rt-thread/components/pthreads/mqueue.c

#include "mqueue.h"
#include "pthread_internal.h"

static mqd_t posix_mq_list = RT_NULL;
static struct rt_semaphore posix_mq_lock;
void posix_mq_system_init()
{
	rt_sem_init(&posix_mq_lock, "pmq", 1, RT_IPC_FLAG_FIFO);
}

rt_inline void posix_mq_insert(mqd_t pmq)
{
	pmq->next = posix_mq_list;
	posix_mq_list = pmq;
}

static void posix_mq_delete(mqd_t pmq)
{
	mqd_t iter;
	if (posix_mq_list == pmq)
	{
		posix_mq_list = pmq->next;

		rt_mq_delete(pmq->mq);
		rt_free(pmq);

		return;
	}
	for (iter = posix_mq_list; iter->next != RT_NULL; iter = iter->next)
	{
		if (iter->next == pmq)
		{
			/* delete this mq */
			if (pmq->next != RT_NULL)
				iter->next = pmq->next;
			else
				iter->next = RT_NULL;

			/* delete RT-Thread mqueue */
			rt_mq_delete(pmq->mq);
			rt_free(pmq);
			return ;
		}
	}
}

static mqd_t posix_mq_find(const char* name)
{
	mqd_t iter;
	rt_object_t object;

	for (iter = posix_mq_list; iter != RT_NULL; iter = iter->next)
	{
		object = (rt_object_t)(iter->mq);

		if (strncmp(object->name, name, RT_NAME_MAX) == 0)
		{
			return iter;
		}
	}

	return RT_NULL;
}

int mq_setattr(mqd_t mqdes, const struct mq_attr *mqstat,
		struct mq_attr *omqstat)
{
	rt_set_errno(-RT_ERROR);
	return -1;
}

int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat)
{
	if ((mqdes == RT_NULL) || mqstat == RT_NULL)
	{
		rt_set_errno(EBADF);
		return -1;
	}

	mqstat->mq_maxmsg = mqdes->mq->max_msgs;
	mqstat->mq_msgsize = mqdes->mq->msg_size;
	mqstat->mq_curmsgs = 0;
	mqstat->mq_flags = 0;

	return 0;
}

mqd_t mq_open(const char *name, int oflag, ...)
{
	mqd_t mqdes;
	va_list arg;
	mode_t mode;
	struct mq_attr *attr = RT_NULL;

    /* lock posix mqueue list */
    rt_sem_take(&posix_mq_lock, RT_WAITING_FOREVER);

    mqdes = RT_NULL;
	if (oflag & O_CREAT)
	{
	    va_start(arg, oflag);
	    mode = (mode_t) va_arg(arg, unsigned int); mode = mode;
	    attr = (struct mq_attr *) va_arg(arg, struct mq_attr *);
	    va_end(arg);

	    if (oflag & O_EXCL)
	    {
	    	if (posix_mq_find(name) != RT_NULL)
	    	{
	    		rt_set_errno(EEXIST);
	    		goto __return;
	    	}
	    }
	    mqdes = (mqd_t) rt_malloc (sizeof(struct mqdes));
	    if (mqdes == RT_NULL)
	    {
	    	rt_set_errno(ENFILE);
	    	goto __return;
	    }

	    /* create RT-Thread message queue */
		mqdes->mq = rt_mq_create(name, attr->mq_msgsize, attr->mq_maxmsg, RT_IPC_FLAG_FIFO);
		if (mqdes->mq == RT_NULL) /* create failed */
		{
			rt_set_errno(ENFILE);
			goto __return;
		}
		/* initialize reference count */
		mqdes->refcount = 1;
		mqdes->unlinked = 0;

		/* insert mq to posix mq list */
		posix_mq_insert(mqdes);
	}
	else
	{
		/* find mqueue */
		mqdes = posix_mq_find(name);
		if (mqdes != RT_NULL)
		{
			mqdes->refcount ++; /* increase reference count */
		}
		else
		{
			rt_set_errno(ENOENT);
			goto __return;
		}
	}
	rt_sem_release(&posix_mq_lock);
	return mqdes;

__return:
	/* release lock */
	rt_sem_release(&posix_mq_lock);

	/* release allocated memory */
	if (mqdes != RT_NULL)
	{
		if (mqdes->mq != RT_NULL)
		{
			/* delete RT-Thread message queue */
			rt_mq_delete(mqdes->mq);
		}
		rt_free(mqdes);
	}
	return RT_NULL;
}

ssize_t mq_receive(mqd_t mqdes, char *msg_ptr, size_t msg_len, unsigned *msg_prio)
{
	rt_err_t result;

	if ((mqdes == RT_NULL) || (msg_ptr == RT_NULL))
	{
		rt_set_errno(EINVAL);
		return -1;
	}

	result = rt_mq_recv(mqdes->mq, msg_ptr, msg_len, RT_WAITING_FOREVER);
	if (result == RT_EOK)
		return msg_len;

	rt_set_errno(EBADF);
	return -1;
}

int mq_send(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned msg_prio)
{
	rt_err_t result;

	if ((mqdes == RT_NULL) || (msg_ptr == RT_NULL))
	{
		rt_set_errno(EINVAL);
		return -1;
	}

	result = rt_mq_send(mqdes->mq, (void*)msg_ptr, msg_len);
	if (result == RT_EOK)
		return 0;

	rt_set_errno(EBADF);
	return -1;
}

ssize_t mq_timedreceive(mqd_t mqdes, char *msg_ptr, size_t msg_len,
	unsigned *msg_prio, const struct timespec *abs_timeout)
{
	int tick;
	rt_err_t result;

	/* parameters check */
	if ((mqdes == RT_NULL) || (msg_ptr == RT_NULL))
	{
		rt_set_errno(EINVAL);
		return -1;
	}

	tick = clock_time_to_tick(abs_timeout);

	result = rt_mq_recv(mqdes->mq, msg_ptr, msg_len, tick);
	if (result == RT_EOK) return msg_len;

	if (result == -RT_ETIMEOUT)
		rt_set_errno(ETIMEDOUT);
	else
		rt_set_errno(EBADMSG);

	return -1;
}

int mq_timedsend(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned msg_prio,
		const struct timespec *abs_timeout)
{
	/* RT-Thread does not support timed send */
	return mq_send(mqdes, msg_ptr, msg_len, msg_prio);
}

int mq_notify(mqd_t mqdes, const struct sigevent *notification)
{
	rt_set_errno(-RT_ERROR);
	return -1;
}

int mq_close(mqd_t mqdes)
{
	if (mqdes == RT_NULL)
	{
		rt_set_errno(EINVAL);
		return -1;
	}

    /* lock posix mqueue list */
    rt_sem_take(&posix_mq_lock, RT_WAITING_FOREVER);
    mqdes->refcount --;
    if (mqdes->refcount == 0)
    {
    	/* delete from posix mqueue list */
    	if (mqdes->unlinked)
    		posix_mq_delete(mqdes);
    }
    rt_sem_release(&posix_mq_lock);

    return 0;
}

int mq_unlink(const char *name)
{
	mqd_t pmq;

    /* lock posix mqueue list */
    rt_sem_take(&posix_mq_lock, RT_WAITING_FOREVER);
    pmq = posix_mq_find(name);
    if (pmq != RT_NULL)
    {
    	pmq->unlinked = 1;
    	if (pmq->refcount == 0)
    	{
    		/* remove this mqueue */
    		posix_mq_delete(pmq);
    	}
        rt_sem_release(&posix_mq_lock);
        return 0;
    }
    rt_sem_release(&posix_mq_lock);

    /* no this entry */
    rt_set_errno(ENOENT);
    return -1;
}