#include <stdio.h>
#include "ipcTools.h"
#include <sys/sem.h>
#include <stdlib.h>

int semalloc(key_t key, int valInit) {
  int semid = semget(key,1,0);
  if (semid == -1){
    semid = semget(key,1,IPC_CREAT|IPC_EXCL|0644);
    if (semid == -1)
      return -1;
    if (semctl(semid,0,SETVAL,valInit) == -1) {
      /* il faut detruire le semaphore */
      semctl(semid,0,IPC_RMID,0);
      return -1;
    }  
  }
  return semid;
}

static   struct sembuf sP = {0,-1,0};
static   struct sembuf sV = {0, 1,0};

void P(int semid){
  semop(semid,&sP,1);
}

void V(int semid) {
  semop(semid,&sV,1);
}

int semfree(int semid) {
  return semctl(semid,0,IPC_RMID);
}

void* shmalloc(key_t cle, int taille){
	void* res;
	
	int id = shmget(cle,1, 0600);/*si zone existe deja :*/
	if(id == -1){	/*sinon creation*/
		id = shmget(cle, taille, IPC_CREAT|IPC_EXCL|0644);
	}
	if(id==-1) return 0;
	res = shmat(id,0,0);	/*attachement a la mem loc*/
	if(res==(void*)-1){	/*si echec liberation*/
		shmctl(id,IPC_RMID, 0);
		return 0;
	}
	return res;
} // 0 = echec


int shmfree(key_t cle){
	int id = shmget(cle,  1, 0);
	return shmctl(id, IPC_RMID,0);
} // -1 impossible (ou deja recup) 0 si ok