/* $Id$
 * ============================================================================
 *
 * = LIBRARY
 *    pace
 *
 * = FILENAME
 *    pace/emulation/mqueue.h
 *
 * = AUTHOR
 *    John Heitmann
 *
 * = DESCRIPTION
 *    An implementation of POSIX message queues originally built for Linux,
 *    which lacks mqueue.h. Some ideas were taken from the W. Richard Stevens
 *    book Unix Network Programming Interprocess Communications Volume 2
 *    Second Edition.
 *    Memory Mapped io is used to enable a quick but persistent queue.
 *
 * ============================================================================ */

#ifndef PACE_EMU_MQUEUE_H
#define PACE_EMU_MQUEUE_H

#if defined (PACE_HAS_CPLUSPLUS)
extern "C" {
#endif /* PACE_HAS_CPLUSPLUS */

#define PACE_MQ_ATTR
typedef struct mq_attr
{
  long mq_flags;
  long mq_maxmsg;
  long mq_msgsize;
  long mq_curmsgs;
} pace_mq_attr;

struct mqd
{
  long length;
  int oflag;
  char* mptr;
};

#define PACE_MQD_T
typedef struct mqd* pace_mqd_t;

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
pace_mqd_t mq_open (const char* name,
                    int oflag,
                    pace_mode_t mode,
                    pace_mq_attr* attr);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
int mq_close (pace_mqd_t mqdes);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
int mq_unlink (const char* name);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
int mq_send (pace_mqd_t mqdes,
             const char* ptr,
             pace_size_t length,
             unsigned int priority);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
pace_ssize_t mq_receive (pace_mqd_t mqdes,
                         char * msg_ptr,
                         pace_size_t msg_len,
                         unsigned int * nmsg_prio);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
int mq_getattr (pace_mqd_t mqdes, pace_mq_attr * mqstat);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
int mq_setattr(pace_mqd_t mqdes,
               const pace_mq_attr * mqstat,
               pace_mq_attr * omqstat);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if (PACE_HAS_POSIX_NONUOF_FUNCS)
int mq_notify (pace_mqd_t mqd, const pace_sigevent* notification);
#endif /* PACE_HAS_POSIX_NONUOF_FUNCS */

#if defined (PACE_HAS_CPLUSPLUS)
}
#endif /* PACE_HAS_CPLUSPLUS */

#endif /* PACE_EMU_MQUEUE_H */