source: benchmark/readyQ/churn.rs @ 3606fe4

use std::sync::Arc;
use std::sync::atomic::Ordering;
use std::time::Instant;

use tokio::runtime::Builder;
use tokio::sync;
use tokio::time::{sleep,Duration};

use rand::Rng;

use clap::{Arg, App};
use num_format::{Locale, ToFormattedString};

#[path = "../bench.rs"]
mod bench;

// ==================================================
struct Churner {
        start: sync::Notify,
}

async fn churn_main( this: Arc<Churner>, spots: Arc<Vec<sync::Semaphore>>, exp: Arc<bench::BenchData>, skip_in: bool ) -> u64 {
        let mut skip = skip_in;
        this.start.notified().await;

        let mut count:u64 = 0;
        loop {
                let r : usize = rand::thread_rng().gen();

                let spot : &sync::Semaphore = &spots[r % spots.len()];
                if !skip { spot.add_permits(1); }
                spot.acquire().await.forget();
                skip = false;

                count += 1;
                if  exp.clock_mode && exp.stop.load(Ordering::Relaxed) { break; }
                if !exp.clock_mode && count >= exp.stop_count { break; }
        }

        exp.threads_left.fetch_sub(1, Ordering::SeqCst);
        count
}

// ==================================================
fn main() {
        let options = App::new("Churn Tokio")
                .args(&bench::args())
                .arg(Arg::with_name("nspots")  .short("s").long("spots")  .takes_value(true).default_value("1").help("Number of spots in the system"))
                .get_matches();

        let nthreads  = options.value_of("nthreads").unwrap().parse::<usize>().unwrap();
        let nprocs    = options.value_of("nprocs").unwrap().parse::<usize>().unwrap();
        let nspots    = options.value_of("nspots").unwrap().parse::<usize>().unwrap();

        let exp = Arc::new(bench::BenchData::new(options, nthreads, None));

        let s = (1000000 as u64).to_formatted_string(&Locale::en);
        assert_eq!(&s, "1,000,000");

        let spots : Arc<Vec<sync::Semaphore>> = Arc::new((0..nspots).map(|_| {
                sync::Semaphore::new(0)
        }).collect());

        let thddata : Vec<Arc<Churner>> = (0..nthreads).map(|_| {
                Arc::new(Churner{
                        start: sync::Notify::new(),
                })
        }).collect();

        let mut global_counter :u64 = 0;
        let mut duration : std::time::Duration = std::time::Duration::from_secs(0);
        let runtime = Builder::new_multi_thread()
                .worker_threads(nprocs)
                .enable_all()
                .build()
                .unwrap();

        runtime.block_on(async {
                let threads: Vec<_> = (0..nthreads).map(|i| {
                        tokio::spawn(churn_main(thddata[i].clone(), spots.clone(), exp.clone(), i < nspots))
                }).collect();
                println!("Starting");

                sleep(Duration::from_millis(100)).await;

                let start = Instant::now();

                for i in 0..nthreads {
                        thddata[i].start.notify_one();
                }

                duration = exp.wait(&start).await;

                println!("\nDone");

                for i in 0..nspots {
                        spots[i].add_permits(10000);
                }

                for t in threads {
                        let c = t.await.unwrap();
                        global_counter += c;
                }
        });

        println!("Duration (ms)        : {}", (duration.as_millis()).to_formatted_string(&Locale::en));
        println!("Number of processors : {}", (nprocs).to_formatted_string(&Locale::en));
        println!("Number of threads    : {}", (nthreads).to_formatted_string(&Locale::en));
        println!("Number of spots      : {}", "6");
        println!("Total Operations(ops): {:>15}", (global_counter).to_formatted_string(&Locale::en));
        println!("Ops per second       : {:>15}", (((global_counter as f64) / duration.as_secs() as f64) as u64).to_formatted_string(&Locale::en));
        println!("ns per ops           : {:>15}", ((duration.as_nanos() as f64 / global_counter as f64) as u64).to_formatted_string(&Locale::en));
        println!("Ops per threads      : {:>15}", (global_counter / nthreads as u64).to_formatted_string(&Locale::en));
        println!("Ops per procs        : {:>15}", (global_counter / nprocs as u64).to_formatted_string(&Locale::en));
        println!("Ops/sec/procs        : {:>15}", ((((global_counter as f64) / nprocs as f64) / duration.as_secs() as f64) as u64).to_formatted_string(&Locale::en));
        println!("ns per ops/procs     : {:>15}", ((duration.as_nanos() as f64 / (global_counter as f64 / nprocs as f64)) as u64).to_formatted_string(&Locale::en));
}