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Async I/O for Zig

pike

A minimal cross-platform high-performance async I/O library written in Zig.

Features

  • [x] Reactor/proactor-based I/O notification support
    • [x] epoll (linux)
    • [x] kqueue (darwin)
    • [x] i/o completion ports (windows)
  • [x] Async POSIX socket support
    • [x] bind, listen, connect, accept
    • [x] read, recv, recvFrom
    • [x] write, send, sendTo
    • [x] get/set socket options
  • [x] Async Windows socket support
    • [x] bind, listen, connect, accept
    • [x] read, recv, recvFrom
    • [x] write, send, sendTo
    • [x] get/set socket options
  • [x] Async signal support
    • [x] signalfd for epoll (linux)
    • [x] EVFILT_SIGNAL for kqueue (darwin)
    • [x] SetConsoleCtrlHandler for i/o completion ports (windows)
  • [x] Async event support
    • [x] sigaction (posix)
    • [x] SetConsoleCtrlHandler (windows)

Design

Notifier

A Notifier notifies of the completion of I/O events, or of the read/write-readiness of registered file descriptors/handles.

Should a Notifier report the completion of I/O events, it is designated to wrap around a proactor-based I/O notification layer in the operating system such as I/O completion ports on Windows.

Should a Notifier report the read/write-readiness of registered file descriptors/handles, it is designated to wrap around a reactor-based I/O notification layer in the operating system such as epoll on Linux, or kqueue on Darwin-based operating systems.

The Notifier's purpose is to drive the execution of asynchronous I/O syscalls upon the notification of a reactor/proactor-based I/O event by dispatching suspended asynchronous function frames to be resumed by a thread pool/scheduler (e.g. kprotty/zap).

Handle

A Handle's implementation is specific to a Notifier implementation, though overall wraps around and represents a file descriptor/handle in a program.

Subject to the Notifier implementation a Handle's implementation falls under, state required to drive asynchronous I/O syscalls through a Handle is kept inside a Handle.

An example would be an intrusive linked list of suspended asynchronous function frames that are to be resumed upon the recipient of a notification that a file descriptor/handle is ready to be written to/read from.