copied from the pxar crate, intended for polling a future once
this is helpful for testing async code
(this needs to resolve in the first poll otherwise it will
not work)
Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
proxmox/src/tools/mod.rs | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/proxmox/src/tools/mod.rs b/proxmox/src/tools/mod.rs
index 45f46f9..e938d90 100644
--- a/proxmox/src/tools/mod.rs
+++ b/proxmox/src/tools/mod.rs
@@ -227,3 +227,39 @@ pub fn nodename() -> &'static str {
&NODENAME
}
+
+#[cfg(test)]
+pub mod poll_once {
+ use std::future::Future;
+ use std::pin::Pin;
+ use std::task::{Context, Poll};
+
+ pub fn poll_result_once<T, R>(mut fut: T) -> std::io::Result<R>
+ where
+ T: Future<Output = std::io::Result<R>>,
+ {
+ let waker = std::task::RawWaker::new(std::ptr::null(), &WAKER_VTABLE);
+ let waker = unsafe { std::task::Waker::from_raw(waker) };
+ let mut cx = Context::from_waker(&waker);
+ unsafe {
+ match Pin::new_unchecked(&mut fut).poll(&mut cx) {
+ Poll::Pending => Err(crate::sys::error::io_err_other(
+ "got Poll::Pending synchronous context",
+ )),
+ Poll::Ready(r) => r,
+ }
+ }
+ }
+
+ const WAKER_VTABLE: std::task::RawWakerVTable =
+ std::task::RawWakerVTable::new(forbid_clone, forbid_wake, forbid_wake, ignore_drop);
+
+ unsafe fn forbid_clone(_: *const ()) -> std::task::RawWaker {
+ panic!("tried to clone waker for synchronous task");
+ }
+
+ unsafe fn forbid_wake(_: *const ()) {
+ panic!("tried to wake synchronous task");
+ }
+ unsafe fn ignore_drop(_: *const ()) {}
+}
--
2.20.1