# rpools

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A minimalist rust workerpool implementation that uses channels to synchronize the jobs. It can spawn a fixed number of worker threads, that waits for a job queue.

## Install

```
$ cargo add rpools
``` 

## Usage

* **A simple workerpool**
```rust
 use rpools::pool::WorkerPool;
 use std::sync::mpsc::channel;
 use std::sync::{Arc, Mutex};

 let n_workers = 4;
 let n_jobs = 8;
 let pool = WorkerPool::new(n_workers);

 let (tx, rx) = channel();
 let atx = Arc::new(Mutex::new(tx));
 for _ in 0..n_jobs {
     let atx = atx.clone();
     pool.execute(move|| {
         let tx = atx.lock().unwrap();

            // a long task goes here
            // send results to channel (use it to sync the pool with the parent thread)

         tx.send(1).expect("channel will be there waiting for the pool");
     });
 }

 assert_eq!(rx.iter().take(n_jobs).fold(0, |a, b| a + b), 8);
```

* **Use sync module to synchronize your pool**

```rust
let njobs = 20;
let nworkers = 3;
let pool = pool::WorkerPool::new(nworkers);
let atomic = Arc::new(AtomicUsize::new(0));
let wg = WaitGroup::default();

// send the jobs to the pool
for _ in 0..njobs {
    let wg = wg.clone();
    let atomic = atomic.clone();
    pool.execute(move || {
        atomic.fetch_add(1, Ordering::Relaxed);
        drop(wg);
    });
}

// wait for the pool finnishes
wg.wait();
assert_eq!(njobs, atomic.load(Ordering::Relaxed));
```