9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * CDDL HEADER START
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * The contents of this file are subject to the terms of the
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Common Development and Distribution License (the "License").
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * You may not use this file except in compliance with the License.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * or http://www.opensolaris.org/os/licensing.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * See the License for the specific language governing permissions
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * and limitations under the License.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * When distributing Covered Code, include this CDDL HEADER in each
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * If applicable, add the following below this CDDL HEADER, with the
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * fields enclosed by brackets "[]" replaced with your own identifying
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * information: Portions Copyright [yyyy] [name of copyright owner]
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * CDDL HEADER END
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Copyright (c) 2002-2003, Network Appliance, Inc. All rights reserved.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Use is subject to license terms.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * MODULE: dapl_ring_buffer_util.c
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * PURPOSE: Ring buffer management
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Description: Support and management functions for ring buffers
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * $Id: dapl_ring_buffer_util.c,v 1.9 2003/07/08 14:23:35 sjs2 Exp $
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor#include "dapl_ring_buffer_util.h"
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * dapls_rbuf_alloc
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Given a DAPL_RING_BUFFER, initialize it and provide memory for
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * the ringbuf itself. A passed in size will be adjusted to the next
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * largest power of two number to simplify management.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Input:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * rbuf pointer to DAPL_RING_BUFFER
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * size number of elements to allocate & manage
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Output:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * none
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Returns:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * DAT_SUCCESS
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * DAT_INSUFFICIENT_RESOURCES
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill TaylorDAT_RETURN
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylordapls_rbuf_alloc(
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor INOUT DAPL_RING_BUFFER *rbuf,
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor IN DAT_COUNT size)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor{
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor unsigned int rsize; /* real size */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor /*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * The circular buffer must be allocated one too large.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * This eliminates any need for a distinct counter, as that
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * having the two pointers equal always means "empty" -- never "full"
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor size++;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor /* Put size on a power of 2 boundary */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rsize = 1;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor while ((DAT_COUNT)rsize < size) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rsize <<= 1;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->base = (void *) dapl_os_alloc(rsize * sizeof (void *));
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if (rbuf->base != NULL) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->lim = rsize - 1;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->head = 0;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->tail = 0;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_lock_init(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor } else {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (DAT_INSUFFICIENT_RESOURCES | DAT_RESOURCE_MEMORY);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (DAT_SUCCESS);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor}
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * dapls_rbuf_realloc
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Resizes an empty DAPL_RING_BUFFER. This function is not thread safe;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * adding or removing elements from a ring buffer while resizing
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * will have indeterminate results.
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Input:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * rbuf pointer to DAPL_RING_BUFFER
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * size number of elements to allocate & manage
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Output:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * none
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Returns:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * DAT_SUCCESS
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * DAT_INVALID_STATE
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * DAT_INSUFFICIENT_RESOURCES
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill TaylorDAT_RETURN
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylordapls_rbuf_realloc(
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor INOUT DAPL_RING_BUFFER *rbuf,
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor IN DAT_COUNT size)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor{
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor int rsize; /* real size */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor DAT_RETURN dat_status;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dat_status = DAT_SUCCESS;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor /* if the ring buffer is not empty */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if (rbuf->head != rbuf->tail) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dat_status = DAT_ERROR(DAT_INVALID_STATE, 0);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor goto bail;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor /* Put size on a power of 2 boundary */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rsize = 1;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor while (rsize < size) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rsize <<= 1;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->base = (void *)dapl_os_realloc(rbuf->base,
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rsize * sizeof (void *));
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if (NULL == rbuf->base) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dat_status = DAT_ERROR(DAT_INSUFFICIENT_RESOURCES,
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor DAT_RESOURCE_MEMORY);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor goto bail;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->lim = rsize - 1;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylorbail:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (dat_status);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor}
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * dapls_rbuf_destroy
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Release the buffer and reset pointers to a DAPL_RING_BUFFER
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Input:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * rbuf pointer to DAPL_RING_BUFFER
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Output:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * none
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Returns:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * none
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylorvoid
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylordapls_rbuf_destroy(
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor IN DAPL_RING_BUFFER *rbuf)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor{
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if ((NULL == rbuf) ||
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor (NULL == rbuf->base)) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_lock_destroy(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_free(rbuf->base, (rbuf->lim + 1) * sizeof (void *));
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->base = NULL;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->lim = 0;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor}
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * dapls_rbuf_add
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Add an entry to the ring buffer
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Input:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * rbuf pointer to DAPL_RING_BUFFER
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * entry entry to add
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Output:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * none
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Returns:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * DAT_SUCCESS
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * DAT_INSUFFICIENT_RESOURCES (queue full)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill TaylorDAT_RETURN
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylordapls_rbuf_add(
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor IN DAPL_RING_BUFFER *rbuf,
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor IN void *entry)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor{
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor DAPL_ATOMIC pos;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_lock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor pos = rbuf->head;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if (((pos + 1) & rbuf->lim) != rbuf->tail) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->base[pos] = entry;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->head = (pos + 1) & rbuf->lim;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_unlock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (DAT_SUCCESS);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_unlock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (DAT_ERROR(DAT_INSUFFICIENT_RESOURCES, DAT_RESOURCE_MEMORY));
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor}
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * dapls_rbuf_remove
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Remove an entry from the ring buffer
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Input:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * rbuf pointer to DAPL_RING_BUFFER
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Output:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * entry entry removed from the ring buffer
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Returns:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * a pointer to a buffer entry
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylorvoid *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylordapls_rbuf_remove(
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor IN DAPL_RING_BUFFER *rbuf)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor{
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor DAPL_ATOMIC pos;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_lock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if (rbuf->head != rbuf->tail) {
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor pos = rbuf->tail;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor rbuf->tail = (pos + 1) & rbuf->lim;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_unlock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (rbuf->base[pos]);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor }
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_unlock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (NULL);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor}
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor/*
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * dapli_rbuf_count
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Return the number of entries in use in the ring buffer
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Input:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * rbuf pointer to DAPL_RING_BUFFER
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Output:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * none
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * Returns:
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor * count of entries
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor *
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor */
9e39c5ba00a55fa05777cc94b148296af305e135Bill TaylorDAT_COUNT
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylordapls_rbuf_count(
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor IN DAPL_RING_BUFFER *rbuf)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor{
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor int head;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor int tail;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_lock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor head = rbuf->head;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor tail = rbuf->tail;
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor dapl_os_unlock(&rbuf->lock);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if (head == tail)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (0);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor if (head > tail)
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return (head - tail);
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor /* add 1 to lim as it is a mask, number of entries - 1 */
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor return ((rbuf->lim + 1 - tail + head));
9e39c5ba00a55fa05777cc94b148296af305e135Bill Taylor}