| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.28.2/src/runtime/task/mod.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mod.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../../normalize.css"><link rel="stylesheet" href="../../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../../ayu.css" disabled><link rel="stylesheet" href="../../../../dark.css" disabled><link rel="stylesheet" href="../../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../../storage.js"></script><script defer src="../../../../source-script.js"></script><script defer src="../../../../source-files.js"></script><script defer src="../../../../main.js"></script><noscript><link rel="stylesheet" href="../../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../../tokio/index.html"><div class="logo-container"><img class="rust-logo" src="../../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../../tokio/index.html"><img class="rust-logo" src="../../../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="doccomment">//! The task module. |
| //! |
| //! The task module contains the code that manages spawned tasks and provides a |
| //! safe API for the rest of the runtime to use. Each task in a runtime is |
| //! stored in an OwnedTasks or LocalOwnedTasks object. |
| //! |
| //! # Task reference types |
| //! |
| //! A task is usually referenced by multiple handles, and there are several |
| //! types of handles. |
| //! |
| //! * OwnedTask - tasks stored in an OwnedTasks or LocalOwnedTasks are of this |
| //! reference type. |
| //! |
| //! * JoinHandle - each task has a JoinHandle that allows access to the output |
| //! of the task. |
| //! |
| //! * Waker - every waker for a task has this reference type. There can be any |
| //! number of waker references. |
| //! |
| //! * Notified - tracks whether the task is notified. |
| //! |
| //! * Unowned - this task reference type is used for tasks not stored in any |
| //! runtime. Mainly used for blocking tasks, but also in tests. |
| //! |
| //! The task uses a reference count to keep track of how many active references |
| //! exist. The Unowned reference type takes up two ref-counts. All other |
| //! reference types take up a single ref-count. |
| //! |
| //! Besides the waker type, each task has at most one of each reference type. |
| //! |
| //! # State |
| //! |
| //! The task stores its state in an atomic usize with various bitfields for the |
| //! necessary information. The state has the following bitfields: |
| //! |
| //! * RUNNING - Tracks whether the task is currently being polled or cancelled. |
| //! This bit functions as a lock around the task. |
| //! |
| //! * COMPLETE - Is one once the future has fully completed and has been |
| //! dropped. Never unset once set. Never set together with RUNNING. |
| //! |
| //! * NOTIFIED - Tracks whether a Notified object currently exists. |
| //! |
| //! * CANCELLED - Is set to one for tasks that should be cancelled as soon as |
| //! possible. May take any value for completed tasks. |
| //! |
| //! * JOIN_INTEREST - Is set to one if there exists a JoinHandle. |
| //! |
| //! * JOIN_WAKER - Acts as an access control bit for the join handle waker. The |
| //! protocol for its usage is described below. |
| //! |
| //! The rest of the bits are used for the ref-count. |
| //! |
| //! # Fields in the task |
| //! |
| //! The task has various fields. This section describes how and when it is safe |
| //! to access a field. |
| //! |
| //! * The state field is accessed with atomic instructions. |
| //! |
| //! * The OwnedTask reference has exclusive access to the `owned` field. |
| //! |
| //! * The Notified reference has exclusive access to the `queue_next` field. |
| //! |
| //! * The `owner_id` field can be set as part of construction of the task, but |
| //! is otherwise immutable and anyone can access the field immutably without |
| //! synchronization. |
| //! |
| //! * If COMPLETE is one, then the JoinHandle has exclusive access to the |
| //! stage field. If COMPLETE is zero, then the RUNNING bitfield functions as |
| //! a lock for the stage field, and it can be accessed only by the thread |
| //! that set RUNNING to one. |
| //! |
| //! * The waker field may be concurrently accessed by different threads: in one |
| //! thread the runtime may complete a task and *read* the waker field to |
| //! invoke the waker, and in another thread the task's JoinHandle may be |
| //! polled, and if the task hasn't yet completed, the JoinHandle may *write* |
| //! a waker to the waker field. The JOIN_WAKER bit ensures safe access by |
| //! multiple threads to the waker field using the following rules: |
| //! |
| //! 1. JOIN_WAKER is initialized to zero. |
| //! |
| //! 2. If JOIN_WAKER is zero, then the JoinHandle has exclusive (mutable) |
| //! access to the waker field. |
| //! |
| //! 3. If JOIN_WAKER is one, then the JoinHandle has shared (read-only) |
| //! access to the waker field. |
| //! |
| //! 4. If JOIN_WAKER is one and COMPLETE is one, then the runtime has shared |
| //! (read-only) access to the waker field. |
| //! |
| //! 5. If the JoinHandle needs to write to the waker field, then the |
| //! JoinHandle needs to (i) successfully set JOIN_WAKER to zero if it is |
| //! not already zero to gain exclusive access to the waker field per rule |
| //! 2, (ii) write a waker, and (iii) successfully set JOIN_WAKER to one. |
| //! |
| //! 6. The JoinHandle can change JOIN_WAKER only if COMPLETE is zero (i.e. |
| //! the task hasn't yet completed). |
| //! |
| //! Rule 6 implies that the steps (i) or (iii) of rule 5 may fail due to a |
| //! race. If step (i) fails, then the attempt to write a waker is aborted. If |
| //! step (iii) fails because COMPLETE is set to one by another thread after |
| //! step (i), then the waker field is cleared. Once COMPLETE is one (i.e. |
| //! task has completed), the JoinHandle will not modify JOIN_WAKER. After the |
| //! runtime sets COMPLETE to one, it invokes the waker if there is one. |
| //! |
| //! All other fields are immutable and can be accessed immutably without |
| //! synchronization by anyone. |
| //! |
| //! # Safety |
| //! |
| //! This section goes through various situations and explains why the API is |
| //! safe in that situation. |
| //! |
| //! ## Polling or dropping the future |
| //! |
| //! Any mutable access to the future happens after obtaining a lock by modifying |
| //! the RUNNING field, so exclusive access is ensured. |
| //! |
| //! When the task completes, exclusive access to the output is transferred to |
| //! the JoinHandle. If the JoinHandle is already dropped when the transition to |
| //! complete happens, the thread performing that transition retains exclusive |
| //! access to the output and should immediately drop it. |
| //! |
| //! ## Non-Send futures |
| //! |
| //! If a future is not Send, then it is bound to a LocalOwnedTasks. The future |
| //! will only ever be polled or dropped given a LocalNotified or inside a call |
| //! to LocalOwnedTasks::shutdown_all. In either case, it is guaranteed that the |
| //! future is on the right thread. |
| //! |
| //! If the task is never removed from the LocalOwnedTasks, then it is leaked, so |
| //! there is no risk that the task is dropped on some other thread when the last |
| //! ref-count drops. |
| //! |
| //! ## Non-Send output |
| //! |
| //! When a task completes, the output is placed in the stage of the task. Then, |
| //! a transition that sets COMPLETE to true is performed, and the value of |
| //! JOIN_INTEREST when this transition happens is read. |
| //! |
| //! If JOIN_INTEREST is zero when the transition to COMPLETE happens, then the |
| //! output is immediately dropped. |
| //! |
| //! If JOIN_INTEREST is one when the transition to COMPLETE happens, then the |
| //! JoinHandle is responsible for cleaning up the output. If the output is not |
| //! Send, then this happens: |
| //! |
| //! 1. The output is created on the thread that the future was polled on. Since |
| //! only non-Send futures can have non-Send output, the future was polled on |
| //! the thread that the future was spawned from. |
| //! 2. Since `JoinHandle<Output>` is not Send if Output is not Send, the |
| //! JoinHandle is also on the thread that the future was spawned from. |
| //! 3. Thus, the JoinHandle will not move the output across threads when it |
| //! takes or drops the output. |
| //! |
| //! ## Recursive poll/shutdown |
| //! |
| //! Calling poll from inside a shutdown call or vice-versa is not prevented by |
| //! the API exposed by the task module, so this has to be safe. In either case, |
| //! the lock in the RUNNING bitfield makes the inner call return immediately. If |
| //! the inner call is a `shutdown` call, then the CANCELLED bit is set, and the |
| //! poll call will notice it when the poll finishes, and the task is cancelled |
| //! at that point. |
| |
| </span><span class="comment">// Some task infrastructure is here to support `JoinSet`, which is currently |
| // unstable. This should be removed once `JoinSet` is stabilized. |
| </span><span class="attribute">#![cfg_attr(not(tokio_unstable), allow(dead_code))] |
| |
| </span><span class="kw">mod </span>core; |
| <span class="kw">use </span><span class="self">self</span>::core::Cell; |
| <span class="kw">use </span><span class="self">self</span>::core::Header; |
| |
| <span class="kw">mod </span>error; |
| <span class="kw">pub use </span><span class="self">self</span>::error::JoinError; |
| |
| <span class="kw">mod </span>harness; |
| <span class="kw">use </span><span class="self">self</span>::harness::Harness; |
| |
| <span class="kw">mod </span>id; |
| <span class="attribute">#[cfg_attr(not(tokio_unstable), allow(unreachable_pub))] |
| </span><span class="kw">pub use </span>id::{id, try_id, Id}; |
| |
| <span class="macro">cfg_rt_multi_thread! </span>{ |
| <span class="kw">mod </span>inject; |
| <span class="kw">pub</span>(<span class="kw">super</span>) <span class="kw">use </span><span class="self">self</span>::inject::Inject; |
| } |
| |
| <span class="attribute">#[cfg(feature = <span class="string">"rt"</span>)] |
| </span><span class="kw">mod </span>abort; |
| <span class="kw">mod </span>join; |
| |
| <span class="attribute">#[cfg(feature = <span class="string">"rt"</span>)] |
| </span><span class="kw">pub use </span><span class="self">self</span>::abort::AbortHandle; |
| |
| <span class="kw">pub use </span><span class="self">self</span>::join::JoinHandle; |
| |
| <span class="kw">mod </span>list; |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">use </span><span class="self">self</span>::list::{LocalOwnedTasks, OwnedTasks}; |
| |
| <span class="kw">mod </span>raw; |
| <span class="kw">use </span><span class="self">self</span>::raw::RawTask; |
| |
| <span class="kw">mod </span>state; |
| <span class="kw">use </span><span class="self">self</span>::state::State; |
| |
| <span class="kw">mod </span>waker; |
| |
| <span class="kw">use </span><span class="kw">crate</span>::future::Future; |
| <span class="kw">use </span><span class="kw">crate</span>::util::linked_list; |
| |
| <span class="kw">use </span>std::marker::PhantomData; |
| <span class="kw">use </span>std::ptr::NonNull; |
| <span class="kw">use </span>std::{fmt, mem}; |
| |
| <span class="doccomment">/// An owned handle to the task, tracked by ref count. |
| </span><span class="attribute">#[repr(transparent)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Task<S: <span class="lifetime">'static</span>> { |
| raw: RawTask, |
| _p: PhantomData<S>, |
| } |
| |
| <span class="kw">unsafe impl</span><S> Send <span class="kw">for </span>Task<S> {} |
| <span class="kw">unsafe impl</span><S> Sync <span class="kw">for </span>Task<S> {} |
| |
| <span class="doccomment">/// A task was notified. |
| </span><span class="attribute">#[repr(transparent)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Notified<S: <span class="lifetime">'static</span>>(Task<S>); |
| |
| <span class="comment">// safety: This type cannot be used to touch the task without first verifying |
| // that the value is on a thread where it is safe to poll the task. |
| </span><span class="kw">unsafe impl</span><S: Schedule> Send <span class="kw">for </span>Notified<S> {} |
| <span class="kw">unsafe impl</span><S: Schedule> Sync <span class="kw">for </span>Notified<S> {} |
| |
| <span class="doccomment">/// A non-Send variant of Notified with the invariant that it is on a thread |
| /// where it is safe to poll it. |
| </span><span class="attribute">#[repr(transparent)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>LocalNotified<S: <span class="lifetime">'static</span>> { |
| task: Task<S>, |
| _not_send: PhantomData<<span class="kw-2">*const </span>()>, |
| } |
| |
| <span class="doccomment">/// A task that is not owned by any OwnedTasks. Used for blocking tasks. |
| /// This type holds two ref-counts. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>UnownedTask<S: <span class="lifetime">'static</span>> { |
| raw: RawTask, |
| _p: PhantomData<S>, |
| } |
| |
| <span class="comment">// safety: This type can only be created given a Send task. |
| </span><span class="kw">unsafe impl</span><S> Send <span class="kw">for </span>UnownedTask<S> {} |
| <span class="kw">unsafe impl</span><S> Sync <span class="kw">for </span>UnownedTask<S> {} |
| |
| <span class="doccomment">/// Task result sent back. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">type </span><span class="prelude-ty">Result</span><T> = std::result::Result<T, JoinError>; |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">trait </span>Schedule: Sync + Sized + <span class="lifetime">'static </span>{ |
| <span class="doccomment">/// The task has completed work and is ready to be released. The scheduler |
| /// should release it immediately and return it. The task module will batch |
| /// the ref-dec with setting other options. |
| /// |
| /// If the scheduler has already released the task, then None is returned. |
| </span><span class="kw">fn </span>release(<span class="kw-2">&</span><span class="self">self</span>, task: <span class="kw-2">&</span>Task<<span class="self">Self</span>>) -> <span class="prelude-ty">Option</span><Task<<span class="self">Self</span>>>; |
| |
| <span class="doccomment">/// Schedule the task |
| </span><span class="kw">fn </span>schedule(<span class="kw-2">&</span><span class="self">self</span>, task: Notified<<span class="self">Self</span>>); |
| |
| <span class="doccomment">/// Schedule the task to run in the near future, yielding the thread to |
| /// other tasks. |
| </span><span class="kw">fn </span>yield_now(<span class="kw-2">&</span><span class="self">self</span>, task: Notified<<span class="self">Self</span>>) { |
| <span class="self">self</span>.schedule(task); |
| } |
| |
| <span class="doccomment">/// Polling the task resulted in a panic. Should the runtime shutdown? |
| </span><span class="kw">fn </span>unhandled_panic(<span class="kw-2">&</span><span class="self">self</span>) { |
| <span class="comment">// By default, do nothing. This maintains the 1.0 behavior. |
| </span>} |
| } |
| |
| <span class="macro">cfg_rt! </span>{ |
| <span class="doccomment">/// This is the constructor for a new task. Three references to the task are |
| /// created. The first task reference is usually put into an OwnedTasks |
| /// immediately. The Notified is sent to the scheduler as an ordinary |
| /// notification. |
| </span><span class="kw">fn </span>new_task<T, S>( |
| task: T, |
| scheduler: S, |
| id: Id, |
| ) -> (Task<S>, Notified<S>, JoinHandle<T::Output>) |
| <span class="kw">where |
| </span>S: Schedule, |
| T: Future + <span class="lifetime">'static</span>, |
| T::Output: <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span>raw = RawTask::new::<T, S>(task, scheduler, id); |
| <span class="kw">let </span>task = Task { |
| raw, |
| _p: PhantomData, |
| }; |
| <span class="kw">let </span>notified = Notified(Task { |
| raw, |
| _p: PhantomData, |
| }); |
| <span class="kw">let </span>join = JoinHandle::new(raw); |
| |
| (task, notified, join) |
| } |
| |
| <span class="doccomment">/// Creates a new task with an associated join handle. This method is used |
| /// only when the task is not going to be stored in an `OwnedTasks` list. |
| /// |
| /// Currently only blocking tasks use this method. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>unowned<T, S>(task: T, scheduler: S, id: Id) -> (UnownedTask<S>, JoinHandle<T::Output>) |
| <span class="kw">where |
| </span>S: Schedule, |
| T: Send + Future + <span class="lifetime">'static</span>, |
| T::Output: Send + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span>(task, notified, join) = new_task(task, scheduler, id); |
| |
| <span class="comment">// This transfers the ref-count of task and notified into an UnownedTask. |
| // This is valid because an UnownedTask holds two ref-counts. |
| </span><span class="kw">let </span>unowned = UnownedTask { |
| raw: task.raw, |
| _p: PhantomData, |
| }; |
| std::mem::forget(task); |
| std::mem::forget(notified); |
| |
| (unowned, join) |
| } |
| } |
| |
| <span class="kw">impl</span><S: <span class="lifetime">'static</span>> Task<S> { |
| <span class="kw">unsafe fn </span>from_raw(ptr: NonNull<Header>) -> Task<S> { |
| Task { |
| raw: RawTask::from_raw(ptr), |
| _p: PhantomData, |
| } |
| } |
| |
| <span class="kw">fn </span>header(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>Header { |
| <span class="self">self</span>.raw.header() |
| } |
| |
| <span class="kw">fn </span>header_ptr(<span class="kw-2">&</span><span class="self">self</span>) -> NonNull<Header> { |
| <span class="self">self</span>.raw.header_ptr() |
| } |
| } |
| |
| <span class="kw">impl</span><S: <span class="lifetime">'static</span>> Notified<S> { |
| <span class="kw">fn </span>header(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>Header { |
| <span class="self">self</span>.<span class="number">0</span>.header() |
| } |
| } |
| |
| <span class="macro">cfg_rt_multi_thread! </span>{ |
| <span class="kw">impl</span><S: <span class="lifetime">'static</span>> Notified<S> { |
| <span class="kw">unsafe fn </span>from_raw(ptr: NonNull<Header>) -> Notified<S> { |
| Notified(Task::from_raw(ptr)) |
| } |
| } |
| |
| <span class="kw">impl</span><S: <span class="lifetime">'static</span>> Task<S> { |
| <span class="kw">fn </span>into_raw(<span class="self">self</span>) -> NonNull<Header> { |
| <span class="kw">let </span>ret = <span class="self">self</span>.raw.header_ptr(); |
| mem::forget(<span class="self">self</span>); |
| ret |
| } |
| } |
| |
| <span class="kw">impl</span><S: <span class="lifetime">'static</span>> Notified<S> { |
| <span class="kw">fn </span>into_raw(<span class="self">self</span>) -> NonNull<Header> { |
| <span class="self">self</span>.<span class="number">0</span>.into_raw() |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><S: Schedule> Task<S> { |
| <span class="doccomment">/// Preemptively cancels the task as part of the shutdown process. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>shutdown(<span class="self">self</span>) { |
| <span class="kw">let </span>raw = <span class="self">self</span>.raw; |
| mem::forget(<span class="self">self</span>); |
| raw.shutdown(); |
| } |
| } |
| |
| <span class="kw">impl</span><S: Schedule> LocalNotified<S> { |
| <span class="doccomment">/// Runs the task. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>run(<span class="self">self</span>) { |
| <span class="kw">let </span>raw = <span class="self">self</span>.task.raw; |
| mem::forget(<span class="self">self</span>); |
| raw.poll(); |
| } |
| } |
| |
| <span class="kw">impl</span><S: Schedule> UnownedTask<S> { |
| <span class="comment">// Used in test of the inject queue. |
| </span><span class="attribute">#[cfg(test)] |
| #[cfg_attr(tokio_wasm, allow(dead_code))] |
| </span><span class="kw">pub</span>(<span class="kw">super</span>) <span class="kw">fn </span>into_notified(<span class="self">self</span>) -> Notified<S> { |
| Notified(<span class="self">self</span>.into_task()) |
| } |
| |
| <span class="kw">fn </span>into_task(<span class="self">self</span>) -> Task<S> { |
| <span class="comment">// Convert into a task. |
| </span><span class="kw">let </span>task = Task { |
| raw: <span class="self">self</span>.raw, |
| _p: PhantomData, |
| }; |
| mem::forget(<span class="self">self</span>); |
| |
| <span class="comment">// Drop a ref-count since an UnownedTask holds two. |
| </span>task.header().state.ref_dec(); |
| |
| task |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>run(<span class="self">self</span>) { |
| <span class="kw">let </span>raw = <span class="self">self</span>.raw; |
| mem::forget(<span class="self">self</span>); |
| |
| <span class="comment">// Transfer one ref-count to a Task object. |
| </span><span class="kw">let </span>task = Task::<S> { |
| raw, |
| _p: PhantomData, |
| }; |
| |
| <span class="comment">// Use the other ref-count to poll the task. |
| </span>raw.poll(); |
| <span class="comment">// Decrement our extra ref-count |
| </span>drop(task); |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>shutdown(<span class="self">self</span>) { |
| <span class="self">self</span>.into_task().shutdown() |
| } |
| } |
| |
| <span class="kw">impl</span><S: <span class="lifetime">'static</span>> Drop <span class="kw">for </span>Task<S> { |
| <span class="kw">fn </span>drop(<span class="kw-2">&mut </span><span class="self">self</span>) { |
| <span class="comment">// Decrement the ref count |
| </span><span class="kw">if </span><span class="self">self</span>.header().state.ref_dec() { |
| <span class="comment">// Deallocate if this is the final ref count |
| </span><span class="self">self</span>.raw.dealloc(); |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><S: <span class="lifetime">'static</span>> Drop <span class="kw">for </span>UnownedTask<S> { |
| <span class="kw">fn </span>drop(<span class="kw-2">&mut </span><span class="self">self</span>) { |
| <span class="comment">// Decrement the ref count |
| </span><span class="kw">if </span><span class="self">self</span>.raw.header().state.ref_dec_twice() { |
| <span class="comment">// Deallocate if this is the final ref count |
| </span><span class="self">self</span>.raw.dealloc(); |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><S> fmt::Debug <span class="kw">for </span>Task<S> { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, fmt: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| <span class="macro">write!</span>(fmt, <span class="string">"Task({:p})"</span>, <span class="self">self</span>.header()) |
| } |
| } |
| |
| <span class="kw">impl</span><S> fmt::Debug <span class="kw">for </span>Notified<S> { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, fmt: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| <span class="macro">write!</span>(fmt, <span class="string">"task::Notified({:p})"</span>, <span class="self">self</span>.<span class="number">0</span>.header()) |
| } |
| } |
| |
| <span class="doccomment">/// # Safety |
| /// |
| /// Tasks are pinned. |
| </span><span class="kw">unsafe impl</span><S> linked_list::Link <span class="kw">for </span>Task<S> { |
| <span class="kw">type </span>Handle = Task<S>; |
| <span class="kw">type </span>Target = Header; |
| |
| <span class="kw">fn </span>as_raw(handle: <span class="kw-2">&</span>Task<S>) -> NonNull<Header> { |
| handle.raw.header_ptr() |
| } |
| |
| <span class="kw">unsafe fn </span>from_raw(ptr: NonNull<Header>) -> Task<S> { |
| Task::from_raw(ptr) |
| } |
| |
| <span class="kw">unsafe fn </span>pointers(target: NonNull<Header>) -> NonNull<linked_list::Pointers<Header>> { |
| <span class="self">self</span>::core::Trailer::addr_of_owned(Header::get_trailer(target)) |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../../" data-current-crate="tokio" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
