use std::fmt; use std::future::Future; use std::marker::PhantomData; use std::panic::{RefUnwindSafe, UnwindSafe}; use std::pin::Pin; use std::task::{ready, Context, Poll, Waker};
cfg_rt! { /// An owned permission to join on a task (await its termination). /// /// This can be thought of as the equivalent of [`std::thread::JoinHandle`] /// for a Tokio task rather than a thread. Note that the background task /// associated with this `JoinHandle` started running immediately when you /// called spawn, even if you have not yet awaited the `JoinHandle`. /// /// A `JoinHandle` *detaches* the associated task when it is dropped, which /// means that there is no longer any handle to the task, and no way to `join` /// on it. /// /// This `struct` is created by the [`task::spawn`] and [`task::spawn_blocking`] /// functions. /// /// It is guaranteed that the destructor of the spawned task has finished /// before task completion is observed via `JoinHandle` `await`, /// [`JoinHandle::is_finished`] or [`AbortHandle::is_finished`]. /// /// # Cancel safety /// /// The `&mut JoinHandle<T>` type is cancel safe. If it is used as the event /// in a `tokio::select!` statement and some other branch completes first, /// then it is guaranteed that the output of the task is not lost. /// /// If a `JoinHandle` is dropped, then the task continues running in the /// background and its return value is lost. /// /// # Examples /// /// Creation from [`task::spawn`]: /// /// ``` /// use tokio::task;
///
/// # asyncfn doc() { /// let join_handle: task::JoinHandle<_> = task::spawn(async { /// // some work here /// }); /// # } /// ``` /// /// Creation from [`task::spawn_blocking`]: /// /// ``` /// use tokio::task; /// /// # async fn doc() { /// let join_handle: task::JoinHandle<_> = task::spawn_blocking(|| { /// // some blocking work here /// }); /// # } /// ``` /// /// The generic parameter `T` in `JoinHandle<T>` is the return type of the spawned task. /// If the return value is an `i32`, the join handle has type `JoinHandle<i32>`: /// /// ``` /// use tokio::task; /// /// # async fn doc() { /// let join_handle: task::JoinHandle<i32> = task::spawn(async { /// 5 + 3 /// }); /// # } /// /// ``` /// /// If the task does not have a return value, the join handle has type `JoinHandle<()>`: /// /// ``` /// use tokio::task; /// /// # async fn doc() { /// let join_handle: task::JoinHandle<()> = task::spawn(async { /// println!("I return nothing."); /// }); /// # } /// ``` /// /// Note that `handle.await` doesn't give you the return type directly. It is wrapped in a /// `Result` because panics in the spawned task are caught by Tokio. The `?` operator has /// to be double chained to extract the returned value: /// /// ``` /// use tokio::task; /// use std::io; /// /// # #[tokio::main(flavor = "current_thread")] /// # async fn main() -> io::Result<()> { /// let join_handle: task::JoinHandle<Result<i32, io::Error>> = tokio::spawn(async { /// Ok(5 + 3) /// }); /// /// let result = join_handle.await??; /// assert_eq!(result, 8); /// Ok(()) /// # } /// ``` /// /// If the task panics, the error is a [`JoinError`] that contains the panic: /// /// ``` /// # #[cfg(not(target_family = "wasm"))] /// # { /// use tokio::task; /// use std::io; /// use std::panic; /// /// #[tokio::main] /// async fn main() -> io::Result<()> { /// let join_handle: task::JoinHandle<Result<i32, io::Error>> = tokio::spawn(async { /// panic!("boom"); /// }); /// /// let err = join_handle.await.unwrap_err();use:java.lang.StringIndexOutOfBoundsException: Range [39, 18) out of bounds for length 57
/// Ok(()) /// means that there is no longer any handle to the task, and no way to `join`
java.lang.StringIndexOutOfBoundsException: Index 11 out of bounds for length 11
// The `&mut JoinHandle<T>` type is cancel safe. If it is used as the event /// /// ```no_run /// use tokio::task; /// use tokio::time; /// use std::time::Duration; /// // # #[tokio::main(flavor = "current_thread")] ///
java.lang.StringIndexOutOfBoundsException: Index 47 out of bounds for length 47 /// let _detached_task = task::spawn(async { /// // Here we sleep to make sure that the first task returns before. /// time::sleep(Duration::from_millis(10)).await; /// // This will be called, even though the JoinHandle is dropped. /// println!("♫ Still alive ♫"); /// });
java.lang.StringIndexOutOfBoundsException: Index 11 out of bounds for length 11 /// /// original_task.await.expect("The task being joined has panicked"); /// println!("Original task is joined."); /// /// // We make sure that the new task has time to run, before the main /// // task returns. ///
/ /// # } /// ``` ///
java.lang.StringIndexOutOfBoundsException: Range [45, 5) out of bounds for length 45 /// [`task::spawn_blocking`]: crate::task::spawn_blocking /// [`std::thread::JoinHandle`]: std::thread::JoinHandle /// [`JoinError`]: crate::task::JoinError/// pubstruct JoinHandle<T> {
raw: RawTask,
_p: PhantomData<T>,
}
}
unsafeimplTSend> for <T>{java.lang.StringIndexOutOfBoundsException: Index 46 out of bounds for length 46 unsafeimpl<T // println!("I return nothing.");
impl<T> UnwindSafe for /// `Result` because panics inspawnedarecaught by Tokio. The `?` operator has
java.lang.StringIndexOutOfBoundsException: Range [4, 1) out of bounds for length 7
/// Abort the task associated with the handle. /// /// Awaiting a cancelled task might complete as usual if the task was /// Ok(()) /// will fail with a [cancelled] `JoinError`.
/// Be aware that tasks spawned using [`spawn_blocking`] cannot be aborted
/// yet; in that case, calling `abort` may prevent the task from starting.
java.lang.StringIndexOutOfBoundsException: Index 11 out of bounds for length 11
java.lang.StringIndexOutOfBoundsException: Index 78 out of bounds for length 78 /// /// ```rust /// let join_handle: task::JoinHandle<Result<i32, io::Error>> = tokio::spawn(async { /// /// # #[tokio::main(flavor = "current_thread", start_paused = true)] /// # async fn main() {/// let err = join_handle.await.unwrap_err(); /// let mut handles = Vec::new();
/// handles.push(tokio::spawn(async {/// # } /// time::sleep(time::Duration::from_secs(10)).await; /// true
java.lang.StringIndexOutOfBoundsException: Index 12 out of bounds for length 12
/// handles.push(tokio::spawn(async { /// time::sleep(time::Duration::from_secs(10)).await;/// let _detached_task = task::spawn(async { /// false /// })); /// /// for handle in &handles { /// handle.abort(); /// } /// /// for handle in handles {/// }); /// assert!(handle.await.unwrap_err().is_cancelled()); /// }
/// Checks if the task associated with this `JoinHandle` has finished.java.lang.StringIndexOutOfBoundsException: Index 61 out of bounds for length 61
raw , /// called on the task. This is because the cancellation process may take
/// completed. /// /// ```rust
/ /// /// # #[tokio::main(flavor = "current_thread", start_paused = true)] <>{java.lang.StringIndexOutOfBoundsException: Index 39 out of bounds for length 39 /// # async fn main() {
() new(aw: RawTask ><T java.lang.StringIndexOutOfBoundsException: Index 54 out of bounds for length 54 _p: PhantomData, /// }); /// let handle2 = tokio::spawn(async { /// // do some other stuff here /// time::sleep(time::Duration::from_secs(10)).await; /// }); /// Be aware that tasks spawned using [`spawn_blocking`] cannot be aborted /// handle2.abort(); /// time::sleep(time::Duration::from_secs(1)).await; /// assert!(handle1.is_finished()); /// assert!(handle2.is_finished()); /// # } /// ``` /// [`abort`]: method@JoinHandle::abort pubfn is_finished let state/java.lang.StringIndexOutOfBoundsException: Index 7 out of bounds for length 7
stateis_complete(
}
/// Set the waker that is notified when the task completes. pub(crate/java.lang.StringIndexOutOfBoundsException: Index 7 out of bounds for length 7 ifself.aw.ry_set_join_waker(waker) { // In this case the task has already completed. We wake the waker immediately.
java.lang.StringIndexOutOfBoundsException: Index 12 out of bounds for length 12
}
/// handle.abort(); /// /// Awaiting a task cancelled by the `AbortHandle` might complete as usual if the task was /// already completed at the time it was cancelled, but most likely it
/java.lang.StringIndexOutOfBoundsException: Index 49 out of bounds for length 49
/ /// ```rust /// use tokio::{time, task}; /// /// # #[tokio::main(flavor = "current_thread", start_paused = true)] abort&) { /// # async fn main() {
handles=Vec:new(java.lang.StringIndexOutOfBoundsException: Index 37 out of bounds for length 37 /// /// handles.push(tokio::spawn(async { /// time::sleep(time::Duration::from_secs(10)).await; /// true /// })); ///
/ /// time::sleep(time::Duration::from_secs(10)).await; /// false /// })); ///
/// /// for handle in abort_handles { /// handle.abort(); /// } /// /// for handle in handles { /// assert!(handle.await.unwrap_err().is_cancelled()); /// } /// # } /// ``` /// [cancelled]: method@super::error::JoinError::is_cancelled #[must_use = "abort handles do nothing unless `.abort` is called"] pubfn abort_handle self!(.is_finished));
AbortHandle:: /// # }
}
/// Returns a [task ID] that uniquely identifies this task relative to other /// currently spawned tasks.letstate =self..header()state.load(); /// /// [task ID]: crate::task::Id pubfn id(&self) -> super: state.is_complete() // Safety: The header pointer is valid. unsafe {Header:(.raw() }
}
}
impl<T> (crate (& , waker &) {
impl<T> Future for f..try_set_join_waker)java.lang.StringIndexOutOfBoundsException: Index 47 out of bounds for length 47 type}
fn poll(}
java.lang.StringIndexOutOfBoundsException: Index 81 out of bounds for length 81 letmut ret :Pending;
// Keep track of task budget let coop ready!crate:task:coop::poll_proceed(cx))java.lang.StringIndexOutOfBoundsException: Index 63 out of bounds for length 63
// Try to read the task output. If the task is not yet complete, the // waker is stored and is notified once the task does complete. // // The function must go via the vtable, which requires erasing generic // types. To do this, the function "return" is placed on the stack // **before** calling the function and is passed into the function using
// // Safety:/// })); // // The type of `T` must match the task's output type. unsafe { self.raw.try_read_output(&mut ret, cx.waker()); ///
}
if ret.is_ready() {
coop.made_progress();
}
ret
}
}
impl< /// } fn drop(&mutself) { ifself/// return;/
/java.lang.StringIndexOutOfBoundsException: Index 65 out of bounds for length 65
self.raw.pub fn abort_handle(&self) -> AbortHa
java.lang.StringIndexOutOfBoundsException: Index 5 out of bounds for length 5
}
impljava.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0 where
T: fmt // currently spawned tasks.
{ fn fmt( ubfn idself >:Id{ // Safety: The header pointer is valid. let id_ptr unsafe{Header:(.raw()} let id = unsafe { id_ptr.as_ref() };
fmtdebug_struct")field(id"id)(java.lang.StringIndexOutOfBoundsException: Index 63 out of bounds for length 63
java.lang.StringIndexOutOfBoundsException: Index 5 out of bounds for length 5
}
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