1#![allow(
2 clippy::cognitive_complexity,
3 clippy::large_enum_variant,
4 clippy::module_inception,
5 clippy::needless_doctest_main
6)]
7#![warn(
8 missing_debug_implementations,
9 missing_docs,
10 rust_2018_idioms,
11 unreachable_pub
12)]
13#![deny(unused_must_use)]
14#![doc(test(
15 no_crate_inject,
16 attr(deny(warnings, rust_2018_idioms), allow(dead_code, unused_variables))
17))]
18#![cfg_attr(docsrs, feature(doc_cfg))]
19#![cfg_attr(docsrs, allow(unused_attributes))]
20#![cfg_attr(loom, allow(dead_code, unreachable_pub))]
21#![cfg_attr(windows, allow(rustdoc::broken_intra_doc_links))]
22
23//! A runtime for writing reliable network applications without compromising speed.
24//!
25//! Tokio is an event-driven, non-blocking I/O platform for writing asynchronous
26//! applications with the Rust programming language. At a high level, it
27//! provides a few major components:
28//!
29//! * Tools for [working with asynchronous tasks][tasks], including
30//! [synchronization primitives and channels][sync] and [timeouts, sleeps, and
31//! intervals][time].
32//! * APIs for [performing asynchronous I/O][io], including [TCP and UDP][net] sockets,
33//! [filesystem][fs] operations, and [process] and [signal] management.
34//! * A [runtime] for executing asynchronous code, including a task scheduler,
35//! an I/O driver backed by the operating system's event queue (`epoll`, `kqueue`,
36//! `IOCP`, etc...), and a high performance timer.
37//!
38//! Guide level documentation is found on the [website].
39//!
40//! [tasks]: #working-with-tasks
41//! [sync]: crate::sync
42//! [time]: crate::time
43//! [io]: #asynchronous-io
44//! [net]: crate::net
45//! [fs]: crate::fs
46//! [process]: crate::process
47//! [signal]: crate::signal
48//! [fs]: crate::fs
49//! [runtime]: crate::runtime
50//! [website]: https://tokio.rs/tokio/tutorial
51//!
52//! # A Tour of Tokio
53//!
54//! Tokio consists of a number of modules that provide a range of functionality
55//! essential for implementing asynchronous applications in Rust. In this
56//! section, we will take a brief tour of Tokio, summarizing the major APIs and
57//! their uses.
58//!
59//! The easiest way to get started is to enable all features. Do this by
60//! enabling the `full` feature flag:
61//!
62//! ```toml
63//! tokio = { version = "1", features = ["full"] }
64//! ```
65//!
66//! ### Authoring applications
67//!
68//! Tokio is great for writing applications and most users in this case shouldn't
69//! worry too much about what features they should pick. If you're unsure, we suggest
70//! going with `full` to ensure that you don't run into any road blocks while you're
71//! building your application.
72//!
73//! #### Example
74//!
75//! This example shows the quickest way to get started with Tokio.
76//!
77//! ```toml
78//! tokio = { version = "1", features = ["full"] }
79//! ```
80//!
81//! ### Authoring libraries
82//!
83//! As a library author your goal should be to provide the lightest weight crate
84//! that is based on Tokio. To achieve this you should ensure that you only enable
85//! the features you need. This allows users to pick up your crate without having
86//! to enable unnecessary features.
87//!
88//! #### Example
89//!
90//! This example shows how you may want to import features for a library that just
91//! needs to `tokio::spawn` and use a `TcpStream`.
92//!
93//! ```toml
94//! tokio = { version = "1", features = ["rt", "net"] }
95//! ```
96//!
97//! ## Working With Tasks
98//!
99//! Asynchronous programs in Rust are based around lightweight, non-blocking
100//! units of execution called [_tasks_][tasks]. The [`tokio::task`] module provides
101//! important tools for working with tasks:
102//!
103//! * The [`spawn`] function and [`JoinHandle`] type, for scheduling a new task
104//! on the Tokio runtime and awaiting the output of a spawned task, respectively,
105//! * Functions for [running blocking operations][blocking] in an asynchronous
106//! task context.
107//!
108//! The [`tokio::task`] module is present only when the "rt" feature flag
109//! is enabled.
110//!
111//! [tasks]: task/index.html#what-are-tasks
112//! [`tokio::task`]: crate::task
113//! [`spawn`]: crate::task::spawn()
114//! [`JoinHandle`]: crate::task::JoinHandle
115//! [blocking]: task/index.html#blocking-and-yielding
116//!
117//! The [`tokio::sync`] module contains synchronization primitives to use when
118//! needing to communicate or share data. These include:
119//!
120//! * channels ([`oneshot`], [`mpsc`], [`watch`], and [`broadcast`]), for sending values
121//! between tasks,
122//! * a non-blocking [`Mutex`], for controlling access to a shared, mutable
123//! value,
124//! * an asynchronous [`Barrier`] type, for multiple tasks to synchronize before
125//! beginning a computation.
126//!
127//! The `tokio::sync` module is present only when the "sync" feature flag is
128//! enabled.
129//!
130//! [`tokio::sync`]: crate::sync
131//! [`Mutex`]: crate::sync::Mutex
132//! [`Barrier`]: crate::sync::Barrier
133//! [`oneshot`]: crate::sync::oneshot
134//! [`mpsc`]: crate::sync::mpsc
135//! [`watch`]: crate::sync::watch
136//! [`broadcast`]: crate::sync::broadcast
137//!
138//! The [`tokio::time`] module provides utilities for tracking time and
139//! scheduling work. This includes functions for setting [timeouts][timeout] for
140//! tasks, [sleeping][sleep] work to run in the future, or [repeating an operation at an
141//! interval][interval].
142//!
143//! In order to use `tokio::time`, the "time" feature flag must be enabled.
144//!
145//! [`tokio::time`]: crate::time
146//! [sleep]: crate::time::sleep()
147//! [interval]: crate::time::interval()
148//! [timeout]: crate::time::timeout()
149//!
150//! Finally, Tokio provides a _runtime_ for executing asynchronous tasks. Most
151//! applications can use the [`#[tokio::main]`][main] macro to run their code on the
152//! Tokio runtime. However, this macro provides only basic configuration options. As
153//! an alternative, the [`tokio::runtime`] module provides more powerful APIs for configuring
154//! and managing runtimes. You should use that module if the `#[tokio::main]` macro doesn't
155//! provide the functionality you need.
156//!
157//! Using the runtime requires the "rt" or "rt-multi-thread" feature flags, to
158//! enable the current-thread [single-threaded scheduler][rt] and the [multi-thread
159//! scheduler][rt-multi-thread], respectively. See the [`runtime` module
160//! documentation][rt-features] for details. In addition, the "macros" feature
161//! flag enables the `#[tokio::main]` and `#[tokio::test]` attributes.
162//!
163//! [main]: attr.main.html
164//! [`tokio::runtime`]: crate::runtime
165//! [`Builder`]: crate::runtime::Builder
166//! [`Runtime`]: crate::runtime::Runtime
167//! [rt]: runtime/index.html#current-thread-scheduler
168//! [rt-multi-thread]: runtime/index.html#multi-thread-scheduler
169//! [rt-features]: runtime/index.html#runtime-scheduler
170//!
171//! ## CPU-bound tasks and blocking code
172//!
173//! Tokio is able to concurrently run many tasks on a few threads by repeatedly
174//! swapping the currently running task on each thread. However, this kind of
175//! swapping can only happen at `.await` points, so code that spends a long time
176//! without reaching an `.await` will prevent other tasks from running. To
177//! combat this, Tokio provides two kinds of threads: Core threads and blocking threads.
178//!
179//! The core threads are where all asynchronous code runs, and Tokio will by default
180//! spawn one for each CPU core. You can use the environment variable `TOKIO_WORKER_THREADS`
181//! to override the default value.
182//!
183//! The blocking threads are spawned on demand, can be used to run blocking code
184//! that would otherwise block other tasks from running and are kept alive when
185//! not used for a certain amount of time which can be configured with [`thread_keep_alive`].
186//! Since it is not possible for Tokio to swap out blocking tasks, like it
187//! can do with asynchronous code, the upper limit on the number of blocking
188//! threads is very large. These limits can be configured on the [`Builder`].
189//!
190//! To spawn a blocking task, you should use the [`spawn_blocking`] function.
191//!
192//! [`Builder`]: crate::runtime::Builder
193//! [`spawn_blocking`]: crate::task::spawn_blocking()
194//! [`thread_keep_alive`]: crate::runtime::Builder::thread_keep_alive()
195//!
196//! ```
197//! #[tokio::main]
198//! async fn main() {
199//! // This is running on a core thread.
200//!
201//! let blocking_task = tokio::task::spawn_blocking(|| {
202//! // This is running on a blocking thread.
203//! // Blocking here is ok.
204//! });
205//!
206//! // We can wait for the blocking task like this:
207//! // If the blocking task panics, the unwrap below will propagate the
208//! // panic.
209//! blocking_task.await.unwrap();
210//! }
211//! ```
212//!
213//! If your code is CPU-bound and you wish to limit the number of threads used
214//! to run it, you should use a separate thread pool dedicated to CPU bound tasks.
215//! For example, you could consider using the [rayon] library for CPU-bound
216//! tasks. It is also possible to create an extra Tokio runtime dedicated to
217//! CPU-bound tasks, but if you do this, you should be careful that the extra
218//! runtime runs _only_ CPU-bound tasks, as IO-bound tasks on that runtime
219//! will behave poorly.
220//!
221//! Hint: If using rayon, you can use a [`oneshot`] channel to send the result back
222//! to Tokio when the rayon task finishes.
223//!
224//! [rayon]: https://docs.rs/rayon
225//! [`oneshot`]: crate::sync::oneshot
226//!
227//! ## Asynchronous IO
228//!
229//! As well as scheduling and running tasks, Tokio provides everything you need
230//! to perform input and output asynchronously.
231//!
232//! The [`tokio::io`] module provides Tokio's asynchronous core I/O primitives,
233//! the [`AsyncRead`], [`AsyncWrite`], and [`AsyncBufRead`] traits. In addition,
234//! when the "io-util" feature flag is enabled, it also provides combinators and
235//! functions for working with these traits, forming as an asynchronous
236//! counterpart to [`std::io`].
237//!
238//! Tokio also includes APIs for performing various kinds of I/O and interacting
239//! with the operating system asynchronously. These include:
240//!
241//! * [`tokio::net`], which contains non-blocking versions of [TCP], [UDP], and
242//! [Unix Domain Sockets][UDS] (enabled by the "net" feature flag),
243//! * [`tokio::fs`], similar to [`std::fs`] but for performing filesystem I/O
244//! asynchronously (enabled by the "fs" feature flag),
245//! * [`tokio::signal`], for asynchronously handling Unix and Windows OS signals
246//! (enabled by the "signal" feature flag),
247//! * [`tokio::process`], for spawning and managing child processes (enabled by
248//! the "process" feature flag).
249//!
250//! [`tokio::io`]: crate::io
251//! [`AsyncRead`]: crate::io::AsyncRead
252//! [`AsyncWrite`]: crate::io::AsyncWrite
253//! [`AsyncBufRead`]: crate::io::AsyncBufRead
254//! [`std::io`]: std::io
255//! [`tokio::net`]: crate::net
256//! [TCP]: crate::net::tcp
257//! [UDP]: crate::net::UdpSocket
258//! [UDS]: crate::net::unix
259//! [`tokio::fs`]: crate::fs
260//! [`std::fs`]: std::fs
261//! [`tokio::signal`]: crate::signal
262//! [`tokio::process`]: crate::process
263//!
264//! # Examples
265//!
266//! A simple TCP echo server:
267//!
268//! ```no_run
269//! use tokio::net::TcpListener;
270//! use tokio::io::{AsyncReadExt, AsyncWriteExt};
271//!
272//! #[tokio::main]
273//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
274//! let listener = TcpListener::bind("127.0.0.1:8080").await?;
275//!
276//! loop {
277//! let (mut socket, _) = listener.accept().await?;
278//!
279//! tokio::spawn(async move {
280//! let mut buf = [0; 1024];
281//!
282//! // In a loop, read data from the socket and write the data back.
283//! loop {
284//! let n = match socket.read(&mut buf).await {
285//! // socket closed
286//! Ok(0) => return,
287//! Ok(n) => n,
288//! Err(e) => {
289//! eprintln!("failed to read from socket; err = {:?}", e);
290//! return;
291//! }
292//! };
293//!
294//! // Write the data back
295//! if let Err(e) = socket.write_all(&buf[0..n]).await {
296//! eprintln!("failed to write to socket; err = {:?}", e);
297//! return;
298//! }
299//! }
300//! });
301//! }
302//! }
303//! ```
304//!
305//! # Feature flags
306//!
307//! Tokio uses a set of [feature flags] to reduce the amount of compiled code. It
308//! is possible to just enable certain features over others. By default, Tokio
309//! does not enable any features but allows one to enable a subset for their use
310//! case. Below is a list of the available feature flags. You may also notice
311//! above each function, struct and trait there is listed one or more feature flags
312//! that are required for that item to be used. If you are new to Tokio it is
313//! recommended that you use the `full` feature flag which will enable all public APIs.
314//! Beware though that this will pull in many extra dependencies that you may not
315//! need.
316//!
317//! - `full`: Enables all features listed below except `test-util` and `tracing`.
318//! - `rt`: Enables `tokio::spawn`, the current-thread scheduler,
319//! and non-scheduler utilities.
320//! - `rt-multi-thread`: Enables the heavier, multi-threaded, work-stealing scheduler.
321//! - `io-util`: Enables the IO based `Ext` traits.
322//! - `io-std`: Enable `Stdout`, `Stdin` and `Stderr` types.
323//! - `net`: Enables `tokio::net` types such as `TcpStream`, `UnixStream` and
324//! `UdpSocket`, as well as (on Unix-like systems) `AsyncFd` and (on
325//! FreeBSD) `PollAio`.
326//! - `time`: Enables `tokio::time` types and allows the schedulers to enable
327//! the built in timer.
328//! - `process`: Enables `tokio::process` types.
329//! - `macros`: Enables `#[tokio::main]` and `#[tokio::test]` macros.
330//! - `sync`: Enables all `tokio::sync` types.
331//! - `signal`: Enables all `tokio::signal` types.
332//! - `fs`: Enables `tokio::fs` types.
333//! - `test-util`: Enables testing based infrastructure for the Tokio runtime.
334//! - `parking_lot`: As a potential optimization, use the `_parking_lot_` crate's
335//! synchronization primitives internally. Also, this
336//! dependency is necessary to construct some of our primitives
337//! in a `const` context. `MSRV` may increase according to the
338//! `_parking_lot_` release in use.
339//!
340//! _Note: `AsyncRead` and `AsyncWrite` traits do not require any features and are
341//! always available._
342//!
343//! ## Unstable features
344//!
345//! Some feature flags are only available when specifying the `tokio_unstable` flag:
346//!
347//! - `tracing`: Enables tracing events.
348//!
349//! Likewise, some parts of the API are only available with the same flag:
350//!
351//! - [`task::Builder`]
352//! - Some methods on [`task::JoinSet`]
353//! - [`runtime::RuntimeMetrics`]
354//! - [`runtime::Builder::on_task_spawn`]
355//! - [`runtime::Builder::on_task_terminate`]
356//! - [`runtime::Builder::unhandled_panic`]
357//! - [`runtime::TaskMeta`]
358//!
359//! This flag enables **unstable** features. The public API of these features
360//! may break in 1.x releases. To enable these features, the `--cfg
361//! tokio_unstable` argument must be passed to `rustc` when compiling. This
362//! serves to explicitly opt-in to features which may break semver conventions,
363//! since Cargo [does not yet directly support such opt-ins][unstable features].
364//!
365//! You can specify it in your project's `.cargo/config.toml` file:
366//!
367//! ```toml
368//! [build]
369//! rustflags = ["--cfg", "tokio_unstable"]
370//! ```
371//!
372//! <div class="warning">
373//! The <code>[build]</code> section does <strong>not</strong> go in a
374//! <code>Cargo.toml</code> file. Instead it must be placed in the Cargo config
375//! file <code>.cargo/config.toml</code>.
376//! </div>
377//!
378//! Alternatively, you can specify it with an environment variable:
379//!
380//! ```sh
381//! ## Many *nix shells:
382//! export RUSTFLAGS="--cfg tokio_unstable"
383//! cargo build
384//! ```
385//!
386//! ```powershell
387//! ## Windows PowerShell:
388//! $Env:RUSTFLAGS="--cfg tokio_unstable"
389//! cargo build
390//! ```
391//!
392//! [unstable features]: https://internals.rust-lang.org/t/feature-request-unstable-opt-in-non-transitive-crate-features/16193#why-not-a-crate-feature-2
393//! [feature flags]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-features-section
394//!
395//! # Supported platforms
396//!
397//! Tokio currently guarantees support for the following platforms:
398//!
399//! * Linux
400//! * Windows
401//! * Android (API level 21)
402//! * macOS
403//! * iOS
404//! * FreeBSD
405//!
406//! Tokio will continue to support these platforms in the future. However,
407//! future releases may change requirements such as the minimum required libc
408//! version on Linux, the API level on Android, or the supported FreeBSD
409//! release.
410//!
411//! Beyond the above platforms, Tokio is intended to work on all platforms
412//! supported by the mio crate. You can find a longer list [in mio's
413//! documentation][mio-supported]. However, these additional platforms may
414//! become unsupported in the future.
415//!
416//! Note that Wine is considered to be a different platform from Windows. See
417//! mio's documentation for more information on Wine support.
418//!
419//! [mio-supported]: https://crates.io/crates/mio#platforms
420//!
421//! ## `WASM` support
422//!
423//! Tokio has some limited support for the `WASM` platform. Without the
424//! `tokio_unstable` flag, the following features are supported:
425//!
426//! * `sync`
427//! * `macros`
428//! * `io-util`
429//! * `rt`
430//! * `time`
431//!
432//! Enabling any other feature (including `full`) will cause a compilation
433//! failure.
434//!
435//! The `time` module will only work on `WASM` platforms that have support for
436//! timers (e.g. wasm32-wasi). The timing functions will panic if used on a `WASM`
437//! platform that does not support timers.
438//!
439//! Note also that if the runtime becomes indefinitely idle, it will panic
440//! immediately instead of blocking forever. On platforms that don't support
441//! time, this means that the runtime can never be idle in any way.
442//!
443//! ## Unstable `WASM` support
444//!
445//! Tokio also has unstable support for some additional `WASM` features. This
446//! requires the use of the `tokio_unstable` flag.
447//!
448//! Using this flag enables the use of `tokio::net` on the wasm32-wasi target.
449//! However, not all methods are available on the networking types as `WASI`
450//! currently does not support the creation of new sockets from within `WASM`.
451//! Because of this, sockets must currently be created via the `FromRawFd`
452//! trait.
453
454// Test that pointer width is compatible. This asserts that e.g. usize is at
455// least 32 bits, which a lot of components in Tokio currently assumes.
456//
457// TODO: improve once we have MSRV access to const eval to make more flexible.
458#[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
459compile_error! {
460 "Tokio requires the platform pointer width to be at least 32 bits"
461}
462
463#[cfg(all(
464 not(tokio_unstable),
465 target_family = "wasm",
466 any(
467 feature = "fs",
468 feature = "io-std",
469 feature = "net",
470 feature = "process",
471 feature = "rt-multi-thread",
472 feature = "signal"
473 )
474))]
475compile_error!("Only features sync,macros,io-util,rt,time are supported on wasm.");
476
477#[cfg(all(not(tokio_unstable), tokio_taskdump))]
478compile_error!("The `tokio_taskdump` feature requires `--cfg tokio_unstable`.");
479
480#[cfg(all(
481 tokio_taskdump,
482 not(doc),
483 not(all(
484 target_os = "linux",
485 any(target_arch = "aarch64", target_arch = "x86", target_arch = "x86_64")
486 ))
487))]
488compile_error!(
489 "The `tokio_taskdump` feature is only currently supported on \
490linux, on `aarch64`, `x86` and `x86_64`."
491);
492
493// Includes re-exports used by macros.
494//
495// This module is not intended to be part of the public API. In general, any
496// `doc(hidden)` code is not part of Tokio's public and stable API.
497#[macro_use]
498#[doc(hidden)]
499pub mod macros;
500
501cfg_fs! {
502 pub mod fs;
503}
504
505mod future;
506
507pub mod io;
508pub mod net;
509
510mod loom;
511
512cfg_process! {
513 pub mod process;
514}
515
516#[cfg(any(
517 feature = "fs",
518 feature = "io-std",
519 feature = "net",
520 all(windows, feature = "process"),
521))]
522mod blocking;
523
524cfg_rt! {
525 pub mod runtime;
526}
527cfg_not_rt! {
528 pub(crate) mod runtime;
529}
530
531cfg_signal! {
532 pub mod signal;
533}
534
535cfg_signal_internal! {
536 #[cfg(not(feature = "signal"))]
537 #[allow(dead_code)]
538 #[allow(unreachable_pub)]
539 pub(crate) mod signal;
540}
541
542cfg_sync! {
543 pub mod sync;
544}
545cfg_not_sync! {
546 mod sync;
547}
548
549pub mod task;
550cfg_rt! {
551 pub use task::spawn;
552}
553
554cfg_time! {
555 pub mod time;
556}
557
558mod trace {
559 use std::future::Future;
560 use std::pin::Pin;
561 use std::task::{Context, Poll};
562
563 cfg_taskdump! {
564 pub(crate) use crate::runtime::task::trace::trace_leaf;
565 }
566
567 cfg_not_taskdump! {
568 #[inline(always)]
569 #[allow(dead_code)]
570 pub(crate) fn trace_leaf(_: &mut std::task::Context<'_>) -> std::task::Poll<()> {
571 std::task::Poll::Ready(())
572 }
573 }
574
575 #[cfg_attr(not(feature = "sync"), allow(dead_code))]
576 pub(crate) fn async_trace_leaf() -> impl Future<Output = ()> {
577 struct Trace;
578
579 impl Future for Trace {
580 type Output = ();
581
582 #[inline(always)]
583 fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
584 trace_leaf(cx)
585 }
586 }
587
588 Trace
589 }
590}
591
592mod util;
593
594/// Due to the `Stream` trait's inclusion in `std` landing later than Tokio's 1.0
595/// release, most of the Tokio stream utilities have been moved into the [`tokio-stream`]
596/// crate.
597///
598/// # Why was `Stream` not included in Tokio 1.0?
599///
600/// Originally, we had planned to ship Tokio 1.0 with a stable `Stream` type
601/// but unfortunately the [RFC] had not been merged in time for `Stream` to
602/// reach `std` on a stable compiler in time for the 1.0 release of Tokio. For
603/// this reason, the team has decided to move all `Stream` based utilities to
604/// the [`tokio-stream`] crate. While this is not ideal, once `Stream` has made
605/// it into the standard library and the `MSRV` period has passed, we will implement
606/// stream for our different types.
607///
608/// While this may seem unfortunate, not all is lost as you can get much of the
609/// `Stream` support with `async/await` and `while let` loops. It is also possible
610/// to create a `impl Stream` from `async fn` using the [`async-stream`] crate.
611///
612/// [`tokio-stream`]: https://docs.rs/tokio-stream
613/// [`async-stream`]: https://docs.rs/async-stream
614/// [RFC]: https://github.com/rust-lang/rfcs/pull/2996
615///
616/// # Example
617///
618/// Convert a [`sync::mpsc::Receiver`] to an `impl Stream`.
619///
620/// ```rust,no_run
621/// use tokio::sync::mpsc;
622///
623/// let (tx, mut rx) = mpsc::channel::<usize>(16);
624///
625/// let stream = async_stream::stream! {
626/// while let Some(item) = rx.recv().await {
627/// yield item;
628/// }
629/// };
630/// ```
631pub mod stream {}
632
633// local re-exports of platform specific things, allowing for decent
634// documentation to be shimmed in on docs.rs
635
636#[cfg(all(docsrs, unix))]
637pub mod doc;
638
639#[cfg(any(feature = "net", feature = "fs"))]
640#[cfg(all(docsrs, unix))]
641#[allow(unused)]
642pub(crate) use self::doc::os;
643
644#[cfg(not(all(docsrs, unix)))]
645#[allow(unused)]
646pub(crate) use std::os;
647
648cfg_macros! {
649 /// Implementation detail of the `select!` macro. This macro is **not**
650 /// intended to be used as part of the public API and is permitted to
651 /// change.
652 #[doc(hidden)]
653 pub use tokio_macros::select_priv_declare_output_enum;
654
655 /// Implementation detail of the `select!` macro. This macro is **not**
656 /// intended to be used as part of the public API and is permitted to
657 /// change.
658 #[doc(hidden)]
659 pub use tokio_macros::select_priv_clean_pattern;
660
661 cfg_rt! {
662 #[cfg(feature = "rt-multi-thread")]
663 #[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
664 #[doc(inline)]
665 pub use tokio_macros::main;
666
667 #[cfg(feature = "rt-multi-thread")]
668 #[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
669 #[doc(inline)]
670 pub use tokio_macros::test;
671
672 cfg_not_rt_multi_thread! {
673 #[doc(inline)]
674 pub use tokio_macros::main_rt as main;
675
676 #[doc(inline)]
677 pub use tokio_macros::test_rt as test;
678 }
679 }
680
681 // Always fail if rt is not enabled.
682 cfg_not_rt! {
683 #[doc(inline)]
684 pub use tokio_macros::main_fail as main;
685
686 #[doc(inline)]
687 pub use tokio_macros::test_fail as test;
688 }
689}
690
691// TODO: rm
692#[cfg(feature = "io-util")]
693#[cfg(test)]
694fn is_unpin<T: Unpin>() {}
695
696/// fuzz test (`fuzz_linked_list`)
697#[cfg(fuzzing)]
698pub mod fuzz;
699