tot_nr_reads = malloc(sizeof(*tot_nr_reads) * nr_readers);
tot_nr_writes = malloc(sizeof(*tot_nr_writes) * nr_writers);
per_thread_lock = malloc(sizeof(*per_thread_lock) * nr_readers);
tot_nr_reads = malloc(sizeof(*tot_nr_reads) * nr_readers);
tot_nr_writes = malloc(sizeof(*tot_nr_writes) * nr_writers);
per_thread_lock = malloc(sizeof(*per_thread_lock) * nr_readers);