Skip to content


Switch branches/tags


A Simple, Light-Weight Asynchronous C++ Framework

license language feature last commit

English | 中文

The async_simple is a library offering simple, light-weight and easy-to-use components to write asynchronous codes. The components offered include the Lazy (based on C++20 stackless coroutine), the Uthread (based on stackful coroutine) and the traditional Future/Promise.

Install Dependencies

The build of async_simple need libaio, googletest and cmake. Both libaio and googletest are optional. (Testing before using is highly suggested.)

Using apt (ubuntu and debian's)

# Install libaio
sudo apt install libaio-dev -y

# Install gtest
sudo apt install libgtest-dev -y
sudo apt install cmake -y
cd /usr/src/googletest/gtest
sudo mkdir build && cd build
sudo cmake .. && sudo make install
cd .. && sudo rm -rf build
cd /usr/src/googletest/gmock
sudo mkdir build && cd build
sudo cmake .. && sudo make install
cd .. && sudo rm -rf build

Using yum (CentOS and fedora)

# Install libaio
sudo yum install libaio-devel -y

sudo yum install cmake -y
# Try to build gtest and gmock from source

Using Homebrew (macOS)

brew install cmake
brew install googletest

Build Dependencies From Source

# libaio (optional)
# you can skip this if you install libaio from packages
git clone
cd libaio
sudo make install
# gmock and gtest
git clone -b v1.8.x
cd googletest
mkdir build && cd build
cmake .. && sudo make install

Install Clang Compiler

Required Compiler: clang (>= 11.0.1) or gcc (>= 10.3)

Demo example dependency

Demo example depends on standalone asio(, the commit id:f70f65ae54351c209c3a24704624144bfe8e70a3


$ mkdir build && cd build
# Specify [-DASYNC_SIMPLE_ENABLE_TESTS=OFF] to skip tests.
CXX=clang++ CC=clang cmake ../ -DCMAKE_BUILD_TYPE=[Release|Debug] [-DASYNC_SIMPLE_ENABLE_TESTS=OFF]
# for gcc, use CXX=g++ CC=gcc
make -j4
make test # optional
make install # sudo if required

Get Started

After installing and reading Lazy to get familiar with API, here is a demo use Lazy to count char in a file.

How to Contribute

  1. Read the How to fix issue document firstly.
  2. Run tests and git-clang-format HEAD^ locally for the change.
  3. Create a PR, fill in the PR template.
  4. Choose one or more reviewers from contributors: (ChuanqiXu9, RainMark, foreverhy, qicosmos).
  5. Get approved and merged.

Performance Monitoring

We could monitor the performance change history in:


async_simple is distributed under the Apache License (Version 2.0) This product contains various third-party components under other open source licenses. See the NOTICE file for more information.


Simple, light-weight and easy-to-use asynchronous components







No releases published


No packages published