NIOFileHandle.withUnsafeDescriptor is missing an overload that takes an asynchronous closure

[jakepetroules]

swift-nio/Sources/NIOFS/FileHandleProtocol.swift

Line 124 in 77b84ac

func withUnsafeDescriptor<R: Sendable>(

Can we get an overload which accepts an async closure?

[glbrntt]

withUnsafeDescriptor is an escape hatch allowing you to do use the descriptor directly for (potentially) blocking work in the context of the underlying thread pool, so the closure is intentionally not async. The async from the function call is from waiting to enqueue the blocking work in the thread pool.

What are you trying to achieve exactly?

[jakepetroules]

Trying to hand the fd off to SwiftSubprocess API, which puts the fd in non-blocking mode and read/writes to it in an async-friendly manner. And that API is async only.

[glbrntt]

Would detaching the file descriptor work here? Or do you need to the NIOFS file handle back after using the subprocess API?

[jakepetroules]

It would be preferable not to detach so that the caller does not become responsible for closing.