crearProcSemPosix.cpp

#include <iostream>
#include <semaphore.h>
#include <unistd.h>
#include <cstdlib>
#include <cstring>
#include <cerrno>

using namespace std;

void* cliente(void *);
void* servidor(void *);

int
main(int argc, char *argv[]) {

  sem_t *sem = new sem_t;

  if (sem_init(sem, 0, 0) == -1) {
    cerr << "Error creando el semaforo: " <<
      strerror(errno) << endl;
    return EXIT_FAILURE;
  }

  pthread_t hSrv;
  pthread_t hCln;

  pthread_create(&hSrv, nullptr, servidor, (void *) sem);
  pthread_create(&hCln, nullptr, cliente, (void *) sem);

  pthread_join(hSrv, nullptr);
  pthread_join(hCln, nullptr);

  return EXIT_SUCCESS;
}

void* cliente(void *arg) {

  sem_t *sem = (sem_t *) arg;
  for (;;) {
    sleep(10);
    sem_post(sem);
  }
}

void* servidor(void *arg) {

  sem_t *sem = (sem_t *) arg;

  for (;;) {
    cout << "Esperando para imprimir" << endl;
    sem_wait(sem);
    cout << "Impresion lista" << endl;
  }
}