Get Rid Of GoProcess pls

[bonedaddy]

This repository might've been useful 5 years ago when it was first created, but context has gotten really good first-class support in Golang, and its entirely possible to do exactly what goprocess does, except better, and more efficient.

Generally I see goprocess being used in a lot of places where goroutines are created. This makes creating a goroutine a very non-lightweight operation which is the exact opposite. Creating a goroutine should be lightweight!

Consider what happens everytime the Go function is called from goprocess, and this is done a lot!!! (https://github.com/jbenet/goprocess/blob/7f9d9ed286badffcf2122cfeb383ec37daf92508/impl-mutex.go#L26).

	return &process{
		teardown: tf,
		closed:   make(chan struct{}),
		closing:  make(chan struct{}),
		waitfors: make(map[*processLink]struct{}),
		children: make(map[*processLink]struct{}),
	}

That means every single goroutine we spin up creates a fuck ton of allocation. And its done twice every time Go is called!

// This is because having the process you
func Go(f ProcessFunc) Process {
	// return GoChild(Background(), f)

	// we use two processes, one for communication, and
	// one for ensuring we wait on the function (unclosable from the outside).
	p := newProcess(nil)
	waitFor := newProcess(nil)
	p.WaitFor(waitFor) // prevent p from closing
	go func() {
		f(p)
		waitFor.Close() // allow p to close.
		p.Close()       // ensure p closes.
	}()
	return p
}

There's so many simpler and more idiomatic approaches like:

go func() {
select {
case <-ctx.Done():
default:
}
  // do stuff
}()

In some of the forks I have for libp2p, and ipfs libraries the profiling I do makes jbenet/goprocess
show up as a noticeable consumer of resources, and I encourage this to be done by libp2p developers because it's pretty clear goprocess needs to go.

[marten-seemann]

goprocess was completely removed from the libp2p code base. This was not an easy change, see libp2p/go-libp2p#1193 and libp2p/go-libp2p#1266 for example.