1 /* Simple OpenMP test program that calls printf() from a parallel section. */
2
3 #include <assert.h> // assert()
4 #include <omp.h>
5 #include <stdio.h>
6 #include <stdlib.h> // atoi()
7 #include <unistd.h> // getopt()
8
usage(const char * const exe)9 static void usage(const char* const exe)
10 {
11 fprintf(stderr,
12 "Usage: %s [-h] [-i <n>] [-q] [-t<n>]\n"
13 "-h: display this information.\n"
14 "-i <n>: number of loop iterations.\n"
15 "-q: quiet mode -- do not print computed error.\n"
16 "-t <n>: number of OMP threads.\n",
17 exe);
18 }
19
main(int argc,char ** argv)20 int main(int argc, char** argv)
21 {
22 int i;
23 int optchar;
24 int silent = 0;
25 int tid;
26 int num_iterations = 2;
27 int num_threads = 2;
28
29 while ((optchar = getopt(argc, argv, "hi:qt:")) != EOF)
30 {
31 switch (optchar)
32 {
33 case 'h': usage(argv[0]); return 1;
34 case 'i': num_iterations = atoi(optarg); break;
35 case 'q': silent = 1; break;
36 case 't': num_threads = atoi(optarg); break;
37 default:
38 return 1;
39 }
40 }
41
42 /*
43 * Not the most user-friendly way of error checking, but still better than
44 * no error checking.
45 */
46 assert(num_iterations > 0);
47 assert(num_threads > 0);
48
49 omp_set_num_threads(num_threads);
50 omp_set_dynamic(0);
51
52 #pragma omp parallel for private(tid)
53 for (i = 0; i < num_iterations; i++)
54 {
55 tid = omp_get_thread_num();
56 if (! silent)
57 {
58 fprintf(stderr,
59 "iteration %d; thread number = %d; number of threads = %d\n",
60 i, tid, omp_get_num_threads());
61 }
62 else
63 {
64 fprintf(stderr, "%s", "");
65 }
66 }
67
68 fprintf(stderr, "Finished.\n");
69
70 return 0;
71 }
72