Skip to content

Wait for overlapped WriteFile completion in Rust #7383

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
youknowone merged 1 commit into from
Mar 8, 2026
+20 −0
Merged

Wait for overlapped WriteFile completion in Rust #7383

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions crates/vm/src/stdlib/_winapi.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1251,6 +1251,26 @@ mod _winapi {

err
};

// Without GIL, the Python-level PipeConnection._send_bytes has a
// race on _send_ov when the caller (SimpleQueue) skips locking on
// Windows. Wait for completion here so the caller never sees
// ERROR_IO_PENDING and never blocks in WaitForMultipleObjects,
// keeping the _send_ov window negligibly small.
if err == ERROR_IO_PENDING {
let event = ov.inner.lock().overlapped.hEvent;
vm.allow_threads(|| unsafe {
windows_sys::Win32::System::Threading::WaitForSingleObject(
event,
windows_sys::Win32::System::Threading::INFINITE,
);
});
let result = vm
.ctx
.new_tuple(vec![ov.into_pyobject(vm), vm.ctx.new_int(0u32).into()]);
return Ok(result.into());
}

let result = vm
.ctx
.new_tuple(vec![ov.into_pyobject(vm), vm.ctx.new_int(err).into()]);
Expand Down
Loading