1 // RUN: %libomp-compile
2 // RUN: env OMP_DISPLAY_AFFINITY=TRUE OMP_NUM_THREADS=4 OMP_PLACES='{0,1},{2,3},{4,5},{6,7}' %libomp-run | %python %S/check.py -c 'CHECK' %s
3
4 // Affinity Display examples
5 #include <stdio.h>
6 #include <stdlib.h> // also null is in <stddef.h>
7 #include <stddef.h>
8 #include <omp.h>
9 #include <string.h>
10
11 // ENVIRONMENT
12 // OMP_DISPLAY_AFFINITY=TRUE
13 // OMP_NUM_THREADS=4
14 // OMP_PLACES='{0,1},{2,3},{4,5},{6,7}'
15
16 // CHECK: num_threads=1 OMP: pid [0-9]+ tid [0-9]+ thread [0-4] bound to OS proc set \{([0-7])|(0,1)|(undefined)\}
17 // CHECK: num_threads=4 Thread id [0-3] reporting in
18 // CHECK: num_threads=4 OMP: pid [0-9]+ tid [0-9]+ thread [0-4] bound to OS proc set \{([0-7])|([0246],[1357])|(undefined)\}
19 // CHECK: num_threads=1 Default Affinity Format is:
20 // CHECK: num_threads=1 Affinity Format set to: host=%20H tid=%0.4n binds_to=%A
21 // CHECK: num_threads=4 tid=[0-3] affinity:host=[a-zA-Z0-9_.-]+[ ]+tid=000[0-4][ ]+binds_to=(([0-7])|([0246],[1357])|(undefined))
22
23 #define FORMAT_STORE 80
24 #define BUFFER_STORE 80
25
main(int argc,char ** argv)26 int main(int argc, char** argv) {
27 int i, n, tid, max_req_store = 0;
28 size_t nchars;
29 char default_format[FORMAT_STORE];
30 char my_format[] = "host=%20H tid=%0.4n binds_to=%A";
31 char **buffer;
32
33 // CODE SEGMENT 1 AFFINITY DISPLAY
34 omp_display_affinity(NULL);
35
36 // OMP_DISPLAY_AFFINITY=TRUE,
37 // Affinity reported for 1 parallel region
38 #pragma omp parallel
39 {
40 printf("Thread id %d reporting in.\n", omp_get_thread_num());
41 }
42
43 // Get and Display Default Affinity Format
44 nchars = omp_get_affinity_format(default_format, (size_t)FORMAT_STORE);
45 printf("Default Affinity Format is: %s\n", default_format);
46
47 if (nchars > FORMAT_STORE) {
48 printf("Caution: Reported Format is truncated. Increase\n");
49 printf(" FORMAT_STORE by %d.\n", (int)nchars - FORMAT_STORE);
50 }
51
52 // Set Affinity Format
53 omp_set_affinity_format(my_format);
54 printf("Affinity Format set to: %s\n", my_format);
55
56 // CODE SEGMENT 3 CAPTURE AFFINITY
57 // Set up buffer for affinity of n threads
58 n = omp_get_max_threads();
59 buffer = (char **)malloc(sizeof(char *) * n);
60 for (i = 0; i < n; i++) {
61 buffer[i] = (char *)malloc(sizeof(char) * BUFFER_STORE);
62 }
63
64 // Capture Affinity using Affinity Format set above.
65 // Use critical reduction to check size of buffer areas
66 #pragma omp parallel private(tid, nchars)
67 {
68 tid = omp_get_thread_num();
69 nchars = omp_capture_affinity(buffer[tid], (size_t)BUFFER_STORE, NULL);
70 #pragma omp critical
71 {
72 if (nchars > max_req_store)
73 max_req_store = nchars;
74 }
75 }
76
77 for (i = 0; i < n; i++) {
78 printf("tid=%d affinity:%s:\n", i, buffer[i]);
79 }
80 // for 4 threads with OMP_PLACES='{0,1},{2,3},{4,5},{6,7}'
81 // host=%20H tid=%0.4n binds_to=%A
82 // host=<hostname> tid=0000 binds_to=0,1
83 // host=<hostname> tid=0001 binds_to=2,3
84 // host=<hostname> tid=0002 binds_to=4,5
85 // host=<hostname> tid=0003 binds_to=6,7
86
87 if (max_req_store > BUFFER_STORE) {
88 printf("Caution: Affinity string truncated. Increase\n");
89 printf(" BUFFER_STORE by %d\n", max_req_store - BUFFER_STORE);
90 }
91 return 0;
92 }
93