use crate::{BackgroundExecutor, Task};use std::{    future::Future,    pin::Pin,    sync::atomic::{AtomicUsize, Ordering::SeqCst},    task,    time::Duration,}; pub use util::*; /// A helper trait for building complex objects with imperative conditionals in a fluent style.pub trait FluentBuilder {    /// Imperatively modify self with the given closure.    fn map<U>(self, f: impl FnOnce(Self) -> U) -> U    where        Self: Sized,    {        f(self)    }     /// Conditionally modify self with the given closure.    fn when(self, condition: bool, then: impl FnOnce(Self) -> Self) -> Self    where        Self: Sized,    {        self.map(|this| if condition { then(this) } else { this })    }     /// Conditionally modify self with the given closure.    fn when_else(        self,        condition: bool,        then: impl FnOnce(Self) -> Self,        else_fn: impl FnOnce(Self) -> Self,    ) -> Self    where        Self: Sized,    {        self.map(|this| if condition { then(this) } else { else_fn(this) })    }     /// Conditionally unwrap and modify self with the given closure, if the given option is Some.    fn when_some<T>(self, option: Option<T>, then: impl FnOnce(Self, T) -> Self) -> Self    where        Self: Sized,    {        self.map(|this| {            if let Some(value) = option {                then(this, value)            } else {                this            }        })    }    /// Conditionally unwrap and modify self with the given closure, if the given option is None.    fn when_none<T>(self, option: &Option<T>, then: impl FnOnce(Self) -> Self) -> Self    where        Self: Sized,    {        self.map(|this| if option.is_some() { this } else { then(this) })    }} /// Extensions for Future types that provide additional combinators and utilities.pub trait FutureExt {    /// Requires a Future to complete before the specified duration has elapsed.    /// Similar to tokio::timeout.    fn with_timeout(self, timeout: Duration, executor: &BackgroundExecutor) -> WithTimeout<Self>    where        Self: Sized;} impl<T: Future> FutureExt for T {    fn with_timeout(self, timeout: Duration, executor: &BackgroundExecutor) -> WithTimeout<Self>    where        Self: Sized,    {        WithTimeout {            future: self,            timer: executor.timer(timeout),        }    }} #[pin_project::pin_project]pub struct WithTimeout<T> {    #[pin]    future: T,    #[pin]    timer: Task<()>,} #[derive(Debug, thiserror::Error)]#[error("Timed out before future resolved")]/// Error returned by with_timeout when the timeout duration elapsed before the future resolvedpub struct Timeout; impl<T: Future> Future for WithTimeout<T> {    type Output = Result<T::Output, Timeout>;     fn poll(self: Pin<&mut Self>, cx: &mut task::Context) -> task::Poll<Self::Output> {        let this = self.project();         if let task::Poll::Ready(output) = this.future.poll(cx) {            task::Poll::Ready(Ok(output))        } else if this.timer.poll(cx).is_ready() {            task::Poll::Ready(Err(Timeout))        } else {            task::Poll::Pending        }    }} /// Increment the given atomic counter if it is not zero./// Return the new value of the counter.pub(crate) fn atomic_incr_if_not_zero(counter: &AtomicUsize) -> usize {    let mut loaded = counter.load(SeqCst);    loop {        if loaded == 0 {            return 0;        }        match counter.compare_exchange_weak(loaded, loaded + 1, SeqCst, SeqCst) {            Ok(x) => return x + 1,            Err(actual) => loaded = actual,        }    }} #[cfg(test)]mod tests {    use crate::TestAppContext;     use super::*;     #[gpui::test]    async fn test_with_timeout(cx: &mut TestAppContext) {        Task::ready(())            .with_timeout(Duration::from_secs(1), &cx.executor())            .await            .expect("Timeout should be noop");         let long_duration = Duration::from_secs(6000);        let short_duration = Duration::from_secs(1);        cx.executor()            .timer(long_duration)            .with_timeout(short_duration, &cx.executor())            .await            .expect_err("timeout should have triggered");         let fut = cx            .executor()            .timer(long_duration)            .with_timeout(short_duration, &cx.executor());        cx.executor().advance_clock(short_duration * 2);        futures::FutureExt::now_or_never(fut)            .unwrap_or_else(|| panic!("timeout should have triggered"))            .expect_err("timeout");    }}