Struct EventFd 

pub struct EventFd { /* private fields */ }

A cross-runtime wake signal backed by a Linux eventfd.

Write to signal, read to consume. Multiple signals coalesce into one. The fd can be registered with any event loop (epoll, io_uring, kqueue fallback).

Implementations

impl EventFd

pub fn new() -> Result<Self>

Create a new eventfd in semaphore mode.

EFD_NONBLOCK ensures reads/writes never block the calling thread. EFD_CLOEXEC prevents fd leaks across fork/exec.

pub fn notify(&self) -> Result<()>

Signal the other side to wake up.

Writes 1 to the eventfd counter. Multiple writes accumulate but a single read clears all pending signals.

pub fn try_read(&self) -> Result<u64>

Consume the pending signal count, returning the accumulated value.

Returns Ok(0) if no signal was pending (EAGAIN on non-blocking fd). Returns Ok(n) where n is the accumulated signal count.

pub fn as_fd(&self) -> RawFd

Get the raw file descriptor for registration with an event loop.

The caller can register this fd with:

• Tokio: AsyncFd::new()
• Glommio: GlommioDma::from_raw_fd() or similar
• io_uring: IORING_OP_READ on the fd

Trait Implementations

impl Send for EventFd

impl Sync for EventFd