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typedef unsigned short ushort;
struct sembuf {
ushort sem_num;
short sem_op;
short sem_flg;
};
union semun {
int val;
struct semid_ds *buf;
ushort *array;
struct seminfo *__buf;
void *__pad;
};
static union semun semctl_arg;
static int semid;
static void up(int sem){
struct sembuf sb;
sb.sem_num = (unsigned short) sem;
sb.sem_op = 1;
sb.sem_flg = 0x1000 ;
if(semop(semid, &sb, 1) == -1) error("up failure");
if(semctl(semid, sb.sem_num, 12 , semctl_arg) == 0)
printf("%s had processes sleeping on it!\n",
({ "MUTEX ", "BARB_SEM 1", "BARB_SEM 2", "CUST_SEM 1", "CUST_SEM 2", "WA
IT_SEM 1", "WAIT_SEM 2", "WAIT_SEM 3", "WAIT_SEM 4"} [( sb.sem_num )]) );
}
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