why forking?

paulsm4 · 03-09-2009, 08:05 PM

Quote:

So you're telling me theres no possible way to do multitasking without forking?

No! That's not at all what wje_lq is saying!

Quote:

You have either to fork() or to use threads of some sort. Unless you have special requirements, fork() is the way to go.

Did you catch the "or" in there?

He and I disagree: I suggested "unless you have special requirements, 'pthread_create()' is the way to go". But there are pros and cons on either side, and there's no "right" or "wrong" answer. Wje_lq correctly points out some very good reasons for preferring "fork" over "pthread_create()".

SUGGESTION:
Look up "threads" and "processes" in Wikipedia (or something like that).

In general, a "process" is what you get from "fork()".

In general, a "thread" is what you get from "pthread_create()".

There are many different kinds of "concurrency", and lots of subtle (and not-so-subtle) issues involved.

BOTTOM LINE:
"fork()" and "pthread_create()" are different .. and there's a place for both in your toolbox!

Please post back with more questions once you've had a chance to look at the distinction between "process" and "thread".

Sergei Steshenko · 03-09-2009, 09:58 PM

Quote:

Originally Posted by the_ultimate_samurai

i have actually had this same problem. i cant figure out the advantages of forking opposed to multithreading.

the things mentioned above seem like they could be just as easily done with a thread...so why fork?

If you want to run the same function in parallel, the function should be thread-safe, i.e., for example, it shouldn't use global/static data.

When forking you do not have the limitation, i.e. you have a copy of both data and code, and each code body deals with its own global/static data.

This is my understanding.