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/*
* 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 (c) 2000 by Sun Microsystems, Inc.
* All rights reserved.
*/
#ifndef DSVCD_CONTAINER_H
#define DSVCD_CONTAINER_H
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <synch.h>
#include "dsvclockd.h"
/*
* Container-related data structures, functions and constants. See
* comments in container.c for a description of how to use the exported
* functions.
*/
#ifdef __cplusplus
extern "C" {
#endif
/*
* Number of seconds to wait for container lockholders to relinquish all
* locks on a given container (when it's being destroyed).
*/
#define CN_DESTROY_WAIT 60
/*
* Describes a thread waiting to access a given container; exactly one per
* waiting thread.
*/
typedef struct dsvcd_waitlist {
struct dsvcd_waitlist *wl_next; /* next waiter in list */
struct dsvcd_waitlist *wl_prev; /* prev waiter in list */
cond_t wl_cv; /* our condition variable */
dsvcd_locktype_t wl_locktype; /* type of lock we want */
} dsvcd_waitlist_t;
/*
* States for the host lock state machine. The state machine is a simple
* cycle of UNLOCKED->PENDING->{RD,WR}LOCKED->UNLOCKED->...
*/
enum cn_hlockstate { CN_HUNLOCKED, CN_HPENDING, CN_HRDLOCKED, CN_HWRLOCKED };
/*
* Describes a given container within a datastore. There is at most one of
* these per datastore container (there may be none if there are no current
* consumers of a given container within a datastore). If there is more
* than one open handle to a given container (through multiple calls to
* open_d?()) there will still only be one dsvcd_container_t for that
* container. This object is used to synchronize access to an underlying
* container through use of its custom reader/writer lock (it can't use the
* rwlock_t's built into Solaris because we need locks that do not care if
* the unlocking thread is the same as the locking thread). It also
* contains other per-container information like the container id.
*/
typedef struct dsvcd_container {
char *cn_id; /* container's id */
boolean_t cn_crosshost; /* synchronize across hosts */
boolean_t cn_closing; /* container is going away */
mutex_t cn_lock; /* protects preceding fields */
dsvcd_waitlist_t *cn_whead; /* head of wait list */
dsvcd_waitlist_t *cn_wtail; /* tail of wait list */
int cn_nholds; /* num readers (-1 == writer) */
mutex_t cn_nholds_lock; /* for nholds and waitlist */
int cn_hlockfd; /* host lock file descriptor */
int cn_hlockcount; /* current # of host locks */
enum cn_hlockstate cn_hlockstate; /* host lock state */
cond_t cn_hlockcv; /* host lock condvar */
mutex_t cn_hlock_lock; /* mutex for cn_hlock* */
/*
* These fields are used to keep metadata state regarding the
* container and are actually maintained by the containing
* datastore, not the container.
*/
uint_t cn_nout; /* number checked out */
time_t cn_lastrel; /* last released */
uint32_t cn_idhash; /* hash before modulation */
struct dsvcd_container *cn_next; /* hash chain next */
struct dsvcd_container *cn_prev; /* hash chain prev */
} dsvcd_container_t;
extern dsvcd_container_t *cn_create(const char *, boolean_t);
extern void cn_destroy(dsvcd_container_t *);
extern int cn_rdlock(dsvcd_container_t *, boolean_t);
extern int cn_wrlock(dsvcd_container_t *, boolean_t);
extern int cn_unlock(dsvcd_container_t *);
extern dsvcd_locktype_t cn_locktype(dsvcd_container_t *);
#ifdef __cplusplus
}
#endif
#endif /* DSVCD_CONTAINER_H */
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