reader_time = calloc(num_read, sizeof(*reader_time));
writer_time = calloc(num_write, sizeof(*writer_time));
tid_reader = calloc(num_read, sizeof(*tid_reader));
reader_time = calloc(num_read, sizeof(*reader_time));
writer_time = calloc(num_write, sizeof(*writer_time));
tid_reader = calloc(num_read, sizeof(*tid_reader));