Subversion Repositories or1k_old

#include <stdarg.h>
#include <linux/stddef.h>
 
#include "msgqueue.h"
 
/*
 * Function: struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
 * Purpose : Allocate a message queue entry
 * Params  : msgq - message queue to claim entry for
 * Returns : message queue entry or NULL.
 */
static struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
{
	struct msgqueue_entry *mq;
 
	if ((mq = msgq->free) != NULL)
		msgq->free = mq->next;
 
	return mq;
}
 
/*
 * Function: void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
 * Purpose : free a message queue entry
 * Params  : msgq - message queue to free entry from
 *	     mq   - message queue entry to free
 */
static void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
{
	if (mq) {
		mq->next = msgq->free;
		msgq->free = mq;
	}
}
 
/*
 * Function: void msgqueue_initialise(MsgQueue_t *msgq)
 * Purpose : initialise a message queue
 * Params  : msgq - queue to initialise
 */
void msgqueue_initialise(MsgQueue_t *msgq)
{
	int i;
 
	msgq->qe = NULL;
	msgq->free = &msgq->entries[0];
 
	for (i = 0; i < NR_MESSAGES; i++)
		msgq->entries[i].next = &msgq->entries[i + 1];
 
	msgq->entries[NR_MESSAGES - 1].next = NULL;
}
 
 
/*
 * Function: void msgqueue_free(MsgQueue_t *msgq)
 * Purpose : free a queue
 * Params  : msgq - queue to free
 */
void msgqueue_free(MsgQueue_t *msgq)
{
}
 
/*
 * Function: int msgqueue_msglength(MsgQueue_t *msgq)
 * Purpose : calculate the total length of all messages on the message queue
 * Params  : msgq - queue to examine
 * Returns : number of bytes of messages in queue
 */
int msgqueue_msglength(MsgQueue_t *msgq)
{
	struct msgqueue_entry *mq = msgq->qe;
	int length = 0;
 
	for (mq = msgq->qe; mq; mq = mq->next)
		length += mq->msg.length;
 
	return length;
}
 
/*
 * Function: char *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
 * Purpose : return a message
 * Params  : msgq   - queue to obtain message from
 *         : msgno  - message number
 * Returns : pointer to message string, or NULL
 */
struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
{
	struct msgqueue_entry *mq;
 
	for (mq = msgq->qe; mq && msgno; mq = mq->next, msgno--);
 
	return mq ? &mq->msg : NULL;
}
 
/*
 * Function: int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
 * Purpose : add a message onto a message queue
 * Params  : msgq   - queue to add message on
 *	     length - length of message
 *	     ...    - message bytes
 * Returns : != 0 if successful
 */
int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
{
	struct msgqueue_entry *mq = mqe_alloc(msgq);
	va_list ap;
 
	if (mq) {
		struct msgqueue_entry **mqp;
		int i;
 
		va_start(ap, length);
		for (i = 0; i < length; i++)
			mq->msg.msg[i] = va_arg(ap, unsigned char);
		va_end(ap);
 
		mq->msg.length = length;
		mq->msg.fifo = 0;
		mq->next = NULL;
 
		mqp = &msgq->qe;
		while (*mqp)
			mqp = &(*mqp)->next;
 
		*mqp = mq;
	}
 
	return mq != NULL;
}
 
/*
 * Function: void msgqueue_flush(MsgQueue_t *msgq)
 * Purpose : flush all messages from message queue
 * Params  : msgq - queue to flush
 */
void msgqueue_flush(MsgQueue_t *msgq)
{
	struct msgqueue_entry *mq, *mqnext;
 
	for (mq = msgq->qe; mq; mq = mqnext) {
		mqnext = mq->next;
		mqe_free(msgq, mq);
	}
	msgq->qe = NULL;
}