/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#ifndef	_SYS_TASKQ_IMPL_H

#define	_SYS_TASKQ_IMPL_H

#include <sys/taskq.h>

#include <sys/inttypes.h>

#include <sys/vmem.h>

#include <sys/list.h>

#include <sys/kstat.h>

#ifdef	__cplusplus

extern "C" {

#endif

typedef struct taskq_bucket taskq_bucket_t;

typedef struct taskq_ent {

	struct taskq_ent	*tqent_next;

	struct taskq_ent	*tqent_prev;

	task_func_t		*tqent_func;

	void			*tqent_arg;

	kthread_t		*tqent_thread;

	kcondvar_t		tqent_cv;

} taskq_ent_t;

/*

 * Taskq Statistics fields are not protected by any locks.

 */

typedef struct tqstat {

	uint_t		tqs_hits;

	uint_t		tqs_misses;

	uint_t		tqs_overflow;	/* no threads to allocate   */

	uint_t		tqs_tcreates;	/* threads created 	*/

	uint_t		tqs_tdeaths;	/* threads died		*/

	uint_t		tqs_maxthreads;	/* max # of alive threads */

	uint_t		tqs_nomem;	/* # of times there were no memory */

	uint_t		tqs_disptcreates;

} tqstat_t;

/*

 * Per-CPU hash bucket manages taskq_bent_t structures using freelist.

 */

struct taskq_bucket {

	kmutex_t	tqbucket_lock;

	taskq_t		*tqbucket_taskq;	/* Enclosing taskq */

	taskq_ent_t	tqbucket_freelist;

	uint_t		tqbucket_nalloc;	/* # of allocated entries */

	uint_t		tqbucket_nfree;		/* # of free entries */

	kcondvar_t	tqbucket_cv;

	ushort_t	tqbucket_flags;

	hrtime_t	tqbucket_totaltime;

	tqstat_t	tqbucket_stat;

};

/*

 * Bucket flags.

 */

#define	TQBUCKET_CLOSE		0x01

#define	TQBUCKET_SUSPEND	0x02

#define	TASKQ_INTERFACE_FLAGS	0x0000ffff	/* defined in <sys/taskq.h> */

/*

 * taskq implementation flags: bit range 16-31

 */

#define	TASKQ_CHANGING		0x00010000	/* nthreads != target */

#define	TASKQ_SUSPENDED		0x00020000	/* taskq is suspended */

#define	TASKQ_NOINSTANCE	0x00040000	/* no instance number */

#define	TASKQ_THREAD_CREATED	0x00080000	/* a thread has been created */

#define	TASKQ_DUTY_CYCLE	0x00100000	/* using the SDC class */

struct taskq {

	char		tq_name[TASKQ_NAMELEN + 1];

	kmutex_t	tq_lock;

	krwlock_t	tq_threadlock;

	kcondvar_t	tq_dispatch_cv;

	kcondvar_t	tq_wait_cv;

	kcondvar_t	tq_exit_cv;

	pri_t		tq_pri;		/* Scheduling priority */

	uint_t		tq_flags;

	int		tq_active;

	int		tq_nthreads;

	int		tq_nthreads_target;

	int		tq_nthreads_max;

	int		tq_threads_ncpus_pct;

	int		tq_nalloc;

	int		tq_minalloc;

	int		tq_maxalloc;

	kcondvar_t	tq_maxalloc_cv;

	int		tq_maxalloc_wait;

	taskq_ent_t	*tq_freelist;

	taskq_ent_t	tq_task;

	int		tq_maxsize;

	taskq_bucket_t	*tq_buckets;	/* Per-cpu array of buckets */

	int		tq_instance;

	uint_t		tq_nbuckets;	/* # of buckets	(2^n)	    */

	union {

		kthread_t *_tq_thread;

		kthread_t **_tq_threadlist;

	}		tq_thr;

	list_node_t	tq_cpupct_link;	/* linkage for taskq_cpupct_list */

	struct proc	*tq_proc;	/* process for taskq threads */

	int		tq_cpupart;	/* cpupart id bound to */

	uint_t		tq_DC;		/* duty cycle for SDC */

	/*

	 * Statistics.

	 */

	kstat_t		*tq_kstat;	/* Exported statistics */

	hrtime_t	tq_totaltime;	/* Time spent processing tasks */

	uint64_t	tq_tasks;	/* Total # of tasks posted */

	uint64_t	tq_executed;	/* Total # of tasks executed */

	int		tq_maxtasks;	/* Max number of tasks in the queue */

	int		tq_tcreates;

	int		tq_tdeaths;

};

#define	tq_thread tq_thr._tq_thread

#define	tq_threadlist tq_thr._tq_threadlist

/* The MAX guarantees we have at least one thread */

#define	TASKQ_THREADS_PCT(ncpus, pct)	MAX(((ncpus) * (pct)) / 100, 1)

#ifdef	__cplusplus

}

#endif

#endif	/* _SYS_TASKQ_IMPL_H */