threads1: use more threads, model more reference counting

- Switch from a single additional thread (receiving/holding a single `Arc::clone` reference) running a loop modeling 10 sequential jobs, to a loop generating 10 threads each modeling 1 job (each getting their own `Arc::clone` reference)
- use the previously ignored `for` loop var to keep the execution timing approx the same
- Print a more descriptive waiting message (taking an opportunity to use comment to disambiguate the count)
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Donald Guy 2021-05-04 18:49:13 -04:00 committed by GitHub
parent 7cd635fa84
commit 791120c0c1
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@ -1,10 +1,7 @@
// threads1.rs
// Make this compile! Execute `rustlings hint threads1` for hints :)
// The idea is the thread spawned on line 22 is completing jobs while the main thread is
// monitoring progress until 10 jobs are completed. Because of the difference between the
// spawned threads' sleep time, and the waiting threads sleep time, when you see 6 lines
// of "waiting..." and the program ends without timing out when running,
// you've got it :)
// The idea is the threads spawned on line 22 are completing jobs while the main thread is
// monitoring progress until 10 jobs are completed.
// I AM NOT DONE
@ -18,15 +15,18 @@ struct JobStatus {
fn main() {
let status = Arc::new(JobStatus { jobs_completed: 0 });
let status_shared = status.clone();
thread::spawn(move || {
for _ in 0..10 {
thread::sleep(Duration::from_millis(250));
status_shared.jobs_completed += 1;
}
});
for i in 0..10 {
let status_ref = Arc::clone(&status);
thread::spawn(move || {
thread::sleep(Duration::from_millis(250 * i));
status_ref.jobs_completed += 1;
});
}
while status.jobs_completed < 10 {
println!("waiting... ");
println!("waiting for {} jobs ({} jobs running)... ",
(10 - status.jobs_completed),
(Arc::strong_count(&status) - 1) // subtract one for refrence in _this_ thread
);
thread::sleep(Duration::from_millis(500));
}
}