Sorry, too much sugar,

In the below please replace eval() with exec().

On Wednesday, July 16, 2003, at 06:04 PM, Shawn Corey wrote:

Hi,

As far as I know, fork re-uses the same program image; that's what the sticky bit is all about (see man 2 chmod). It does re-create the data image for an new program. This leads to the confusion I've been having; how can you create a thread that's not perl? Perl (OK, advance perl implementations) allows threads but these threads must be within the same perl program. A thread that runs another program/script is a fork. A thread runs the same program image with the same data image. Forks (processes) run a different program image and a different (necessary) data image. I see no advantage in creating a thread that loads a different process. Calling fork() and eval() is more understandable than threading then eval(). Could someone clear up my confusion?

On Wednesday, July 16, 2003, at 04:37 PM, Dan Sugalski wrote:

At 1:15 PM -0700 7/16/03, Rich Morin wrote:
At 8:33 PM +0100 7/16/03, David Cantrell wrote:
As far as the program is concerned, it's a complete copy.  But yes,
most modern virtual memory implementations will, I believe, do copy
on write.  I haven't actually tested this on OS X though :-)

OK, I'm curious; how _would_ one go about testing this?

The easiest way to do so is to snag the Darwin source and take a look at some of the low-level MMU manipulation code in the kernel. It should be pretty obvious whether (though not necessarily how :) it's done.
--
Dan


--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk



Mr. Shawn Corey, B.Sc.
        President
        Corey Consultants Inc.
(613) 823-4132
http://www.magma.ca/~shawn/
mailto:[EMAIL PROTECTED]

Perl: You have to love a language that lets you bless your thingy.


Mr. Shawn Corey, B.Sc.
        President
        Corey Consultants Inc.
(613) 823-4132
http://www.magma.ca/~shawn/
mailto:[EMAIL PROTECTED]

Perl: You have to love a language that lets you bless your thingy.



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