Elaborato_SO/src/custom_sem.c

34 lines
786 B
C

#include <sys/sem.h>
#include <sys/stat.h>
#include <custom_sem.h>
#include <structures.h>
#include <errExit.h>
void semOp(int semid, short sem_num, short sem_op) {
struct sembuf sop = {.sem_num = sem_num, .sem_op = sem_op, .sem_flg = 0};
if (semop(semid, &sop, 1) == -1) {
errExit("semop", "semOp");
}
}
int getSemid(key_t key, int size){
int semid = semget(key, size, S_IRUSR | S_IWUSR | IPC_CREAT);
if (semid == -1) {
errExit("semget", "getSemid");
}
return semid;
}
// mette i semafori a 0 e 2
void resetServerSem(int semid){
unsigned short val[2] = {0, 2};
union semun arg;
arg.array = val;
if (semctl(semid, 0 , SETALL, arg) == -1) {
errExit("semctl", "getSemid");
}
}