async/await echo server + α in rust.

• Echo server: This uses blocking socket I/O and handles only one connection at a time.
• Multi-threaded echo server: This is almost same as the blocking one except that it spawn a thread for a each connection to handle multiple connections.
• Epoll echo server : This uses epoll to handle multiple connections in one thread.
• Async/await echo server : Epoll echo server using async/await syntax. I use the same strategy as the async-book to spawn and execute futures. There is a dedicated thread to perform epoll_wait(), which is the same as the async-std.

Linux only. Just for learning purposes.

The below figure shows the sequence of accept in async/await echo server.

1. Run a server
   • e.g., cargo run --bin aa_echo
2. Connect to the server in other terminal
   • e.g., nc 127.0.0.1 8080 and then type something

• async-book

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