diff options
Diffstat (limited to '')
| -rw-r--r-- | vendor/futures-task/.cargo-checksum.json | 1 | ||||
| -rw-r--r-- | vendor/futures-task/Cargo.toml | 33 | ||||
| -rw-r--r-- | vendor/futures-task/LICENSE-APACHE | 202 | ||||
| -rw-r--r-- | vendor/futures-task/LICENSE-MIT | 26 | ||||
| -rw-r--r-- | vendor/futures-task/README.md | 23 | ||||
| -rw-r--r-- | vendor/futures-task/build.rs | 42 | ||||
| -rw-r--r-- | vendor/futures-task/no_atomic_cas.rs | 13 | ||||
| -rw-r--r-- | vendor/futures-task/src/arc_wake.rs | 49 | ||||
| -rw-r--r-- | vendor/futures-task/src/future_obj.rs | 337 | ||||
| -rw-r--r-- | vendor/futures-task/src/lib.rs | 50 | ||||
| -rw-r--r-- | vendor/futures-task/src/noop_waker.rs | 63 | ||||
| -rw-r--r-- | vendor/futures-task/src/spawn.rs | 192 | ||||
| -rw-r--r-- | vendor/futures-task/src/waker.rs | 59 | ||||
| -rw-r--r-- | vendor/futures-task/src/waker_ref.rs | 63 |
14 files changed, 1153 insertions, 0 deletions
diff --git a/vendor/futures-task/.cargo-checksum.json b/vendor/futures-task/.cargo-checksum.json new file mode 100644 index 000000000..6a5f8a143 --- /dev/null +++ b/vendor/futures-task/.cargo-checksum.json @@ -0,0 +1 @@ +{"files":{"Cargo.toml":"984bf931be396558123b5ebca33f16f0e24468c7b1aea54f7a11271c42f168e0","LICENSE-APACHE":"275c491d6d1160553c32fd6127061d7f9606c3ea25abfad6ca3f6ed088785427","LICENSE-MIT":"6652c868f35dfe5e8ef636810a4e576b9d663f3a17fb0f5613ad73583e1b88fd","README.md":"8d029604e66d3fc39468bd937859e642c843ad43f8dddfb4f9cbb467a111f9e6","build.rs":"f6e21c09f18cc405bd7048cb7a2958f92d5414b9ca6b301d137e120a84fa020a","no_atomic_cas.rs":"ff8be002b49a5cd9e4ca0db17b1c9e6b98e55f556319eb6b953dd6ff52c397a6","src/arc_wake.rs":"0e3f7d7883b75337b0b92ff55e477f0bf96f6eb08def7d953676a289fd9696ec","src/future_obj.rs":"10dab39a613d938823f09c3ecdbf7e199ac173a775fd8c5db675c7ecb3b429a2","src/lib.rs":"c55281988768d44d3305b2352c7ebb66e6449797239c07b14257a2d8e612e06b","src/noop_waker.rs":"41246601dab77f69bf09257afc3321031a5a31a7eda51787029870eda9922356","src/spawn.rs":"afcf46b98d62e78d2c974f91df32590bd78fe8c79031e4ae7accf9270e1f6224","src/waker.rs":"748d4a045ea9be605a67f3c20607cc3a5ba20036942c0016cc4299df0446507c","src/waker_ref.rs":"8e3ce1aea4f433ce04c2d15eb065d89582527c1a3a15886c445eb3a78f4fd0d6"},"package":"6ee7c6485c30167ce4dfb83ac568a849fe53274c831081476ee13e0dce1aad72"}
\ No newline at end of file diff --git a/vendor/futures-task/Cargo.toml b/vendor/futures-task/Cargo.toml new file mode 100644 index 000000000..0cc029577 --- /dev/null +++ b/vendor/futures-task/Cargo.toml @@ -0,0 +1,33 @@ +# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO +# +# When uploading crates to the registry Cargo will automatically +# "normalize" Cargo.toml files for maximal compatibility +# with all versions of Cargo and also rewrite `path` dependencies +# to registry (e.g., crates.io) dependencies. +# +# If you are reading this file be aware that the original Cargo.toml +# will likely look very different (and much more reasonable). +# See Cargo.toml.orig for the original contents. + +[package] +edition = "2018" +rust-version = "1.36" +name = "futures-task" +version = "0.3.19" +description = "Tools for working with tasks.\n" +homepage = "https://rust-lang.github.io/futures-rs" +license = "MIT OR Apache-2.0" +repository = "https://github.com/rust-lang/futures-rs" +[package.metadata.docs.rs] +all-features = true + +[dependencies] + +[dev-dependencies] + +[features] +alloc = [] +cfg-target-has-atomic = [] +default = ["std"] +std = ["alloc"] +unstable = [] diff --git a/vendor/futures-task/LICENSE-APACHE b/vendor/futures-task/LICENSE-APACHE new file mode 100644 index 000000000..9eb0b097f --- /dev/null +++ b/vendor/futures-task/LICENSE-APACHE @@ -0,0 +1,202 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + +TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + +1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. For the purposes of this definition, + "control" means (i) the power, direct or indirect, to cause the + direction or management of such entity, whether by contract or + otherwise, or (ii) ownership of fifty percent (50%) or more of the + outstanding shares, or (iii) beneficial ownership of such entity. + + "You" (or "Your") shall mean an individual or Legal Entity + exercising permissions granted by this License. + + "Source" form shall mean the preferred form for making modifications, + including but not limited to software source code, documentation + source, and configuration files. + + "Object" form shall mean any form resulting from mechanical + transformation or translation of a Source form, including but + not limited to compiled object code, generated documentation, + and conversions to other media types. + + "Work" shall mean the work of authorship, whether in Source or + Object form, made available under the License, as indicated by a + copyright notice that is included in or attached to the work + (an example is provided in the Appendix below). + + "Derivative Works" shall mean any work, whether in Source or Object + form, that is based on (or derived from) the Work and for which the + editorial revisions, annotations, elaborations, or other modifications + represent, as a whole, an original work of authorship. For the purposes + of this License, Derivative Works shall not include works that remain + separable from, or merely link (or bind by name) to the interfaces of, + the Work and Derivative Works thereof. + + "Contribution" shall mean any work of authorship, including + the original version of the Work and any modifications or additions + to that Work or Derivative Works thereof, that is intentionally + submitted to Licensor for inclusion in the Work by the copyright owner + or by an individual or Legal Entity authorized to submit on behalf of + the copyright owner. For the purposes of this definition, "submitted" + means any form of electronic, verbal, or written communication sent + to the Licensor or its representatives, including but not limited to + communication on electronic mailing lists, source code control systems, + and issue tracking systems that are managed by, or on behalf of, the + Licensor for the purpose of discussing and improving the Work, but + excluding communication that is conspicuously marked or otherwise + designated in writing by the copyright owner as "Not a Contribution." + + "Contributor" shall mean Licensor and any individual or Legal Entity + on behalf of whom a Contribution has been received by Licensor and + subsequently incorporated within the Work. + +2. Grant of Copyright License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + copyright license to reproduce, prepare Derivative Works of, + publicly display, publicly perform, sublicense, and distribute the + Work and such Derivative Works in Source or Object form. + +3. Grant of Patent License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + (except as stated in this section) patent license to make, have made, + use, offer to sell, sell, import, and otherwise transfer the Work, + where such license applies only to those patent claims licensable + by such Contributor that are necessarily infringed by their + Contribution(s) alone or by combination of their Contribution(s) + with the Work to which such Contribution(s) was submitted. If You + institute patent litigation against any entity (including a + cross-claim or counterclaim in a lawsuit) alleging that the Work + or a Contribution incorporated within the Work constitutes direct + or contributory patent infringement, then any patent licenses + granted to You under this License for that Work shall terminate + as of the date such litigation is filed. + +4. Redistribution. You may reproduce and distribute copies of the + Work or Derivative Works thereof in any medium, with or without + modifications, and in Source or Object form, provided that You + meet the following conditions: + + (a) You must give any other recipients of the Work or + Derivative Works a copy of this License; and + + (b) You must cause any modified files to carry prominent notices + stating that You changed the files; and + + (c) You must retain, in the Source form of any Derivative Works + that You distribute, all copyright, patent, trademark, and + attribution notices from the Source form of the Work, + excluding those notices that do not pertain to any part of + the Derivative Works; and + + (d) If the Work includes a "NOTICE" text file as part of its + distribution, then any Derivative Works that You distribute must + include a readable copy of the attribution notices contained + within such NOTICE file, excluding those notices that do not + pertain to any part of the Derivative Works, in at least one + of the following places: within a NOTICE text file distributed + as part of the Derivative Works; within the Source form or + documentation, if provided along with the Derivative Works; or, + within a display generated by the Derivative Works, if and + wherever such third-party notices normally appear. The contents + of the NOTICE file are for informational purposes only and + do not modify the License. You may add Your own attribution + notices within Derivative Works that You distribute, alongside + or as an addendum to the NOTICE text from the Work, provided + that such additional attribution notices cannot be construed + as modifying the License. + + You may add Your own copyright statement to Your modifications and + may provide additional or different license terms and conditions + for use, reproduction, or distribution of Your modifications, or + for any such Derivative Works as a whole, provided Your use, + reproduction, and distribution of the Work otherwise complies with + the conditions stated in this License. + +5. Submission of Contributions. Unless You explicitly state otherwise, + any Contribution intentionally submitted for inclusion in the Work + by You to the Licensor shall be under the terms and conditions of + this License, without any additional terms or conditions. + Notwithstanding the above, nothing herein shall supersede or modify + the terms of any separate license agreement you may have executed + with Licensor regarding such Contributions. + +6. Trademarks. This License does not grant permission to use the trade + names, trademarks, service marks, or product names of the Licensor, + except as required for reasonable and customary use in describing the + origin of the Work and reproducing the content of the NOTICE file. + +7. Disclaimer of Warranty. Unless required by applicable law or + agreed to in writing, Licensor provides the Work (and each + Contributor provides its Contributions) on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied, including, without limitation, any warranties or conditions + of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A + PARTICULAR PURPOSE. You are solely responsible for determining the + appropriateness of using or redistributing the Work and assume any + risks associated with Your exercise of permissions under this License. + +8. Limitation of Liability. In no event and under no legal theory, + whether in tort (including negligence), contract, or otherwise, + unless required by applicable law (such as deliberate and grossly + negligent acts) or agreed to in writing, shall any Contributor be + liable to You for damages, including any direct, indirect, special, + incidental, or consequential damages of any character arising as a + result of this License or out of the use or inability to use the + Work (including but not limited to damages for loss of goodwill, + work stoppage, computer failure or malfunction, or any and all + other commercial damages or losses), even if such Contributor + has been advised of the possibility of such damages. + +9. Accepting Warranty or Additional Liability. While redistributing + the Work or Derivative Works thereof, You may choose to offer, + and charge a fee for, acceptance of support, warranty, indemnity, + or other liability obligations and/or rights consistent with this + License. However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + +END OF TERMS AND CONDITIONS + +APPENDIX: How to apply the Apache License to your work. + + To apply the Apache License to your work, attach the following + boilerplate notice, with the fields enclosed by brackets "[]" + replaced with your own identifying information. (Don't include + the brackets!) The text should be enclosed in the appropriate + comment syntax for the file format. We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + +Copyright (c) 2016 Alex Crichton +Copyright (c) 2017 The Tokio Authors + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. diff --git a/vendor/futures-task/LICENSE-MIT b/vendor/futures-task/LICENSE-MIT new file mode 100644 index 000000000..8ad082ec4 --- /dev/null +++ b/vendor/futures-task/LICENSE-MIT @@ -0,0 +1,26 @@ +Copyright (c) 2016 Alex Crichton +Copyright (c) 2017 The Tokio Authors + +Permission is hereby granted, free of charge, to any +person obtaining a copy of this software and associated +documentation files (the "Software"), to deal in the +Software without restriction, including without +limitation the rights to use, copy, modify, merge, +publish, distribute, sublicense, and/or sell copies of +the Software, and to permit persons to whom the Software +is furnished to do so, subject to the following +conditions: + +The above copyright notice and this permission notice +shall be included in all copies or substantial portions +of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF +ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED +TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A +PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT +SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR +IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. diff --git a/vendor/futures-task/README.md b/vendor/futures-task/README.md new file mode 100644 index 000000000..79f12da88 --- /dev/null +++ b/vendor/futures-task/README.md @@ -0,0 +1,23 @@ +# futures-task + +Tools for working with tasks. + +## Usage + +Add this to your `Cargo.toml`: + +```toml +[dependencies] +futures-task = "0.3" +``` + +The current `futures-task` requires Rust 1.36 or later. + +## License + +Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or +[MIT license](LICENSE-MIT) at your option. + +Unless you explicitly state otherwise, any contribution intentionally submitted +for inclusion in the work by you, as defined in the Apache-2.0 license, shall +be dual licensed as above, without any additional terms or conditions. diff --git a/vendor/futures-task/build.rs b/vendor/futures-task/build.rs new file mode 100644 index 000000000..07b50bd55 --- /dev/null +++ b/vendor/futures-task/build.rs @@ -0,0 +1,42 @@ +#![warn(rust_2018_idioms, single_use_lifetimes)] + +use std::env; + +include!("no_atomic_cas.rs"); + +// The rustc-cfg listed below are considered public API, but it is *unstable* +// and outside of the normal semver guarantees: +// +// - `futures_no_atomic_cas` +// Assume the target does *not* support atomic CAS operations. +// This is usually detected automatically by the build script, but you may +// need to enable it manually when building for custom targets or using +// non-cargo build systems that don't run the build script. +// +// With the exceptions mentioned above, the rustc-cfg strings below are +// *not* public API. Please let us know by opening a GitHub issue if your build +// environment requires some way to enable these cfgs other than by executing +// our build script. +fn main() { + let target = match env::var("TARGET") { + Ok(target) => target, + Err(e) => { + println!( + "cargo:warning={}: unable to get TARGET environment variable: {}", + env!("CARGO_PKG_NAME"), + e + ); + return; + } + }; + + // Note that this is `no_*`, not `has_*`. This allows treating + // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't + // run. This is needed for compatibility with non-cargo build systems that + // don't run the build script. + if NO_ATOMIC_CAS_TARGETS.contains(&&*target) { + println!("cargo:rustc-cfg=futures_no_atomic_cas"); + } + + println!("cargo:rerun-if-changed=no_atomic_cas.rs"); +} diff --git a/vendor/futures-task/no_atomic_cas.rs b/vendor/futures-task/no_atomic_cas.rs new file mode 100644 index 000000000..4708bf853 --- /dev/null +++ b/vendor/futures-task/no_atomic_cas.rs @@ -0,0 +1,13 @@ +// This file is @generated by no_atomic_cas.sh. +// It is not intended for manual editing. + +const NO_ATOMIC_CAS_TARGETS: &[&str] = &[ + "avr-unknown-gnu-atmega328", + "bpfeb-unknown-none", + "bpfel-unknown-none", + "msp430-none-elf", + "riscv32i-unknown-none-elf", + "riscv32imc-unknown-none-elf", + "thumbv4t-none-eabi", + "thumbv6m-none-eabi", +]; diff --git a/vendor/futures-task/src/arc_wake.rs b/vendor/futures-task/src/arc_wake.rs new file mode 100644 index 000000000..aa6de0fc4 --- /dev/null +++ b/vendor/futures-task/src/arc_wake.rs @@ -0,0 +1,49 @@ +use alloc::sync::Arc; + +/// A way of waking up a specific task. +/// +/// By implementing this trait, types that are expected to be wrapped in an `Arc` +/// can be converted into [`Waker`] objects. +/// Those Wakers can be used to signal executors that a task it owns +/// is ready to be `poll`ed again. +/// +/// Currently, there are two ways to convert `ArcWake` into [`Waker`]: +/// +/// * [`waker`](super::waker()) converts `Arc<impl ArcWake>` into [`Waker`]. +/// * [`waker_ref`](super::waker_ref()) converts `&Arc<impl ArcWake>` into [`WakerRef`] that +/// provides access to a [`&Waker`][`Waker`]. +/// +/// [`Waker`]: std::task::Waker +/// [`WakerRef`]: super::WakerRef +// Note: Send + Sync required because `Arc<T>` doesn't automatically imply +// those bounds, but `Waker` implements them. +pub trait ArcWake: Send + Sync { + /// Indicates that the associated task is ready to make progress and should + /// be `poll`ed. + /// + /// This function can be called from an arbitrary thread, including threads which + /// did not create the `ArcWake` based [`Waker`]. + /// + /// Executors generally maintain a queue of "ready" tasks; `wake` should place + /// the associated task onto this queue. + /// + /// [`Waker`]: std::task::Waker + fn wake(self: Arc<Self>) { + Self::wake_by_ref(&self) + } + + /// Indicates that the associated task is ready to make progress and should + /// be `poll`ed. + /// + /// This function can be called from an arbitrary thread, including threads which + /// did not create the `ArcWake` based [`Waker`]. + /// + /// Executors generally maintain a queue of "ready" tasks; `wake_by_ref` should place + /// the associated task onto this queue. + /// + /// This function is similar to [`wake`](ArcWake::wake), but must not consume the provided data + /// pointer. + /// + /// [`Waker`]: std::task::Waker + fn wake_by_ref(arc_self: &Arc<Self>); +} diff --git a/vendor/futures-task/src/future_obj.rs b/vendor/futures-task/src/future_obj.rs new file mode 100644 index 000000000..48ec12beb --- /dev/null +++ b/vendor/futures-task/src/future_obj.rs @@ -0,0 +1,337 @@ +use core::{ + fmt, + future::Future, + marker::PhantomData, + mem, + pin::Pin, + task::{Context, Poll}, +}; + +/// A custom trait object for polling futures, roughly akin to +/// `Box<dyn Future<Output = T> + 'a>`. +/// +/// This custom trait object was introduced as currently it is not possible to +/// take `dyn Trait` by value and `Box<dyn Trait>` is not available in no_std +/// contexts. +pub struct LocalFutureObj<'a, T> { + future: *mut (dyn Future<Output = T> + 'static), + drop_fn: unsafe fn(*mut (dyn Future<Output = T> + 'static)), + _marker: PhantomData<&'a ()>, +} + +// As LocalFutureObj only holds pointers, even if we move it, the pointed to values won't move, +// so this is safe as long as we don't provide any way for a user to directly access the pointers +// and move their values. +impl<T> Unpin for LocalFutureObj<'_, T> {} + +#[allow(single_use_lifetimes)] +#[allow(clippy::transmute_ptr_to_ptr)] +unsafe fn remove_future_lifetime<'a, T>( + ptr: *mut (dyn Future<Output = T> + 'a), +) -> *mut (dyn Future<Output = T> + 'static) { + mem::transmute(ptr) +} + +#[allow(single_use_lifetimes)] +unsafe fn remove_drop_lifetime<'a, T>( + ptr: unsafe fn(*mut (dyn Future<Output = T> + 'a)), +) -> unsafe fn(*mut (dyn Future<Output = T> + 'static)) { + mem::transmute(ptr) +} + +impl<'a, T> LocalFutureObj<'a, T> { + /// Create a `LocalFutureObj` from a custom trait object representation. + #[inline] + pub fn new<F: UnsafeFutureObj<'a, T> + 'a>(f: F) -> Self { + Self { + future: unsafe { remove_future_lifetime(f.into_raw()) }, + drop_fn: unsafe { remove_drop_lifetime(F::drop) }, + _marker: PhantomData, + } + } + + /// Converts the `LocalFutureObj` into a `FutureObj`. + /// + /// # Safety + /// + /// To make this operation safe one has to ensure that the `UnsafeFutureObj` + /// instance from which this `LocalFutureObj` was created actually + /// implements `Send`. + #[inline] + pub unsafe fn into_future_obj(self) -> FutureObj<'a, T> { + FutureObj(self) + } +} + +impl<T> fmt::Debug for LocalFutureObj<'_, T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("LocalFutureObj").finish() + } +} + +impl<'a, T> From<FutureObj<'a, T>> for LocalFutureObj<'a, T> { + #[inline] + fn from(f: FutureObj<'a, T>) -> Self { + f.0 + } +} + +impl<T> Future for LocalFutureObj<'_, T> { + type Output = T; + + #[inline] + fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> { + unsafe { Pin::new_unchecked(&mut *self.future).poll(cx) } + } +} + +impl<T> Drop for LocalFutureObj<'_, T> { + fn drop(&mut self) { + unsafe { (self.drop_fn)(self.future) } + } +} + +/// A custom trait object for polling futures, roughly akin to +/// `Box<dyn Future<Output = T> + Send + 'a>`. +/// +/// This custom trait object was introduced as currently it is not possible to +/// take `dyn Trait` by value and `Box<dyn Trait>` is not available in no_std +/// contexts. +/// +/// You should generally not need to use this type outside of `no_std` or when +/// implementing `Spawn`, consider using `BoxFuture` instead. +pub struct FutureObj<'a, T>(LocalFutureObj<'a, T>); + +impl<T> Unpin for FutureObj<'_, T> {} +unsafe impl<T> Send for FutureObj<'_, T> {} + +impl<'a, T> FutureObj<'a, T> { + /// Create a `FutureObj` from a custom trait object representation. + #[inline] + pub fn new<F: UnsafeFutureObj<'a, T> + Send>(f: F) -> Self { + Self(LocalFutureObj::new(f)) + } +} + +impl<T> fmt::Debug for FutureObj<'_, T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("FutureObj").finish() + } +} + +impl<T> Future for FutureObj<'_, T> { + type Output = T; + + #[inline] + fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> { + Pin::new(&mut self.0).poll(cx) + } +} + +/// A custom implementation of a future trait object for `FutureObj`, providing +/// a vtable with drop support. +/// +/// This custom representation is typically used only in `no_std` contexts, +/// where the default `Box`-based implementation is not available. +/// +/// # Safety +/// +/// See the safety notes on individual methods for what guarantees an +/// implementor must provide. +pub unsafe trait UnsafeFutureObj<'a, T>: 'a { + /// Convert an owned instance into a (conceptually owned) fat pointer. + /// + /// # Safety + /// + /// ## Implementor + /// + /// The trait implementor must guarantee that it is safe to convert the + /// provided `*mut (dyn Future<Output = T> + 'a)` into a `Pin<&mut (dyn + /// Future<Output = T> + 'a)>` and call methods on it, non-reentrantly, + /// until `UnsafeFutureObj::drop` is called with it. + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a); + + /// Drops the future represented by the given fat pointer. + /// + /// # Safety + /// + /// ## Implementor + /// + /// The trait implementor must guarantee that it is safe to call this + /// function once per `into_raw` invocation. + /// + /// ## Caller + /// + /// The caller must ensure: + /// + /// * the pointer passed was obtained from an `into_raw` invocation from + /// this same trait object + /// * the pointer is not currently in use as a `Pin<&mut (dyn Future<Output + /// = T> + 'a)>` + /// * the pointer must not be used again after this function is called + unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)); +} + +unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for &'a mut F +where + F: Future<Output = T> + Unpin + 'a, +{ + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) { + self as *mut dyn Future<Output = T> + } + + unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {} +} + +unsafe impl<'a, T> UnsafeFutureObj<'a, T> for &'a mut (dyn Future<Output = T> + Unpin + 'a) { + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) { + self as *mut dyn Future<Output = T> + } + + unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {} +} + +unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<&'a mut F> +where + F: Future<Output = T> + 'a, +{ + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) { + unsafe { self.get_unchecked_mut() as *mut dyn Future<Output = T> } + } + + unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {} +} + +unsafe impl<'a, T> UnsafeFutureObj<'a, T> for Pin<&'a mut (dyn Future<Output = T> + 'a)> { + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) { + unsafe { self.get_unchecked_mut() as *mut dyn Future<Output = T> } + } + + unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {} +} + +#[cfg(feature = "alloc")] +mod if_alloc { + use super::*; + use alloc::boxed::Box; + + unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for Box<F> + where + F: Future<Output = T> + 'a, + { + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) { + Box::into_raw(self) + } + + unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) { + drop(Box::from_raw(ptr as *mut F)) + } + } + + unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + 'a> { + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) { + Box::into_raw(self) + } + + unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) { + drop(Box::from_raw(ptr)) + } + } + + unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + Send + 'a> { + fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) { + Box::into_raw(self) + } + + unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) { + drop(Box::from_raw(ptr)) + } + } + + unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<Box<F>> + where + F: Future<Output = T> + 'a, + { + fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) { + let ptr = unsafe { self.as_mut().get_unchecked_mut() as *mut _ }; + mem::forget(self); + ptr + } + + unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) { + drop(Pin::from(Box::from_raw(ptr))) + } + } + + unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + 'a>> { + fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) { + let ptr = unsafe { self.as_mut().get_unchecked_mut() as *mut _ }; + mem::forget(self); + ptr + } + + unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) { + drop(Pin::from(Box::from_raw(ptr))) + } + } + + unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + Send + 'a>> { + fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) { + let ptr = unsafe { self.as_mut().get_unchecked_mut() as *mut _ }; + mem::forget(self); + ptr + } + + unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) { + drop(Pin::from(Box::from_raw(ptr))) + } + } + + impl<'a, F: Future<Output = ()> + Send + 'a> From<Box<F>> for FutureObj<'a, ()> { + fn from(boxed: Box<F>) -> Self { + Self::new(boxed) + } + } + + impl<'a> From<Box<dyn Future<Output = ()> + Send + 'a>> for FutureObj<'a, ()> { + fn from(boxed: Box<dyn Future<Output = ()> + Send + 'a>) -> Self { + Self::new(boxed) + } + } + + impl<'a, F: Future<Output = ()> + Send + 'a> From<Pin<Box<F>>> for FutureObj<'a, ()> { + fn from(boxed: Pin<Box<F>>) -> Self { + Self::new(boxed) + } + } + + impl<'a> From<Pin<Box<dyn Future<Output = ()> + Send + 'a>>> for FutureObj<'a, ()> { + fn from(boxed: Pin<Box<dyn Future<Output = ()> + Send + 'a>>) -> Self { + Self::new(boxed) + } + } + + impl<'a, F: Future<Output = ()> + 'a> From<Box<F>> for LocalFutureObj<'a, ()> { + fn from(boxed: Box<F>) -> Self { + Self::new(boxed) + } + } + + impl<'a> From<Box<dyn Future<Output = ()> + 'a>> for LocalFutureObj<'a, ()> { + fn from(boxed: Box<dyn Future<Output = ()> + 'a>) -> Self { + Self::new(boxed) + } + } + + impl<'a, F: Future<Output = ()> + 'a> From<Pin<Box<F>>> for LocalFutureObj<'a, ()> { + fn from(boxed: Pin<Box<F>>) -> Self { + Self::new(boxed) + } + } + + impl<'a> From<Pin<Box<dyn Future<Output = ()> + 'a>>> for LocalFutureObj<'a, ()> { + fn from(boxed: Pin<Box<dyn Future<Output = ()> + 'a>>) -> Self { + Self::new(boxed) + } + } +} diff --git a/vendor/futures-task/src/lib.rs b/vendor/futures-task/src/lib.rs new file mode 100644 index 000000000..c72460744 --- /dev/null +++ b/vendor/futures-task/src/lib.rs @@ -0,0 +1,50 @@ +//! Tools for working with tasks. + +#![cfg_attr(not(feature = "std"), no_std)] +#![warn(missing_debug_implementations, missing_docs, rust_2018_idioms, unreachable_pub)] +// It cannot be included in the published code because this lints have false positives in the minimum required version. +#![cfg_attr(test, warn(single_use_lifetimes))] +#![doc(test( + no_crate_inject, + attr( + deny(warnings, rust_2018_idioms, single_use_lifetimes), + allow(dead_code, unused_assignments, unused_variables) + ) +))] + +#[cfg(feature = "alloc")] +extern crate alloc; + +mod spawn; +pub use crate::spawn::{LocalSpawn, Spawn, SpawnError}; + +#[cfg(not(futures_no_atomic_cas))] +#[cfg(feature = "alloc")] +mod arc_wake; +#[cfg(not(futures_no_atomic_cas))] +#[cfg(feature = "alloc")] +pub use crate::arc_wake::ArcWake; + +#[cfg(not(futures_no_atomic_cas))] +#[cfg(feature = "alloc")] +mod waker; +#[cfg(not(futures_no_atomic_cas))] +#[cfg(feature = "alloc")] +pub use crate::waker::waker; + +#[cfg(not(futures_no_atomic_cas))] +#[cfg(feature = "alloc")] +mod waker_ref; +#[cfg(not(futures_no_atomic_cas))] +#[cfg(feature = "alloc")] +pub use crate::waker_ref::{waker_ref, WakerRef}; + +mod future_obj; +pub use crate::future_obj::{FutureObj, LocalFutureObj, UnsafeFutureObj}; + +mod noop_waker; +pub use crate::noop_waker::noop_waker; +pub use crate::noop_waker::noop_waker_ref; + +#[doc(no_inline)] +pub use core::task::{Context, Poll, RawWaker, RawWakerVTable, Waker}; diff --git a/vendor/futures-task/src/noop_waker.rs b/vendor/futures-task/src/noop_waker.rs new file mode 100644 index 000000000..f76a8a2e9 --- /dev/null +++ b/vendor/futures-task/src/noop_waker.rs @@ -0,0 +1,63 @@ +//! Utilities for creating zero-cost wakers that don't do anything. + +use core::ptr::null; +use core::task::{RawWaker, RawWakerVTable, Waker}; + +unsafe fn noop_clone(_data: *const ()) -> RawWaker { + noop_raw_waker() +} + +unsafe fn noop(_data: *const ()) {} + +const NOOP_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(noop_clone, noop, noop, noop); + +const fn noop_raw_waker() -> RawWaker { + RawWaker::new(null(), &NOOP_WAKER_VTABLE) +} + +/// Create a new [`Waker`] which does +/// nothing when `wake()` is called on it. +/// +/// # Examples +/// +/// ``` +/// use futures::task::noop_waker; +/// let waker = noop_waker(); +/// waker.wake(); +/// ``` +#[inline] +pub fn noop_waker() -> Waker { + // FIXME: Since 1.46.0 we can use transmute in consts, allowing this function to be const. + unsafe { Waker::from_raw(noop_raw_waker()) } +} + +/// Get a static reference to a [`Waker`] which +/// does nothing when `wake()` is called on it. +/// +/// # Examples +/// +/// ``` +/// use futures::task::noop_waker_ref; +/// let waker = noop_waker_ref(); +/// waker.wake_by_ref(); +/// ``` +#[inline] +pub fn noop_waker_ref() -> &'static Waker { + struct SyncRawWaker(RawWaker); + unsafe impl Sync for SyncRawWaker {} + + static NOOP_WAKER_INSTANCE: SyncRawWaker = SyncRawWaker(noop_raw_waker()); + + // SAFETY: `Waker` is #[repr(transparent)] over its `RawWaker`. + unsafe { &*(&NOOP_WAKER_INSTANCE.0 as *const RawWaker as *const Waker) } +} + +#[cfg(test)] +mod tests { + #[test] + #[cfg(feature = "std")] + fn issue_2091_cross_thread_segfault() { + let waker = std::thread::spawn(super::noop_waker_ref).join().unwrap(); + waker.wake_by_ref(); + } +} diff --git a/vendor/futures-task/src/spawn.rs b/vendor/futures-task/src/spawn.rs new file mode 100644 index 000000000..f4e63397b --- /dev/null +++ b/vendor/futures-task/src/spawn.rs @@ -0,0 +1,192 @@ +use crate::{FutureObj, LocalFutureObj}; +use core::fmt; + +/// The `Spawn` trait allows for pushing futures onto an executor that will +/// run them to completion. +pub trait Spawn { + /// Spawns a future that will be run to completion. + /// + /// # Errors + /// + /// The executor may be unable to spawn tasks. Spawn errors should + /// represent relatively rare scenarios, such as the executor + /// having been shut down so that it is no longer able to accept + /// tasks. + fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError>; + + /// Determines whether the executor is able to spawn new tasks. + /// + /// This method will return `Ok` when the executor is *likely* + /// (but not guaranteed) to accept a subsequent spawn attempt. + /// Likewise, an `Err` return means that `spawn` is likely, but + /// not guaranteed, to yield an error. + #[inline] + fn status(&self) -> Result<(), SpawnError> { + Ok(()) + } +} + +/// The `LocalSpawn` is similar to [`Spawn`], but allows spawning futures +/// that don't implement `Send`. +pub trait LocalSpawn { + /// Spawns a future that will be run to completion. + /// + /// # Errors + /// + /// The executor may be unable to spawn tasks. Spawn errors should + /// represent relatively rare scenarios, such as the executor + /// having been shut down so that it is no longer able to accept + /// tasks. + fn spawn_local_obj(&self, future: LocalFutureObj<'static, ()>) -> Result<(), SpawnError>; + + /// Determines whether the executor is able to spawn new tasks. + /// + /// This method will return `Ok` when the executor is *likely* + /// (but not guaranteed) to accept a subsequent spawn attempt. + /// Likewise, an `Err` return means that `spawn` is likely, but + /// not guaranteed, to yield an error. + #[inline] + fn status_local(&self) -> Result<(), SpawnError> { + Ok(()) + } +} + +/// An error that occurred during spawning. +pub struct SpawnError { + _priv: (), +} + +impl fmt::Debug for SpawnError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("SpawnError").field(&"shutdown").finish() + } +} + +impl fmt::Display for SpawnError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "Executor is shutdown") + } +} + +#[cfg(feature = "std")] +impl std::error::Error for SpawnError {} + +impl SpawnError { + /// Spawning failed because the executor has been shut down. + pub fn shutdown() -> Self { + Self { _priv: () } + } + + /// Check whether spawning failed to the executor being shut down. + pub fn is_shutdown(&self) -> bool { + true + } +} + +impl<Sp: ?Sized + Spawn> Spawn for &Sp { + fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError> { + Sp::spawn_obj(self, future) + } + + fn status(&self) -> Result<(), SpawnError> { + Sp::status(self) + } +} + +impl<Sp: ?Sized + Spawn> Spawn for &mut Sp { + fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError> { + Sp::spawn_obj(self, future) + } + + fn status(&self) -> Result<(), SpawnError> { + Sp::status(self) + } +} + +impl<Sp: ?Sized + LocalSpawn> LocalSpawn for &Sp { + fn spawn_local_obj(&self, future: LocalFutureObj<'static, ()>) -> Result<(), SpawnError> { + Sp::spawn_local_obj(self, future) + } + + fn status_local(&self) -> Result<(), SpawnError> { + Sp::status_local(self) + } +} + +impl<Sp: ?Sized + LocalSpawn> LocalSpawn for &mut Sp { + fn spawn_local_obj(&self, future: LocalFutureObj<'static, ()>) -> Result<(), SpawnError> { + Sp::spawn_local_obj(self, future) + } + + fn status_local(&self) -> Result<(), SpawnError> { + Sp::status_local(self) + } +} + +#[cfg(feature = "alloc")] +mod if_alloc { + use super::*; + use alloc::{boxed::Box, rc::Rc}; + + impl<Sp: ?Sized + Spawn> Spawn for Box<Sp> { + fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError> { + (**self).spawn_obj(future) + } + + fn status(&self) -> Result<(), SpawnError> { + (**self).status() + } + } + + impl<Sp: ?Sized + LocalSpawn> LocalSpawn for Box<Sp> { + fn spawn_local_obj(&self, future: LocalFutureObj<'static, ()>) -> Result<(), SpawnError> { + (**self).spawn_local_obj(future) + } + + fn status_local(&self) -> Result<(), SpawnError> { + (**self).status_local() + } + } + + impl<Sp: ?Sized + Spawn> Spawn for Rc<Sp> { + fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError> { + (**self).spawn_obj(future) + } + + fn status(&self) -> Result<(), SpawnError> { + (**self).status() + } + } + + impl<Sp: ?Sized + LocalSpawn> LocalSpawn for Rc<Sp> { + fn spawn_local_obj(&self, future: LocalFutureObj<'static, ()>) -> Result<(), SpawnError> { + (**self).spawn_local_obj(future) + } + + fn status_local(&self) -> Result<(), SpawnError> { + (**self).status_local() + } + } + + #[cfg(not(futures_no_atomic_cas))] + impl<Sp: ?Sized + Spawn> Spawn for alloc::sync::Arc<Sp> { + fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError> { + (**self).spawn_obj(future) + } + + fn status(&self) -> Result<(), SpawnError> { + (**self).status() + } + } + + #[cfg(not(futures_no_atomic_cas))] + impl<Sp: ?Sized + LocalSpawn> LocalSpawn for alloc::sync::Arc<Sp> { + fn spawn_local_obj(&self, future: LocalFutureObj<'static, ()>) -> Result<(), SpawnError> { + (**self).spawn_local_obj(future) + } + + fn status_local(&self) -> Result<(), SpawnError> { + (**self).status_local() + } + } +} diff --git a/vendor/futures-task/src/waker.rs b/vendor/futures-task/src/waker.rs new file mode 100644 index 000000000..a7310a07a --- /dev/null +++ b/vendor/futures-task/src/waker.rs @@ -0,0 +1,59 @@ +use super::arc_wake::ArcWake; +use alloc::sync::Arc; +use core::mem; +use core::task::{RawWaker, RawWakerVTable, Waker}; + +pub(super) fn waker_vtable<W: ArcWake>() -> &'static RawWakerVTable { + &RawWakerVTable::new( + clone_arc_raw::<W>, + wake_arc_raw::<W>, + wake_by_ref_arc_raw::<W>, + drop_arc_raw::<W>, + ) +} + +/// Creates a [`Waker`] from an `Arc<impl ArcWake>`. +/// +/// The returned [`Waker`] will call +/// [`ArcWake.wake()`](ArcWake::wake) if awoken. +pub fn waker<W>(wake: Arc<W>) -> Waker +where + W: ArcWake + 'static, +{ + let ptr = Arc::into_raw(wake) as *const (); + + unsafe { Waker::from_raw(RawWaker::new(ptr, waker_vtable::<W>())) } +} + +// FIXME: panics on Arc::clone / refcount changes could wreak havoc on the +// code here. We should guard against this by aborting. + +#[allow(clippy::redundant_clone)] // The clone here isn't actually redundant. +unsafe fn increase_refcount<T: ArcWake>(data: *const ()) { + // Retain Arc, but don't touch refcount by wrapping in ManuallyDrop + let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T)); + // Now increase refcount, but don't drop new refcount either + let _arc_clone: mem::ManuallyDrop<_> = arc.clone(); +} + +// used by `waker_ref` +unsafe fn clone_arc_raw<T: ArcWake>(data: *const ()) -> RawWaker { + increase_refcount::<T>(data); + RawWaker::new(data, waker_vtable::<T>()) +} + +unsafe fn wake_arc_raw<T: ArcWake>(data: *const ()) { + let arc: Arc<T> = Arc::from_raw(data as *const T); + ArcWake::wake(arc); +} + +// used by `waker_ref` +unsafe fn wake_by_ref_arc_raw<T: ArcWake>(data: *const ()) { + // Retain Arc, but don't touch refcount by wrapping in ManuallyDrop + let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T)); + ArcWake::wake_by_ref(&arc); +} + +unsafe fn drop_arc_raw<T: ArcWake>(data: *const ()) { + drop(Arc::<T>::from_raw(data as *const T)) +} diff --git a/vendor/futures-task/src/waker_ref.rs b/vendor/futures-task/src/waker_ref.rs new file mode 100644 index 000000000..791c69012 --- /dev/null +++ b/vendor/futures-task/src/waker_ref.rs @@ -0,0 +1,63 @@ +use super::arc_wake::ArcWake; +use super::waker::waker_vtable; +use alloc::sync::Arc; +use core::marker::PhantomData; +use core::mem::ManuallyDrop; +use core::ops::Deref; +use core::task::{RawWaker, Waker}; + +/// A [`Waker`] that is only valid for a given lifetime. +/// +/// Note: this type implements [`Deref<Target = Waker>`](std::ops::Deref), +/// so it can be used to get a `&Waker`. +#[derive(Debug)] +pub struct WakerRef<'a> { + waker: ManuallyDrop<Waker>, + _marker: PhantomData<&'a ()>, +} + +impl<'a> WakerRef<'a> { + /// Create a new [`WakerRef`] from a [`Waker`] reference. + pub fn new(waker: &'a Waker) -> Self { + // copy the underlying (raw) waker without calling a clone, + // as we won't call Waker::drop either. + let waker = ManuallyDrop::new(unsafe { core::ptr::read(waker) }); + Self { waker, _marker: PhantomData } + } + + /// Create a new [`WakerRef`] from a [`Waker`] that must not be dropped. + /// + /// Note: this if for rare cases where the caller created a [`Waker`] in + /// an unsafe way (that will be valid only for a lifetime to be determined + /// by the caller), and the [`Waker`] doesn't need to or must not be + /// destroyed. + pub fn new_unowned(waker: ManuallyDrop<Waker>) -> Self { + Self { waker, _marker: PhantomData } + } +} + +impl Deref for WakerRef<'_> { + type Target = Waker; + + fn deref(&self) -> &Waker { + &self.waker + } +} + +/// Creates a reference to a [`Waker`] from a reference to `Arc<impl ArcWake>`. +/// +/// The resulting [`Waker`] will call +/// [`ArcWake.wake()`](ArcWake::wake) if awoken. +#[inline] +pub fn waker_ref<W>(wake: &Arc<W>) -> WakerRef<'_> +where + W: ArcWake, +{ + // simply copy the pointer instead of using Arc::into_raw, + // as we don't actually keep a refcount by using ManuallyDrop.< + let ptr = (&**wake as *const W) as *const (); + + let waker = + ManuallyDrop::new(unsafe { Waker::from_raw(RawWaker::new(ptr, waker_vtable::<W>())) }); + WakerRef::new_unowned(waker) +} |