原创一年没写了.今天回来看看,顺便发个缓冲环的c代码

 2007-12-21 22:35  3267 8 8 分类: MCU/ 嵌入式

曾经在sina的blog上发了,不过每人关注过,呵呵,看来那里还不是嵌入式方面的领地,还是回来吧.

一般在串口等驱动中经常遇到把固定缓冲区首尾相接的情况.例如232,485等这样的通信接口.写了一个针对这样条件下的缓冲环,已经测试通过.

大家用的好,别忘留个记号,呵呵.

memring.h 文件

typedef struct _memring MEMRING;

struct _memring
{
int head;
int tail;
int length;
unsigned char *pring;
int (*dataLengthInRing)(struct _memring* );
int (*ringIsEmtpy)(struct _memring* );
int (*ringIsFull)(struct _memring* );
void(*dataPushRing)(struct _memring* ,unsigned char );
unsigned char (*dataPopRing)(struct _memring* );
};

memring.c 文件

#include "memring.h"
#include "2410add.h"

int memDataLengthInRing(struct _memring * memring)
{
unsigned int savereg;
int ret;
//disable all interrupt
savereg=rINTMSK;
rINTMSK=0XFFFFFFFF;
ret=(memring->length + memring->tail-memring->head ) % memring->length;
//recover
rINTMSK=savereg;
return ret;
}

int memRingIsEmpty(struct _memring * memring)
{
unsigned int savereg;
int ret;
//disable all interrupt
savereg=rINTMSK;
rINTMSK=0XFFFFFFFF;
ret=(memring->head == memring->tail);
//recover
rINTMSK=savereg;
return ret;
}

int memRingIsFull(struct _memring * memring)
{
unsigned int savereg;
int ret;
//disable all interrupt
savereg=rINTMSK;
rINTMSK=0XFFFFFFFF;

ret=( ((memring->tail+1) % memring->length ) == memring->head);

//recover
rINTMSK=savereg;
return ret;
}

void memDataPushRing(struct _memring * memring,unsigned char ch)
{
unsigned int savereg;

//disable all interrupt
savereg=rINTMSK;
rINTMSK=0XFFFFFFFF;

memring->pring[memring->tail] = (ch);
memring->tail = ( memring->tail + 1 ) % memring->length;

//recover
rINTMSK=savereg;
}

unsigned char memDataPopRing(struct _memring * memring)
{
unsigned int savereg;
unsigned char ch;
//disable all interrupt
savereg=rINTMSK;
rINTMSK=0XFFFFFFFF;

ch = memring->pring[memring->head];
memring->head = ( memring->head + 1 ) % memring->length;
//recover
rINTMSK=savereg;
return ch;
}

void memringCreat(struct _memring * memring,unsigned char * buff,int length)
{

memring->head = 0;
memring->tail = 0;

memring->length = length;
memring->pring = buff;

memring->dataLengthInRing = memDataLengthInRing;
memring->ringIsEmtpy      = memRingIsEmpty;
memring->ringIsFull       = memRingIsFull;
memring->dataPushRing     = memDataPushRing;
memring->dataPopRing      = memDataPopRing;
}