How can I implement a blocking queue mechanism with futures::sync::mpsc::channel?










1














I am trying to understand how futures::sync::mpsc::Receiver works. In the below example, the receiver thread sleeps for two seconds and the sender sends every second.



I expect that the sender will need to be blocked because of the wait and then send when the buffer is released.



What I see instead is that it is deadlocked after a time. Increasing the buffer of the channel only extends the time until it is blocked.



What should I do to make the sender send data when the buffer is available and put some backpressure to the sender in such cases? futures::sync::mpsc::channel has its own documentation, but I do not understand how to use it properly.



extern crate futures;
extern crate tokio_core;

use std::thread, time;

use futures::sync::mpsc;
use futures::Future, Sink, Stream;

use tokio_core::reactor::Core;

#[derive(Debug)]
struct Stats
pub success: usize,
pub failure: usize,


fn main()
let mut core = Core::new().expect("Failed to create core");
let remote = core.remote();

let (tx, rx) = mpsc::channel(1);

thread::spawn(move









share|improve this question























  • Where does futures::done come from? It's not a part of the current version of the futures crate.
    – Shepmaster
    Nov 13 at 3:05















1














I am trying to understand how futures::sync::mpsc::Receiver works. In the below example, the receiver thread sleeps for two seconds and the sender sends every second.



I expect that the sender will need to be blocked because of the wait and then send when the buffer is released.



What I see instead is that it is deadlocked after a time. Increasing the buffer of the channel only extends the time until it is blocked.



What should I do to make the sender send data when the buffer is available and put some backpressure to the sender in such cases? futures::sync::mpsc::channel has its own documentation, but I do not understand how to use it properly.



extern crate futures;
extern crate tokio_core;

use std::thread, time;

use futures::sync::mpsc;
use futures::Future, Sink, Stream;

use tokio_core::reactor::Core;

#[derive(Debug)]
struct Stats
pub success: usize,
pub failure: usize,


fn main()
let mut core = Core::new().expect("Failed to create core");
let remote = core.remote();

let (tx, rx) = mpsc::channel(1);

thread::spawn(move









share|improve this question























  • Where does futures::done come from? It's not a part of the current version of the futures crate.
    – Shepmaster
    Nov 13 at 3:05













1












1








1







I am trying to understand how futures::sync::mpsc::Receiver works. In the below example, the receiver thread sleeps for two seconds and the sender sends every second.



I expect that the sender will need to be blocked because of the wait and then send when the buffer is released.



What I see instead is that it is deadlocked after a time. Increasing the buffer of the channel only extends the time until it is blocked.



What should I do to make the sender send data when the buffer is available and put some backpressure to the sender in such cases? futures::sync::mpsc::channel has its own documentation, but I do not understand how to use it properly.



extern crate futures;
extern crate tokio_core;

use std::thread, time;

use futures::sync::mpsc;
use futures::Future, Sink, Stream;

use tokio_core::reactor::Core;

#[derive(Debug)]
struct Stats
pub success: usize,
pub failure: usize,


fn main()
let mut core = Core::new().expect("Failed to create core");
let remote = core.remote();

let (tx, rx) = mpsc::channel(1);

thread::spawn(move









share|improve this question















I am trying to understand how futures::sync::mpsc::Receiver works. In the below example, the receiver thread sleeps for two seconds and the sender sends every second.



I expect that the sender will need to be blocked because of the wait and then send when the buffer is released.



What I see instead is that it is deadlocked after a time. Increasing the buffer of the channel only extends the time until it is blocked.



What should I do to make the sender send data when the buffer is available and put some backpressure to the sender in such cases? futures::sync::mpsc::channel has its own documentation, but I do not understand how to use it properly.



extern crate futures;
extern crate tokio_core;

use std::thread, time;

use futures::sync::mpsc;
use futures::Future, Sink, Stream;

use tokio_core::reactor::Core;

#[derive(Debug)]
struct Stats
pub success: usize,
pub failure: usize,


fn main()
let mut core = Core::new().expect("Failed to create core");
let remote = core.remote();

let (tx, rx) = mpsc::channel(1);

thread::spawn(move






rust future rust-tokio






share|improve this question















share|improve this question













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edited Nov 13 at 3:04









Shepmaster

147k12282416




147k12282416










asked Nov 12 at 14:11









Akiner Alkan

560215




560215











  • Where does futures::done come from? It's not a part of the current version of the futures crate.
    – Shepmaster
    Nov 13 at 3:05
















  • Where does futures::done come from? It's not a part of the current version of the futures crate.
    – Shepmaster
    Nov 13 at 3:05















Where does futures::done come from? It's not a part of the current version of the futures crate.
– Shepmaster
Nov 13 at 3:05




Where does futures::done come from? It's not a part of the current version of the futures crate.
– Shepmaster
Nov 13 at 3:05












1 Answer
1






active

oldest

votes


















2














  1. Never call wait inside of a future. That's blocking, and blocking should never be done inside a future.


  2. Never call sleep inside of a future. That's blocking, and blocking should never be done inside a future.


  3. Channel backpressure is implemented by the fact that send consumes the Sender and returns a future. The future yields the Sender back to you when there is room in the queue.


extern crate futures; // 0.1.25
extern crate tokio; // 0.1.11

use futures::future, sync::mpsc, Future, Sink, Stream;
use std::time::Duration;
use tokio::timer::Interval;

#[derive(Debug)]
struct Stats
pub success: usize,
pub failure: usize,


fn main()
tokio::run(future::lazy(





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    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    2














    1. Never call wait inside of a future. That's blocking, and blocking should never be done inside a future.


    2. Never call sleep inside of a future. That's blocking, and blocking should never be done inside a future.


    3. Channel backpressure is implemented by the fact that send consumes the Sender and returns a future. The future yields the Sender back to you when there is room in the queue.


    extern crate futures; // 0.1.25
    extern crate tokio; // 0.1.11

    use futures::future, sync::mpsc, Future, Sink, Stream;
    use std::time::Duration;
    use tokio::timer::Interval;

    #[derive(Debug)]
    struct Stats
    pub success: usize,
    pub failure: usize,


    fn main()
    tokio::run(future::lazy(





    share|improve this answer

























      2














      1. Never call wait inside of a future. That's blocking, and blocking should never be done inside a future.


      2. Never call sleep inside of a future. That's blocking, and blocking should never be done inside a future.


      3. Channel backpressure is implemented by the fact that send consumes the Sender and returns a future. The future yields the Sender back to you when there is room in the queue.


      extern crate futures; // 0.1.25
      extern crate tokio; // 0.1.11

      use futures::future, sync::mpsc, Future, Sink, Stream;
      use std::time::Duration;
      use tokio::timer::Interval;

      #[derive(Debug)]
      struct Stats
      pub success: usize,
      pub failure: usize,


      fn main()
      tokio::run(future::lazy(





      share|improve this answer























        2












        2








        2






        1. Never call wait inside of a future. That's blocking, and blocking should never be done inside a future.


        2. Never call sleep inside of a future. That's blocking, and blocking should never be done inside a future.


        3. Channel backpressure is implemented by the fact that send consumes the Sender and returns a future. The future yields the Sender back to you when there is room in the queue.


        extern crate futures; // 0.1.25
        extern crate tokio; // 0.1.11

        use futures::future, sync::mpsc, Future, Sink, Stream;
        use std::time::Duration;
        use tokio::timer::Interval;

        #[derive(Debug)]
        struct Stats
        pub success: usize,
        pub failure: usize,


        fn main()
        tokio::run(future::lazy(





        share|improve this answer












        1. Never call wait inside of a future. That's blocking, and blocking should never be done inside a future.


        2. Never call sleep inside of a future. That's blocking, and blocking should never be done inside a future.


        3. Channel backpressure is implemented by the fact that send consumes the Sender and returns a future. The future yields the Sender back to you when there is room in the queue.


        extern crate futures; // 0.1.25
        extern crate tokio; // 0.1.11

        use futures::future, sync::mpsc, Future, Sink, Stream;
        use std::time::Duration;
        use tokio::timer::Interval;

        #[derive(Debug)]
        struct Stats
        pub success: usize,
        pub failure: usize,


        fn main()
        tokio::run(future::lazy(






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 13 at 3:30









        Shepmaster

        147k12282416




        147k12282416



























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