mirror_zfs/lib/libspl/include/sys/taskq.h

// SPDX-License-Identifier: CDDL-1.0
/*
 * 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 https://opensource.org/licenses/CDDL-1.0.
 * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
 */

#ifndef _SYS_TASKQ_H
#define	_SYS_TASKQ_H

#include <pthread.h>
#include <stdint.h>
#include <sys/kmem.h>
#include <sys/thread.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/condvar.h>

/*
 * Task queues
 */

#define	TASKQ_NAMELEN	31

typedef uintptr_t taskqid_t;
typedef void (task_func_t)(void *);

typedef struct taskq_ent {
	struct taskq_ent	*tqent_next;
	struct taskq_ent	*tqent_prev;
	task_func_t		*tqent_func;
	void			*tqent_arg;
	uintptr_t		tqent_flags;
} taskq_ent_t;

typedef 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;
	kthread_t	**tq_threadlist;
	int		tq_flags;
	int		tq_active;
	int		tq_nthreads;
	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;
} taskq_t;

#define	TQENT_FLAG_PREALLOC	0x1	/* taskq_dispatch_ent used */

#define	TASKQ_PREPOPULATE	0x0001
#define	TASKQ_CPR_SAFE		0x0002	/* Use CPR safe protocol */
#define	TASKQ_DYNAMIC		0x0004	/* Use dynamic thread scheduling */
#define	TASKQ_THREADS_CPU_PCT	0x0008	/* Scale # threads by # cpus */
#define	TASKQ_DC_BATCH		0x0010	/* Mark threads as batch */

#define	TQ_SLEEP	KM_SLEEP	/* Can block for memory */
#define	TQ_NOSLEEP	KM_NOSLEEP	/* cannot block for memory; may fail */
#define	TQ_NOQUEUE	0x02		/* Do not enqueue if can't dispatch */
#define	TQ_FRONT	0x08		/* Queue in front */

#define	TASKQID_INVALID		((taskqid_t)0)

extern taskq_t *_system_taskq(void);
extern taskq_t *_system_delay_taskq(void);

#define	system_taskq		_system_taskq()
#define	system_delay_taskq	_system_delay_taskq()

extern taskq_t	*taskq_create(const char *, int, pri_t, int, int, uint_t);
extern taskq_t	*taskq_create_synced(const char *, int, pri_t, int, int, uint_t,
    kthread_t ***);
#define	taskq_create_proc(a, b, c, d, e, p, f) \
	    (taskq_create(a, b, c, d, e, f))
#define	taskq_create_sysdc(a, b, d, e, p, dc, f) \
	    ((void) sizeof (dc), taskq_create(a, b, maxclsyspri, d, e, f))
extern taskqid_t taskq_dispatch(taskq_t *, task_func_t, void *, uint_t);
extern taskqid_t taskq_dispatch_delay(taskq_t *, task_func_t, void *, uint_t,
    clock_t);
extern void	taskq_dispatch_ent(taskq_t *, task_func_t, void *, uint_t,
    taskq_ent_t *);
extern int	taskq_empty_ent(taskq_ent_t *);
extern void	taskq_init_ent(taskq_ent_t *);
extern void	taskq_destroy(taskq_t *);
extern void	taskq_wait(taskq_t *);
extern void	taskq_wait_id(taskq_t *, taskqid_t);
extern void	taskq_wait_outstanding(taskq_t *, taskqid_t);
extern int	taskq_member(taskq_t *, kthread_t *);
extern taskq_t	*taskq_of_curthread(void);
extern int	taskq_cancel_id(taskq_t *, taskqid_t);
extern void	system_taskq_init(void);
extern void	system_taskq_fini(void);

#endif /* _SYS_TASKQ_H */