46 lines
1.5 KiB
Rust
46 lines
1.5 KiB
Rust
// In this exercise, we are given a `Vec` of `u32` called `numbers` with values
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// ranging from 0 to 99. We would like to use this set of numbers within 8
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// different threads simultaneously. Each thread is going to get the sum of
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// every eighth value with an offset.
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//
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// The first thread (offset 0), will sum 0, 8, 16, …
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// The second thread (offset 1), will sum 1, 9, 17, …
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// The third thread (offset 2), will sum 2, 10, 18, …
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// …
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// The eighth thread (offset 7), will sum 7, 15, 23, …
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//
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// Each thread should own a reference-counting pointer to the vector of
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// numbers. But `Rc` isn't thread-safe. Therefore, we need to use `Arc`.
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//
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// Don't get distracted by how threads are spawned and joined. We will practice
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// that later in the exercises about threads.
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// Don't change the lines below.
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#![forbid(unused_imports)]
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use std::{sync::Arc, thread};
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fn main() {
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let numbers: Vec<_> = (0..100u32).collect();
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// TODO: Define `shared_numbers` by using `Arc`.
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// let shared_numbers = ???;
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let mut join_handles = Vec::new();
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for offset in 0..8 {
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// TODO: Define `child_numbers` using `shared_numbers`.
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// let child_numbers = ???;
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let handle = thread::spawn(move || {
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let sum: u32 = child_numbers.iter().filter(|&&n| n % 8 == offset).sum();
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println!("Sum of offset {offset} is {sum}");
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});
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join_handles.push(handle);
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}
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for handle in join_handles.into_iter() {
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handle.join().unwrap();
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}
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}
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