Re: [9fans] rfork(), getss() etc etc

[nigel@9fs.org]

>>	Check the examples of use. Really.

Linuxthreads is a very good example.

>>	Ferchrissake, you've explicitly asked for shared address space. It

Well, yes, but stacks are a special case. Each process has to take care
not to write outside of it's own data, fine. This is called good programming
technique, and does not require any special coding.

Ensuring that the stack is not overflowed requires either compiler
assistance, or contortions in programming.

If I thought that splitting the stack was an unreasonable thing to ask for,
I wouldn't. The thing is, fork() does it so it can't be hard. Also, I have solid
examples of operating systems which provide a choice.

>>	(Thread_Data *) (ESP & -Alignment) + Alignement - sizeof(Thread_Data)

Hadn't escaped my radar. We're getting into machine dependency here again,
but it is a solution that I had tried.

>>	consequences - you are welcome, just let's avoid imitating *.advocacy.

One man's advocacy is another man's technical discussion. I simply do not
buy the "clone() is perfect and cannot be changed" attitude, or for that
matter the "FreeBSD rfork() is perfect and cannot be changed" attitude either.
In both cases, the problem could be solved by adding a spot of functionality,
and taking away none.

So one could add this feature, break nothing, and aid a whole class of applications.
Why not?