mirror of
https://github.com/notohh/rustlings.git
synced 2024-12-23 11:48:09 -05:00
41 lines
1.2 KiB
Rust
41 lines
1.2 KiB
Rust
// Building on the last exercise, we want all of the threads to complete their
|
|
// work. But this time, the spawned threads need to be in charge of updating a
|
|
// shared value: `JobStatus.jobs_done`
|
|
|
|
use std::{
|
|
sync::{Arc, Mutex},
|
|
thread,
|
|
time::Duration,
|
|
};
|
|
|
|
struct JobStatus {
|
|
jobs_done: u32,
|
|
}
|
|
|
|
fn main() {
|
|
// `Arc` isn't enough if you want a **mutable** shared state.
|
|
// We need to wrap the value with a `Mutex`.
|
|
let status = Arc::new(Mutex::new(JobStatus { jobs_done: 0 }));
|
|
// ^^^^^^^^^^^ ^
|
|
|
|
let mut handles = Vec::new();
|
|
for _ in 0..10 {
|
|
let status_shared = Arc::clone(&status);
|
|
let handle = thread::spawn(move || {
|
|
thread::sleep(Duration::from_millis(250));
|
|
|
|
// Lock before you update a shared value.
|
|
status_shared.lock().unwrap().jobs_done += 1;
|
|
// ^^^^^^^^^^^^^^^^
|
|
});
|
|
handles.push(handle);
|
|
}
|
|
|
|
// Waiting for all jobs to complete.
|
|
for handle in handles {
|
|
handle.join().unwrap();
|
|
}
|
|
|
|
println!("Jobs done: {}", status.lock().unwrap().jobs_done);
|
|
// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
}
|