asyncio

High-performance asynchronous network I/O library for C/C++.

Note: not related to the Python asyncio module — this is an independent C/C++ library that only shares the name.

• Single event loop API over native OS backends: epoll (Linux, Android), kqueue (macOS, FreeBSD), I/O completion ports (Windows)
• Composable asynchronous operations with timeouts, cancellation, object/operation pooling and a synchronous fast path
• Every primitive comes in two flavors: callback API (aio*) and stackful coroutine API (io*; x86, x86_64, aarch64)
• TCP/UDP sockets, pipes/devices, timers, user events
• Protocols on top of the core: TLS (OpenSSL), HTTP client, SMTP client, Bitcoin network protocol and ZMTP (ZeroMQ); RLPx (Ethereum) is a work-in-progress stub
• Incremental zero-copy HTTP/URI parsers (p2putils)

Dependencies

The build is driven by cxx-pm, a source-based C++ package manager. It bootstraps itself at the first CMake configure and downloads/builds third-party dependencies, so the first configure requires network access and can take a while. OpenSSL is always installed; ZeroMQ and GTest are installed when their corresponding features are enabled. Built packages are cached in ~/.cxxpm and shared between projects.

Linux & macOS build

mkdir build && cd build
cmake ../src -DCMAKE_BUILD_TYPE=Release
make -j

Or the same with modern CMake from the repository root:

cmake -S src -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j

Feature options (shown with defaults):

-DASYNCIO_ENABLE_BTC=ON    # Bitcoin network protocol
-DASYNCIO_ENABLE_ZMTP=ON   # ZMTP (ZeroMQ) protocol
-DASYNCIO_ENABLE_RLPX=ON   # RLPx (Ethereum) protocol (stub)
-DASYNCIO_BUILD_TESTS=OFF  # unit tests (GTest)

TLS, HTTP and SMTP support is always built; OpenSSL is a required dependency.

Windows build with Visual Studio

• Install latest cmake from https://cmake.org/download
• Clone git repository
• Run 'x64 Native Tools Command Prompt for VS 20xx' from start menu
• Run 'cmake-gui' from terminal
• Select source ("src" subdirectory in git repo) and your build directory, run 'Configure' (can take a long time!) and 'Generate'.
• Open Visual Studio solution and build all targets

Force x86_64 architecture on macOS with Apple Silicon

mkdir x86_64-Darwin && cd x86_64-Darwin
cmake ../src -DCMAKE_OSX_ARCHITECTURES=x86_64
make -j

License

MIT