1 files changed, 58 insertions, 0 deletions
diff --git a/third_party/rust/tokio-0.1.22/examples/hello_world.rs b/third_party/rust/tokio-0.1.22/examples/hello_world.rs
new file mode 100644
index 0000000000..c82762691a
--- /dev/null
+++ b/third_party/rust/tokio-0.1.22/examples/hello_world.rs
@@ -0,0 +1,58 @@
+//! Hello world server.
+//!
+//! A simple client that opens a TCP stream, writes "hello world\n", and closes
+//! the connection.
+//!
+//! You can test this out by running:
+//!
+//!     ncat -l 6142
+//!
+//! And then in another terminal run:
+//!
+//!     cargo run --example hello_world
+
+#![deny(warnings)]
+
+extern crate tokio;
+
+use tokio::io;
+use tokio::net::TcpStream;
+use tokio::prelude::*;
+
+pub fn main() -> Result<(), Box<std::error::Error>> {
+    let addr = "127.0.0.1:6142".parse()?;
+
+    // Open a TCP stream to the socket address.
+    //
+    // Note that this is the Tokio TcpStream, which is fully async.
+    let client = TcpStream::connect(&addr)
+        .and_then(|stream| {
+            println!("created stream");
+            io::write_all(stream, "hello world\n").then(|result| {
+                println!("wrote to stream; success={:?}", result.is_ok());
+                Ok(())
+            })
+        })
+        .map_err(|err| {
+            // All tasks must have an `Error` type of `()`. This forces error
+            // handling and helps avoid silencing failures.
+            //
+            // In our example, we are only going to log the error to STDOUT.
+            println!("connection error = {:?}", err);
+        });
+
+    // Start the Tokio runtime.
+    //
+    // The Tokio is a pre-configured "out of the box" runtime for building
+    // asynchronous applications. It includes both a reactor and a task
+    // scheduler. This means applications are multithreaded by default.
+    //
+    // This function blocks until the runtime reaches an idle state. Idle is
+    // defined as all spawned tasks have completed and all I/O resources (TCP
+    // sockets in our case) have been dropped.
+    println!("About to create the stream and write to it...");
+    tokio::run(client);
+    println!("Stream has been created and written to.");
+
+    Ok(())
+}