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) 2002-2003, Network Appliance, Inc. All rights reserved.
24  */
25 
26 /*
27  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 
34 /*
35  *
36  * MODULE: dat_init.c
37  *
38  * PURPOSE: DAT registry implementation for uDAPL
39  * Description: init and fini functions for DAT module.
40  *
41  * $Id: dat_init.c,v 1.12 2003/07/09 11:26:06 hobie16 Exp $
42  */
43 
44 #include "dat_init.h"
45 
46 #include "dat_dr.h"
47 #include "dat_osd.h"
48 
49 #ifndef DAT_NO_STATIC_REGISTRY
50 #include "dat_sr.h"
51 #endif
52 
53 
54 /*
55  *
56  * Global Variables
57  *
58  */
59 
60 /*
61  * Ideally, the following two rules could be enforced:
62  *
63  * - The DAT Registry's initialization function is executed before that
64  *   of any DAT Providers and hence all calls into the registry occur
65  *   after the registry module is initialized.
66  *
67  * - The DAT Registry's deinitialization function is executed after that
68  *   of any DAT Providers and hence all calls into the registry occur
69  *   before the registry module is deinitialized.
70  *
71  * However, on many platforms few guarantees are provided regarding the
72  * order in which modules initialization and deinitialization functions
73  * are invoked.
74  *
75  * To understand why these rules are difficult to enforce using only
76  * features common to all platforms, consider the Linux platform. The order
77  * in which Linux shared libraries are loaded into a process's address space
78  * is undefined. When a DAT consumer explicitly links to DAT provider
79  * libraries, the order in which library initialization and deinitialization
80  * functions are invoked becomes important. For example if the DAPL provider
81  * calls dat_registry_add_provider() before the registry has been initialized,
82  * an error will occur.
83  *
84  * We assume that modules are loaded with a single thread. Given
85  * this assumption, we can use a simple state variable to determine
86  * the state of the DAT registry.
87  */
88 
89 static DAT_MODULE_STATE 	g_module_state = DAT_MODULE_STATE_UNINITIALIZED;
90 
91 
92 /*
93  * Function: dat_module_get_state
94  */
95 
96 DAT_MODULE_STATE
dat_module_get_state(void)97 dat_module_get_state(void)
98 {
99 	return (g_module_state);
100 }
101 
102 
103 /*
104  *  Function: dat_init
105  */
106 
107 void
dat_init(void)108 dat_init(void)
109 {
110 	if (DAT_MODULE_STATE_UNINITIALIZED == g_module_state) {
111 	/*
112 	 * update the module state flag immediately in case there
113 	 * is a recursive call to dat_init().
114 	 */
115 		g_module_state = DAT_MODULE_STATE_INITIALIZING;
116 
117 		dat_os_dbg_init();
118 
119 		dat_os_dbg_print(DAT_OS_DBG_TYPE_GENERIC,
120 		    "DAT Registry: Started (dat_init)\n");
121 
122 #ifndef DAT_NO_STATIC_REGISTRY
123 		(void) dat_sr_init();
124 #endif
125 		(void) dat_dr_init();
126 
127 		g_module_state = DAT_MODULE_STATE_INITIALIZED;
128 	}
129 }
130 
131 
132 /*
133  * Function: dat_fini
134  */
135 
136 void
dat_fini(void)137 dat_fini(void)
138 {
139 	if (DAT_MODULE_STATE_INITIALIZED == g_module_state) {
140 		g_module_state = DAT_MODULE_STATE_DEINITIALIZING;
141 
142 		(void) dat_dr_fini();
143 #ifndef DAT_NO_STATIC_REGISTRY
144 		(void) dat_sr_fini();
145 #endif
146 		dat_os_dbg_print(DAT_OS_DBG_TYPE_GENERIC,
147 		    "DAT Registry: Stopped (dat_fini)\n");
148 
149 		g_module_state = DAT_MODULE_STATE_DEINITIALIZED;
150 	}
151 }
152 
153 
154 /*
155  * Local variables:
156  *  c-indent-level: 4
157  *  c-basic-offset: 4
158  *  tab-width: 8
159  * End:
160  */
161