1 /******************************************************************************
2 * FILE: omp_hello.c
3 * DESCRIPTION:
4 *   OpenMP Example - Hello World - C/C++ Version
5 *   In this simple example, the master thread forks a parallel region.
6 *   All threads in the team obtain their unique thread number and print it.
7 *   The master thread only prints the total number of threads.  Two OpenMP
8 *   library routines are used to obtain the number of threads and each
9 *   thread's number.
10 * AUTHOR: Blaise Barney  5/99
11 * LAST REVISED: 04/06/05
12 ******************************************************************************/
13 #include <omp.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16 
17 int main (int argc, char *argv[]) {
18 
19 int nthreads, tid;
20 
21 /* Fork a team of threads giving them their own copies of variables */
22 #pragma omp parallel private(nthreads, tid)
23   {
24 
25   /* Obtain thread number */
26   tid = omp_get_thread_num();
27   printf("Hello World from thread = %d\n", tid);
28 
29   /* Only master thread does this */
30   if (tid == 0)
31     {
32     nthreads = omp_get_num_threads();
33     printf("Number of threads = %d\n", nthreads);
34     }
35 
36   }  /* All threads join master thread and disband */
37 
38   return 0;
39 }
40