Upgrade async_task to 4.3.0 This project was upgraded with external_updater. Usage: tools/external_updater/updater.sh update rust/crates/async-task For more info, check https://cs.android.com/android/platform/superproject/+/master:tools/external_updater/README.md Test: TreeHugger Change-Id: I45dca5604ff41679993b26a30a1dbfb40fe680f1
diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json index d3b06d7..e80a435 100644 --- a/.cargo_vcs_info.json +++ b/.cargo_vcs_info.json
@@ -1,6 +1,6 @@ { "git": { - "sha1": "de0c79d171e95d1cbbd4becf678cc43ea689551e" + "sha1": "f910d25edb04d05a24c9e58d73a4e5d8a31163a6" }, "path_in_vcs": "" } \ No newline at end of file diff --git a/Android.bp b/Android.bp index 8c176c1..a46517c 100644 --- a/Android.bp +++ b/Android.bp
@@ -42,7 +42,7 @@ host_supported: true, crate_name: "async_task", cargo_env_compat: true, - cargo_pkg_version: "4.2.0", + cargo_pkg_version: "4.3.0", srcs: ["src/lib.rs"], edition: "2018", features: [
diff --git a/CHANGELOG.md b/CHANGELOG.md index fe87187..d0a3e0b 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md
@@ -1,3 +1,9 @@ +# Version 4.3.0 + +- Bump MSRV to Rust 1.47. (#30) +- Evaluate the layouts for the tasks at compile time. (#30) +- Add layout_info field to TaskVTable so that debuggers can decode raw tasks. (#29) + # Version 4.2.0 - Add `Task::is_finished`. (#19)
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diff --git a/Cargo.toml b/Cargo.toml index 7847dd8..6e989e5 100644 --- a/Cargo.toml +++ b/Cargo.toml
@@ -11,12 +11,13 @@ [package] edition = "2018" -rust-version = "1.39" +rust-version = "1.47" name = "async-task" -version = "4.2.0" +version = "4.3.0" authors = ["Stjepan Glavina <stjepang@gmail.com>"] exclude = ["/.*"] description = "Task abstraction for building executors" +readme = "README.md" keywords = [ "futures", "task",
diff --git a/Cargo.toml.orig b/Cargo.toml.orig index 7dc7c73..8c611bf 100644 --- a/Cargo.toml.orig +++ b/Cargo.toml.orig
@@ -3,10 +3,10 @@ # When publishing a new version: # - Update CHANGELOG.md # - Create "v4.x.y" git tag -version = "4.2.0" +version = "4.3.0" authors = ["Stjepan Glavina <stjepang@gmail.com>"] edition = "2018" -rust-version = "1.39" +rust-version = "1.47" license = "Apache-2.0 OR MIT" repository = "https://github.com/smol-rs/async-task" description = "Task abstraction for building executors"
diff --git a/METADATA b/METADATA index 9a5cdf5..799c6da 100644 --- a/METADATA +++ b/METADATA
@@ -1,3 +1,7 @@ +# This project was upgraded with external_updater. +# Usage: tools/external_updater/updater.sh update rust/crates/async-task +# For more info, check https://cs.android.com/android/platform/superproject/+/master:tools/external_updater/README.md + name: "async_task" description: "Task abstraction for building executors" third_party { @@ -7,13 +11,13 @@ } url { type: ARCHIVE - value: "https://static.crates.io/crates/async_task/async_task-4.2.0.crate" + value: "https://static.crates.io/crates/async_task/async_task-4.3.0.crate" } - version: "4.2.0" + version: "4.3.0" license_type: NOTICE last_upgrade_date { year: 2022 - month: 6 - day: 22 + month: 12 + day: 6 } } diff --git a/src/lib.rs b/src/lib.rs index 4a868bf..dd689ec 100644 --- a/src/lib.rs +++ b/src/lib.rs
@@ -74,6 +74,17 @@ extern crate alloc; +/// We can't use `?` in const contexts yet, so this macro acts +/// as a workaround. +macro_rules! leap { + ($x: expr) => {{ + match ($x) { + Some(val) => val, + None => return None, + } + }}; +} + mod header; mod raw; mod runnable; diff --git a/src/raw.rs b/src/raw.rs index 9b5854c..bb031da 100644 --- a/src/raw.rs +++ b/src/raw.rs
@@ -1,4 +1,4 @@ -use alloc::alloc::Layout; +use alloc::alloc::Layout as StdLayout; use core::cell::UnsafeCell; use core::future::Future; use core::mem::{self, ManuallyDrop}; @@ -9,7 +9,7 @@ use crate::header::Header; use crate::state::*; -use crate::utils::{abort, abort_on_panic, extend}; +use crate::utils::{abort, abort_on_panic, max, Layout}; use crate::Runnable; /// The vtable for a task. @@ -34,6 +34,12 @@ /// Creates a new waker associated with the task. pub(crate) clone_waker: unsafe fn(ptr: *const ()) -> RawWaker, + + /// The memory layout of the task. This information enables + /// debuggers to decode raw task memory blobs. Do not remove + /// the field, even if it appears to be unused. + #[allow(unused)] + pub(crate) layout_info: &'static Option<TaskLayout>, } /// Memory layout of a task. @@ -45,7 +51,7 @@ #[derive(Clone, Copy)] pub(crate) struct TaskLayout { /// Memory layout of the whole task. - pub(crate) layout: Layout, + pub(crate) layout: StdLayout, /// Offset into the task at which the schedule function is stored. pub(crate) offset_s: usize, @@ -80,6 +86,39 @@ } } +impl<F, T, S> RawTask<F, T, S> { + const TASK_LAYOUT: Option<TaskLayout> = Self::eval_task_layout(); + + /// Computes the memory layout for a task. + #[inline] + const fn eval_task_layout() -> Option<TaskLayout> { + // Compute the layouts for `Header`, `S`, `F`, and `T`. + let layout_header = Layout::new::<Header>(); + let layout_s = Layout::new::<S>(); + let layout_f = Layout::new::<F>(); + let layout_r = Layout::new::<T>(); + + // Compute the layout for `union { F, T }`. + let size_union = max(layout_f.size(), layout_r.size()); + let align_union = max(layout_f.align(), layout_r.align()); + let layout_union = Layout::from_size_align(size_union, align_union); + + // Compute the layout for `Header` followed `S` and `union { F, T }`. + let layout = layout_header; + let (layout, offset_s) = leap!(layout.extend(layout_s)); + let (layout, offset_union) = leap!(layout.extend(layout_union)); + let offset_f = offset_union; + let offset_r = offset_union; + + Some(TaskLayout { + layout: unsafe { layout.into_std() }, + offset_s, + offset_f, + offset_r, + }) + } +} + impl<F, T, S> RawTask<F, T, S> where F: Future<Output = T>, @@ -97,7 +136,9 @@ /// It is assumed that initially only the `Runnable` and the `Task` exist. pub(crate) fn allocate(future: F, schedule: S) -> NonNull<()> { // Compute the layout of the task for allocation. Abort if the computation fails. - let task_layout = abort_on_panic(|| Self::task_layout()); + // + // n.b. notgull: task_layout now automatically aborts instead of panicking + let task_layout = Self::task_layout(); unsafe { // Allocate enough space for the entire task. @@ -120,6 +161,7 @@ destroy: Self::destroy, run: Self::run, clone_waker: Self::clone_waker, + layout_info: &Self::TASK_LAYOUT, }, }); @@ -149,32 +191,12 @@ } } - /// Returns the memory layout for a task. + /// Returns the layout of the task. #[inline] fn task_layout() -> TaskLayout { - // Compute the layouts for `Header`, `S`, `F`, and `T`. - let layout_header = Layout::new::<Header>(); - let layout_s = Layout::new::<S>(); - let layout_f = Layout::new::<F>(); - let layout_r = Layout::new::<T>(); - - // Compute the layout for `union { F, T }`. - let size_union = layout_f.size().max(layout_r.size()); - let align_union = layout_f.align().max(layout_r.align()); - let layout_union = unsafe { Layout::from_size_align_unchecked(size_union, align_union) }; - - // Compute the layout for `Header` followed `S` and `union { F, T }`. - let layout = layout_header; - let (layout, offset_s) = extend(layout, layout_s); - let (layout, offset_union) = extend(layout, layout_union); - let offset_f = offset_union; - let offset_r = offset_union; - - TaskLayout { - layout, - offset_s, - offset_f, - offset_r, + match Self::TASK_LAYOUT { + Some(tl) => tl, + None => abort(), } } diff --git a/src/task.rs b/src/task.rs index 7d1c433..8ecd746 100644 --- a/src/task.rs +++ b/src/task.rs
@@ -99,6 +99,7 @@ /// # Examples /// /// ``` + /// # if cfg!(miri) { return; } // Miri does not support epoll /// use smol::{future, Executor, Timer}; /// use std::thread; /// use std::time::Duration; @@ -485,6 +486,7 @@ /// # Examples /// /// ``` + /// # if cfg!(miri) { return; } // Miri does not support epoll /// use smol::{future, Executor, Timer}; /// use std::thread; /// use std::time::Duration; diff --git a/src/utils.rs b/src/utils.rs index cb9b65e..189e9af 100644 --- a/src/utils.rs +++ b/src/utils.rs
@@ -1,4 +1,4 @@ -use core::alloc::Layout; +use core::alloc::Layout as StdLayout; use core::mem; /// Aborts the process. @@ -36,29 +36,92 @@ t } -/// Returns the layout for `a` followed by `b` and the offset of `b`. -/// -/// This function was adapted from the currently unstable `Layout::extend()`: -/// https://doc.rust-lang.org/nightly/std/alloc/struct.Layout.html#method.extend -#[inline] -pub(crate) fn extend(a: Layout, b: Layout) -> (Layout, usize) { - let new_align = a.align().max(b.align()); - let pad = padding_needed_for(a, b.align()); - - let offset = a.size().checked_add(pad).unwrap(); - let new_size = offset.checked_add(b.size()).unwrap(); - - let layout = Layout::from_size_align(new_size, new_align).unwrap(); - (layout, offset) +/// A version of `alloc::alloc::Layout` that can be used in the const +/// position. +#[derive(Clone, Copy, Debug)] +pub(crate) struct Layout { + size: usize, + align: usize, } -/// Returns the padding after `layout` that aligns the following address to `align`. -/// -/// This function was adapted from the currently unstable `Layout::padding_needed_for()`: -/// https://doc.rust-lang.org/nightly/std/alloc/struct.Layout.html#method.padding_needed_for +impl Layout { + /// Creates a new `Layout` with the given size and alignment. + #[inline] + pub(crate) const fn from_size_align(size: usize, align: usize) -> Self { + Self { size, align } + } + + /// Creates a new `Layout` for the given sized type. + #[inline] + pub(crate) const fn new<T>() -> Self { + Self::from_size_align(mem::size_of::<T>(), mem::align_of::<T>()) + } + + /// Convert this into the standard library's layout type. + /// + /// # Safety + /// + /// - `align` must be non-zero and a power of two. + /// - When rounded up to the nearest multiple of `align`, the size + /// must not overflow. + #[inline] + pub(crate) const unsafe fn into_std(self) -> StdLayout { + StdLayout::from_size_align_unchecked(self.size, self.align) + } + + /// Get the alignment of this layout. + #[inline] + pub(crate) const fn align(&self) -> usize { + self.align + } + + /// Get the size of this layout. + #[inline] + pub(crate) const fn size(&self) -> usize { + self.size + } + + /// Returns the layout for `a` followed by `b` and the offset of `b`. + /// + /// This function was adapted from the currently unstable `Layout::extend()`: + /// https://doc.rust-lang.org/nightly/std/alloc/struct.Layout.html#method.extend + #[inline] + pub(crate) const fn extend(self, other: Layout) -> Option<(Layout, usize)> { + let new_align = max(self.align(), other.align()); + let pad = self.padding_needed_for(other.align()); + + let offset = leap!(self.size().checked_add(pad)); + let new_size = leap!(offset.checked_add(other.size())); + + // return None if any of the following are true: + // - align is 0 (implied false by is_power_of_two()) + // - align is not a power of 2 + // - size rounded up to align overflows + if !new_align.is_power_of_two() || new_size > core::usize::MAX - (new_align - 1) { + return None; + } + + let layout = Layout::from_size_align(new_size, new_align); + Some((layout, offset)) + } + + /// Returns the padding after `layout` that aligns the following address to `align`. + /// + /// This function was adapted from the currently unstable `Layout::padding_needed_for()`: + /// https://doc.rust-lang.org/nightly/std/alloc/struct.Layout.html#method.padding_needed_for + #[inline] + pub(crate) const fn padding_needed_for(self, align: usize) -> usize { + let len = self.size(); + let len_rounded_up = len.wrapping_add(align).wrapping_sub(1) & !align.wrapping_sub(1); + len_rounded_up.wrapping_sub(len) + } +} + #[inline] -pub(crate) fn padding_needed_for(layout: Layout, align: usize) -> usize { - let len = layout.size(); - let len_rounded_up = len.wrapping_add(align).wrapping_sub(1) & !align.wrapping_sub(1); - len_rounded_up.wrapping_sub(len) +pub(crate) const fn max(left: usize, right: usize) -> usize { + if left > right { + left + } else { + right + } } 