1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 2000 by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 27 #ifndef DSVCD_CONTAINER_H 28 #define DSVCD_CONTAINER_H 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #include <sys/types.h> 33 #include <synch.h> 34 35 #include "dsvclockd.h" 36 37 /* 38 * Container-related data structures, functions and constants. See 39 * comments in container.c for a description of how to use the exported 40 * functions. 41 */ 42 43 #ifdef __cplusplus 44 extern "C" { 45 #endif 46 47 /* 48 * Number of seconds to wait for container lockholders to relinquish all 49 * locks on a given container (when it's being destroyed). 50 */ 51 #define CN_DESTROY_WAIT 60 52 53 /* 54 * Describes a thread waiting to access a given container; exactly one per 55 * waiting thread. 56 */ 57 typedef struct dsvcd_waitlist { 58 struct dsvcd_waitlist *wl_next; /* next waiter in list */ 59 struct dsvcd_waitlist *wl_prev; /* prev waiter in list */ 60 cond_t wl_cv; /* our condition variable */ 61 dsvcd_locktype_t wl_locktype; /* type of lock we want */ 62 } dsvcd_waitlist_t; 63 64 /* 65 * States for the host lock state machine. The state machine is a simple 66 * cycle of UNLOCKED->PENDING->{RD,WR}LOCKED->UNLOCKED->... 67 */ 68 enum cn_hlockstate { CN_HUNLOCKED, CN_HPENDING, CN_HRDLOCKED, CN_HWRLOCKED }; 69 70 /* 71 * Describes a given container within a datastore. There is at most one of 72 * these per datastore container (there may be none if there are no current 73 * consumers of a given container within a datastore). If there is more 74 * than one open handle to a given container (through multiple calls to 75 * open_d?()) there will still only be one dsvcd_container_t for that 76 * container. This object is used to synchronize access to an underlying 77 * container through use of its custom reader/writer lock (it can't use the 78 * rwlock_t's built into Solaris because we need locks that do not care if 79 * the unlocking thread is the same as the locking thread). It also 80 * contains other per-container information like the container id. 81 */ 82 typedef struct dsvcd_container { 83 char *cn_id; /* container's id */ 84 boolean_t cn_crosshost; /* synchronize across hosts */ 85 boolean_t cn_closing; /* container is going away */ 86 mutex_t cn_lock; /* protects preceding fields */ 87 88 dsvcd_waitlist_t *cn_whead; /* head of wait list */ 89 dsvcd_waitlist_t *cn_wtail; /* tail of wait list */ 90 int cn_nholds; /* num readers (-1 == writer) */ 91 mutex_t cn_nholds_lock; /* for nholds and waitlist */ 92 93 int cn_hlockfd; /* host lock file descriptor */ 94 int cn_hlockcount; /* current # of host locks */ 95 enum cn_hlockstate cn_hlockstate; /* host lock state */ 96 cond_t cn_hlockcv; /* host lock condvar */ 97 mutex_t cn_hlock_lock; /* mutex for cn_hlock* */ 98 99 /* 100 * These fields are used to keep metadata state regarding the 101 * container and are actually maintained by the containing 102 * datastore, not the container. 103 */ 104 uint_t cn_nout; /* number checked out */ 105 time_t cn_lastrel; /* last released */ 106 uint32_t cn_idhash; /* hash before modulation */ 107 struct dsvcd_container *cn_next; /* hash chain next */ 108 struct dsvcd_container *cn_prev; /* hash chain prev */ 109 } dsvcd_container_t; 110 111 extern dsvcd_container_t *cn_create(const char *, boolean_t); 112 extern void cn_destroy(dsvcd_container_t *); 113 extern int cn_rdlock(dsvcd_container_t *, boolean_t); 114 extern int cn_wrlock(dsvcd_container_t *, boolean_t); 115 extern int cn_unlock(dsvcd_container_t *); 116 extern dsvcd_locktype_t cn_locktype(dsvcd_container_t *); 117 118 #ifdef __cplusplus 119 } 120 #endif 121 122 #endif /* DSVCD_CONTAINER_H */ 123