/*

 * Copyright (c) 2004-2007 Voltaire, Inc. All rights reserved.

 * Copyright (c) 2002-2005 Mellanox Technologies LTD. All rights reserved.

 * Copyright (c) 1996-2003 Intel Corporation. All rights reserved.

 *

 * This software is available to you under a choice of one of two

 * licenses.  You may choose to be licensed under the terms of the GNU

 * General Public License (GPL) Version 2, available from the file

 * COPYING in the main directory of this source tree, or the

 * OpenIB.org BSD license below:

 *

 *     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.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 *

 */

/*

 * Abstract:

 *	Implementation of thread pool.

 *

 */

#if HAVE_CONFIG_H

#  include <config.h>

#endif				/* HAVE_CONFIG_H */

#include <stdlib.h>

#include <string.h>

#include <pthread.h>

#include <complib/cl_threadpool.h>

static void cleanup_mutex(void *arg)

{

	pthread_mutex_unlock(&((cl_thread_pool_t *) arg)->mutex);

}

static void *thread_pool_routine(void *context)

{

	cl_thread_pool_t *p_thread_pool = (cl_thread_pool_t *) context;

	do {

		pthread_mutex_lock(&p_thread_pool->mutex);

		pthread_cleanup_push(cleanup_mutex, p_thread_pool);

		while (!p_thread_pool->events)

			pthread_cond_wait(&p_thread_pool->cond,

					  &p_thread_pool->mutex);

		p_thread_pool->events--;

		pthread_cleanup_pop(1);

		/* The event has been signalled.  Invoke the callback. */

		(*p_thread_pool->pfn_callback) (p_thread_pool->context);

	} while (1);

	return NULL;

}

cl_status_t cl_thread_pool_init(IN cl_thread_pool_t * const p_thread_pool,

				IN unsigned count,

				IN void (*pfn_callback) (void *),

				IN void *context, IN const char *const name)

{

	int i;

	CL_ASSERT(p_thread_pool);

	CL_ASSERT(pfn_callback);

	memset(p_thread_pool, 0, sizeof(*p_thread_pool));

	if (!count)

		count = cl_proc_count();

	pthread_mutex_init(&p_thread_pool->mutex, NULL);

	pthread_cond_init(&p_thread_pool->cond, NULL);

	p_thread_pool->events = 0;

	p_thread_pool->pfn_callback = pfn_callback;

	p_thread_pool->context = context;

	p_thread_pool->tid = calloc(count, sizeof(*p_thread_pool->tid));

	if (!p_thread_pool->tid) {

		cl_thread_pool_destroy(p_thread_pool);

		return CL_INSUFFICIENT_MEMORY;

	}

	p_thread_pool->running_count = count;

	for (i = 0; i < count; i++) {

		if (pthread_create(&p_thread_pool->tid[i], NULL,

				   thread_pool_routine, p_thread_pool) != 0) {

			cl_thread_pool_destroy(p_thread_pool);

			return CL_INSUFFICIENT_RESOURCES;

		}

	}

	return (CL_SUCCESS);

}

void cl_thread_pool_destroy(IN cl_thread_pool_t * const p_thread_pool)

{

	int i;

	CL_ASSERT(p_thread_pool);

	for (i = 0; i < p_thread_pool->running_count; i++)

		if (p_thread_pool->tid[i])

			pthread_cancel(p_thread_pool->tid[i]);

	for (i = 0; i < p_thread_pool->running_count; i++)

		if (p_thread_pool->tid[i])

			pthread_join(p_thread_pool->tid[i], NULL);

	p_thread_pool->running_count = 0;

	free(p_thread_pool->tid);

	pthread_cond_destroy(&p_thread_pool->cond);

	pthread_mutex_destroy(&p_thread_pool->mutex);

	p_thread_pool->events = 0;

}

cl_status_t cl_thread_pool_signal(IN cl_thread_pool_t * const p_thread_pool)

{

	int ret;

	CL_ASSERT(p_thread_pool);

	pthread_mutex_lock(&p_thread_pool->mutex);

	p_thread_pool->events++;

	ret = pthread_cond_signal(&p_thread_pool->cond);

	pthread_mutex_unlock(&p_thread_pool->mutex);

	return ret;

}