Function accum_using_channel

src/core/array.rs:1092–1151

()

    #[test]
    fn accum_using_channel() {
        // ANCHOR: accum_using_channel
        let ops: Vec<_> = vec![Op::Add, Op::Sub, Op::Div, Op::Mul, Op::Add, Op::Div];
        let ops_len: usize = ops.len();

        // Set active GPU/device on main thread on which
        // subsequent Array objects are created
        set_device(0);

        let mut c = constant(0.0f32, dim4!(3, 3));
        let a = constant(1.0f32, dim4!(3, 3));
        let b = constant(2.0f32, dim4!(3, 3));

        let (tx, rx) = mpsc::channel();

        let threads: Vec<_> = ops
            .into_iter()
            .map(|op| {
                // a and b are internally reference counted by ArrayFire. Unless there
                // is prior known need that they may be modified, you can simply clone
                // the objects pass them to threads
                let x = a.clone();
                let y = b.clone();

                let tx_clone = tx.clone();

                thread::spawn(move || {
                    //Both of objects are created on device 0 in main thread
                    //Every thread needs to set the device that it is going to
                    //work on. Note that all Array objects must have been created
                    //on same device as of date this is written on.
                    set_device(0);

                    let c = match op {
                        Op::Add => x + y,
                        Op::Sub => x - y,
                        Op::Div => x / y,
                        Op::Mul => x * y,
                    };
                    tx_clone.send(c).unwrap();
                })
            })
            .collect();

        for _i in 0..ops_len {
            c += rx.recv().unwrap();
        }

        //Need to join other threads as main thread holds arrayfire context
        for child in threads {
            let _ = child.join();
        }

        //af_print!("C after accumulating results", &c);
        //[3 3 1 1]
        //    8.0000     8.0000     8.0000
        //    8.0000     8.0000     8.0000
        //    8.0000     8.0000     8.0000