base/include/rtai_mq.h

Go to the documentation of this file.

/*
 * pqueues interface for Real Time Linux.
 *
 * Copyright (©) 1999 Zentropic Computing, All rights reserved
 *  
 * Authors:         Trevor Woolven (trevw@zentropix.com)
 *
 * Original date:   Thu 15 Jul 1999
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * 2005, cleaned and revised Paolo Mantegazza <mantegazza@aero.polimi.it>.
 *
 */

#ifndef _RTAI_MQ_H
#define _RTAI_MQ_H

#include <linux/version.h>
#include <rtai_sem.h>

#define MQ_OPEN_MAX 8   /* Maximum number of message queues per process */
#define MQ_PRIO_MAX 32  /* Maximum number of message priorities */
#define MQ_BLOCK    0   /* Flag to set queue into blocking mode */
#define MQ_NONBLOCK 1   /* Flag to set queue into non-blocking mode */
#define MQ_NAME_MAX 80  /* Maximum length of a queue name string */

#define MQ_MIN_MSG_PRIORITY 0           /* Lowest priority message */
#define MQ_MAX_MSG_PRIORITY MQ_PRIO_MAX     /* Highest priority message */

#define MAX_PQUEUES     4       /* Maximum number of message queues in module */
#define MAX_MSGSIZE     50      /* Maximum message size per queue (bytes) */
#define MAX_MSGS        10      /* Maximum number of messages per queue */

typedef struct mq_attr {
    long mq_maxmsg;     /* Maximum number of messages in queue */
    long mq_msgsize;        /* Maximum size of a message (in bytes) */
    long mq_flags;      /* Blocking/Non-blocking behaviour specifier */
    long mq_curmsgs;        /* Number of messages currently in queue */
} MQ_ATTR;

#define INVALID_PQUEUE  0

#ifdef __KERNEL__

#include <linux/types.h>

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,6)
typedef int mqd_t;
#endif

#ifndef __cplusplus

typedef int mq_bool_t;

#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif

typedef struct msg_hdr {
    size_t size;        /* Actual message size */
    uint priority;      /* Usage priority (message/task) */
    void *next;         /* Pointer to next message on queue */
} MSG_HDR;

#define MSG_HDR_SIZE    (sizeof(MSG_HDR))

typedef struct queue_control {
    int nodind;
    void **nodes;
    void *base;     /* Pointer to the base of the queue in memory */
    void *head;     /* Pointer to the element at the front of the queue */
    void *tail;     /* Pointer to the element at the back of the queue */
    MQ_ATTR attrs;  /* Queue attributes */
} Q_CTRL;

typedef struct msg {
    MSG_HDR hdr;
    char data;      /* Anchor point for message data */
} MQMSG;

struct notify {
    RT_TASK *task;
    struct sigevent data;
};

typedef struct _pqueue_descr_struct {
    RT_TASK *owner;     /* Task that created the queue */
    int open_count;     /* Count of the number of tasks that have */
                /*  'opened' the queue for access */
    char q_name[MQ_NAME_MAX];   /* Name supplied for queue */
    uint q_id;          /* Queue Id (index into static list of queues) */
    mq_bool_t marked_for_deletion;  /* Queue can be deleted once all tasks have  */
                /*  closed it   */
    Q_CTRL data;        /* Data queue (real messages) */
    mode_t permissions;     /* Permissions granted by creator (ugo, rwx) */
    struct notify notify;   /* Notification data (empty -> !empty) */
    SEM emp_cond;       /* For blocking on empty queue */
    SEM full_cond;      /* For blocking on full queue */
    SEM mutex;          /* For synchronisation of queue */
} MSG_QUEUE;

struct _pqueue_access_data {
    int q_id;
    int oflags;         /* Queue access permissions & blocking spec */
};

typedef struct _pqueue_access_struct {
    RT_TASK *this_task;
    int n_open_pqueues;
    struct _pqueue_access_data q_access[MQ_OPEN_MAX];
} *QUEUE_CTRL;

typedef enum {
    FOR_READ,
    FOR_WRITE
} Q_ACCESS;

#else /* __cplusplus */
extern "C" {
#endif /* !__cplusplus */

int __rtai_mq_init(void);

void __rtai_mq_exit(void);

mqd_t mq_open(char *mq_name, int oflags, mode_t permissions, struct mq_attr *mq_attr);

size_t _mq_receive(mqd_t mq, char *msg_buffer, size_t buflen, unsigned int *msgprio, int space);
static inline size_t mq_receive(mqd_t mq, char *msg_buffer, size_t buflen, unsigned int *msgprio)
{
    return _mq_receive(mq, msg_buffer, buflen, msgprio, 1);
}

int _mq_send(mqd_t mq, const char *msg, size_t msglen, unsigned int msgprio, int space);
static inline int mq_send(mqd_t mq, const char *msg, size_t msglen, unsigned int msgprio)
{
    return _mq_send(mq, msg, msglen, msgprio, 1);
}

int mq_close(mqd_t mq);

int mq_getattr(mqd_t mq, struct mq_attr *attrbuf);

int mq_setattr(mqd_t mq, const struct mq_attr *new_attrs, struct mq_attr *old_attrs);

int mq_notify(mqd_t mq, const struct sigevent *notification);

int mq_unlink(char *mq_name);

size_t _mq_timedreceive(mqd_t mq, char *msg_buffer, size_t buflen, unsigned int *msgprio, const struct timespec *abstime, int space);
static inline size_t mq_timedreceive(mqd_t mq, char *msg_buffer, size_t buflen, unsigned int *msgprio, const struct timespec *abstime)
{
    return _mq_timedreceive(mq, msg_buffer, buflen, msgprio, abstime, 1);
}

int _mq_timedsend(mqd_t mq, const char *msg, size_t msglen, unsigned int msgprio, const struct timespec *abstime, int space);
static inline int mq_timedsend(mqd_t mq, const char *msg, size_t msglen, unsigned int msgprio, const struct timespec *abstime)
{
    return _mq_timedsend(mq, msg, msglen, msgprio, abstime, 1);
}

#ifdef __cplusplus
}
#endif /* __cplusplus */

#else /* !__KERNEL__ */

#include <signal.h>
#include <rtai_lxrt.h>

#define MQIDX  0

typedef int mqd_t;

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

RTAI_PROTO(mqd_t, mq_open,(char *mq_name, int oflags, mode_t permissions, struct mq_attr *mq_attr))
{
    struct {char *mq_name; int oflags; mode_t permissions; struct mq_attr *mq_attr; int namesize, attrsize; } arg = { mq_name, oflags, permissions, mq_attr, strlen(mq_name) + 1, sizeof(struct mq_attr) };
    return (mqd_t)rtai_lxrt(MQIDX, SIZARG, MQ_OPEN, &arg).i[LOW];
}

RTAI_PROTO(size_t, mq_receive,(mqd_t mq, char *msg_buffer, size_t buflen, unsigned int *msgprio))
{
    struct { mqd_t mq; char *msg_buffer; size_t buflen; unsigned int *msgprio; int space; } arg = { mq, msg_buffer, buflen, msgprio, 0 };
    return (size_t)rtai_lxrt(MQIDX, SIZARG, MQ_RECEIVE, &arg).i[LOW];
}

RTAI_PROTO(int, mq_send,(mqd_t mq, const char *msg, size_t msglen, unsigned int msgprio))
{
    struct { mqd_t mq; const char *msg; size_t msglen; unsigned int msgprio; int space; } arg = { mq, msg, msglen, msgprio, 0 };
    return rtai_lxrt(MQIDX, SIZARG, MQ_SEND, &arg).i[LOW];
}

RTAI_PROTO(int, mq_close,(mqd_t mq))
{
    struct { mqd_t mq; } arg = { mq };
    return rtai_lxrt(MQIDX, SIZARG, MQ_CLOSE, &arg).i[LOW];
}

RTAI_PROTO(int, mq_getattr,(mqd_t mq, struct mq_attr *attrbuf))
{
    struct { mqd_t mq; struct mq_attr *attrbuf; int attrsize; } arg = { mq, attrbuf, sizeof(struct mq_attr) };
    return rtai_lxrt(MQIDX, SIZARG, MQ_GETATTR, &arg).i[LOW];
}

RTAI_PROTO(int, mq_setattr,(mqd_t mq, const struct mq_attr *new_attrs, struct mq_attr *old_attrs))
{
    struct { mqd_t mq; const struct mq_attr *new_attrs; struct mq_attr *old_attrs; int attrsize; } arg = { mq, new_attrs, old_attrs, sizeof(struct mq_attr) };
    return rtai_lxrt(MQIDX, SIZARG, MQ_SETATTR, &arg).i[LOW];
}

RTAI_PROTO(int, mq_notify,(mqd_t mq, const struct sigevent *notification))
{
    struct { mqd_t mq; const struct sigevent *notification; int size; } arg = { mq, notification, sizeof(struct sigevent) };
    return rtai_lxrt(MQIDX, SIZARG, MQ_NOTIFY, &arg).i[LOW];
}

RTAI_PROTO(int, mq_unlink,(char *mq_name))
{
    struct { char *mq_name; int size; } arg = { mq_name, strlen(mq_name) + 1};
    return rtai_lxrt(MQIDX, SIZARG, MQ_UNLINK, &arg).i[LOW];
}

RTAI_PROTO(size_t, mq_timedreceive,(mqd_t mq, char *msg_buffer, size_t buflen, unsigned int *msgprio, const struct timespec *abstime))
{
    struct { mqd_t mq; char *msg_buffer; size_t buflen; unsigned int *msgprio; const struct timespec *abstime; int space; } arg = { mq, msg_buffer, buflen, msgprio, abstime, 0 };
    return (size_t)rtai_lxrt(MQIDX, SIZARG, MQ_TIMEDRECEIVE, &arg).i[LOW];
}

RTAI_PROTO(int, mq_timedsend,(mqd_t mq, const char *msg, size_t msglen, unsigned int msgprio, const struct timespec *abstime))
{
    struct { mqd_t mq; const char *msg; size_t msglen; unsigned int msgprio; const struct timespec *abstime; int space; } arg = { mq, msg, msglen, msgprio, abstime, 0 };
    return rtai_lxrt(MQIDX, SIZARG, MQ_TIMEDSEND, &arg).i[LOW];
}

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* __KERNEL__ */

#endif  /* !_RTAI_MQ_H */

---