Struct DriverConfig 

pub struct DriverConfig {
    pub backend: Backend,
    pub events: usize,
    pub recv_budget: usize,
    pub uring_entries: u32,
    pub uring_buffers: u16,
    pub uring_fixed_files: bool,
    pub uring_max_files: u32,
    pub uring_simulate_failure: Option<i32>,
    pub iocp_eager_recv: bool,
    pub accepts_outstanding: usize,
    pub udp_recvs_outstanding: usize,
    pub busy_poll: Duration,
}

Driver settings. The defaults suit a server loop.

Fields

backend: Backend

Which back end to use.

events: usize

Most OS events taken per wait (epoll and kqueue events, IOCP entries). The array starts at 64 entries and doubles, up to this, whenever a wait fills it, so a busy loop drains every ready event in one call and an idle one keeps a small array.

recv_budget: usize

Most receives per connection per turn before others get a go (epoll, kqueue, IOCP).

uring_entries: u32

io_uring: submission queue entries (the completion queue is four times larger).

uring_buffers: u16

io_uring: entries of the provided-buffer ring (a power of two, at most 32768).

uring_fixed_files: bool

io_uring: use registered (fixed) file descriptors for connections.

uring_max_files: u32

io_uring: size of the fixed file table (connections per loop that can use it; others use plain descriptors).

uring_simulate_failure: Option<i32>

io_uring: pretend io_uring_setup failed with this errno, to test the fallback. The environment variable SIMOOM_IO_URING_FAIL=<errno> does the same.

iocp_eager_recv: bool

IOCP: post receives with a buffer instead of the zero-byte idiom: one system call per receive instead of two, but every connection waiting for data holds a receive buffer. Off by default.

accepts_outstanding: usize

IOCP: AcceptEx calls kept outstanding per listener.

udp_recvs_outstanding: usize

UDP: receives kept outstanding per socket on IOCP.

busy_poll: Duration

Adaptive busy polling: after a turn that delivered events, the driver may poll without blocking for up to this long before it sleeps, saving a sleep and a wake-up when the next event comes within a few microseconds. It spins only while events have been arriving sooner than a quarter of this window after busy turns (measured by an occasional probe spin), so at moderate load it sleeps exactly as without busy polling and costs no CPU per request; an idle loop never spins. Duration::ZERO turns it off. The environment variable SIMOOM_BUSY_POLL_US overrides it. Default 30 µs.

Trait Implementations

impl Clone for DriverConfig

fn clone(&self) -> DriverConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DriverConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for DriverConfig

fn default() -> DriverConfig

Returns the “default value” for a type.