37 lines
860 B
Rust
37 lines
860 B
Rust
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use std::cell::{Ref, RefCell};
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use std::thread::{spawn, JoinHandle};
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pub struct Future<T: Send + 'static> {
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thread: RefCell<Option<JoinHandle<T>>>,
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data: RefCell<Option<T>>,
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}
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impl<T: Send + 'static> Future<T> {
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pub fn new<F>(f: F) -> Future<T>
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where
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F: Fn() -> T,
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F: Send + 'static,
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{
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let thread = spawn(f);
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Future {
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thread: RefCell::new(Some(thread)),
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data: RefCell::new(None),
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}
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}
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pub fn data(&self) -> Ref<'_, Option<T>> {
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let mut thread_opt = self.thread.borrow_mut();
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if thread_opt.is_some() {
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let thread_tmp = thread_opt.take();
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let thread = thread_tmp.unwrap();
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if let Ok(data) = thread.join() {
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self.data.replace(Some(data));
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}
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}
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self.data.borrow()
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}
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}
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