Re: Safe way to write interrupt driven circular buffer tx rx?

On Aug 29, 6:21 am, "Sven" <S...@xxxxxxx> wrote:
Can someone point out source code for a safe circular buffer receiver
transmitter? It's for sending and receiving bytes via RS232.

/
*--------------------------------------------------------------------------
* Filename: queue.h
*
* Description: Generic circular queue macros
*
* Notes
*
* The queue macros are safe when used in producer/consumer fashion.
* User must check queue full/empty conditions prior to enqueuing/
* dequeueing.
*
* Example Usage
*
* #include "queue.h"
*
* #define MY_Q_SIZE 10
*
* struct
* {
* queue_hdr_t hdr; // must be named
"hdr"
* my_type_t items[MY_Q_SIZE+1]; // must be named "items", 1
space wasted
* } my_q;
*
* my_type_t an_item;
*
* QUEUE_INIT(my_q);
*
* if (!QUEUE_FULL(q))
* {
* QUEUE_PUT(my_q,an_item);
* }
*
* if (!QUEUE_EMPTY(q))
* {
* QUEUE_GET(my_q,an_item);
* }
*
--------------------------------------------------------------------------
*/
#ifndef __QUEUE_H__
#define __QUEUE_H__

/*-------------------------------- Includes
--------------------------------*/
#include "types.h"

/*---------------------------- Defines & Types
-----------------------------*/
#define QUEUE_INIT(q) \
q.hdr.front = q.hdr.rear = 0; \
q.hdr.size = sizeof(q.items) / sizeof(q.items[0]);

#define QUEUE_PUT(q,item) \
q.items[q.hdr.rear] = item; \
q.hdr.rear = (q.hdr.rear+1) % q.hdr.size;

#define QUEUE_GET(q,item) \
item = q.items[q.hdr.front]; \
q.hdr.front = (q.hdr.front + 1) % q.hdr.size;

#define QUEUE_FRONT(q,item) \
item = q.items[q.hdr.front]

#define QUEUE_EMPTY(q) (q.hdr.front == q.hdr.rear)
#define QUEUE_FULL(q) ((q.hdr.rear + 1) % q.hdr.size == q.hdr.front)

/* Private - do not access directly */
typedef struct
{
int front;
int rear;
int size;
} queue_hdr_t;

/*---------------------------- Global Variables
----------------------------*/

/*--------------------------- Function Prototypes
--------------------------*/

#endif

.