1 /******************************************************************************
2 * FILE: omp_workshare2.c
3 * DESCRIPTION:
4 * OpenMP Example - Sections Work-sharing - C/C++ Version
5 * In this example, the OpenMP SECTION directive is used to assign
6 * different array operations to threads that execute a SECTION. Each
7 * thread receives its own copy of the result array to work with.
8 * AUTHOR: Blaise Barney 5/99
9 * LAST REVISED: 04/06/05
10 ******************************************************************************/
11 #include <omp.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #define N 50
15
main(int argc,char * argv[])16 int main (int argc, char *argv[]) {
17
18 int i, nthreads, tid;
19 float a[N], b[N], c[N];
20
21 /* Some initializations */
22 for (i=0; i<N; i++)
23 a[i] = b[i] = i * 1.0;
24
25 #pragma omp parallel shared(a,b,nthreads) private(c,i,tid)
26 {
27 tid = omp_get_thread_num();
28 if (tid == 0)
29 {
30 nthreads = omp_get_num_threads();
31 printf("Number of threads = %d\n", nthreads);
32 }
33 printf("Thread %d starting...\n",tid);
34
35 #pragma omp sections nowait
36 {
37 #pragma omp section
38 {
39 printf("Thread %d doing section 1\n",tid);
40 for (i=0; i<N; i++)
41 {
42 c[i] = a[i] + b[i];
43 printf("Thread %d: c[%d]= %f\n",tid,i,c[i]);
44 }
45 }
46
47 #pragma omp section
48 {
49 printf("Thread %d doing section 2\n",tid);
50 for (i=0; i<N; i++)
51 {
52 c[i] = a[i] * b[i];
53 printf("Thread %d: c[%d]= %f\n",tid,i,c[i]);
54 }
55 }
56
57 } /* end of sections */
58
59 printf("Thread %d done.\n",tid);
60
61 } /* end of parallel section */
62
63 return 0;
64 }
65