PRACE NPT

#ifndef SEMAPHORE_H

#define SEMAPHORE_H

#include <sys/types.h>

#include <sys/ipc.h>

#include <sys/sem.h>

#ifndef SEMUN_IN_SEM_H

union semun

{

  int val;                    /* value for SETVAL */

  struct semid_ds *buf;       /* buffer for IPC_STAT, IPC_SET */

  unsigned short int *array;  /* array for GETALL, SETALL */

  struct seminfo *__buf;      /* buffer for IPC_INFO */

};

#endif

class Semaphore

{

public:

  // numSems is the number of semaphores to be in the set

  // semKey is the ID number for the semaphore set

  // val is the initial value for the semaphores, no values will be assigned

  // if the default (0) is specified.

  Semaphore(int semKey, int numSems = 1, int val = 0);

  // clear the semaphores and return an error code.

  int clear_sem();

  // create the semaphores

  // count is the initial value assigned to each semaphore

  int create(int count);

  // get the handle to a semaphore set previously created

  int get_semid();

  int decrement_and_wait(int nr_sem);

  int get_mutex();

  int put_mutex();

private:

  union semun m_arg;

  int m_semid;

  int m_semflg;

  bool m_semopen;

  int m_semKey;

  int m_numSems;

};

#endif