mirror of https://github.com/smol-rs/smol
45 lines
1.3 KiB
Rust
45 lines
1.3 KiB
Rust
// TODO: document
|
|
#[cfg(target_os = "linux")]
|
|
fn main() -> std::io::Result<()> {
|
|
use std::io;
|
|
use std::os::unix::io::AsRawFd;
|
|
use std::time::{Duration, Instant};
|
|
|
|
use smol::Async;
|
|
use timerfd::{SetTimeFlags, TimerFd, TimerState};
|
|
|
|
/// Converts a `nix::Error` into `std::io::Error`.
|
|
fn io_err(err: nix::Error) -> io::Error {
|
|
match err {
|
|
nix::Error::Sys(code) => code.into(),
|
|
err => io::Error::new(io::ErrorKind::Other, Box::new(err)),
|
|
}
|
|
}
|
|
|
|
/// Sleeps using a `TimerFd`.
|
|
async fn sleep(dur: Duration) -> io::Result<()> {
|
|
// Create a timer.
|
|
let mut timer = TimerFd::new()?;
|
|
timer.set_state(TimerState::Oneshot(dur), SetTimeFlags::Default);
|
|
|
|
// When the timer fires, a 64-bit integer can be read from it.
|
|
Async::new(timer)?
|
|
.with(|t| nix::unistd::read(t.as_raw_fd(), &mut [0u8; 8]).map_err(io_err))
|
|
.await?;
|
|
Ok(())
|
|
}
|
|
|
|
smol::run(async {
|
|
let start = Instant::now();
|
|
println!("Sleeping...");
|
|
sleep(Duration::from_secs(1)).await?;
|
|
println!("Woke up after {:?}", start.elapsed());
|
|
Ok(())
|
|
})
|
|
}
|
|
|
|
#[cfg(not(target_os = "linux"))]
|
|
fn main() {
|
|
println!("This example works only on Linux!");
|
|
}
|