#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>

#include "err_sys.c"
#include "shm.h"
#include "bib.semafor.c"

int       shmid[NBUFF], clisem, servsem;
Mesg     *mesgptr[NBUFF];

main()
{
  register int i;
  /*
   * Obtine segmentele de memorie partajata.
   */

  for (i = 0; i < NBUFF; i++) {
    if ((shmid[i] = shmget(SHMKEY + i, sizeof(Mesg), 0)) < 0)
      err_sys(" Client:Nu poate obtine memorie partajata ");
    if ((mesgptr[i] = (Mesg *) shmat(shmid[i], (char *) 0,
				     0)) == (Mesg *) - 1)
      err_sys("Client: Nu poate atasa memorie partajata");
  }

  /*
   * Deschide doua semafoare, create deja de server
   */

  if ((clisem = sem_create(SHMKEY1, 1)) < 0)
    err_sys("Clieny: Nu poate obtine semafor client");
  if ((servsem = sem_create(SHMKEY2, 0)) < 0)
    err_sys("Client: Nu poate obtine semafor server");

  client();

  /*
   * Deataseaza memoria partajata si inchide semafoarele.
   * Procesul client o va folosi ultimul, asa ca el o va sterge
   */

  for (i = 0; i < NBUFF; i++) {
    if (shmdt(mesgptr[i]) < 0)
      err_sys("Client: Nu pot elibera memoria partajata");

    if (shmctl(shmid[i], IPC_RMID, (struct shmid_ds *) 0) < 0)
      err_sys("Client: Nu poate sterge memoria partajata");
  }

  sem_close(clisem);
  sem_close(servsem);

  exit(0);
}

client()
{
  int       i, n;

  /*
   * Citeste numele de fisier de la intrarea stamdard si-l
   * depune in memoria partajata
   */

  sem_wait(clisem);
  if (fgets(mesgptr[0]->mesg_data, MAXMESGDATA, stdin) == NULL)
    err_sys("Eroare la citirea numelui de fisier");
  n = strlen(mesgptr[0]->mesg_data);
  if (mesgptr[0]->mesg_data[n - 1] == '\n')
    n--;
  mesgptr[0]->mesg_len = n;
  sem_signal(servsem);

  /*
   * Asteapta dupa server sa-l plaseze undeva in memoria
   * partajata
   */

  for (;;) {
    for (i = 0; i < NBUFF; i++) {
      sem_wait(clisem);
      if ((n = mesgptr[i]->mesg_len) <= 0)
	goto GATA;
      if (write(1, mesgptr[i]->mesg_data, n) != n)
	err_sys("Eroare la scrierea datelor");
      sem_signal(servsem);
    }
  }
GATA:
  if (n < 0)
    err_sys("server: eroare la citire");
}