Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 260 insertions, 0 deletions

diff --git a/third_party/rust/futures/src/lib.rs b/third_party/rust/futures/src/lib.rs
new file mode 100644
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+++ b/third_party/rust/futures/src/lib.rs
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+//! Abstractions for asynchronous programming.
+//!
+//! This crate provides a number of core abstractions for writing asynchronous
+//! code:
+//!
+//! - [Futures](crate::future) are single eventual values produced by
+//!   asynchronous computations. Some programming languages (e.g. JavaScript)
+//!   call this concept "promise".
+//! - [Streams](crate::stream) represent a series of values
+//!   produced asynchronously.
+//! - [Sinks](crate::sink) provide support for asynchronous writing of
+//!   data.
+//! - [Executors](crate::executor) are responsible for running asynchronous
+//!   tasks.
+//!
+//! The crate also contains abstractions for [asynchronous I/O](crate::io) and
+//! [cross-task communication](crate::channel).
+//!
+//! Underlying all of this is the *task system*, which is a form of lightweight
+//! threading. Large asynchronous computations are built up using futures,
+//! streams and sinks, and then spawned as independent tasks that are run to
+//! completion, but *do not block* the thread running them.
+//!
+//! The following example describes how the task system context is built and used
+//! within macros and keywords such as async and await!.
+//!
+//! ```rust
+//! # use futures::channel::mpsc;
+//! # use futures::executor; ///standard executors to provide a context for futures and streams
+//! # use futures::executor::ThreadPool;
+//! # use futures::StreamExt;
+//! #
+//! fn main() {
+//!     # {
+//!     let pool = ThreadPool::new().expect("Failed to build pool");
+//!     let (tx, rx) = mpsc::unbounded::<i32>();
+//!
+//!     // Create a future by an async block, where async is responsible for an
+//!     // implementation of Future. At this point no executor has been provided
+//!     // to this future, so it will not be running.
+//!     let fut_values = async {
+//!         // Create another async block, again where the Future implementation
+//!         // is generated by async. Since this is inside of a parent async block,
+//!         // it will be provided with the executor of the parent block when the parent
+//!         // block is executed.
+//!         //
+//!         // This executor chaining is done by Future::poll whose second argument
+//!         // is a std::task::Context. This represents our executor, and the Future
+//!         // implemented by this async block can be polled using the parent async
+//!         // block's executor.
+//!         let fut_tx_result = async move {
+//!             (0..100).for_each(|v| {
+//!                 tx.unbounded_send(v).expect("Failed to send");
+//!             })
+//!         };
+//!
+//!         // Use the provided thread pool to spawn the generated future
+//!         // responsible for transmission
+//!         pool.spawn_ok(fut_tx_result);
+//!
+//!         let fut_values = rx
+//!             .map(|v| v * 2)
+//!             .collect();
+//!
+//!         // Use the executor provided to this async block to wait for the
+//!         // future to complete.
+//!         fut_values.await
+//!     };
+//!
+//!     // Actually execute the above future, which will invoke Future::poll and
+//!     // subsequently chain appropriate Future::poll and methods needing executors
+//!     // to drive all futures. Eventually fut_values will be driven to completion.
+//!     let values: Vec<i32> = executor::block_on(fut_values);
+//!
+//!     println!("Values={:?}", values);
+//!     # }
+//!     # std::thread::sleep(std::time::Duration::from_millis(500)); // wait for background threads closed: https://github.com/rust-lang/miri/issues/1371
+//! }
+//! ```
+//!
+//! The majority of examples and code snippets in this crate assume that they are
+//! inside an async block as written above.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+#![warn(
+    missing_debug_implementations,
+    missing_docs,
+    rust_2018_idioms,
+    single_use_lifetimes,
+    unreachable_pub
+)]
+#![doc(test(
+    no_crate_inject,
+    attr(
+        deny(warnings, rust_2018_idioms, single_use_lifetimes),
+        allow(dead_code, unused_assignments, unused_variables)
+    )
+))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+#[cfg(all(feature = "bilock", not(feature = "unstable")))]
+compile_error!("The `bilock` feature requires the `unstable` feature as an explicit opt-in to unstable features");
+
+#[doc(no_inline)]
+pub use futures_core::future::{Future, TryFuture};
+#[doc(no_inline)]
+pub use futures_util::future::{FutureExt, TryFutureExt};
+
+#[doc(no_inline)]
+pub use futures_core::stream::{Stream, TryStream};
+#[doc(no_inline)]
+pub use futures_util::stream::{StreamExt, TryStreamExt};
+
+#[doc(no_inline)]
+pub use futures_sink::Sink;
+#[doc(no_inline)]
+pub use futures_util::sink::SinkExt;
+
+#[cfg(feature = "std")]
+#[doc(no_inline)]
+pub use futures_io::{AsyncBufRead, AsyncRead, AsyncSeek, AsyncWrite};
+#[cfg(feature = "std")]
+#[doc(no_inline)]
+pub use futures_util::{AsyncBufReadExt, AsyncReadExt, AsyncSeekExt, AsyncWriteExt};
+
+// Macro reexports
+pub use futures_core::ready; // Readiness propagation
+pub use futures_util::pin_mut;
+#[cfg(feature = "std")]
+#[cfg(feature = "async-await")]
+pub use futures_util::select;
+#[cfg(feature = "async-await")]
+pub use futures_util::{join, pending, poll, select_biased, try_join}; // Async-await
+
+// Module reexports
+#[doc(inline)]
+pub use futures_util::{future, never, sink, stream, task};
+
+#[cfg(feature = "std")]
+#[cfg(feature = "async-await")]
+pub use futures_util::stream_select;
+
+#[cfg(feature = "alloc")]
+#[doc(inline)]
+pub use futures_channel as channel;
+#[cfg(feature = "alloc")]
+#[doc(inline)]
+pub use futures_util::lock;
+
+#[cfg(feature = "std")]
+#[doc(inline)]
+pub use futures_util::io;
+
+#[cfg(feature = "executor")]
+#[cfg_attr(docsrs, doc(cfg(feature = "executor")))]
+pub mod executor {
+    //! Built-in executors and related tools.
+    //!
+    //! All asynchronous computation occurs within an executor, which is
+    //! capable of spawning futures as tasks. This module provides several
+    //! built-in executors, as well as tools for building your own.
+    //!
+    //!
+    //! This module is only available when the `executor` feature of this
+    //! library is activated.
+    //!
+    //! # Using a thread pool (M:N task scheduling)
+    //!
+    //! Most of the time tasks should be executed on a [thread pool](ThreadPool).
+    //! A small set of worker threads can handle a very large set of spawned tasks
+    //! (which are much lighter weight than threads). Tasks spawned onto the pool
+    //! with the [`spawn_ok`](ThreadPool::spawn_ok) function will run ambiently on
+    //! the created threads.
+    //!
+    //! # Spawning additional tasks
+    //!
+    //! Tasks can be spawned onto a spawner by calling its [`spawn_obj`] method
+    //! directly. In the case of `!Send` futures, [`spawn_local_obj`] can be used
+    //! instead.
+    //!
+    //! # Single-threaded execution
+    //!
+    //! In addition to thread pools, it's possible to run a task (and the tasks
+    //! it spawns) entirely within a single thread via the [`LocalPool`] executor.
+    //! Aside from cutting down on synchronization costs, this executor also makes
+    //! it possible to spawn non-`Send` tasks, via [`spawn_local_obj`]. The
+    //! [`LocalPool`] is best suited for running I/O-bound tasks that do relatively
+    //! little work between I/O operations.
+    //!
+    //! There is also a convenience function [`block_on`] for simply running a
+    //! future to completion on the current thread.
+    //!
+    //! [`spawn_obj`]: https://docs.rs/futures/0.3/futures/task/trait.Spawn.html#tymethod.spawn_obj
+    //! [`spawn_local_obj`]: https://docs.rs/futures/0.3/futures/task/trait.LocalSpawn.html#tymethod.spawn_local_obj
+
+    pub use futures_executor::{
+        block_on, block_on_stream, enter, BlockingStream, Enter, EnterError, LocalPool,
+        LocalSpawner,
+    };
+
+    #[cfg(feature = "thread-pool")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "thread-pool")))]
+    pub use futures_executor::{ThreadPool, ThreadPoolBuilder};
+}
+
+#[cfg(feature = "compat")]
+#[cfg_attr(docsrs, doc(cfg(feature = "compat")))]
+pub mod compat {
+    //! Interop between `futures` 0.1 and 0.3.
+    //!
+    //! This module is only available when the `compat` feature of this
+    //! library is activated.
+
+    pub use futures_util::compat::{
+        Compat, Compat01As03, Compat01As03Sink, CompatSink, Executor01As03, Executor01CompatExt,
+        Executor01Future, Future01CompatExt, Sink01CompatExt, Stream01CompatExt,
+    };
+
+    #[cfg(feature = "io-compat")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "io-compat")))]
+    pub use futures_util::compat::{AsyncRead01CompatExt, AsyncWrite01CompatExt};
+}
+
+pub mod prelude {
+    //! A "prelude" for crates using the `futures` crate.
+    //!
+    //! This prelude is similar to the standard library's prelude in that you'll
+    //! almost always want to import its entire contents, but unlike the
+    //! standard library's prelude you'll have to do so manually:
+    //!
+    //! ```
+    //! # #[allow(unused_imports)]
+    //! use futures::prelude::*;
+    //! ```
+    //!
+    //! The prelude may grow over time as additional items see ubiquitous use.
+
+    pub use crate::future::{self, Future, TryFuture};
+    pub use crate::sink::{self, Sink};
+    pub use crate::stream::{self, Stream, TryStream};
+
+    #[doc(no_inline)]
+    #[allow(unreachable_pub)]
+    pub use crate::future::{FutureExt as _, TryFutureExt as _};
+    #[doc(no_inline)]
+    pub use crate::sink::SinkExt as _;
+    #[doc(no_inline)]
+    #[allow(unreachable_pub)]
+    pub use crate::stream::{StreamExt as _, TryStreamExt as _};
+
+    #[cfg(feature = "std")]
+    pub use crate::io::{AsyncBufRead, AsyncRead, AsyncSeek, AsyncWrite};
+
+    #[cfg(feature = "std")]
+    #[doc(no_inline)]
+    #[allow(unreachable_pub)]
+    pub use crate::io::{
+        AsyncBufReadExt as _, AsyncReadExt as _, AsyncSeekExt as _, AsyncWriteExt as _,
+    };
+}