diff --git a/examples/ctrl-c.rs b/examples/ctrl-c.rs new file mode 100644 index 000000000..ae67cac17 --- /dev/null +++ b/examples/ctrl-c.rs @@ -0,0 +1,59 @@ +extern crate futures; +extern crate tokio_core; +extern crate tokio_signal; + +use futures::{Stream, Future}; +use tokio_core::reactor::Core; + +/// how many signals to handle before exiting +const STOP_AFTER: u64 = 10; + +fn main() { + // set up a Tokio event loop + let mut core = Core::new().unwrap(); + + // tokio_signal provides a convenience builder for Ctrl+C + // this even works cross-platform: linux and windows! + // + // `fn ctrl_c()` produces a `Future` of the actual stream-initialisation + // the `flatten_stream()` convenience method lazily defers that + // initialisation, allowing us to use it 'as if' it is already the + // stream we want, reducing boilerplate Future-handling. + let endless_stream = tokio_signal::ctrl_c(&core.handle()).flatten_stream(); + // don't keep going forever: convert the endless stream to a bounded one. + let limited_stream = endless_stream.take(STOP_AFTER); + + // how many Ctrl+C have we received so far? + let mut counter = 0; + + println!("This program is now waiting for you to press Ctrl+C {0} times. + * If running via `cargo run --example ctrl-c`, Ctrl+C also kills it, \ + due to https://github.com/rust-lang-nursery/rustup.rs/issues/806 + * If running the binary directly, the Ctrl+C is properly trapped. + Terminate by repeating Ctrl+C {0} times, or ahead of time by \ + opening a second terminal and issuing `pkill -sigkil ctrl-c`", + STOP_AFTER); + + // Stream::for_each is a powerful primitive provided by the Futures crate. + // It turns a Stream into a Future that completes after all stream-items + // have been completed, or the first time the closure returns an error + let future = limited_stream.for_each(|()| { + + // Note how we manipulate the counter without any fancy synchronisation. + // The borrowchecker realises there can't be any conflicts, so the closure + // can just capture it. + counter += 1; + println!("Ctrl+C received {} times! {} more before exit", + counter, STOP_AFTER-counter); + + // return Ok-result to continue handling the stream + Ok(()) + }); + + // Up until now, we haven't really DONE anything, just prepared + // now it's time to actually schedule, and thus execute, the stream + // on our event loop + core.run(future).unwrap(); + + println!("Stream ended, quiting the program."); +} diff --git a/examples/log.rs b/examples/log.rs deleted file mode 100644 index 6d147362a..000000000 --- a/examples/log.rs +++ /dev/null @@ -1,17 +0,0 @@ -extern crate futures; -extern crate tokio_core; -extern crate tokio_signal; - -use futures::stream::Stream; -use tokio_core::reactor::Core; - -fn main() { - let mut core = Core::new().unwrap(); - let ctrlc = tokio_signal::ctrl_c(&core.handle()); - let stream = core.run(ctrlc).unwrap(); - - core.run(stream.for_each(|()| { - println!("Ctrl-C received!"); - Ok(()) - })).unwrap(); -}