1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
# Tokio
**NOTE**: Tokio's [`master`](https://github.com/tokio-rs/tokio) is currently undergoing heavy development. This branch and the alpha releases will see API breaking changes and there are currently significant performance regressions that still need to be fixed before the final release. Use the [`v0.1.x`](https://github.com/tokio-rs/tokio/tree/v0.1.x) branch for stable releases.
A runtime for writing reliable, asynchronous, and slim applications with
the Rust programming language. It is:
* **Fast**: Tokio's zero-cost abstractions give you bare-metal
performance.
* **Reliable**: Tokio leverages Rust's ownership, type system, and
concurrency model to reduce bugs and ensure thread safety.
* **Scalable**: Tokio has a minimal footprint, and handles backpressure
and cancellation naturally.
[![Crates.io][crates-badge]][crates-url]
[![MIT licensed][mit-badge]][mit-url]
[![Build Status][azure-badge]][azure-url]
[![Gitter chat][gitter-badge]][gitter-url]
[crates-badge]: https://img.shields.io/crates/v/tokio.svg
[crates-url]: https://crates.io/crates/tokio
[mit-badge]: https://img.shields.io/badge/license-MIT-blue.svg
[mit-url]: LICENSE
[azure-badge]: https://dev.azure.com/tokio-rs/Tokio/_apis/build/status/tokio-rs.tokio?branchName=master
[azure-url]: https://dev.azure.com/tokio-rs/Tokio/_build/latest?definitionId=1&branchName=master
[gitter-badge]: https://img.shields.io/gitter/room/tokio-rs/tokio.svg
[gitter-url]: https://gitter.im/tokio-rs/tokio
[Website](https://tokio.rs) |
[Guides](https://tokio.rs/docs/) |
[API Docs](https://docs.rs/tokio/latest/tokio) |
[Chat](https://gitter.im/tokio-rs/tokio)
## Overview
Tokio is an event-driven, non-blocking I/O platform for writing
asynchronous applications with the Rust programming language. At a high
level, it provides a few major components:
* A multithreaded, work-stealing based task [scheduler].
* A reactor backed by the operating system's event queue (epoll, kqueue,
IOCP, etc...).
* Asynchronous [TCP and UDP][net] sockets.
These components provide the runtime components necessary for building
an asynchronous application.
[net]: https://docs.rs/tokio/latest/tokio/net/index.html
[scheduler]: https://docs.rs/tokio/latest/tokio/runtime/index.html
## Example
A basic TCP echo server with Tokio:
```rust
use tokio::net::TcpListener;
use tokio::prelude::*;
use std::net::SocketAddr;
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let mut listener = TcpListener::bind(&addr).await?;
loop {
let (mut socket, _) = listener.accept().await?;
tokio::spawn(async move {
let mut buf = [0; 1024];
// In a loop, read data from the socket and write the data back.
loop {
let n = match socket.read(&mut buf).await {
// socket closed
Ok(n) if n == 0 => return,
Ok(n) => n,
Err(e) => {
println!("failed to read from socket; err = {:?}", e);
return;
}
};
// Write the data back
if let Err(e) = socket.write_all(&buf[0..n]).await {
println!("failed to write to socket; err = {:?}", e);
return;
}
}
});
}
}
```
More examples can be found [here](examples). Note that the `master` branch
is currently being updated to use `async` / `await`. The examples are
not fully ported. Examples for stable Tokio can be found
[here](https://github.com/tokio-rs/tokio/tree/v0.1.x/tokio/examples).
## Getting Help
First, see if the answer to your question can be found in the [Guides] or the
[API documentation]. If the answer is not there, there is an active community in
the [Tokio Gitter channel][chat]. We would be happy to try to answer your
question. Last, if that doesn't work, try opening an [issue] with the question.
[Guides]: https://tokio.rs/docs/
[API documentation]: https://docs.rs/tokio/latest/tokio
[chat]: https://gitter.im/tokio-rs/tokio
[issue]: https://github.com/tokio-rs/tokio/issues/new
## Contributing
:balloon: Thanks for your help improving the project! We are so happy to have
you! We have a [contributing guide][guide] to help you get involved in the Tokio
project.
[guide]: CONTRIBUTING.md
## Related Projects
In addition to the crates in this repository, the Tokio project also maintains
several other libraries, including:
* [`tracing`] (formerly `tokio-trace`): A framework for application-level
tracing and async-aware diagnostics.
* [`mio`]: A low-level, cross-platform abstraction over OS I/O APIs that powers
`tokio`.
* [`bytes`]: Utilities for working with bytes, including efficient byte buffers.
[`tracing`]: https://github.com/tokio-rs/tracing
[`mio`]: https://github.com/tokio-rs/mio
[`bytes`]: https://github.com/tokio-rs/bytes
## Supported Rust Versions
Tokio is built against the latest stable, nightly, and beta Rust releases. The
minimum version supported is the stable release from three months before the
current stable release version. For example, if the latest stable Rust is 1.29,
the minimum version supported is 1.26. The current Tokio version is not
guaranteed to build on Rust versions earlier than the minimum supported version.
## License
This project is licensed under the [MIT license](LICENSE).
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in Tokio by you, shall be licensed as MIT, without any additional
terms or conditions.
|
