Threads vs Processes

[sjdevnull at yahoo.com]

sturlamolden wrote:
> Chance Ginger wrote:
>
> > Not quite that simple. In most modern OS's today there is something
> > called COW - copy on write. What happens is when you fork a process
> > it will make an identical copy. Whenever the forked process does
> > write will it make a copy of the memory. So it isn't quite as bad.
>
> A noteable exception is a toy OS from a manufacturer in Redmond,
> Washington. It does not do COW fork. It does not even fork.

That's only true for Windows 98/95/Windows 3.x and other DOS-based
Windows versions.

NTCreateProcess with SectionHandle=NULL creates a new process with a
COW version of the parent process's address space.

It's not called "fork", but it does the same thing.  There's a new name
for it in Win2K or XP (maybe CreateProcessEx?) but the functionality
has been there since the NT 3.x days at least and is in all modern
Windows versions.