for (unsigned i = 1; i < num_workers; i++) {
ThreadData* data = new ThreadData(*this, i);
this->workers[i] = xbt_os_thread_create(nullptr, worker_main, data, nullptr);
for (unsigned i = 1; i < num_workers; i++) {
ThreadData* data = new ThreadData(*this, i);
this->workers[i] = xbt_os_thread_create(nullptr, worker_main, data, nullptr);