Struct wookie::Local

pub struct Local<F> { /* fields omitted */ }

An allocator-less single-future stepping executor for test suites that tracks wakers.

Unlike Wookie, does not require a global allocator at the cost of unsafe polling.

Examples

use core::task::Poll;
use wookie::local;
local!(future: async { true });
assert_eq!(unsafe { future.poll() }, Poll::Ready(true));

// you can also just give a variable name if you have one:
let future = async { true };
local!(future);
assert_eq!(unsafe { future.poll() }, Poll::Ready(true));

// we can find out about the state of wakers any time:
assert_eq!(future.cloned(), 0);
assert_eq!(future.dropped(), 0);
assert_eq!(future.woken(), 0);
// or equivalently...
future.stats().assert(0, 0, 0);

Implementations

impl<F: Future> Local<F>

pub fn new(future: F) -> Local<F>

Creates a new Local without pinning it to the stack. You probably want the local! macro.

pub fn woken(self: &mut Pin<&mut Self>) -> u16

Returns how many times the waker has been woken. This count is cumulative, it is never reset and is allowed to overflow.

pub fn cloned(self: &mut Pin<&mut Self>) -> u16

Returns how many times the waker has been cloned. This count is cumulative, it is never reset and is allowed to overflow.

pub fn dropped(self: &mut Pin<&mut Self>) -> u16

Returns how many times a clone of the waker has been dropped. This count is cumulative, it is never reset and is allowed to overflow.

pub fn stats(self: &mut Pin<&mut Self>) -> Stats

Returns statistics about use of our wakers.

pub fn live(self: &mut Pin<&mut Self>) -> u16

Returns how many times a clone of the waker has been dropped. This count is cumulative, it is never reset and is allowed to overflow.

pub unsafe fn poll(self: &mut Pin<&mut Self>) -> Poll<<F as Future>::Output>

Polls the contained future once.

Example

use core::task::Poll;
use wookie::local;
local!(future: async { true });
assert_eq!(unsafe { future.poll() }, Poll::Ready(true));

Safety

You must not allow the Waker the future is polled with to exist longer than self.

pub unsafe fn poll_while_woken(
    self: &mut Pin<&mut Self>
) -> Poll<<F as Future>::Output>

Polls the contained future to completion, so long as the previous poll caused one or more wakes.

Example

use core::task::Poll;
use wookie::local;
local!(future: async { true });
assert_eq!(unsafe { future.poll_while_woken() }, Poll::Ready(true));

Safety

You must not allow the Waker the future is polled with to exist longer than self.