/*

 * CDDL HEADER START

 *

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

 * Common Development and Distribution License, Version 1.0 only

 * (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 2005 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#ifndef _SYS_TXG_H

#define	_SYS_TXG_H

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/spa.h>

#include <sys/zfs_context.h>

#ifdef	__cplusplus

extern "C" {

#endif

#define	TXG_CONCURRENT_STATES	3	/* open, quiescing, syncing	*/

#define	TXG_SIZE		4		/* next power of 2	*/

#define	TXG_MASK		(TXG_SIZE - 1)	/* mask for size	*/

#define	TXG_INITIAL		TXG_SIZE	/* initial txg 		*/

#define	TXG_IDX			(txg & TXG_MASK)

#define	TXG_WAIT		1ULL

#define	TXG_NOWAIT		2ULL

typedef struct tx_cpu tx_cpu_t;

typedef struct txg_handle {

	tx_cpu_t	*th_cpu;

	uint64_t	th_txg;

} txg_handle_t;

typedef struct txg_node {

	struct txg_node	*tn_next[TXG_SIZE];

	uint8_t		tn_member[TXG_SIZE];

} txg_node_t;

typedef struct txg_list {

	kmutex_t	tl_lock;

	size_t		tl_offset;

	txg_node_t	*tl_head[TXG_SIZE];

} txg_list_t;

struct dsl_pool;

extern void txg_init(struct dsl_pool *dp, uint64_t txg);

extern void txg_fini(struct dsl_pool *dp);

extern void txg_sync_start(struct dsl_pool *dp);

extern void txg_sync_stop(struct dsl_pool *dp);

extern uint64_t txg_hold_open(struct dsl_pool *dp, txg_handle_t *txghp);

extern void txg_rele_to_quiesce(txg_handle_t *txghp);

extern void txg_rele_to_sync(txg_handle_t *txghp);

extern void txg_suspend(struct dsl_pool *dp);

extern void txg_resume(struct dsl_pool *dp);

/*

 * Wait until the given transaction group has finished syncing.

 * Try to make this happen as soon as possible (eg. kick off any

 * necessary syncs immediately).  If txg==0, wait for the currently open

 * txg to finish syncing.

 */

extern void txg_wait_synced(struct dsl_pool *dp, uint64_t txg);

/*

 * Wait until the given transaction group, or one after it, is

 * the open transaction group.  Try to make this happen as soon

 * as possible (eg. kick off any necessary syncs immediately).

 * If txg == 0, wait for the next open txg.

 */

extern void txg_wait_open(struct dsl_pool *dp, uint64_t txg);

/*

 * Returns TRUE if we are "backed up" waiting for the syncing

 * transaction to complete; otherwise returns FALSE.

 */

extern int txg_stalled(struct dsl_pool *dp);

/*

 * Per-txg object lists.

 */

#define	TXG_CLEAN(txg)	((txg) - 1)

extern void txg_list_create(txg_list_t *tl, size_t offset);

extern void txg_list_destroy(txg_list_t *tl);

extern int txg_list_empty(txg_list_t *tl, uint64_t txg);

extern int txg_list_add(txg_list_t *tl, void *p, uint64_t txg);

extern void *txg_list_remove(txg_list_t *tl, uint64_t txg);

extern void *txg_list_remove_this(txg_list_t *tl, void *p, uint64_t txg);

extern int txg_list_member(txg_list_t *tl, void *p, uint64_t txg);

extern void *txg_list_head(txg_list_t *tl, uint64_t txg);

extern void *txg_list_next(txg_list_t *tl, void *p, uint64_t txg);

#ifdef	__cplusplus

}

#endif

#endif	/* _SYS_TXG_H */