RT-Thread - IPC Communicate

#ifdef RT_USING_MAILBOX
/**
 * mailbox structure
 */
struct rt_mailbox
{
    struct rt_ipc_object parent;                        /**< inherit from ipc_object */

    rt_uint32_t         *msg_pool;                      /**< start address of message buffer */

    rt_uint16_t          size;                          /**< size of message pool */

    rt_uint16_t          entry;                         /**< index of messages in msg_pool */
    rt_uint16_t          in_offset;                     /**< input offset of the message buffer */
    rt_uint16_t          out_offset;                    /**< output offset of the message buffer */

    rt_list_t            suspend_sender_thread;         /**< sender thread suspended on this mailbox */
};
typedef struct rt_mailbox *rt_mailbox_t;
#endif

/**
 * This function will create a mailbox object from system resource
 *
 * @param name the name of mailbox
 * @param size the size of mailbox
 * @param flag the flag of mailbox
 *
 * @return the created mailbox, RT_NULL on error happen
 */
rt_mailbox_t rt_mb_create(const char *name, rt_size_t size, rt_uint8_t flag)
{
    rt_mailbox_t mb;

    RT_DEBUG_NOT_IN_INTERRUPT;

    /* allocate object */
    mb = (rt_mailbox_t)rt_object_allocate(RT_Object_Class_MailBox, name);
    if (mb == RT_NULL)
        return mb;

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

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

/* init mailbox */
mb->size     = size;
mb->msg_pool = RT_KERNEL_MALLOC(mb->size * sizeof(rt_uint32_t));
if (mb->msg_pool == RT_NULL)
{
    /* delete mailbox object */
    rt_object_delete(&(mb->parent.parent));

    return RT_NULL;
}

    mb->entry      = 0;
    mb->in_offset  = 0;
    mb->out_offset = 0;

    /* init an additional list of sender suspend thread */
    rt_list_init(&(mb->suspend_sender_thread));

    return mb;
}
RTM_EXPORT(rt_mb_create);

/**
 * This function will initialize a mailbox and put it under control of resource
 * management.
 *
 * @param mb the mailbox object
 * @param name the name of mailbox
 * @param msgpool the begin address of buffer to save received mail
 * @param size the size of mailbox
 * @param flag the flag of mailbox
 *
 * @return the operation status, RT_EOK on successful
 */
rt_err_t rt_mb_init(rt_mailbox_t mb,
                    const char  *name,
                    void        *msgpool,
                    rt_size_t    size,
                    rt_uint8_t   flag)
{
    RT_ASSERT(mb != RT_NULL);

    /* init object */
    rt_object_init(&(mb->parent.parent), RT_Object_Class_MailBox, name);

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

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

    /* init mailbox */
    mb->msg_pool   = msgpool;
    mb->size       = size;
    mb->entry      = 0;
    mb->in_offset  = 0;
    mb->out_offset = 0;

    /* init an additional list of sender suspend thread */
    rt_list_init(&(mb->suspend_sender_thread));

    return RT_EOK;
}
RTM_EXPORT(rt_mb_init);

/**
 * This function will delete a mailbox object and release the memory
 *
 * @param mb the mailbox object
 *
 * @return the error code
 */
rt_err_t rt_mb_delete(rt_mailbox_t mb)
{
    RT_DEBUG_NOT_IN_INTERRUPT;

    /* parameter check */
    RT_ASSERT(mb != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mb->parent.parent) == RT_Object_Class_MailBox);
    RT_ASSERT(rt_object_is_systemobject(&mb->parent.parent) == RT_FALSE);

    /* resume all suspended thread */
    rt_ipc_list_resume_all(&(mb->parent.suspend_thread));

    /* also resume all mailbox private suspended thread */
    rt_ipc_list_resume_all(&(mb->suspend_sender_thread));

    /* free mailbox pool */
    RT_KERNEL_FREE(mb->msg_pool);

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

    return RT_EOK;
}
RTM_EXPORT(rt_mb_delete);

/**
 * This function will detach a mailbox from resource management
 *
 * @param mb the mailbox object
 *
 * @return the operation status, RT_EOK on successful
 */
rt_err_t rt_mb_detach(rt_mailbox_t mb)
{
    /* parameter check */
    RT_ASSERT(mb != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mb->parent.parent) == RT_Object_Class_MailBox);
    RT_ASSERT(rt_object_is_systemobject(&mb->parent.parent));

    /* resume all suspended thread */
    rt_ipc_list_resume_all(&(mb->parent.suspend_thread));
    /* also resume all mailbox private suspended thread */
    rt_ipc_list_resume_all(&(mb->suspend_sender_thread));

    /* detach mailbox object */
    rt_object_detach(&(mb->parent.parent));

    return RT_EOK;
}
RTM_EXPORT(rt_mb_detach);

/**
 * This function will send a mail to mailbox object. If the mailbox is full,
 * current thread will be suspended until timeout.
 *
 * @param mb the mailbox object
 * @param value the mail
 * @param timeout the waiting time
 *
 * @return the error code
 */
rt_err_t rt_mb_send_wait(rt_mailbox_t mb,
                         rt_uint32_t  value,
                         rt_int32_t   timeout)
{
    struct rt_thread *thread;
    register rt_ubase_t temp;
    rt_uint32_t tick_delta;

    /* parameter check */
    RT_ASSERT(mb != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mb->parent.parent) == RT_Object_Class_MailBox);

    /* initialize delta tick */
    tick_delta = 0;
    /* get current thread */
    thread = rt_thread_self();

    RT_OBJECT_HOOK_CALL(rt_object_put_hook, (&(mb->parent.parent)));

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

    /* for non-blocking call */
    if (mb->entry == mb->size && timeout == 0)
    {
        rt_hw_interrupt_enable(temp);

        return -RT_EFULL;
    }

    /* mailbox is full */
    while (mb->entry == mb->size)
    {
        /* reset error number in thread */
        thread->error = RT_EOK;

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

            return -RT_EFULL;
        }

RT_DEBUG_IN_THREAD_CONTEXT;
/* suspend current thread */
rt_ipc_list_suspend(&(mb->suspend_sender_thread),
                    thread,
                    mb->parent.parent.flag);

/* has waiting time, start thread timer */
if (timeout > 0)
{
    /* get the start tick of timer */
    tick_delta = rt_tick_get();

    RT_DEBUG_LOG(RT_DEBUG_IPC, ("mb_send_wait: start timer of thread:%s\n",
                                thread->name));

    /* 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();

    /* resume from suspend state */
    if (thread->error != RT_EOK)
    {
        /* return error */
        return thread->error;
    }

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

    /* if it's not waiting forever and then re-calculate timeout tick */
    if (timeout > 0)
    {
        tick_delta = rt_tick_get() - tick_delta;
        timeout -= tick_delta;
        if (timeout < 0)
            timeout = 0;
    }
}

/* set ptr */
mb->msg_pool[mb->in_offset] = value;
/* increase input offset */
++ mb->in_offset;
if (mb->in_offset >= mb->size)
    mb->in_offset = 0;
/* increase message entry */
mb->entry ++;

    /* resume suspended thread */
    if (!rt_list_isempty(&mb->parent.suspend_thread))
    {
        rt_ipc_list_resume(&(mb->parent.suspend_thread));

        /* enable interrupt */
        rt_hw_interrupt_enable(temp);

        rt_schedule();

        return RT_EOK;
    }

    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

    return RT_EOK;
}
RTM_EXPORT(rt_mb_send_wait);

/**
 * This function will send a mail to mailbox object, if there are threads
 * suspended on mailbox object, it will be waked up. This function will return
 * immediately, if you want blocking send, use rt_mb_send_wait instead.
 *
 * @param mb the mailbox object
 * @param value the mail
 *
 * @return the error code
 */
rt_err_t rt_mb_send(rt_mailbox_t mb, rt_uint32_t value)
{
    return rt_mb_send_wait(mb, value, 0);
}
RTM_EXPORT(rt_mb_send);

/**
 * This function will receive a mail from mailbox object, if there is no mail
 * in mailbox object, the thread shall wait for a specified time.
 *
 * @param mb the mailbox object
 * @param value the received mail will be saved in
 * @param timeout the waiting time
 *
 * @return the error code
 */
rt_err_t rt_mb_recv(rt_mailbox_t mb, rt_uint32_t *value, rt_int32_t timeout)
{
    struct rt_thread *thread;
    register rt_ubase_t temp;
    rt_uint32_t tick_delta;

    /* parameter check */
    RT_ASSERT(mb != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mb->parent.parent) == RT_Object_Class_MailBox);

    /* initialize delta tick */
    tick_delta = 0;
    /* get current thread */
    thread = rt_thread_self();

    RT_OBJECT_HOOK_CALL(rt_object_trytake_hook, (&(mb->parent.parent)));

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

    /* for non-blocking call */
    if (mb->entry == 0 && timeout == 0)
    {
        rt_hw_interrupt_enable(temp);

        return -RT_ETIMEOUT;
    }

    /* mailbox is empty */
    while (mb->entry == 0)
    {
        /* 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;
        }

RT_DEBUG_IN_THREAD_CONTEXT;
/* suspend current thread */
rt_ipc_list_suspend(&(mb->parent.suspend_thread),
                    thread,
                    mb->parent.parent.flag);

/* has waiting time, start thread timer */
if (timeout > 0)
{
    /* get the start tick of timer */
    tick_delta = rt_tick_get();

    RT_DEBUG_LOG(RT_DEBUG_IPC, ("mb_recv: start timer of thread:%s\n",
                                thread->name));

    /* 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();

    /* resume from suspend state */
    if (thread->error != RT_EOK)
    {
        /* return error */
        return thread->error;
    }

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

    /* if it's not waiting forever and then re-calculate timeout tick */
    if (timeout > 0)
    {
        tick_delta = rt_tick_get() - tick_delta;
        timeout -= tick_delta;
        if (timeout < 0)
            timeout = 0;
    }
}

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

/* increase output offset */
++ mb->out_offset;
if (mb->out_offset >= mb->size)
    mb->out_offset = 0;
/* decrease message entry */
mb->entry --;

    /* resume suspended thread */
    if (!rt_list_isempty(&(mb->suspend_sender_thread)))
    {
        rt_ipc_list_resume(&(mb->suspend_sender_thread));

        /* enable interrupt */
        rt_hw_interrupt_enable(temp);

        RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mb->parent.parent)));

        rt_schedule();

        return RT_EOK;
    }

    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

    RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mb->parent.parent)));

    return RT_EOK;
}
RTM_EXPORT(rt_mb_recv);

#ifdef RT_USING_MESSAGEQUEUE
/**
 * message queue structure
 */
struct rt_messagequeue
{
    struct rt_ipc_object parent;                        /**< inherit from ipc_object */

    void                *msg_pool;                      /**< start address of message queue */

    rt_uint16_t          msg_size;                      /**< message size of each message */
    rt_uint16_t          max_msgs;                      /**< max number of messages */

    rt_uint16_t          entry;                         /**< index of messages in the queue */

    void                *msg_queue_head;                /**< list head */
    void                *msg_queue_tail;                /**< list tail */
    void                *msg_queue_free;                /**< pointer indicated the free node of queue */
};
typedef struct rt_messagequeue *rt_mq_t;
#endif

/**
 * 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_t  flag)
{
    struct rt_messagequeue *mq;
    struct rt_mq_message *head;
    register rt_base_t temp;

    RT_DEBUG_NOT_IN_INTERRUPT;

    /* 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_KERNEL_MALLOC((mq->msg_size + sizeof(struct rt_mq_message)) * 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_t *)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;
}
RTM_EXPORT(rt_mq_create);

/**
 * 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_t  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_t *)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;
}
RTM_EXPORT(rt_mq_init);

/**
 * 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)
{
    RT_DEBUG_NOT_IN_INTERRUPT;

    /* parameter check */
    RT_ASSERT(mq != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);
    RT_ASSERT(rt_object_is_systemobject(&mq->parent.parent) == RT_FALSE);

    /* resume all suspended thread */
    rt_ipc_list_resume_all(&(mq->parent.suspend_thread));

    /* free message queue pool */
    RT_KERNEL_FREE(mq->msg_pool);

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

    return RT_EOK;
}
RTM_EXPORT(rt_mq_delete);

/**
 * 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);
    RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);
    RT_ASSERT(rt_object_is_systemobject(&mq->parent.parent));

    /* resume all suspended thread */
    rt_ipc_list_resume_all(&mq->parent.suspend_thread);

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

    return RT_EOK;
}
RTM_EXPORT(rt_mq_detach);

/**
 * 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;

    /* parameter check */
    RT_ASSERT(mq != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);
    RT_ASSERT(buffer != RT_NULL);
    RT_ASSERT(size != 0);

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

    RT_OBJECT_HOOK_CALL(rt_object_put_hook, (&(mq->parent.parent)));

    /* 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;

/* enable interrupt */
rt_hw_interrupt_enable(temp);

/* the msg is the new tailer of list, the next shall be NULL */
msg->next = RT_NULL;
/* copy buffer */
rt_memcpy(msg + 1, buffer, size);

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

/* 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 (!rt_list_isempty(&mq->parent.suspend_thread))
    {
        rt_ipc_list_resume(&(mq->parent.suspend_thread));

        /* enable interrupt */
        rt_hw_interrupt_enable(temp);

        rt_schedule();

        return RT_EOK;
    }

    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

    return RT_EOK;
}
RTM_EXPORT(rt_mq_send);

/**
 * This function will send an urgent 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;

    /* parameter check */
    RT_ASSERT(mq != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);
    RT_ASSERT(buffer != RT_NULL);
    RT_ASSERT(size != 0);

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

    RT_OBJECT_HOOK_CALL(rt_object_put_hook, (&(mq->parent.parent)));

    /* 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;

    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

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

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

/* 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 (!rt_list_isempty(&mq->parent.suspend_thread))
    {
        rt_ipc_list_resume(&(mq->parent.suspend_thread));

        /* enable interrupt */
        rt_hw_interrupt_enable(temp);

        rt_schedule();

        return RT_EOK;
    }

    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

    return RT_EOK;
}
RTM_EXPORT(rt_mq_urgent);

/**
 * 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_t timeout)
{
    struct rt_thread *thread;
    register rt_ubase_t temp;
    struct rt_mq_message *msg;
    rt_uint32_t tick_delta;

    /* parameter check */
    RT_ASSERT(mq != RT_NULL);
    RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);
    RT_ASSERT(buffer != RT_NULL);
    RT_ASSERT(size != 0);

    /* initialize delta tick */
    tick_delta = 0;
    /* get current thread */
    thread = rt_thread_self();
    RT_OBJECT_HOOK_CALL(rt_object_trytake_hook, (&(mq->parent.parent)));

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

    /* for non-blocking call */
    if (mq->entry == 0 && timeout == 0)
    {
        rt_hw_interrupt_enable(temp);

        return -RT_ETIMEOUT;
    }

    /* message queue is empty */
    while (mq->entry == 0)
    {
        RT_DEBUG_IN_THREAD_CONTEXT;

        /* 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_list_suspend(&(mq->parent.suspend_thread),
                    thread,
                    mq->parent.parent.flag);

/* has waiting time, start thread timer */
if (timeout > 0)
{
    /* get the start tick of timer */
    tick_delta = rt_tick_get();

    RT_DEBUG_LOG(RT_DEBUG_IPC, ("set thread:%s to timer list\n",
                                thread->name));

    /* 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)
    {
        /* return error */
        return thread->error;
    }

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

    /* if it's not waiting forever and then re-calculate timeout tick */
    if (timeout > 0)
    {
        tick_delta = rt_tick_get() - tick_delta;
        timeout -= tick_delta;
        if (timeout < 0)
            timeout = 0;
    }
}

/* 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;

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

/* enable interrupt */
rt_hw_interrupt_enable(temp);

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

    /* disable interrupt */
    temp = rt_hw_interrupt_disable();
    /* put message to free list */
    msg->next = (struct rt_mq_message *)mq->msg_queue_free;
    mq->msg_queue_free = msg;
    /* enable interrupt */
    rt_hw_interrupt_enable(temp);

    RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mq->parent.parent)));

    return RT_EOK;
}
RTM_EXPORT(rt_mq_recv);