cs_queue.h
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/*
* Copyright (c) 2002-2004 MontaVista Software, Inc.
* Copyright (c) 2006-2011 Red Hat, Inc.
*
* All rights reserved.
*
* Author: Steven Dake (sdake@redhat.com)
*
* This software licensed under BSD license, the text of which follows:
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of the MontaVista Software, Inc. nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CS_QUEUE_H_DEFINED
#define CS_QUEUE_H_DEFINED
#include <string.h>
#include <stdlib.h>
#include <pthread.h>
#include <errno.h>
#include "assert.h"
struct cs_queue {
int head;
int tail;
int used;
int usedhw;
size_t size;
void *items;
size_t size_per_item;
int iterator;
pthread_mutex_t mutex;
int threaded_mode_enabled;
};
static inline int cs_queue_init (struct cs_queue *cs_queue, size_t cs_queue_items, size_t size_per_item, int threaded_mode_enabled) {
cs_queue->head = 0;
cs_queue->tail = cs_queue_items - 1;
cs_queue->used = 0;
cs_queue->usedhw = 0;
cs_queue->size = cs_queue_items;
cs_queue->size_per_item = size_per_item;
cs_queue->threaded_mode_enabled = threaded_mode_enabled;
cs_queue->items = malloc (cs_queue_items * size_per_item);
if (cs_queue->items == 0) {
return (-ENOMEM);
}
memset (cs_queue->items, 0, cs_queue_items * size_per_item);
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_init (&cs_queue->mutex, NULL);
}
return (0);
}
static inline int cs_queue_reinit (struct cs_queue *cs_queue)
{
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue->head = 0;
cs_queue->tail = cs_queue->size - 1;
cs_queue->used = 0;
cs_queue->usedhw = 0;
memset (cs_queue->items, 0, cs_queue->size * cs_queue->size_per_item);
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return (0);
}
static inline void cs_queue_free (struct cs_queue *cs_queue) {
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_destroy (&cs_queue->mutex);
}
free (cs_queue->items);
}
static inline int cs_queue_is_full (struct cs_queue *cs_queue) {
int full;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
full = ((cs_queue->size - 1) == cs_queue->used);
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return (full);
}
static inline int cs_queue_is_empty (struct cs_queue *cs_queue) {
int empty;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
empty = (cs_queue->used == 0);
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return (empty);
}
static inline void cs_queue_item_add (struct cs_queue *cs_queue, void *item)
{
char *cs_queue_item;
int cs_queue_position;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue_position = cs_queue->head;
cs_queue_item = cs_queue->items;
cs_queue_item += cs_queue_position * cs_queue->size_per_item;
memcpy (cs_queue_item, item, cs_queue->size_per_item);
assert (cs_queue->tail != cs_queue->head);
cs_queue->head = (cs_queue->head + 1) % cs_queue->size;
cs_queue->used++;
if (cs_queue->used > cs_queue->usedhw) {
cs_queue->usedhw = cs_queue->used;
}
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
}
static inline void *cs_queue_item_get (struct cs_queue *cs_queue)
{
char *cs_queue_item;
int cs_queue_position;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue_position = (cs_queue->tail + 1) % cs_queue->size;
cs_queue_item = cs_queue->items;
cs_queue_item += cs_queue_position * cs_queue->size_per_item;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return ((void *)cs_queue_item);
}
static inline void cs_queue_item_remove (struct cs_queue *cs_queue) {
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue->tail = (cs_queue->tail + 1) % cs_queue->size;
assert (cs_queue->tail != cs_queue->head);
cs_queue->used--;
assert (cs_queue->used >= 0);
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
}
static inline void cs_queue_items_remove (struct cs_queue *cs_queue, int rel_count)
{
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue->tail = (cs_queue->tail + rel_count) % cs_queue->size;
assert (cs_queue->tail != cs_queue->head);
cs_queue->used -= rel_count;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
}
static inline void cs_queue_item_iterator_init (struct cs_queue *cs_queue)
{
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue->iterator = (cs_queue->tail + 1) % cs_queue->size;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
}
static inline void *cs_queue_item_iterator_get (struct cs_queue *cs_queue)
{
char *cs_queue_item;
int cs_queue_position;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue_position = (cs_queue->iterator) % cs_queue->size;
if (cs_queue->iterator == cs_queue->head) {
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return (0);
}
cs_queue_item = cs_queue->items;
cs_queue_item += cs_queue_position * cs_queue->size_per_item;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return ((void *)cs_queue_item);
}
static inline int cs_queue_item_iterator_next (struct cs_queue *cs_queue)
{
int next_res;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
cs_queue->iterator = (cs_queue->iterator + 1) % cs_queue->size;
next_res = cs_queue->iterator == cs_queue->head;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return (next_res);
}
static inline void cs_queue_avail (struct cs_queue *cs_queue, int *avail)
{
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
*avail = cs_queue->size - cs_queue->used - 2;
assert (*avail >= 0);
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
}
static inline int cs_queue_used (struct cs_queue *cs_queue) {
int used;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
used = cs_queue->used;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return (used);
}
static inline int cs_queue_usedhw (struct cs_queue *cs_queue) {
int usedhw;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_lock (&cs_queue->mutex);
}
usedhw = cs_queue->usedhw;
if (cs_queue->threaded_mode_enabled) {
pthread_mutex_unlock (&cs_queue->mutex);
}
return (usedhw);
}
#endif /* CS_QUEUE_H_DEFINED */
cs_queue
Definition cs_queue.h:44
cs_queue::used
int used
Definition cs_queue.h:47
cs_queue::threaded_mode_enabled
int threaded_mode_enabled
Definition cs_queue.h:54
cs_queue::size_per_item
size_t size_per_item
Definition cs_queue.h:51
cs_queue::items
void * items
Definition cs_queue.h:50
cs_queue::usedhw
int usedhw
Definition cs_queue.h:48
cs_queue::head
int head
Definition cs_queue.h:45
cs_queue::iterator
int iterator
Definition cs_queue.h:52
cs_queue::mutex
pthread_mutex_t mutex
Definition cs_queue.h:53
cs_queue::tail
int tail
Definition cs_queue.h:46
cs_queue::size
size_t size
Definition cs_queue.h:49