ipc.c.svn-base

RT-Thread是发展中的下一代微内核嵌入式实时操作系统

	/* parameter check */
	RT_ASSERT(mb != RT_NULL);

#ifdef RT_USING_HOOK
	if (rt_object_trytake_hook != RT_NULL) rt_object_trytake_hook(&(mb->parent.parent));
#endif

	/* disable interrupt */
	temp = rt_hw_interrupt_disable();

	/* mailbox is empty */
	if (mb->entry == 0)
	{
		/* get current thread */
		thread = rt_thread_self();

		/* reset error number in thread */
		thread->error = RT_EOK;

		/* no waiting, return timeout */
		if (timeout == 0)
		{
			/* enable interrupt */
			rt_hw_interrupt_enable(temp);

			thread->error = -RT_ETIMEOUT;
			return -RT_ETIMEOUT;
		}

		/* suspend current thread */
		rt_ipc_object_suspend(&(mb->parent), thread);

		/* has waiting time, start thread timer */
		if (timeout > 0)
		{
#ifdef IPC_DEBUG
			rt_kprintf("set thread:%s to timer list\n", thread->name);
#endif
			/* reset the timeout of thread timer and start it */
			rt_timer_control(&(thread->thread_timer), RT_TIMER_CTRL_SET_TIME, &timeout);
			rt_timer_start(&(thread->thread_timer));
		}

		/* enable interrupt */
		rt_hw_interrupt_enable(temp);

		/* re-schedule */
		rt_schedule();

		/* recv message */
		if (thread->error != RT_EOK) /* maybe return RT_ETIMEOUT */
			return thread->error;

		/* disable interrupt */
		temp = rt_hw_interrupt_disable();
	}

	/* fill ptr */
	*value = mb->msg_pool[mb->out_offset];

	/* increase output offset */
	mb->out_offset = (++ mb->out_offset) % mb->size;
	/* decrease message entry */
	mb->entry --;

	/* enable interrupt */
	rt_hw_interrupt_enable(temp);

#ifdef RT_USING_HOOK
	if (rt_object_take_hook != RT_NULL) rt_object_take_hook(&(mb->parent.parent));
#endif

	return RT_EOK;
}

/**
 * This function can get or set some extra attributions of a mailbox object.
 *
 * @param mb the mailbox object
 * @param cmd the execution command
 * @param arg the execution argument
 *
 * @return the error code
 */
rt_err_t rt_mb_control(rt_mailbox_t mb, rt_uint8 cmd, void* arg)
{
	return RT_EOK;
}

#endif /* end of RT_USING_MAILBOX */

#ifdef RT_USING_MESSAGEQUEUE

struct rt_mq_message
{
	struct rt_mq_message* next;
};

/**
 * This function will initialize a message queue and put it under control of resource
 * management.
 *
 * @param mq the message object
 * @param name the name of message queue
 * @param msgpool the beginning address of buffer to save messages
 * @param msg_size the maximum size of message
 * @param pool_size the size of buffer to save messages
 * @param flag the flag of message queue
 *
 * @return the operation status, RT_EOK on successful
 */
rt_err_t rt_mq_init(rt_mq_t mq, const char* name, void *msgpool, rt_size_t msg_size, rt_size_t pool_size, rt_uint8 flag)
{
	struct rt_mq_message* head;
	register rt_base_t temp;

	/* parameter check */
	RT_ASSERT(mq != RT_NULL);

	/* init object */
	rt_object_init(&(mq->parent.parent), RT_Object_Class_MessageQueue, name);

	/* set parent flag */
	mq->parent.parent.flag = flag;

	/* init ipc object */
	rt_ipc_object_init(&(mq->parent));

	/* set messasge pool */
	mq->msg_pool 	= msgpool;

	/* get correct message size */
	mq->msg_size	= RT_ALIGN(msg_size,  RT_ALIGN_SIZE);
	mq->max_msgs	= pool_size / (mq->msg_size + sizeof(struct rt_mq_message));

	/* init message list */
	mq->msg_queue_head = RT_NULL;
	mq->msg_queue_tail = RT_NULL;

	/* init message empty list */
	mq->msg_queue_free = RT_NULL;
	for (temp = 0; temp < mq->max_msgs; temp ++)
	{
		head = (struct rt_mq_message*)((rt_uint8*)mq->msg_pool +
			temp * (mq->msg_size + sizeof(struct rt_mq_message)));
		head->next = mq->msg_queue_free;
		mq->msg_queue_free = head;
	}

	/* the initial entry is zero */
	mq->entry		= 0;

	return RT_EOK;
}

/**
 * This function will detach a message queue object from resource management
 *
 * @param mq the message queue object
 *
 * @return the operation status, RT_EOK on successful
 */
rt_err_t rt_mq_detach(rt_mq_t mq)
{
	/* parameter check */
	RT_ASSERT(mq != RT_NULL);

	/* resume all suspended thread */
	rt_ipc_object_resume_all((struct rt_ipc_object*)mq);

	/* detach message queue object */
	rt_object_detach(&(mq->parent.parent));

	return RT_EOK;
}

#ifdef RT_USING_HEAP
/**
 * This function will create a message queue object from system resource
 *
 * @param name the name of message queue
 * @param msg_size the size of message
 * @param max_msgs the maximum number of message in queue
 * @param flag the flag of message queue
 *
 * @return the created message queue, RT_NULL on error happen
 */
rt_mq_t rt_mq_create (const char* name, rt_size_t msg_size, rt_size_t max_msgs, rt_uint8 flag)
{
	struct rt_messagequeue* mq;
	struct rt_mq_message* head;
	register rt_base_t temp;

	/* allocate object */
	mq = (rt_mq_t) rt_object_allocate(RT_Object_Class_MessageQueue, name);
	if (mq == RT_NULL) return mq;

	/* set parent */
	mq->parent.parent.flag = flag;

	/* init ipc object */
	rt_ipc_object_init(&(mq->parent));

	/* init message queue */

	/* get correct message size */
	mq->msg_size	= RT_ALIGN(msg_size, RT_ALIGN_SIZE);
	mq->max_msgs	= max_msgs;

	/* allocate message pool */
	mq->msg_pool 	= rt_malloc(mq->msg_size * mq->max_msgs);
	if (mq->msg_pool == RT_NULL)
	{
		rt_mq_delete(mq);
		return RT_NULL;
	}

	/* init message list */
	mq->msg_queue_head = RT_NULL;
	mq->msg_queue_tail = RT_NULL;

	/* init message empty list */
	mq->msg_queue_free = RT_NULL;
	for (temp = 0; temp < mq->max_msgs; temp ++)
	{
		head = (struct rt_mq_message*)((rt_uint8*)mq->msg_pool +
			temp * (mq->msg_size + sizeof(struct rt_mq_message)));
		head->next = mq->msg_queue_free;
		mq->msg_queue_free = head;
	}

	/* the initial entry is zero */
	mq->entry		= 0;

	return mq;
}

/**
 * This function will delete a message queue object and release the memory
 *
 * @param mq the message queue object
 *
 * @return the error code
 */
rt_err_t rt_mq_delete (rt_mq_t mq)
{
	/* parameter check */
	RT_ASSERT(mq != RT_NULL);

	/* resume all suspended thread */
	rt_ipc_object_resume_all(&(mq->parent));

	/* free mailbox pool */
	rt_free(mq->msg_pool);

	/* delete mailbox object */
	rt_object_delete(&(mq->parent.parent));

	return RT_EOK;
}
#endif

/**
 * This function will send a message to message queue object, if there are threads 
 * suspended on message queue object, it will be waked up.
 *
 * @param mq the message queue object
 * @param buffer the message
 * @param size the size of buffer
 *
 * @return the error code
 */
rt_err_t rt_mq_send (rt_mq_t mq, void* buffer, rt_size_t size)
{
	register rt_ubase_t temp;
	struct rt_mq_message *msg;

	/* greater than one message size */
	if (size > mq->msg_size) return -RT_ERROR;

#ifdef RT_USING_HOOK
	if (rt_object_put_hook != RT_NULL) rt_object_put_hook(&(mq->parent.parent));
#endif

	/* disable interrupt */
	temp = rt_hw_interrupt_disable();

	/* get a free list, there must be an empty item */
	msg = (struct rt_mq_message*)mq->msg_queue_free;

	/* message queue is full */
	if (msg == RT_NULL)
	{
		/* enable interrupt */
		rt_hw_interrupt_enable(temp);

		return -RT_EFULL;
	}

	/* move free list pointer */
	mq->msg_queue_free = msg->next;

	/* copy buffer */
	rt_memcpy(msg + 1, buffer, size);

	/* link msg to message queue */
	if (mq->msg_queue_tail != RT_NULL)
	{
		/* if the tail exists, */
		((struct rt_mq_message*)mq->msg_queue_tail)->next = msg;
	}
	/* the msg is the new tail of list, the next shall be NULL */
	msg->next = RT_NULL;

	/* set new tail */
	mq->msg_queue_tail = msg;

	/* if the head is empty, set head */
	if (mq->msg_queue_head == RT_NULL)mq->msg_queue_head = msg;

	/* increase message entry */
	mq->entry ++;

	/* resume suspended thread */
	if (mq->parent.suspend_thread_count > 0)
	{
		rt_ipc_object_resume(&(mq->parent));
	}

	/* enable interrupt */
	rt_hw_interrupt_enable(temp);

	rt_schedule();

	return RT_EOK;
}

/**
 * This function will send urgently a message to message queue object, which means
 * the message will be inserted to the head of message queue. If there are threads 
 * suspended on message queue object, it will be waked up.
 *
 * @param mq the message queue object
 * @param buffer the message
 * @param size the size of buffer
 *
 * @return the error code
 */
rt_err_t rt_mq_urgent(rt_mq_t mq, void* buffer, rt_size_t size)
{
	register rt_ubase_t temp;
	struct rt_mq_message *msg;

	/* greater than one message size */
	if (size > mq->msg_size) return -RT_ERROR;

#ifdef RT_USING_HOOK
	if (rt_object_put_hook != RT_NULL) rt_object_put_hook(&(mq->parent.parent));
#endif

	/* disable interrupt */
	temp = rt_hw_interrupt_disable();

	/* get a free list, there must be an empty item */
	msg = (struct rt_mq_message*)mq->msg_queue_free;

	/* message queue is full */
	if (msg == RT_NULL)
	{
		/* enable interrupt */
		rt_hw_interrupt_enable(temp);

		return -RT_EFULL;
	}

	/* move free list pointer */
	mq->msg_queue_free = msg->next;

	/* copy buffer */
	rt_memcpy(msg + 1, buffer, size);

	/* link msg to the beginning of message queue */
	msg->next = mq->msg_queue_head;
	mq->msg_queue_head = msg;

	/* if there is no tail */
	if (mq->msg_queue_tail == RT_NULL) mq->msg_queue_tail = msg;

	/* increase message entry */
	mq->entry ++;

	/* resume suspended thread */
	if (mq->parent.suspend_thread_count > 0)
	{
		rt_ipc_object_resume(&(mq->parent));
	}

	/* enable interrupt */
	rt_hw_interrupt_enable(temp);

	rt_schedule();

	return RT_EOK;
}

/**
 * This function will receive a message from message queue object, if there is no 
 * message in message queue object, the thread shall wait for a specified time.
 *
 * @param mq the message queue object
 * @param buffer the received message will be saved in
 * @param size the size of buffer
 * @param timeout the waiting time
 *
 * @return the error code
 */
rt_err_t rt_mq_recv (rt_mq_t mq, void* buffer, rt_size_t size, rt_int32 timeout)
{
	struct rt_thread *thread;
	register rt_ubase_t temp;
	struct rt_mq_message *msg;

#ifdef RT_USING_HOOK
	if (rt_object_trytake_hook != RT_NULL) rt_object_trytake_hook(&(mq->parent.parent));
#endif

	/* disable interrupt */
	temp = rt_hw_interrupt_disable();

	/* mailbox is empty */
	if (mq->entry == 0)
	{
		/* get current thread */
		thread = rt_thread_self();

		/* reset error number in thread */
		thread->error = RT_EOK;

		/* no waiting, return timeout */
		if (timeout == 0)
		{
			/* enable interrupt */
			rt_hw_interrupt_enable(temp);

			thread->error = -RT_ETIMEOUT;
			return -RT_ETIMEOUT;
		}

		/* suspend current thread */
		rt_ipc_object_suspend(&(mq->parent), thread);

		/* has waiting time, start thread timer */
		if (timeout > 0)
		{
#ifdef IPC_DEBUG
			rt_kprintf("set thread:%s to timer list\n", thread->name);
#endif
			/* reset the timeout of thread timer and start it */
			rt_timer_control(&(thread->thread_timer), RT_TIMER_CTRL_SET_TIME, &timeout);
			rt_timer_start(&(thread->thread_timer));
		}

		/* enable interrupt */
		rt_hw_interrupt_enable(temp);

		/* re-schedule */
		rt_schedule();

		/* recv message */
		if (thread->error != RT_EOK) /* maybe return a RT_ETIMEOUT */
			return thread->error;

		/* disable interrupt */
		temp = rt_hw_interrupt_disable();
	}

	/* get message from queue */
	msg = (struct rt_mq_message*) mq->msg_queue_head;

	/* move message queue head */
	mq->msg_queue_head = msg->next;

	/* reach queue tail, set to NULL */
	if (mq->msg_queue_tail == msg) mq->msg_queue_tail = RT_NULL;

	/* copy message */
	rt_memcpy(buffer, msg + 1,
		size > mq->msg_size? mq->msg_size : size);

	/* put message to free list */
	msg->next = (struct rt_mq_message*)mq->msg_queue_free;
	mq->msg_queue_free = msg;

	/* decrease message entry */
	mq->entry --;

	/* enable interrupt */
	rt_hw_interrupt_enable(temp);

#ifdef RT_USING_HOOK
	if (rt_object_take_hook != RT_NULL) rt_object_take_hook(&(mq->parent.parent));
#endif

	return RT_EOK;
}

/**
 * This function can get or set some extra attributions of a message queue object.
 *
 * @param mq the message queue object
 * @param cmd the execution command
 * @param arg the execution argument
 *
 * @return the error code
 */
rt_err_t rt_mq_control(rt_mq_t mq, rt_uint8 cmd, void* arg)
{
	return RT_EOK;
}

#endif /* end of RT_USING_MESSAGEQUEUE */

/**
 * @ingroup SystemInit
 * This function will init IPC module.
 */
void rt_system_ipc_init()
{
	/* nothing to be done */
}

/*@}*/