我正在使用Tokio库提供的示例,并尝试获得所有当前活动TCP连接的向量。最终,我想通过循环遍历它们并向套接字写入消息来能够向每个活动连接广播消息。
首先,在一个线程中我尝试打印出当前连接数量,而在另一个线程中接受连接。
为此,我正在尝试使用共享向量。目前还没有实现从向量中删除连接的功能,当然也要及时进行删除。
// A tiny async echo server with tokio-core
extern crate futures;
extern crate tokio_core;
extern crate tokio_io;
use futures::{Future, Stream};
use tokio_io::{io, AsyncRead};
use tokio_core::net::TcpListener;
use tokio_core::reactor::Core;
use std::thread;
use std::sync::{Arc, Mutex};
use std::io::stdout;
use std::io::Write;
fn main() {
// Create the event loop that will drive this server
let mut core = Core::new().unwrap();
let handle = core.handle();
// Bind the server's socket
let addr = "127.0.0.1:12345".parse().unwrap();
let tcp = TcpListener::bind(&addr, &handle).unwrap();
let mut connections = Arc::new((Mutex::new(Vec::new())));
thread::spawn(move || {
//Every 10 seconds print out the current number of connections
let mut i;
loop {
i = connections.lock().unwrap().len();
println!("There are {} connections", i);
stdout().flush();
thread::sleep_ms(10000);
}
});
// Iterate incoming connections
let server = tcp.incoming().for_each(|(tcp, _)| {
connections.lock().unwrap().push(tcp);
// Split up the read and write halves
let (reader, writer) = tcp.split();
// Future of the copy
let bytes_copied = io::copy(reader, writer);
// ... after which we'll print what happened
let handle_conn = bytes_copied.map(|(n, _, _)| {
println!("wrote {} bytes", n)
}).map_err(|err| {
println!("IO error {:?}", err)
});
// Spawn the future as a concurrent task
handle.spawn(handle_conn);
Ok(())
});
// Spin up the server on the event loop
core.run(server).unwrap();
}
目前构建失败,出现以下错误:
error[E0382]: capture of moved value: `connections`
--> src/main.rs:36:42
|
26 | thread::spawn(move || {
| ------- value moved (into closure) here
...
36 | let server = tcp.incoming().for_each(|(tcp, _)| {
| ^^^^^^^^^^ value captured here after move
|
= note: move occurs because `connections` has type `std::sync::Arc<std::sync::Mutex<std::vec::Vec<tokio_core::net::TcpStream>>>`, which does not implement the `Copy` trait
error[E0382]: use of moved value: `tcp`
--> src/main.rs:40:32
|
38 | connections.lock().unwrap().push(tcp);
| --- value moved here
39 | // Split up the read and write halves
40 | let (reader, writer) = tcp.split();
| ^^^ value used here after move
|
= note: move occurs because `tcp` has type `tokio_core::net::TcpStream`, which does not implement the `Copy` trait
没有编写任何不安全的代码,是否有可能实现这一点?
Arc<Mutex<_>>
来包装连接,就像你对向量所做的那样,但这会限制你在其中所能做的事情(例如,在.split
调用中无法移动它)。 - MartinHaTh