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1 /******************************************************************************
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2 * FILE: omp_workshare2.c
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3 * DESCRIPTION:
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4 * OpenMP Example - Sections Work-sharing - C/C++ Version
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5 * In this example, the OpenMP SECTION directive is used to assign
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6 * different array operations to threads that execute a SECTION. Each
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7 * thread receives its own copy of the result array to work with.
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8 * AUTHOR: Blaise Barney 5/99
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9 * LAST REVISED: 04/06/05
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10 ******************************************************************************/
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11 #include <omp.h>
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12 #include <stdio.h>
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13 #include <stdlib.h>
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14 #define N 50
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15
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16 int main (int argc, char *argv[]) {
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17
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18 int i, nthreads, tid;
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19 float a[N], b[N], c[N];
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20
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21 /* Some initializations */
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22 for (i=0; i<N; i++)
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23 a[i] = b[i] = i * 1.0;
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24
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25 #pragma omp parallel shared(a,b,nthreads) private(c,i,tid)
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26 {
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27 tid = omp_get_thread_num();
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28 if (tid == 0)
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29 {
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30 nthreads = omp_get_num_threads();
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31 printf("Number of threads = %d\n", nthreads);
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32 }
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33 printf("Thread %d starting...\n",tid);
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34
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35 #pragma omp sections nowait
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36 {
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37 #pragma omp section
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38 {
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39 printf("Thread %d doing section 1\n",tid);
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40 for (i=0; i<N; i++)
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41 {
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42 c[i] = a[i] + b[i];
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43 printf("Thread %d: c[%d]= %f\n",tid,i,c[i]);
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44 }
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45 }
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46
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47 #pragma omp section
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48 {
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49 printf("Thread %d doing section 2\n",tid);
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50 for (i=0; i<N; i++)
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51 {
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52 c[i] = a[i] * b[i];
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53 printf("Thread %d: c[%d]= %f\n",tid,i,c[i]);
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54 }
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55 }
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56
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57 } /* end of sections */
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58
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59 printf("Thread %d done.\n",tid);
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60
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61 } /* end of parallel section */
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62
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63 return 0;
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64 }
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