diff options
| author | Brandon Macer <bobbysox322@gmail.com> | 2021-04-21 08:50:03 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-04-21 14:50:03 +0200 |
| commit | 81be40448777fa338ebced3b0bfc1b32d6370313 (patch) | |
| tree | f93c568a6ffc204e3fdaf5dfd696efcba8ffee6b | |
| parent | 79cc65791715652a7f35a5b7f51309b40033cdb9 (diff) | |
feat(arc1): Add more details to description and hint (#710)
Co-authored-by: bmacer <bmacer@cisco.com>
Co-authored-by: marisa <mokou@fastmail.com>
Co-authored-by: Roberto Vidal <vidal.roberto.j@gmail.com>
| -rw-r--r-- | exercises/standard_library_types/arc1.rs | 19 | ||||
| -rw-r--r-- | info.toml | 7 |
2 files changed, 23 insertions, 3 deletions
diff --git a/exercises/standard_library_types/arc1.rs b/exercises/standard_library_types/arc1.rs index 4ad649f..d167380 100644 --- a/exercises/standard_library_types/arc1.rs +++ b/exercises/standard_library_types/arc1.rs @@ -1,7 +1,21 @@ // arc1.rs +// In this exercise, we are given a Vec of u32 called "numbers" with values ranging +// from 0 to 99 -- [ 0, 1, 2, ..., 98, 99 ] +// We would like to use this set of numbers within 8 different threads simultaneously. +// Each thread is going to get the sum of every eighth value, with an offset. +// The first thread (offset 0), will sum 0, 8, 16, ... +// The second thread (offset 1), will sum 1, 9, 17, ... +// The third thread (offset 2), will sum 2, 10, 18, ... +// ... +// The eighth thread (offset 7), will sum 7, 15, 23, ... + +// Because we are using threads, our values need to be thread-safe. Therefore, +// we are using Arc. We need to make a change in each of the two TODOs. + + // Make this code compile by filling in a value for `shared_numbers` where the -// TODO comment is and create an initial binding for `child_numbers` -// somewhere. Try not to create any copies of the `numbers` Vec! +// first TODO comment is, and create an initial binding for `child_numbers` +// where the second TODO comment is. Try not to create any copies of the `numbers` Vec! // Execute `rustlings hint arc1` for hints :) // I AM NOT DONE @@ -16,6 +30,7 @@ fn main() { let mut joinhandles = Vec::new(); for offset in 0..8 { + let child_numbers = // TODO joinhandles.push(thread::spawn(move || { let mut i = offset; let mut sum = 0; @@ -679,7 +679,12 @@ to avoid creating a copy of `numbers`, you'll need to create `child_numbers` inside the loop but still in the main thread. `child_numbers` should be a clone of the Arc of the numbers instead of a -thread-local copy of the numbers.""" +thread-local copy of the numbers. + +This is a simple exercise if you understand the underlying concepts, but if this +is too much of a struggle, consider reading through all of Chapter 16 in the book: +https://doc.rust-lang.org/stable/book/ch16-00-concurrency.html +""" [[exercises]] name = "iterators1" |