/*++
"This software program is available to you under a choice of one of two
licenses.  You may choose to be licensed under either the GNU General Public
License (GPL) Version 2, June 1991, available at
http://www.fsf.org/copyleft/gpl.html, or the Intel BSD + Patent License,
the text of which follows:

"Recipient" has requested a license and Intel Corporation ("Intel") is willing
to grant a license for the software entitled InfiniBand(tm) System Software
(the "Software") being provided by Intel Corporation.

The following definitions apply to this License:

"Licensed Patents" means patent claims licensable by Intel Corporation which
are necessarily infringed by the use or sale of the Software alone or when
combined with the operating system referred to below.

"Recipient" means the party to whom Intel delivers this Software.
"Licensee" means Recipient and those third parties that receive a license to
any operating system available under the GNU Public License version 2.0 or
later.

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

The license is provided to Recipient and Recipient's Licensees under the
following terms.

Redistribution and use in source and binary forms of the Software, with or
without modification, are permitted provided that the following conditions are
met:
Redistributions of source code of the Software may retain the above copyright
notice, this list of conditions and the following disclaimer.

Redistributions in binary form of the Software may 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 Intel Corporation nor the names of its contributors shall
be used to endorse or promote products derived from this Software without
specific prior written permission.

Intel hereby grants Recipient and Licensees a non-exclusive, worldwide,
royalty-free patent license under Licensed Patents to make, use, sell, offer
to sell, import and otherwise transfer the Software, if any, in source code
and object code form. This license shall include changes to the Software that
are error corrections or other minor changes to the Software that do not add
functionality or features when the Software is incorporated in any version of
a operating system that has been distributed under the GNU General Public
License 2.0 or later.  This patent license shall apply to the combination of
the Software and any operating system licensed under the GNU Public License
version 2.0 or later if, at the time Intel provides the Software to Recipient,
such addition of the Software to the then publicly available versions of such
operating system available under the GNU Public License version 2.0 or later
(whether in gold, beta or alpha form) causes such combination to be covered by
the Licensed Patents. The patent license shall not apply to any other
combinations which include the Software. No hardware per se is licensed
hereunder.

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 INTEL OR ITS 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."
--*/

/*
 * Abstract:
 *	Declaration of thread pool.
 *
 * Environment:
 *	All
 *
 * $Revision: 1.1 $
 */

#ifndef _CL_THREAD_POOL_H_
#define _CL_THREAD_POOL_H_

#include <complib/cl_list.h>
#include <complib/cl_thread.h>
#include <complib/cl_event.h>

/****h* Component Library/Thread Pool
* NAME
*	Thread Pool
*
* DESCRIPTION
*	The Thread Pool manages a user specified number of threads.
*
*	Each thread in the thread pool waits for a user initiated signal before
*	invoking a user specified callback function. All threads in the thread
*	pool invoke the same callback function.
*
*	The thread pool functions operate on a cl_thread_pool_t structure which
*	should be treated as opaque, and should be manipulated only through the
*	provided functions.
*
* SEE ALSO
*	Structures:
*		cl_thread_pool_t
*
*	Initialization:
*		cl_thread_pool_construct, cl_thread_pool_init, cl_thread_pool_destroy
*
*	Manipulation
*		cl_thread_pool_signal
*********/

/****s* Component Library: Thread Pool/cl_thread_pool_t
* NAME
*	cl_thread_pool_t
*
* DESCRIPTION
*	Thread pool structure.
*
*	The cl_thread_pool_t structure should be treated as opaque, and should be
*	manipulated only through the provided functions.
*
* SYNOPSIS
*/
typedef struct _cl_thread_pool {
	cl_pfn_thread_callback_t pfn_callback;
	const void *context;
	cl_list_t thread_list;
	cl_event_t wakeup_event;
	cl_event_t destroy_event;
	boolean_t exit;
	cl_state_t state;
	atomic32_t running_count;

} cl_thread_pool_t;
/*
* FIELDS
*	pfn_callback
*		Callback function for the thread to invoke.
*
*	context
*		Context to pass to the thread callback function.
*
*	thread_list
*		List of threads managed by the thread pool.
*
*	event
*		Event used to signal threads to wake up and do work.
*
*	destroy_event
*		Event used to signal threads to exit.
*
*	exit
*		Flag used to indicates threads to exit.
*
*	state
*		State of the thread pool.
*
*	running_count
*		Number of threads running.
*
* SEE ALSO
*	Thread Pool
*********/

#ifdef __cplusplus
extern "C" {
#endif

/****f* Component Library: Thread Pool/cl_thread_pool_construct
* NAME
*	cl_thread_pool_construct
*
* DESCRIPTION
*	The cl_thread_pool_construct function initializes the state of a
*	thread pool.
*
* SYNOPSIS
*/
	void
	 cl_thread_pool_construct(IN cl_thread_pool_t * const p_thread_pool);
/*
* PARAMETERS
*	p_thread_pool
*		[in] Pointer to a thread pool structure.
*
* RETURN VALUE
*	This function does not return a value.
*
* NOTES
*	Allows calling cl_thread_pool_destroy without first calling
*	cl_thread_pool_init.
*
*	Calling cl_thread_pool_construct is a prerequisite to calling any other
*	thread pool function except cl_thread_pool_init.
*
* SEE ALSO
*	Thread Pool, cl_thread_pool_init, cl_thread_pool_destroy
*********/

/****f* Component Library: Thread Pool/cl_thread_pool_init
* NAME
*	cl_thread_pool_init
*
* DESCRIPTION
*	The cl_thread_pool_init function creates the threads to be
*	managed by a thread pool.
*
* SYNOPSIS
*/
	 cl_status_t
	    cl_thread_pool_init(IN cl_thread_pool_t * const p_thread_pool,
				IN uint32_t thread_count,
				IN cl_pfn_thread_callback_t pfn_callback,
				IN const void *const context,
				IN const char *const name);
/*
* PARAMETERS
*	p_thread_pool
*		[in] Pointer to a thread pool structure to initialize.
*
*	thread_count
*		[in] Number of threads to be managed by the thread pool.
*
*	pfn_callback
*		[in] Address of a function to be invoked by a thread.
*		See the cl_pfn_thread_callback_t function type definition for
*		details about the callback function.
*
*	context
*		[in] Value to pass to the callback function.
*
*	name
*		[in] Name to associate with the threads.  The name may be up to 16
*		characters, including a terminating null character.  All threads
*		created in the pool have the same name.
*
* RETURN VALUES
*	CL_SUCCESS if the thread pool creation succeeded.
*
*	CL_INSUFFICIENT_MEMORY if there was not enough memory to inititalize
*	the thread pool.
*
*	CL_ERROR if the threads could not be created.
*
* NOTES
*	cl_thread_pool_init creates and starts the specified number of threads.
*	If thread_count is zero, the thread pool creates as many threads as there
*	are processors in the system.
*
* SEE ALSO
*	Thread Pool, cl_thread_pool_construct, cl_thread_pool_destroy,
*	cl_thread_pool_signal, cl_pfn_thread_callback_t
*********/

/****f* Component Library: Thread Pool/cl_thread_pool_destroy
* NAME
*	cl_thread_pool_destroy
*
* DESCRIPTION
*	The cl_thread_pool_destroy function performs any necessary cleanup
*	for a thread pool.
*
* SYNOPSIS
*/
	void
	 cl_thread_pool_destroy(IN cl_thread_pool_t * const p_thread_pool);
/*
* PARAMETERS
*	p_thread_pool
*		[in] Pointer to a thread pool structure to destroy.
*
* RETURN VALUE
*	This function does not return a value.
*
* NOTES
*	This function blocks until all threads exit, and must therefore not
*	be called from any of the thread pool's threads. Because of its blocking
*	nature, callers of cl_thread_pool_destroy must ensure that entering a wait
*	state is valid from the calling thread context.
*
*	This function should only be called after a call to
*	cl_thread_pool_construct or cl_thread_pool_init.
*
* SEE ALSO
*	Thread Pool, cl_thread_pool_construct, cl_thread_pool_init
*********/

/****f* Component Library: Thread Pool/cl_thread_pool_signal
* NAME
*	cl_thread_pool_signal
*
* DESCRIPTION
*	The cl_thread_pool_signal function signals a single thread of
*	the thread pool to invoke the thread pool’s callback function.
*
* SYNOPSIS
*/
	 cl_status_t
	    cl_thread_pool_signal(IN cl_thread_pool_t * const p_thread_pool);
/*
* PARAMETERS
*	p_thread_pool
*		[in] Pointer to a thread pool structure to signal.
*
* RETURN VALUES
*	CL_SUCCESS if the thread pool was successfully signalled.
*
*	CL_ERROR otherwise.
*
* NOTES
*	Each call to this function wakes up at most one waiting thread in
*	the thread pool.
*
*	If all threads are running, cl_thread_pool_signal has no effect.
*
* SEE ALSO
*	Thread Pool
*********/

#ifdef __cplusplus
}				/* extern "C" */
#endif
#endif				/* _CL_THREAD_POOL_H_ */
