Linux and Threads

[Daniel Beckham]

Threads are very easy to use.  The only problems that arise are when two 
threads try to use the same global variable  at the same time.  You have to 
consider use mutexes/sempahores to resolve locking and memory 
issues.   But, since a simple daemon like you are proposing wouldn't need 
to use a shared variable, you don't have to worry about those types of issues.

Threads are much more efficient, cleaner and much easier to code that a 
program that forks... you don't have to worry about closing open file 
descriptors and you don't waste memory by making a complete copy of the 
program...  It's also much easier to pass a socket descriptor to a thread 
than it is to pass it to a child that has already forked...

My suggestions, only use fork to turn into a daemon or if your program is 
under 50 lines of code.

Check the man pages for:

pthread_create, pthread_exit and pthread_join. Those should get you started.

Daniel


At 10:02 AM 12/10/99 -0700, you wrote:
>On Thu, 09 Dec 1999, you wrote:
>Hmm, if your application is not performance critical a would
>not use threads. It's doable the way you mentioned but it's a PITA
>to debug. Especially without a (free) debugger on Linux that
>supports multi-threading correctly.
>Why not write a separate daemon (server) program to perform your tasks
>by using fork() for each complex task and communicates with the GUI
>program through standard UDP. It's simple, it's far easier to debug,
>client and server may reside on different hosts and fast enough for
>many purposes.