[SR-12982] Foundation: Stream.getBoundStreams not available

[weissi]

Previous ID	SR-12982
Radar	rdar://problem/64947425
Original Reporter	@weissi
Type	Bug

Environment

docker.io/swiftlang/swift:nightly-master-bionic
Swift version 5.3-dev (LLVM 6049ecf8a0, Swift 4205e46959)
Target: x86_64-unknown-linux-gnu

Additional Detail from JIRA

Votes	1
Component/s	Foundation
Labels	Bug
Assignee	None
Priority	Medium

md5: 7b395a96600be27ba3bccd448b599c4c

Issue Description:

I'm really not an expert in URLSession but I wanted to implement bidirectional streaming with it and I believe I require Stream.getBoundStreams for that (https://developer.apple.com/documentation/foundation/url_loading_system/uploading_streams_of_data).

But:

$ jw-docker-swift-master swift run
docker.io/swiftlang/swift:nightly-master-bionic
/Users/johannes/devel/URLSessionBidiStreaming/Sources/URLSessionBidiStreaming/main.swift:59:16: error: type 'Stream' has no member 'getBoundStreams'
        Stream.getBoundStreams(withBufferSize: 4096,
        ~~~~~~ ^~~~~~~~~~~~~~~

it seems like Streams.getBoundStreams isn't available on Linux.

[weissi]

@swift-ci create

[mickeyl]

Indeed, I spotted this just recently as well. It's kind of a showstopper for one of my projects which is based on a generic stream abstraction (bridging to different transport means like CoreBluetooth, ExternalAccessory, TTY, TCP, etc.).

I first thought it was just the convenience method for gathering the stream pair missing on Linux, but as a matter of fact, the whole `CFSocketStream` infrastructure is absent. I need to have a TCP stream socket pair on Linux – do you know of any existing projects (other than Swift-NIO, which is great in its own right, but too much of a hammer for this very nail) or shall we cooperate on a small socket stream implementation for Posix sockets?