V2Acode/Midware/mbox/Mbox.c

/******************************************************************************
 * 消息邮箱
 * Copyright 2014, 飞联.
 *
 * File Name  : Mbox.c
 * Description: 消息邮箱，也可称作交换消息，实则为一固定单元(4 bytes)的FIFO队列
 *
 * modification history
 * --------------------
 * V1.0, 27-jun-2014, Simon written
 * --------------------
 ******************************************************************************/
#include "mbox.h"
#include <stdio.h>
#include <stdlib.h>

/******************************************************************************
 * Mbox_Create - Create a mailbox from dynamic memory pool.
 *
 * Input: size, the capacity size of mailbox, with 4 bytes of a mail for a unit.
 * Return: return the created mailbox, NULL on error.
 * modification history
 * --------------------
 * 27-jun-2014, Simon written
 * --------------------
 ******************************************************************************/
Mbox_t Mbox_Create(const uint32_t size)
{
	Mbox_t mb;

	mb = (Mbox_t)malloc(sizeof(struct MailBox));
	if(mb == NULL)
		return NULL;

	mb->max_size = size;
	mb->msg_pool = (uint32_t *)malloc(mb->max_size * sizeof(uint32_t));
	if(mb->msg_pool == NULL)
	{
		free(mb);
		return NULL;
	}

	mb->size = 0;
	mb->read_index = 0;
	mb->save_index = 0;

	return mb;
}

/******************************************************************************
 * Mbox_Del - Delete a mailbox and release the memory.
 *
 * Input: mb, a pointer to the mailbox.
 * Return: return the error code.
 * modification history
 * --------------------
 * 27-jun-2014, Simon written
 * --------------------
 ******************************************************************************/
Mbox_Err_t Mbox_Del(Mbox_t mb)
{
	if(mb != NULL)
	{
		if(mb->msg_pool != NULL)
		{
			free(mb->msg_pool);
		}
		mb->msg_pool = NULL;
		free(mb);
	}
	return MBOX_OK;
}

/******************************************************************************
 * Mbox_Post - Send a mail to the mailbox.
 *
 * Input:
 *	mb, a pointer to the mailbox;
 *	msg, the mail.
 * Return: return the error code.
 * modification history
 * --------------------
 * 27-jun-2014, Simon written
 * --------------------
 ******************************************************************************/
Mbox_Err_t Mbox_Post(Mbox_t mb, const uint32_t msg)
{
	if(mb == NULL)
		return MBOX_ERR;

	if(mb->size == mb->max_size)
		return MBOX_ERR;

	Mbox_IrqDisable();
	mb->msg_pool[mb->save_index] = msg;
	++mb->save_index;
	if(mb->save_index >= mb->max_size)
		mb->save_index = 0;
	mb->size++;
	Mbox_IrqEnable();

	return MBOX_OK;
}

/******************************************************************************
 * Mbox_Pend - Receive a mail from mailbox.
 *
 * Input:
 *	mb, a pointer to the mailbox;
 * Output:
 *	msg, the received mail will be saved in.
 * Return: return the error code.
 * modification history
 * --------------------
 * 27-jun-2014, Simon written
 * --------------------
 ******************************************************************************/
Mbox_Err_t Mbox_Pend(Mbox_t mb, uint32_t *msg)
{
	if(mb == NULL)
		return MBOX_ERR;

	if(mb->size == 0)
		return MBOX_ERR;

	Mbox_IrqDisable();
	*msg = mb->msg_pool[mb->read_index];
	++mb->read_index;
	if(mb->read_index >= mb->max_size)
		mb->read_index = 0;
	mb->size--;
	Mbox_IrqEnable();

	return MBOX_OK;
}

/******************************************************************************
 * Mbox_Pend - This function checks the mailbox to see if a message is available.  Unlike Mbox_Pend(),
 *              MboxAccept() does not clear the message is not available.
 * Input:
 *	mb, a pointer to the mailbox;
 * Output:
 *	msg, the received mail will be saved in.
 * Return: return the error code.
 * modification history
 * --------------------
 * 10-jul-2016, Simon written
 * --------------------
 ******************************************************************************/
Mbox_Err_t Mbox_Accept(Mbox_t mb, uint32_t *msg)
{
	if(mb == NULL)
		return MBOX_ERR;

	if(mb->size == 0)
		return MBOX_ERR;

	*msg = mb->msg_pool[mb->read_index];

	return MBOX_OK;
}