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#![allow(unknown_lints, unexpected_cfgs)]
#![allow(clippy::needless_doctest_main)]
#![warn(
missing_debug_implementations,
missing_docs,
rust_2018_idioms,
unreachable_pub
)]
#![doc(test(
no_crate_inject,
attr(deny(warnings, rust_2018_idioms), allow(dead_code, unused_variables))
))]
//! Macros for use with Tokio
// This `extern` is required for older `rustc` versions but newer `rustc`
// versions warn about the unused `extern crate`.
#[allow(unused_extern_crates)]
extern crate proc_macro;
mod entry;
mod select;
use proc_macro::TokenStream;
/// Marks async function to be executed by the selected runtime. This macro
/// helps set up a `Runtime` without requiring the user to use
/// [Runtime](../tokio/runtime/struct.Runtime.html) or
/// [Builder](../tokio/runtime/struct.Builder.html) directly.
///
/// Note: This macro is designed to be simplistic and targets applications that
/// do not require a complex setup. If the provided functionality is not
/// sufficient, you may be interested in using
/// [Builder](../tokio/runtime/struct.Builder.html), which provides a more
/// powerful interface.
///
/// Note: This macro can be used on any function and not just the `main`
/// function. Using it on a non-main function makes the function behave as if it
/// was synchronous by starting a new runtime each time it is called. If the
/// function is called often, it is preferable to create the runtime using the
/// runtime builder so the runtime can be reused across calls.
///
/// # Non-worker async function
///
/// Note that the async function marked with this macro does not run as a
/// worker. The expectation is that other tasks are spawned by the function here.
/// Awaiting on other futures from the function provided here will not
/// perform as fast as those spawned as workers.
///
/// # Multi-threaded runtime
///
/// To use the multi-threaded runtime, the macro can be configured using
///
/// ```
/// #[tokio::main(flavor = "multi_thread", worker_threads = 10)]
/// # async fn main() {}
/// ```
///
/// The `worker_threads` option configures the number of worker threads, and
/// defaults to the number of cpus on the system. This is the default flavor.
///
/// Note: The multi-threaded runtime requires the `rt-multi-thread` feature
/// flag.
///
/// # Current thread runtime
///
/// To use the single-threaded runtime known as the `current_thread` runtime,
/// the macro can be configured using
///
/// ```
/// #[tokio::main(flavor = "current_thread")]
/// # async fn main() {}
/// ```
///
/// ## Function arguments:
///
/// Arguments are allowed for any functions aside from `main` which is special
///
/// ## Usage
///
/// ### Using the multi-thread runtime
///
/// ```rust
/// #[tokio::main]
/// async fn main() {
/// println!("Hello world");
/// }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```rust
/// fn main() {
/// tokio::runtime::Builder::new_multi_thread()
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// println!("Hello world");
/// })
/// }
/// ```
///
/// ### Using current thread runtime
///
/// The basic scheduler is single-threaded.
///
/// ```rust
/// #[tokio::main(flavor = "current_thread")]
/// async fn main() {
/// println!("Hello world");
/// }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```rust
/// fn main() {
/// tokio::runtime::Builder::new_current_thread()
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// println!("Hello world");
/// })
/// }
/// ```
///
/// ### Set number of worker threads
///
/// ```rust
/// #[tokio::main(worker_threads = 2)]
/// async fn main() {
/// println!("Hello world");
/// }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```rust
/// fn main() {
/// tokio::runtime::Builder::new_multi_thread()
/// .worker_threads(2)
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// println!("Hello world");
/// })
/// }
/// ```
///
/// ### Configure the runtime to start with time paused
///
/// ```rust
/// #[tokio::main(flavor = "current_thread", start_paused = true)]
/// async fn main() {
/// println!("Hello world");
/// }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```rust
/// fn main() {
/// tokio::runtime::Builder::new_current_thread()
/// .enable_all()
/// .start_paused(true)
/// .build()
/// .unwrap()
/// .block_on(async {
/// println!("Hello world");
/// })
/// }
/// ```
///
/// Note that `start_paused` requires the `test-util` feature to be enabled.
///
/// ### Rename package
///
/// ```rust
/// use tokio as tokio1;
///
/// #[tokio1::main(crate = "tokio1")]
/// async fn main() {
/// println!("Hello world");
/// }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```rust
/// use tokio as tokio1;
///
/// fn main() {
/// tokio1::runtime::Builder::new_multi_thread()
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// println!("Hello world");
/// })
/// }
/// ```
///
/// ### Configure unhandled panic behavior
///
/// Available options are `shutdown_runtime` and `ignore`. For more details, see
/// [`Builder::unhandled_panic`].
///
/// This option is only compatible with the `current_thread` runtime.
///
/// ```no_run
/// #[cfg(tokio_unstable)]
/// #[tokio::main(flavor = "current_thread", unhandled_panic = "shutdown_runtime")]
/// async fn main() {
/// let _ = tokio::spawn(async {
/// panic!("This panic will shutdown the runtime.");
/// }).await;
/// }
/// # #[cfg(not(tokio_unstable))]
/// # fn main() { }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```no_run
/// #[cfg(tokio_unstable)]
/// fn main() {
/// tokio::runtime::Builder::new_current_thread()
/// .enable_all()
/// .unhandled_panic(UnhandledPanic::ShutdownRuntime)
/// .build()
/// .unwrap()
/// .block_on(async {
/// let _ = tokio::spawn(async {
/// panic!("This panic will shutdown the runtime.");
/// }).await;
/// })
/// }
/// # #[cfg(not(tokio_unstable))]
/// # fn main() { }
/// ```
///
/// **Note**: This option depends on Tokio's [unstable API][unstable]. See [the
/// documentation on unstable features][unstable] for details on how to enable
/// Tokio's unstable features.
///
/// [`Builder::unhandled_panic`]: ../tokio/runtime/struct.Builder.html#method.unhandled_panic
/// [unstable]: ../tokio/index.html#unstable-features
#[proc_macro_attribute]
pub fn main(args: TokenStream, item: TokenStream) -> TokenStream {
entry::main(args.into(), item.into(), true).into()
}
/// Marks async function to be executed by selected runtime. This macro helps set up a `Runtime`
/// without requiring the user to use [Runtime](../tokio/runtime/struct.Runtime.html) or
/// [Builder](../tokio/runtime/struct.Builder.html) directly.
///
/// ## Function arguments:
///
/// Arguments are allowed for any functions aside from `main` which is special
///
/// ## Usage
///
/// ### Using default
///
/// ```rust
/// #[tokio::main(flavor = "current_thread")]
/// async fn main() {
/// println!("Hello world");
/// }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```rust
/// fn main() {
/// tokio::runtime::Builder::new_current_thread()
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// println!("Hello world");
/// })
/// }
/// ```
///
/// ### Rename package
///
/// ```rust
/// use tokio as tokio1;
///
/// #[tokio1::main(crate = "tokio1")]
/// async fn main() {
/// println!("Hello world");
/// }
/// ```
///
/// Equivalent code not using `#[tokio::main]`
///
/// ```rust
/// use tokio as tokio1;
///
/// fn main() {
/// tokio1::runtime::Builder::new_multi_thread()
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// println!("Hello world");
/// })
/// }
/// ```
#[proc_macro_attribute]
pub fn main_rt(args: TokenStream, item: TokenStream) -> TokenStream {
entry::main(args.into(), item.into(), false).into()
}
/// Marks async function to be executed by runtime, suitable to test environment.
/// This macro helps set up a `Runtime` without requiring the user to use
/// [Runtime](../tokio/runtime/struct.Runtime.html) or
/// [Builder](../tokio/runtime/struct.Builder.html) directly.
///
/// Note: This macro is designed to be simplistic and targets applications that
/// do not require a complex setup. If the provided functionality is not
/// sufficient, you may be interested in using
/// [Builder](../tokio/runtime/struct.Builder.html), which provides a more
/// powerful interface.
///
/// # Multi-threaded runtime
///
/// To use the multi-threaded runtime, the macro can be configured using
///
/// ```no_run
/// #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
/// async fn my_test() {
/// assert!(true);
/// }
/// ```
///
/// The `worker_threads` option configures the number of worker threads, and
/// defaults to the number of cpus on the system.
///
/// Note: The multi-threaded runtime requires the `rt-multi-thread` feature
/// flag.
///
/// # Current thread runtime
///
/// The default test runtime is single-threaded. Each test gets a
/// separate current-thread runtime.
///
/// ```no_run
/// #[tokio::test]
/// async fn my_test() {
/// assert!(true);
/// }
/// ```
///
/// ## Usage
///
/// ### Using the multi-thread runtime
///
/// ```no_run
/// #[tokio::test(flavor = "multi_thread")]
/// async fn my_test() {
/// assert!(true);
/// }
/// ```
///
/// Equivalent code not using `#[tokio::test]`
///
/// ```no_run
/// #[test]
/// fn my_test() {
/// tokio::runtime::Builder::new_multi_thread()
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// assert!(true);
/// })
/// }
/// ```
///
/// ### Using current thread runtime
///
/// ```no_run
/// #[tokio::test]
/// async fn my_test() {
/// assert!(true);
/// }
/// ```
///
/// Equivalent code not using `#[tokio::test]`
///
/// ```no_run
/// #[test]
/// fn my_test() {
/// tokio::runtime::Builder::new_current_thread()
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// assert!(true);
/// })
/// }
/// ```
///
/// ### Set number of worker threads
///
/// ```no_run
/// #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
/// async fn my_test() {
/// assert!(true);
/// }
/// ```
///
/// Equivalent code not using `#[tokio::test]`
///
/// ```no_run
/// #[test]
/// fn my_test() {
/// tokio::runtime::Builder::new_multi_thread()
/// .worker_threads(2)
/// .enable_all()
/// .build()
/// .unwrap()
/// .block_on(async {
/// assert!(true);
/// })
/// }
/// ```
///
/// ### Configure the runtime to start with time paused
///
/// ```no_run
/// #[tokio::test(start_paused = true)]
/// async fn my_test() {
/// assert!(true);
/// }
/// ```
///
/// Equivalent code not using `#[tokio::test]`
///
/// ```no_run
/// #[test]
/// fn my_test() {
/// tokio::runtime::Builder::new_current_thread()
/// .enable_all()
/// .start_paused(true)
/// .build()
/// .unwrap()
/// .block_on(async {
/// assert!(true);
/// })
/// }
/// ```
///
/// Note that `start_paused` requires the `test-util` feature to be enabled.
///
/// ### Rename package
///
/// ```rust
/// use tokio as tokio1;
///
/// #[tokio1::test(crate = "tokio1")]
/// async fn my_test() {
/// println!("Hello world");
/// }
/// ```
///
/// ### Configure unhandled panic behavior
///
/// Available options are `shutdown_runtime` and `ignore`. For more details, see
/// [`Builder::unhandled_panic`].
///
/// This option is only compatible with the `current_thread` runtime.
///
/// ```no_run
/// #[cfg(tokio_unstable)]
/// #[tokio::test(flavor = "current_thread", unhandled_panic = "shutdown_runtime")]
/// async fn my_test() {
/// let _ = tokio::spawn(async {
/// panic!("This panic will shutdown the runtime.");
/// }).await;
/// }
/// # #[cfg(not(tokio_unstable))]
/// # fn main() { }
/// ```
///
/// Equivalent code not using `#[tokio::test]`
///
/// ```no_run
/// #[cfg(tokio_unstable)]
/// #[test]
/// fn my_test() {
/// tokio::runtime::Builder::new_current_thread()
/// .enable_all()
/// .unhandled_panic(UnhandledPanic::ShutdownRuntime)
/// .build()
/// .unwrap()
/// .block_on(async {
/// let _ = tokio::spawn(async {
/// panic!("This panic will shutdown the runtime.");
/// }).await;
/// })
/// }
/// # #[cfg(not(tokio_unstable))]
/// # fn main() { }
/// ```
///
/// **Note**: This option depends on Tokio's [unstable API][unstable]. See [the
/// documentation on unstable features][unstable] for details on how to enable
/// Tokio's unstable features.
///
/// [`Builder::unhandled_panic`]: ../tokio/runtime/struct.Builder.html#method.unhandled_panic
/// [unstable]: ../tokio/index.html#unstable-features
#[proc_macro_attribute]
pub fn test(args: TokenStream, item: TokenStream) -> TokenStream {
entry::test(args.into(), item.into(), true).into()
}
/// Marks async function to be executed by runtime, suitable to test environment
///
/// ## Usage
///
/// ```no_run
/// #[tokio::test]
/// async fn my_test() {
/// assert!(true);
/// }
/// ```
#[proc_macro_attribute]
pub fn test_rt(args: TokenStream, item: TokenStream) -> TokenStream {
entry::test(args.into(), item.into(), false).into()
}
/// Always fails with the error message below.
/// ```text
/// The #[tokio::main] macro requires rt or rt-multi-thread.
/// ```
#[proc_macro_attribute]
pub fn main_fail(_args: TokenStream, _item: TokenStream) -> TokenStream {
syn::Error::new(
proc_macro2::Span::call_site(),
"The #[tokio::main] macro requires rt or rt-multi-thread.",
)
.to_compile_error()
.into()
}
/// Always fails with the error message below.
/// ```text
/// The #[tokio::test] macro requires rt or rt-multi-thread.
/// ```
#[proc_macro_attribute]
pub fn test_fail(_args: TokenStream, _item: TokenStream) -> TokenStream {
syn::Error::new(
proc_macro2::Span::call_site(),
"The #[tokio::test] macro requires rt or rt-multi-thread.",
)
.to_compile_error()
.into()
}
/// Implementation detail of the `select!` macro. This macro is **not** intended
/// to be used as part of the public API and is permitted to change.
#[proc_macro]
#[doc(hidden)]
pub fn select_priv_declare_output_enum(input: TokenStream) -> TokenStream {
select::declare_output_enum(input)
}
/// Implementation detail of the `select!` macro. This macro is **not** intended
/// to be used as part of the public API and is permitted to change.
#[proc_macro]
#[doc(hidden)]
pub fn select_priv_clean_pattern(input: TokenStream) -> TokenStream {
select::clean_pattern_macro(input)
}