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1 /*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
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20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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23 * Please see the License for the specific language governing rights and
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26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /*
29 * @OSF_COPYRIGHT@
30 */
31 /*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
49 * School of Computer Science
50 * Carnegie Mellon University
51 * Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56 /*
57 */
58 /*
59 * File: ipc/ipc_entry.h
60 * Author: Rich Draves
61 * Date: 1989
62 *
63 * Definitions for translation entries, which represent
64 * tasks' capabilities for ports and port sets.
65 */
66
67 #ifndef _IPC_IPC_ENTRY_H_
68 #define _IPC_IPC_ENTRY_H_
69
70 #include <mach/mach_types.h>
71 #include <mach/port.h>
72 #include <mach/kern_return.h>
73
74 #include <kern/kern_types.h>
75 #include <kern/zalloc.h>
76
77 #include <ipc/ipc_types.h>
78
79 /*
80 * Spaces hold capabilities for ipc_object_t's.
81 * Each ipc_entry_t records a capability. Most capabilities have
82 * small names, and the entries are elements of a table.
83 * Capabilities can have large names, and a splay tree holds
84 * those entries. The cutoff point between the table and the tree
85 * is adjusted dynamically to minimize memory consumption.
86 *
87 * The ie_index field of entries in the table implements
88 * a ordered hash table with open addressing and linear probing.
89 * This hash table converts (space, object) -> name.
90 * It is used independently of the other fields.
91 *
92 * Free (unallocated) entries in the table have null ie_object
93 * fields. The ie_bits field is zero except for IE_BITS_GEN.
94 * The ie_next (ie_request) field links free entries into a free list.
95 *
96 * The first entry in the table (index 0) is always free.
97 * It is used as the head of the free list.
98 */
99
100 struct ipc_entry {
101 struct ipc_object *ie_object;
102 ipc_entry_bits_t ie_bits;
103 union {
104 mach_port_index_t next; /* next in freelist, or... */
105 ipc_table_index_t request; /* dead name request notify */
106 } index;
107 union {
108 mach_port_index_t table;
109 struct ipc_tree_entry *tree;
110 } hash;
111 };
112
113 #define ie_request index.request
114 #define ie_next index.next
115 #define ie_index hash.table
116
117 #define IE_REQ_NONE 0 /* no request */
118
119 #define IE_BITS_UREFS_MASK 0x0000ffff /* 16 bits of user-reference */
120 #define IE_BITS_UREFS(bits) ((bits) & IE_BITS_UREFS_MASK)
121
122 #define IE_BITS_TYPE_MASK 0x001f0000 /* 5 bits of capability type */
123 #define IE_BITS_TYPE(bits) ((bits) & IE_BITS_TYPE_MASK)
124
125 #define IE_BITS_COLLISION 0x00800000 /* 1 bit for collisions */
126
127
128 #ifndef NO_PORT_GEN
129 #define IE_BITS_GEN_MASK 0xff000000 /* 8 bits for generation */
130 #define IE_BITS_GEN(bits) ((bits) & IE_BITS_GEN_MASK)
131 #define IE_BITS_GEN_ONE 0x04000000 /* low bit of generation */
132 #define IE_BITS_NEW_GEN(old) (((old) + IE_BITS_GEN_ONE) & IE_BITS_GEN_MASK)
133 #else
134 #define IE_BITS_GEN_MASK 0
135 #define IE_BITS_GEN(bits) 0
136 #define IE_BITS_GEN_ONE 0
137 #define IE_BITS_NEW_GEN(old) (old)
138 #endif /* !USE_PORT_GEN */
139
140
141 #define IE_BITS_RIGHT_MASK 0x007fffff /* relevant to the right */
142
143 struct ipc_tree_entry {
144 struct ipc_entry ite_entry;
145 mach_port_name_t ite_name;
146 struct ipc_space *ite_space;
147 struct ipc_tree_entry *ite_lchild;
148 struct ipc_tree_entry *ite_rchild;
149 };
150
151 #define ite_bits ite_entry.ie_bits
152 #define ite_object ite_entry.ie_object
153 #define ite_request ite_entry.ie_request
154 #define ite_next ite_entry.hash.tree
155
156 extern zone_t ipc_tree_entry_zone;
157
158 #define ite_alloc() ((ipc_tree_entry_t) zalloc(ipc_tree_entry_zone))
159 #define ite_free(ite) zfree(ipc_tree_entry_zone, (ite))
160
161 /*
162 * Exported interfaces
163 */
164
165 /* Search for entry in a space by name */
166 extern ipc_entry_t ipc_entry_lookup(
167 ipc_space_t space,
168 mach_port_name_t name);
169
170 /* Allocate an entry in a space */
171 extern kern_return_t ipc_entry_get(
172 ipc_space_t space,
173 mach_port_name_t *namep,
174 ipc_entry_t *entryp);
175
176 /* Allocate an entry in a space, growing the space if necessary */
177 extern kern_return_t ipc_entry_alloc(
178 ipc_space_t space,
179 mach_port_name_t *namep,
180 ipc_entry_t *entryp);
181
182 /* Allocate/find an entry in a space with a specific name */
183 extern kern_return_t ipc_entry_alloc_name(
184 ipc_space_t space,
185 mach_port_name_t name,
186 ipc_entry_t *entryp);
187
188 /* Deallocate an entry from a space */
189 extern void ipc_entry_dealloc(
190 ipc_space_t space,
191 mach_port_name_t name,
192 ipc_entry_t entry);
193
194 /* Grow the table in a space */
195 extern kern_return_t ipc_entry_grow_table(
196 ipc_space_t space,
197 ipc_table_elems_t target_size);
198
199 #endif /* _IPC_IPC_ENTRY_H_ */