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