smq.h revision 03831d35f7499c87d51205817c93e9a8d42c4bae
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2002 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SMQ_H
#define _SMQ_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
#include <sys/types.h>
#include <time.h>
#include "xsem.h"
/* THIS IS CURRENTLY ONLY WRITTEN TO HANDLE A SINGLE PRODUCER, SINGLE */
/* CONSUMER !!!!!!!!!!!!!!!! */
/* Simple message queue */
/* This package allows threads to pass simple messages through shared */
/* local memory. The goal is to keep it simple and somewhat fast */
/* smq_init() creates a simple message queue structure. It returns */
/* 0 on success. You pass it a descriptor, the location of the buffer */
/* where the messages will be stored, and the size of the buffer */
/* (the number of messages that can be stored). The memory allocation */
/* of the simple message buffer is the programmers responsibility. */
/* smq_destroy() deativates a message queue structure */
/* smq_receive() retrieves a message off of the simple message queue. */
/* The message will be removed from the queue when this routine */
/* returns. It suspends the thread until a message is received. */
/* smq_send() places a message on the specified simple message queue. */
/* It returns 0 on success. If the simple message queue is full, */
/* SMQ_FULL is returned. */
/* smq_pendingmsgs() returns the number of pending messages currently */
/* on the queue. It returns 0 on success. */
/* smq_depth() returns the depth of the queue. It returns 0 on */
/* success. */
/* smq_timedreceive() retrieves a message off of the simple message */
/* queue. The message will be removed from the queue when this */
/* routine returns. It suspends the thread until a message is */
/* received or until 'timeout' has expired. It returns 0 on success */
/* and SMQ_TIMEOUT if timeout has expired. */
#define SMQ_INVALID -1
#define SMQ_FULL -2
#define SMQ_NOT_IMPLEMENTED -3
#define SMQ_TIMEOUT -4
#define SMQ_ETIME -5
#define SMQ_ERROR -127
/* Do NOT read or write to these structures directly. They are */
/* implementation dependent and may change over time */
/* Be sure to declare any instantiation of these to be static if */
/* you are alocating them on the stack */
typedef uint32_t smq_msg_t;
typedef struct
{
int smq_control;
int smq_depth; /* maximum message count */
int smq_count; /* current message count */
smq_msg_t *smq_msgBuffer;
xsem_t smq_msgAvail;
smq_msg_t *smq_head;
smq_msg_t *smq_tail;
} smq_t;
int smq_init(smq_t *smq, smq_msg_t *msgbuffer, int depth);
int smq_destroy(smq_t *smq);
int smq_receive(smq_t *smq, smq_msg_t *msg);
int smq_send(smq_t *smq, smq_msg_t *msg);
int smq_pendingmsgs(smq_t *smq, int *num);
int smq_depth(smq_t *smq, int *depth);
int smq_xreceive(smq_t *smq, timestruc_t *timeout, smq_msg_t *msg);
#ifdef __cplusplus
}
#endif
#endif /* _SMQ_H */