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Old stuff/ecole_etude_fac_de_pau/licence_3/systeme-d-exploitation/tp4/main.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <malloc.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <sys/sem.h>

typedef union semun {
       int val;                  /* valeur pour SETVAL */
       struct semid_ds *bufer;     /* buffer pour IPC_STAT, IPC_SET */
       unsigned short int *table;    /* table  pour GETALL, SETALL */
 } semun_t;




int main(int argc, char** argv)
{
  int semid;
  union semun arg;
  struct sembuf buf;
  unsigned short int table[1];
  table[0]=1;
  arg.table = table;
  printf("test table 0 = %d \n\n\n",arg.table[0]);
  
 
  pid_t pid;
  int sem;

  char* test=NULL;
  key_t cle= ftok("./prout",0);
  int id;
  const char source[] = "salut";
  
     semid = semget(IPC_PRIVATE, 1, IPC_CREAT|IPC_EXCL| 0600);
      printf("Semaphore : %d\n",semid);
      arg.val = 1;
      if (semctl(semid, 0, SETVAL,arg) == -1)
	{
	  perror("semctl");
	  exit(-1);
	}

  /*semaphore*/


  pid= fork();
  if (pid == -1) { 
    perror("fork");
    exit(-1);
  }
  else if(pid == 0)
    {
  sleep(1);
  struct sembuf buf;
  int sem;
  printf("On occupe\n");
  buf.sem_num = 0;
  buf.sem_flg = SEM_UNDO;
  buf.sem_op = -1;
  sem = semop(semid, &buf, 1);
      if (sem == -1) 
	{
      perror("semop");
      exit(-1);
	}
  sleep(1);
  char* test;
  key_t cle= ftok("./prout",0);  
  int id;
       id = shmget(cle,0,0);
      if (id == -1)
	{
	  perror("shmget");
	  exit(-1);
	}
      //      printf("Id = %d\n",id);
      test = (char*)shmat(id,0, 0);
      printf("On lit %s\n",test);
      shmdt(test); 

  buf.sem_op = 1;
  sem = semop(semid, &buf, 1);
      if (sem == -1) 
	{
      perror("semop");
      exit(-1);
	}
  
  exit(-1);
    }
  else
    {
         /* Synchro */


      buf.sem_num = 0;
      buf.sem_flg = SEM_UNDO;
      buf.sem_op = -1;
      //      printf("Passage avant  %d %d %d %d\n",sem,buf.sem_num,buf.sem_flg,buf.sem_op);
      sem = semop(semid, &buf, 1);
      if (sem == -1) 
	{
      perror("semop");
      exit(-1);
	}
      printf("on monopolise\n");
      sleep(3);

      buf.sem_op = 1;
        sem = semop(semid, &buf, 1);
      if (sem == -1) 
	{
      perror("semop");
      exit(-1);
	}
      printf("on libere\n");



  
  
      id = shmget(cle,100*sizeof(char),IPC_CREAT|IPC_EXCL|0777);
      if (id == -1)
	{
	  perror("shmget");
	  exit(-1);
	}
      //     printf("Id = %d\n",id);
      test = (char*)shmat(id,0, 0);
      if ((int)test == -1) { perror("error shmat");  exit(-1); }

	//	printf("Adresse %d\n",test);
	memcpy(test,source,sizeof(source)+1);
	printf("On ecrit : %s\n",test);

	kill(pid,SIGUSR1);
	wait();
	shmdt(test);
	shmctl(id, IPC_RMID, NULL);
  /* Liberation */
  buf.sem_op = 1;
  semop(semid, &buf, 1);
  printf("Semaphore apres %d\n",arg.val);

  /*destruction du sémaphore*/
   semctl(semid, 0, IPC_RMID, 0);

    }

  return 1;
}