Question

i was trying to write a simple multithreaded program. It is dumping the core. I have my function that is called when a thread is created below:

void *BusyWork(void *t)
{
   int i;
   int *tid;
   int result=0;
   tid = t;

   printf("Thread %d starting...
",*tid);
   for (i=0; i<10; i++)
   {
       result = result + (i* i);
   }
   printf("thread %d is sleeping for %d sec s
",tid,tid);
   sleep(tid);
   printf("Thread %d done. Result = %e
",tid, result);
   pthread_exit((void*) t);
}

My call to pthread_create function is below inside the main function:

int t;

for(t=0; t<NUM_THREADS; t++) 
{
      printf("Main: creating thread %d
", t);
      rc = pthread_create(&thread[t], &attr, BusyWork, (void *)t);
}

Please help me in finding where is the problem? Thanks in advance.

Answer 1

This line is wrong:

printf("Thread %d starting...
",*tid);

You can achieve what you want with:

printf("Thread %d starting...
",(int) t);

or printf("Thread %d starting... ", tid);

Answer 2

Beginning with this line:

printf("thread %d is sleeping...

All of the references to tid should be *tid.

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