T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

jump through enough hoops for the poll lifetime to work out

Browse Source 
you program rust for a few years and you think you're done tearing your
hair out over lifetimes, well, you'll find yourself wrong
This commit is contained in:
Pat Hickey
2021-04-29 16:44:45 -07:00
parent ab4f5bb674
commit b7efcbe80f
8 changed files with 99 additions and 87 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
crates/wasi-common/cap-std-sync/src/sched/unix.rs
View File

@@ -1,6 +1,5 @@
use cap_std::time::Duration;
use std::convert::TryInto;
use std::ops::Deref;
use std::os::unix::io::{AsRawFd, RawFd};
use wasi_common::{
file::WasiFile,
@@ -23,23 +22,22 @@ impl SyncSched {
#[wiggle::async_trait]
impl WasiSched for SyncSched {
async fn poll_oneoff<'a>(&self, poll: &'_ Poll<'a>) -> Result<(), Error> {
async fn poll_oneoff<'a>(&self, poll: &'a Poll<'a>) -> Result<(), Error> {
if poll.is_empty() {
return Ok(());
}
let mut pollfds = Vec::new();
let timeout = poll.earliest_clock_deadline();
for s in poll.rw_subscriptions() {
match s {
Subscription::Read(f) => {
let raw_fd = wasi_file_raw_fd(f.file()?.deref()).ok_or(
let raw_fd = wasi_file_raw_fd(f.file).ok_or(
Error::invalid_argument().context("read subscription fd downcast failed"),
)?;
pollfds.push(unsafe { PollFd::new(raw_fd, PollFlags::POLLIN) });
}
Subscription::Write(f) => {
let raw_fd = wasi_file_raw_fd(f.file()?.deref()).ok_or(
let raw_fd = wasi_file_raw_fd(f.file).ok_or(
Error::invalid_argument().context("write subscription fd downcast failed"),
)?;
pollfds.push(unsafe { PollFd::new(raw_fd, PollFlags::POLLOUT) });
@@ -49,7 +47,7 @@ impl WasiSched for SyncSched {
}
let ready = loop {
let poll_timeout = if let Some(t) = timeout {
let poll_timeout = if let Some(t) = poll.earliest_clock_deadline() {
let duration = t.duration_until().unwrap_or(Duration::from_secs(0));
(duration.as_millis() + 1) // XXX try always rounding up?
.try_into()
@@ -79,11 +77,7 @@ impl WasiSched for SyncSched {
if let Some(revents) = pollfd.revents() {
let (nbytes, rwsub) = match rwsub {
Subscription::Read(sub) => {
let ready = sub
.file()
.expect("validated file already")
.num_ready_bytes()
.await?;
let ready = sub.file.num_ready_bytes().await?;
(std::cmp::max(ready, 1), sub)
}
Subscription::Write(sub) => (0, sub),
@@ -101,7 +95,7 @@ impl WasiSched for SyncSched {
}
}
} else {
timeout
poll.earliest_clock_deadline()
.expect("timed out")
.result()
.expect("timer deadline is past")