chxnet

An async network I/O library, imitates boost.asio, based on io_uring and liburing, for educational purpose. Now support basic tcp I/O and C++20 coroutine.

TCP echo server with end-of-line marker

UDP example

Simple http server, which always responses with headers of requests

Coroutine, and singled-threaded when_any

Note:

Only gcc is supported, and the minimum version requirement is 12.1.

Full functionality requires a minimum kernel version 5.19. But most basic operations are available on older kernels.

Functionalities or operations that require a kernel version higher than 5.15:

• Cancellation of an async object, 5.19. (If not satisfied, destructor of async objects cannot cancel async tasks associated with itself, leads to bad memory access. To avoid this, use a reference-counter such as shared_ptr.)

Dependency

• liburing

How to build

Run shell:

autoreconf -i -v
./configure
# ./configure --with-liburing=/path/to/liburing if liburing not in system default paths.
# See ./configure --help for details.
make

Design

1. Task management layer (level-1, io_context)

   Level-1 provides async task allocation and life cycle management services for level-2.

2. Async Operation layer (level-2, detail::async_operation)

   All basic I/O operations are implemented in level-2, e.g. async_read and async_write.

3. Userland layer (level-3, I/O objects, async_combine)

   Level-3 provides abstraction and encapsulation based on level-2, such as ip::tcp::socket.

   Users could also combine multiple level-2 operation by async_combine.

TODO

• Add udp support.
• Add kernel-free timer support.
• Add level-3 multithread support.