clean way howto use clib4

@joerg

I have a working vfork for AmigaOS4...
so now its not only MorphOS that has it...

the stack is moved, so never do &local to get the address, before the vfork(), besides closing BPTR file pointers, and doing stuff like that will be like begging for problems and bugs. a lot of stuff must be atomic..
vfork is messy not so easy to see where the vfork thread ends.

I guess pthreads spawn is safer, easier to read. and less likely to break on a system update. (in anycase the way I did it might be quite system friendly... besides the side effects.), unless the OS is updated to 64bit, or we change to a different CPU type.

@LiveForIt

Nice work! Can I try it?

And MorphOS does not have fork() yet, as Piru explained.
I wrote that information because I compiled a program with fork() that ran fine.
However, I didn't notice the warning about the implicit declaration of fork(), and the program ran in a branch where fork() was not used.

@sailor


It is mostly just a prototype, can be nice with a readme and maybe fix exit.. but that might be more speculative code. Something we should avoid, next logical step is to build it into clib4, to avoid workarounds.

for now exit with RemTask(FindTask(NULL)); for it to die witht out closing libraries and classes and so on.

maybe:

#define vforkExit() RemTask(FindTask(NULL));

Maybe put a marker in the child process so it knows it’s a vforked thread.