Fixes https://github.com/denoland/deno/issues/24756. Fixes
https://github.com/denoland/deno/issues/24796.
This also gets vitest working when using
[`--pool=forks`](https://vitest.dev/guide/improving-performance#pool)
(which is the default as of vitest 2.0). Ref
https://github.com/denoland/deno/issues/23882.
---
This PR resolves a handful of issues with child_process IPC. In
particular:
- We didn't support sending typed array views over IPC
- Opening an IPC channel resulted in the event loop never exiting
- Sending a `null` over IPC would terminate the channel
- There was some UB in the read implementation (transmuting an `&[u8]`
to `&mut [u8]`)
- The `send` method wasn't returning anything, so there was no way to
signal backpressure (this also resulted in the benchmark
`child_process_ipc.mjs` being misleading, as it tried to respect
backpressure. That gave node much worse results at larger message sizes,
and gave us much worse results at smaller message sizes).
- We weren't setting up the `channel` property on the `process` global
(or on the `ChildProcess` object), and also didn't have a way to
ref/unref the channel
- Calling `kill` multiple times (or disconnecting the channel, then
calling kill) would throw an error
- Node couldn't spawn a deno subprocess and communicate with it over IPC
This PR implements the child_process IPC pipe between parent and child.
The implementation uses Windows named pipes created by parent and passes
the inheritable file handle to the child.
I've also replace parts of the initial implementation which passed the
raw parent fd to JS with resource ids instead. This way no file handle
is exposed to the JS land (both parent and child).
`IpcJsonStreamResource` can stream upto 800MB/s of JSON data on Win 11
AMD Ryzen 7 16GB (without `memchr` vectorization)
This PR implements the Node child_process IPC functionality in Deno on
Unix systems.
For `fd > 2` a duplex unix pipe is set up between the parent and child
processes. Currently implements data passing via the channel in the JSON
serialization format.
