gcc/libgomp/testsuite/libgomp.c/omp_hello.c

40 lines
1.2 KiB
C

/******************************************************************************
* FILE: omp_hello.c
* DESCRIPTION:
* OpenMP Example - Hello World - C/C++ Version
* In this simple example, the master thread forks a parallel region.
* All threads in the team obtain their unique thread number and print it.
* The master thread only prints the total number of threads. Two OpenMP
* library routines are used to obtain the number of threads and each
* thread's number.
* AUTHOR: Blaise Barney 5/99
* LAST REVISED: 04/06/05
******************************************************************************/
#include <omp.h>
#include <stdio.h>
#include <stdlib.h>
int main (int argc, char *argv[]) {
int nthreads, tid;
/* Fork a team of threads giving them their own copies of variables */
#pragma omp parallel private(nthreads, tid)
{
/* Obtain thread number */
tid = omp_get_thread_num();
printf("Hello World from thread = %d\n", tid);
/* Only master thread does this */
if (tid == 0)
{
nthreads = omp_get_num_threads();
printf("Number of threads = %d\n", nthreads);
}
} /* All threads join master thread and disband */
return 0;
}