struct semid_ds {
struct ipc_perm sem_perm;
time_t sem_otime;
time_t __unused1;
time_t sem_ctime;
time_t __unused2;
char __sem_nsems_pad[sizeof(time_t)-sizeof(short)];
unsigned short sem_nsems;
time_t __unused3;
time_t __unused4;
};