simulation

Scheduling and Time

use simulation::{Environment};#[test]fnordering(){letmut runtime =DeterministicRuntime::new().unwrap();let handle = runtime.localhost_handle();       runtime.block_on(async{let delay1 = handle.delay_from(Duration::from_secs(10));let delay2 = handle.delay_from(Duration::from_secs(30));let handle1 = handle.clone();let completed_at1 =crate::spawn_with_result(&handle1.clone(),asyncmove{               delay1.await;               handle1.now()}).await;let handle2 = handle.clone();let completed_at2 =crate::spawn_with_result(&handle2.clone(),asyncmove{               delay2.await;               handle2.now()}).await;assert!(completed_at1 < completed_at2)});}

Network

Faults

Example

use simulation::{Environment,TcpListener};use futures::{SinkExt,StreamExt};use std::{io, net, time};use tokio::codec::{Framed,LinesCodec};/// Start a client request handler which will write greetings to clients.asyncfnhandle<E>(env:E,socket: <E::TcpListenerasTcpListener>::Stream,addr: net::SocketAddr)whereE:Environment,{// delay the response, in deterministic mode this will immediately progress time.       env.delay_from(time::Duration::from_secs(1));println!("handling connection from {:?}", addr);letmut transport =Framed::new(socket,LinesCodec::new());ifletErr(e) = transport.send(String::from("Hello World!")).await{println!("failed to send response: {:?}", e);}}/// Start a server which will bind to the provided addr and repyl to clients.asyncfnserver<E>(env:E,addr: net::SocketAddr) ->Result<(), io::Error>whereE:Environment,{letmut listener = env.bind(addr).await?;whileletOk((socket, addr)) = listener.accept().await{let request =handle(env.clone(), socket, addr);           env.spawn(request)}Ok(())}/// Create a client which will read a message from the serverasyncfnclient<E>(env:E,addr: net::SocketAddr) ->Result<(), io::Error>whereE:Environment,{loop{match env.connect(addr).await{Err(_) =>{// Sleep if the connection was rejected, retrying later.// In deterministic mode, this will just reorder task execution// without waiting for time to advance.                   env.delay_from(time::Duration::from_secs(1)).await;continue;}Ok(conn) =>{letmut transport =Framed::new(conn,LinesCodec::new());let result = transport.next().await.unwrap().unwrap();assert_eq!(result,"Hello World!");returnOk(());}}}}#[test]fntest(){// Various seed values can be supplied to `DeterministicRuntime::new_with_seed` to find a seed// value for which this example terminates incorrectly.letmut runtime = simulation::deterministic::DeterministicRuntime::new_with_seed(1).unwrap();let handle = runtime.handle();       runtime.block_on(async{           handle.spawn(runtime.latency_fault().run());let bind_addr: net::SocketAddr ="127.0.0.1:8080".parse().unwrap();let server =server(handle.clone(), bind_addr);           handle.spawn(asyncmove{               server.await.unwrap();});client(handle, bind_addr).await.unwrap();})}