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Diffstat (limited to 'third_party/rust/crossbeam-channel/examples')
3 files changed, 153 insertions, 0 deletions
diff --git a/third_party/rust/crossbeam-channel/examples/fibonacci.rs b/third_party/rust/crossbeam-channel/examples/fibonacci.rs new file mode 100644 index 0000000000..e6f5e89c04 --- /dev/null +++ b/third_party/rust/crossbeam-channel/examples/fibonacci.rs @@ -0,0 +1,25 @@ +//! An asynchronous fibonacci sequence generator. + +use std::thread; + +use crossbeam_channel::{bounded, Sender}; + +// Sends the Fibonacci sequence into the channel until it becomes disconnected. +fn fibonacci(sender: Sender<u64>) { + let (mut x, mut y) = (0, 1); + while sender.send(x).is_ok() { + let tmp = x; + x = y; + y += tmp; + } +} + +fn main() { + let (s, r) = bounded(0); + thread::spawn(|| fibonacci(s)); + + // Print the first 20 Fibonacci numbers. + for num in r.iter().take(20) { + println!("{}", num); + } +} diff --git a/third_party/rust/crossbeam-channel/examples/matching.rs b/third_party/rust/crossbeam-channel/examples/matching.rs new file mode 100644 index 0000000000..5421169b9d --- /dev/null +++ b/third_party/rust/crossbeam-channel/examples/matching.rs @@ -0,0 +1,72 @@ +//! Using `select!` to send and receive on the same channel at the same time. +//! +//! This example is based on the following program in Go. +//! +//! Source: +//! - https://web.archive.org/web/20171209034309/https://www.nada.kth.se/~snilsson/concurrency +//! - http://www.nada.kth.se/~snilsson/concurrency/src/matching.go +//! +//! Copyright & License: +//! - Stefan Nilsson +//! - Creative Commons Attribution 3.0 Unported License +//! - https://creativecommons.org/licenses/by/3.0/ +//! +//! ```go +//! func main() { +//! people := []string{"Anna", "Bob", "Cody", "Dave", "Eva"} +//! match := make(chan string, 1) // Make room for one unmatched send. +//! wg := new(sync.WaitGroup) +//! for _, name := range people { +//! wg.Add(1) +//! go Seek(name, match, wg) +//! } +//! wg.Wait() +//! select { +//! case name := <-match: +//! fmt.Printf("No one received %s’s message.\n", name) +//! default: +//! // There was no pending send operation. +//! } +//! } +//! +//! // Seek either sends or receives, whichever possible, a name on the match +//! // channel and notifies the wait group when done. +//! func Seek(name string, match chan string, wg *sync.WaitGroup) { +//! select { +//! case peer := <-match: +//! fmt.Printf("%s received a message from %s.\n", name, peer) +//! case match <- name: +//! // Wait for someone to receive my message. +//! } +//! wg.Done() +//! } +//! ``` + +use crossbeam_channel::{bounded, select}; +use crossbeam_utils::thread; + +fn main() { + let people = vec!["Anna", "Bob", "Cody", "Dave", "Eva"]; + let (s, r) = bounded(1); // Make room for one unmatched send. + + // Either send my name into the channel or receive someone else's, whatever happens first. + let seek = |name, s, r| { + select! { + recv(r) -> peer => println!("{} received a message from {}.", name, peer.unwrap()), + send(s, name) -> _ => {}, // Wait for someone to receive my message. + } + }; + + thread::scope(|scope| { + for name in people { + let (s, r) = (s.clone(), r.clone()); + scope.spawn(move |_| seek(name, s, r)); + } + }) + .unwrap(); + + // Check if there is a pending send operation. + if let Ok(name) = r.try_recv() { + println!("No one received {}’s message.", name); + } +} diff --git a/third_party/rust/crossbeam-channel/examples/stopwatch.rs b/third_party/rust/crossbeam-channel/examples/stopwatch.rs new file mode 100644 index 0000000000..3a7578e00d --- /dev/null +++ b/third_party/rust/crossbeam-channel/examples/stopwatch.rs @@ -0,0 +1,56 @@ +//! Prints the elapsed time every 1 second and quits on Ctrl+C. + +#[cfg(windows)] // signal_hook::iterator does not work on windows +fn main() { + println!("This example does not work on Windows"); +} + +#[cfg(not(windows))] +fn main() { + use std::io; + use std::thread; + use std::time::{Duration, Instant}; + + use crossbeam_channel::{bounded, select, tick, Receiver}; + use signal_hook::consts::SIGINT; + use signal_hook::iterator::Signals; + + // Creates a channel that gets a message every time `SIGINT` is signalled. + fn sigint_notifier() -> io::Result<Receiver<()>> { + let (s, r) = bounded(100); + let mut signals = Signals::new(&[SIGINT])?; + + thread::spawn(move || { + for _ in signals.forever() { + if s.send(()).is_err() { + break; + } + } + }); + + Ok(r) + } + + // Prints the elapsed time. + fn show(dur: Duration) { + println!("Elapsed: {}.{:03} sec", dur.as_secs(), dur.subsec_millis()); + } + + let start = Instant::now(); + let update = tick(Duration::from_secs(1)); + let ctrl_c = sigint_notifier().unwrap(); + + loop { + select! { + recv(update) -> _ => { + show(start.elapsed()); + } + recv(ctrl_c) -> _ => { + println!(); + println!("Goodbye!"); + show(start.elapsed()); + break; + } + } + } +} |