Note Puddle is just a toy project to play with Boost fibers and
io_uring.
Puddle is a minimal asynchronous C++ networking library built with
Boost fibers
and io_uring.
Puddle is based on the helio, though Puddle only supports a single OS thread and is much more basic.
Puddle provides asynchronous networking on a single OS thread using Boost fibers.
To create a TCP server with Puddle, you must implement puddle::Listener which
accepts connections. The Listener::Connection(std::unique_ptr<puddle::Socket> conn)
method is called when a new connection is accepted.
Each connection is run in its own fiber and can use the passed puddle::Socket
to read and write to the socket. When reads and writes block, the fiber will
be descheduled so another fiber can run on the same thread.
See examples/echo for an example.
Each connection has its own fiber. When the connection 'blocks' by making
a socket request, the request will be added to the io_uring submission queue
and the fiber will be descheduled so another fiber can run.
Puddle implements a custom fiber scheduling algorithm which used round-robin
scheduling, similar to the default algorithm. Though when there are no fibers
ready to run, it will submit the queued requests to io_uring and wait for
a completion event. For each completion event, it will mark the fiber blocked
on that event as ready to run so the fiber will be scheduled.
Puddle is built with Bazel.
Build the library with bazel build //puddle:puddle which will build both
bazel-bin/puddle/libpuddle.a and bazel-bin/puddle/libpuddle.so.
You can also run the echo server example with bazel run //examples/echo.