xref: /freebsd/sys/dev/isci/scil/sci_base_observer.h (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0
3  *
4  * This file is provided under a dual BSD/GPLv2 license.  When using or
5  * redistributing this file, you may do so under either license.
6  *
7  * GPL LICENSE SUMMARY
8  *
9  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of version 2 of the GNU General Public License as
13  * published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
23  * The full GNU General Public License is included in this distribution
24  * in the file called LICENSE.GPL.
25  *
26  * BSD LICENSE
27  *
28  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
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30  *
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32  * modification, are permitted provided that the following conditions
33  * are met:
34  *
35  *   * Redistributions of source code must retain the above copyright
36  *     notice, this list of conditions and the following disclaimer.
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42  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
43  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
44  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
45  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
46  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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48  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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53  *
54  * $FreeBSD$
55  */
56 #ifndef _SCI_BASE_OBSERVER_H_
57 #define _SCI_BASE_OBSERVER_H_
58 
59 /**
60  * @file
61  *
62  * @brief This file contains all of the structures, constants, and methods
63  *        common to all base observer object definitions.
64  */
65 
66 #ifdef __cplusplus
67 extern "C" {
68 #endif // __cplusplus
69 
70 #if defined(SCI_LOGGING)
71 
72 struct SCI_BASE_OBSERVER;
73 struct SCI_BASE_SUBJECT;
74 
75 /**
76  * @typedef SCI_BASE_OBSERVER_UPDATE_T
77  *
78  * @brief This type definition defines the format for the update method
79  *        that is invoked for all observers participating in the observer
80  *        design pattern.
81  */
82 typedef void (*SCI_BASE_OBSERVER_UPDATE_T)(
83    struct SCI_BASE_OBSERVER *this_observer,
84    struct SCI_BASE_SUBJECT  *the_subject
85 );
86 
87 /**
88  * @struct SCI_BASE_OBSERVER
89  *
90  * @brief This structure defines the fields necessary for an object that
91  *        intends to participate as an observer.
92  */
93 typedef struct SCI_BASE_OBSERVER
94 {
95    /**
96     * This filed points to the next observer if there is one
97     */
98     struct SCI_BASE_OBSERVER *next;
99 
100    /**
101     * This field defines the function pointer that is invoked in order to
102     * notify the observer of a change in the subject (i.e. observed object).
103     */
104    SCI_BASE_OBSERVER_UPDATE_T update;
105 
106 } SCI_BASE_OBSERVER_T;
107 
108 /**
109  * @brief This method is the basic constructor for the observer
110  *
111  * @param[in] this_observer This parameter specifies the observer to
112  *            be constructed.
113  * @param[in] update This parameter specifies the update method to be
114  *            invoked for this observer.
115  *
116  * @return none
117  */
118 void sci_base_observer_construct(
119    struct SCI_BASE_OBSERVER   *this_observer,
120    SCI_BASE_OBSERVER_UPDATE_T  update
121 );
122 
123 /**
124  * @brief This method performs the actions of construction and attaches to the
125  *        subject.
126  *
127  * @pre The the_subject to be observed must be constructed before this call.
128  *
129  * @param[in] this_observer This parameter specifies the observer to construct
130  *       an attach to the subject.
131  * @param[in] update This parameter is the update function that is passed to
132  *       the constructor.
133  * @param[in] the_subject This parameter specifies the subject to observe.
134  */
135 void sci_base_observer_initialize(
136    struct SCI_BASE_OBSERVER   *this_observer,
137    SCI_BASE_OBSERVER_UPDATE_T  update,
138    struct SCI_BASE_SUBJECT    *the_subject
139 );
140 
141 /**
142  * @brief This method will call the observers update function
143  *
144  * @param[in] this_observer This parameter specifies the observer to be
145  *            notified.
146  * @param[in] the_subject This parameter indicates the subject for which
147  *            the update call is occurring.
148  *
149  * @return none
150  */
151 void sci_base_observer_update(
152    struct SCI_BASE_OBSERVER *this_observer,
153    struct SCI_BASE_SUBJECT  *the_subject
154 );
155 
156 #else // defined(SCI_LOGGING)
157 
158 typedef U8 SCI_BASE_OBSERVER_T;
159 #define sci_base_observer_construct
160 #define sci_base_observer_initialize
161 #define sci_base_observer_update
162 
163 #endif // defined(SCI_LOGGING)
164 
165 #ifdef __cplusplus
166 }
167 #endif // __cplusplus
168 
169 #endif // _SCI_BASE_OBSERVER_H_
170