/*
 * cfuthread_queue.h - This file is part of the libcfu library
 *
 * Copyright (c) 2005 Don Owens. All rights reserved.
 *
 * This code is released under the BSD license:
 *
 * 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 author 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 CFUTHREAD_QUEUE_H
#define CFUTHREAD_QUEUE_H

#include <cfu.h>

CFU_BEGIN_DECLS

/* cfuthread_queue provides a way to serialize requests for a
 * resource where you want the resource to be accessed from a
 * single thread only.  For instance, for a database connection
 * where making calls in separate threads does not work properly,
 * you can use cfuthread_queue.  cfuthread_queue_new() creates a
 * new thread that waits for something to be added to the queue.
 * Once something is added, the thread will process the data by
 * calling the function you pass as an argument to the
 * cfuthread_queue_new() function.
 */

typedef struct cfuthread_queue cfuthread_queue_t;

typedef void * (*cfuthread_queue_fn_t)(void *arg);
typedef void (*cfuthread_queue_init_t)(void *arg);
typedef void (*cfuthread_queue_cleanup_t)(void *arg);

/* Creates a new thread queue structure that will run the given
 * function when a request is received.
*/
cfuthread_queue_t * cfuthread_queue_new(cfuthread_queue_fn_t fn);

/* Same as cfuthread_queue_new(), but with an initialization
 * function that gets called with the argument init_arg when the
 * thread is created, and a cleanup function that gets called with
 * the argument cleanup_arg when the thread exits, e.g., when
 * cfuthread_queue_destroy() is called.
 */
cfuthread_queue_t * cfuthread_queue_new_with_cleanup(cfuthread_queue_fn_t fn,
	cfuthread_queue_init_t init_fn, void *init_arg, cfuthread_queue_cleanup_t cleanup_fn,
	void *cleanup_arg);

/* Add a request to the queue.  data will get passed to the
 * function fn given to cfuthread_queue_new when it reaches the
 * front of the queue.
 */
void * cfuthread_queue_make_request(cfuthread_queue_t * tq, void *data);

/* Free up resources used by the queue, in addition to canceling
 * the thread.
 */
void cfuthread_queue_destroy(cfuthread_queue_t *);

CFU_END_DECLS

#endif