 | let (tx, _rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2123 | assert_eq!(tx.try_send(1), Ok(())); |
2124 | assert_eq!(tx.try_send(1), Err(TrySendError::Full(1))); | |
2125 | } | |
2126 | ||
2127 | #[test] | |
2128 | fn try_send3() { | |
c34b1796 | 2129 | let (tx, rx) = sync_channel::<i32>(1); |
1a4d82fc JJ |
2130 | assert_eq!(tx.try_send(1), Ok(())); |
2131 | drop(rx); | |
2132 | assert_eq!(tx.try_send(1), Err(TrySendError::Disconnected(1))); | |
2133 | } | |
2134 | ||
2135 | #[test] | |
2136 | fn issue_15761() { | |
2137 | fn repro() { | |
2138 | let (tx1, rx1) = sync_channel::<()>(3); | |
2139 | let (tx2, rx2) = sync_channel::<()>(3); | |
2140 | ||
85aaf69f | 2141 | let _t = thread::spawn(move|| { |
1a4d82fc JJ |
2142 | rx1.recv().unwrap(); |
2143 | tx2.try_send(()).unwrap(); | |
2144 | }); | |
2145 | ||
2146 | tx1.try_send(()).unwrap(); | |
2147 | rx2.recv().unwrap(); | |
2148 | } | |
2149 | ||
85aaf69f | 2150 | for _ in 0..100 { |
1a4d82fc JJ |
2151 | repro() |
2152 | } | |
2153 | } | |
2154 | } |