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46 lines
1.6 KiB
Rust
46 lines
1.6 KiB
Rust
// arc1.rs
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//
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// In this exercise, we are given a Vec of u32 called "numbers" with values
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// ranging from 0 to 99 -- [ 0, 1, 2, ..., 98, 99 ] We would like to use this
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// set of numbers within 8 different threads simultaneously. Each thread is
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// going to get the sum of 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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// Because we are using threads, our values need to be thread-safe. Therefore,
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// we are using Arc. We need to make a change in each of the two TODOs.
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//
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// Make this code compile by filling in a value for `shared_numbers` where the
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// first TODO comment is, and create an initial binding for `child_numbers`
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// where the second TODO comment is. Try not to create any copies of the
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// `numbers` Vec!
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//
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// Execute `rustlings hint arc1` or use the `hint` watch subcommand for a hint.
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// I AM NOT DONE
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#![forbid(unused_imports)] // Do not change this, (or the next) line.
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use std::sync::Arc;
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use std::thread;
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fn main() {
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let numbers: Vec<_> = (0..100u32).collect();
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let shared_numbers = // TODO
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let mut joinhandles = Vec::new();
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for offset in 0..8 {
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let child_numbers = // TODO
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joinhandles.push(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 {} is {}", offset, sum);
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}));
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}
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for handle in joinhandles.into_iter() {
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handle.join().unwrap();
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}
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}
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