void parse_and_set_affinity()

in horovod/common/common.cc [148:200]

• 44 lines of code
• 12 McCabe index (conditional complexity)

void parse_and_set_affinity(const char* affinity, int local_size, int local_rank) {
  if (affinity == nullptr) {
    return;
  }

  size_t affinity_len = strlen(affinity);

  // copy is needed because strsep is going to modify the buffer
  char* affinity_copy = (char*)calloc(affinity_len + 1, sizeof(char));
  memcpy(affinity_copy, affinity, affinity_len);
  char* tmp = affinity_copy;
  char *endptr;

  std::vector<int> core_ids(local_size);
  int count = 0;

  while (*tmp != 0 && count < local_size) {
    auto core_id_str = strsep(&tmp, ",");
    errno = 0;
    auto core_id = std::strtol(core_id_str, &endptr, 10);
    if (errno == ERANGE && (core_id == LONG_MAX || core_id == LONG_MIN)
        || (errno != 0 && core_id == 0)){
        LOG(ERROR) << "Core ID value is invalid in " << HOROVOD_THREAD_AFFINITY
                   << "=" << affinity;
        break;
    }

    if (endptr == core_id_str) {
        LOG(ERROR) << "No digits were found in " << HOROVOD_THREAD_AFFINITY
                   << "=" << affinity;
        break;
    }
    
    if (core_id < 0) {
      LOG(ERROR) << "Core ID cannot be less than zero but got "
                 << core_id << " in "
                 << HOROVOD_THREAD_AFFINITY << "=" << affinity;
      break;
    } else {
      core_ids[count] = core_id;
      count++;
    }
  }
    
  if (count < local_size) {
    LOG(ERROR) << "Expected " << local_size << " core ids but got " << count << ". "
               << HOROVOD_THREAD_AFFINITY << "=" << affinity;
  } else {
    set_affinity(core_ids[local_rank]);
  }

  free(affinity_copy);
}