Introduction to Multi-Threaded Programming

Hi,

First of all thanks for this tutorial. Its simple and very clear.
All mistakes in the sample example were already mentioned by others :)
Even I used

while(1) {
pthread_mutex_lock(&count_mutex);
if(x == 4000) {
pthread_mutex_unlock(&count_mutex);
pthread_exit(NULL);
return;
}
x++;
printf("Thread ID%ld: X is now %d.\n",
pthread_self(), x);
pthread_mutex_unlock(&count_mutex);
}

which will ensure x value to be 4000. See I got it from your tutorial :D.
Thanks again.

How would you create a tcp server and client, whereby the server wants to be able to see any move made by the client and vice versa?[c-sharp]

Accessing the variable "x" outside the mutexed area is not really a good idea.
I would rather have used something like this:

void *mythread(void *data) {
start:
  pthread_mutex_lock(&count_mutex);
  if (x < 4000) {
    x++;
    printf("Thread ID%ld: X is now %d.\n", pthread_self(), x);
    pthread_mutex_unlock(&count_mutex);
    goto start;
  }
  else {
    pthread_mutex_unlock(&count_mutex);
  }
  pthread_exit(NULL);
}

This is one of the rare cases where a "goto" is useful ;-)

Thanks for the tutorial.

I think changing the increment line to

if (x < 4000) {x++};

would be better, otherwise the count goes higher than 4000 as the while check is outside the mutex. Otherwise, thanks for the example, it was very clear.

Perhaps you would like to revisit
http://pauillac.inria.fr/~xleroy/linuxthreads/
It's stated that "LinuxThreads is now obsolete and is being replaced by NPTL."
Thank you for the introduction.

This is my first MT program, this tutorial gave me a clear idea..wonderful..!!
ThanX a lot..!!

I think this line :

pthread_t tid[10];

Should be changed into :

pthread_t tids[10];

Because code uses "tids" instead of "tid" ... a small syntax error.

Thank you for the tutorial it helped a lot.

Probably should have covered condition variables.

IT is a wonderfull sample...

I would like to know more about pthreads..

could pls assist me where i could get more information and samples --Jai

Wonderfully written. Convered all the basic issues with MT programming in just a page.