demikernel 1.5.13

Kernel-Bypass LibOS Architecture
Documentation 
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// Copyright(c) Microsoft Corporation.
// Licensed under the MIT license.

use crate::{
    async_timer,
    perftools::profiler,
    timer,
};
use ::anyhow::Result;
use ::std::{
    future::Future,
    task::{
        Context,
        Poll,
        Waker,
    },
};
use std::pin::{
    pin,
    Pin,
};

#[test]
fn test_multiple_roots() -> Result<()> {
    profiler::reset();

    for i in 0..=5 {
        if i == 5 {
            timer!("a");
        }
        {
            timer!("b");
        }
    }

    profiler::PROFILER.with(|p| -> Result<()> {
        let p = p.borrow();

        crate::ensure_eq!(p.roots.len(), 2);

        for root in p.roots.iter() {
            crate::ensure_eq!(root.borrow().get_pred().is_none(), true);
            crate::ensure_eq!(root.borrow().get_succs().is_empty(), true);
        }

        crate::ensure_eq!(p.roots[0].borrow().get_name(), "b");
        crate::ensure_eq!(p.roots[1].borrow().get_name(), "a");

        crate::ensure_eq!(p.roots[0].borrow().get_num_calls(), 6);
        crate::ensure_eq!(p.roots[1].borrow().get_num_calls(), 1);

        Ok(())
    })
}

#[test]
fn test_succ_reuse() -> Result<()> {
    use std::ptr;

    profiler::reset();

    for i in 0..=5 {
        timer!("a");
        if i > 2 {
            timer!("b");
        }
    }

    crate::ensure_eq!(profiler::PROFILER.with(|p| p.borrow().roots.len()), 1);

    profiler::PROFILER.with(|p| -> Result<()> {
        let p = p.borrow();

        crate::ensure_eq!(p.roots.len(), 1);

        let root = p.roots[0].borrow();
        crate::ensure_eq!(root.get_name(), "a");
        crate::ensure_eq!(root.get_pred().is_none(), true);
        crate::ensure_eq!(root.get_succs().len(), 1);
        crate::ensure_eq!(root.get_num_calls(), 6);

        let succ = root.get_succs()[0].borrow();
        crate::ensure_eq!(succ.get_name(), "b");
        crate::ensure_eq!(
            ptr::eq(succ.get_pred().as_ref().unwrap().as_ref(), p.roots[0].as_ref()),
            true
        );
        crate::ensure_eq!(succ.get_succs().is_empty(), true);
        crate::ensure_eq!(succ.get_num_calls(), 3);

        Ok(())
    })
}

#[test]
fn test_reset_during_frame() -> Result<()> {
    profiler::reset();

    for i in 0..=5 {
        timer!("a");
        timer!("b");
        {
            timer!("c");
            if i == 5 {
                profiler::reset();
            }

            crate::ensure_eq!(profiler::PROFILER.with(|p| p.borrow().current.is_some()), true);

            timer!("d");
        }
    }

    profiler::PROFILER.with(|p| -> Result<()> {
        let p = p.borrow();

        crate::ensure_eq!(p.roots.is_empty(), true);
        crate::ensure_eq!(p.current.is_none(), true);

        Ok(())
    })
}

struct DummyCoroutine {
    iterations: usize,
}

impl Future for DummyCoroutine {
    type Output = Result<()>;

    fn poll(self: Pin<&mut Self>, _ctx: &mut Context) -> Poll<Self::Output> {
        match profiler::PROFILER.with(|p| -> Result<()> {
            let p = p.borrow();
            crate::ensure_eq!(p.roots.len(), 1);

            let root = p.roots[0].borrow();
            crate::ensure_eq!(root.get_name(), "dummy");
            crate::ensure_eq!(root.get_num_calls(), self.as_ref().iterations);
            Ok(())
        }) {
            Ok(()) => {
                self.get_mut().iterations += 1;
                Poll::Pending
            },
            Err(e) => Poll::Ready(Err(e)),
        }
    }
}

#[test]
fn test_async() -> Result<()> {
    let mut coroutine = DummyCoroutine { iterations: 0 };
    let mut task = pin!(async_timer!("dummy", pin!(coroutine)));
    let waker = Waker::noop();
    let mut context = Context::from_waker(&waker);

    for _ in 0..10 {
        match Future::poll(task.as_mut(), &mut context) {
            Poll::Pending => (),
            Poll::Ready(r) => return r,
        }
    }

    Ok(())
}