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// RUN: %libomp-compile
// 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
// Affinity Display examples
#include <stdio.h>
#include <stdlib.h> // also null is in <stddef.h>
#include <stddef.h>
#include <omp.h>
#include <string.h>
// ENVIRONMENT
// OMP_DISPLAY_AFFINITY=TRUE
// OMP_NUM_THREADS=4
// OMP_PLACES='{0,1},{2,3},{4,5},{6,7}'
// CHECK: num_threads=1 OMP: pid [0-9]+ tid [0-9]+ thread [0-4] bound to OS proc set \{([0-7])|(0,1)|(undefined)\}
// CHECK: num_threads=4 Thread id [0-3] reporting in
// CHECK: num_threads=4 OMP: pid [0-9]+ tid [0-9]+ thread [0-4] bound to OS proc set \{([0-7])|([0246],[1357])|(undefined)\}
// CHECK: num_threads=1 Default Affinity Format is:
// CHECK: num_threads=1 Affinity Format set to: host=%20H tid=%0.4n binds_to=%A
// CHECK: num_threads=4 tid=[0-3] affinity:host=[a-zA-Z0-9_.-]+[ ]+tid=000[0-4][ ]+binds_to=(([0-7])|([0246],[1357])|(undefined))
#define FORMAT_STORE 80
#define BUFFER_STORE 80
int main(int argc, char** argv) {
int i, n, tid, max_req_store = 0;
size_t nchars;
char default_format[FORMAT_STORE];
char my_format[] = "host=%20H tid=%0.4n binds_to=%A";
char **buffer;
// CODE SEGMENT 1 AFFINITY DISPLAY
omp_display_affinity(NULL);
// OMP_DISPLAY_AFFINITY=TRUE,
// Affinity reported for 1 parallel region
#pragma omp parallel
{
printf("Thread id %d reporting in.\n", omp_get_thread_num());
}
// Get and Display Default Affinity Format
nchars = omp_get_affinity_format(default_format, (size_t)FORMAT_STORE);
printf("Default Affinity Format is: %s\n", default_format);
if (nchars > FORMAT_STORE) {
printf("Caution: Reported Format is truncated. Increase\n");
printf(" FORMAT_STORE by %d.\n", (int)nchars - FORMAT_STORE);
}
// Set Affinity Format
omp_set_affinity_format(my_format);
printf("Affinity Format set to: %s\n", my_format);
// CODE SEGMENT 3 CAPTURE AFFINITY
// Set up buffer for affinity of n threads
n = omp_get_max_threads();
buffer = (char **)malloc(sizeof(char *) * n);
for (i = 0; i < n; i++) {
buffer[i] = (char *)malloc(sizeof(char) * BUFFER_STORE);
}
// Capture Affinity using Affinity Format set above.
// Use critical reduction to check size of buffer areas
#pragma omp parallel private(tid, nchars)
{
tid = omp_get_thread_num();
nchars = omp_capture_affinity(buffer[tid], (size_t)BUFFER_STORE, NULL);
#pragma omp critical
{
if (nchars > max_req_store)
max_req_store = nchars;
}
}
for (i = 0; i < n; i++) {
printf("tid=%d affinity:%s:\n", i, buffer[i]);
}
// for 4 threads with OMP_PLACES='{0,1},{2,3},{4,5},{6,7}'
// host=%20H tid=%0.4n binds_to=%A
// host=<hostname> tid=0000 binds_to=0,1
// host=<hostname> tid=0001 binds_to=2,3
// host=<hostname> tid=0002 binds_to=4,5
// host=<hostname> tid=0003 binds_to=6,7
if (max_req_store > BUFFER_STORE) {
printf("Caution: Affinity string truncated. Increase\n");
printf(" BUFFER_STORE by %d\n", max_req_store - BUFFER_STORE);
}
return 0;
}
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