summaryrefslogtreecommitdiff
path: root/ipc/ipc_table.h
blob: 3bfcc46c6a441532aa95d49d1f92499f8ede8921 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 *	File:	ipc/ipc_table.h
 *	Author:	Rich Draves
 *	Date:	1989
 *
 *	Definitions for tables, used for IPC capabilities (ipc_entry_t)
 *	and dead-name requests (ipc_port_request_t).
 */

#ifndef	_IPC_IPC_TABLE_H_
#define	_IPC_IPC_TABLE_H_

#include <mach/boolean.h>
#include <mach/vm_param.h>

/*
 *	The is_table_next field of an ipc_space_t points to
 *	an ipc_table_size structure.  These structures must
 *	be elements of an array, ipc_table_entries.
 *
 *	The array must end with two elements with the same its_size value.
 *	Except for the terminating element, the its_size values must
 *	be strictly increasing.  The largest (last) its_size value
 *	must be less than or equal to MACH_PORT_INDEX(MACH_PORT_DEAD).
 *	This ensures that
 *		1) MACH_PORT_INDEX(MACH_PORT_DEAD) isn't a valid index
 *		in the table, so ipc_entry_get won't allocate it.
 *		2) MACH_PORT_MAKE(index+1, 0) and MAKE_PORT_MAKE(size, 0)
 *		won't ever overflow.
 *
 *
 *	The ipr_size field of the first element in a table of
 *	dead-name requests (ipc_port_request_t) points to the
 *	ipc_table_size structure.  The structures must be elements
 *	of ipc_table_dnrequests.  ipc_table_dnrequests must end
 *	with an element with zero its_size, and except for this last
 *	element, the its_size values must be strictly increasing.
 *
 *	The is_table_next field points to the ipc_table_size structure
 *	for the next larger size of table, not the one currently in use.
 *	The ipr_size field points to the currently used ipc_table_size.
 */

typedef unsigned int ipc_table_index_t;	/* index into tables */
typedef unsigned int ipc_table_elems_t;	/* size of tables */

typedef struct ipc_table_size {
	ipc_table_elems_t its_size;	/* number of elements in table */
} *ipc_table_size_t;

#define	ITS_NULL	((ipc_table_size_t) 0)

extern ipc_table_size_t ipc_table_entries;
extern ipc_table_size_t ipc_table_dnrequests;

extern void
ipc_table_init();

/*
 *	Note that ipc_table_alloc, ipc_table_realloc, and ipc_table_free
 *	all potentially use the VM system.  Hence simple locks can't
 *	be held across them.
 *
 *	We can't use a copying realloc, because the realloc happens
 *	with the data unlocked.  ipc_table_realloc remaps the data,
 *	so it is OK.
 */

/* Allocate a table */
extern vm_offset_t ipc_table_alloc(
	vm_size_t	size);

/* Reallocate a big table */
extern vm_offset_t ipc_table_realloc(
	vm_size_t	old_size,
	vm_offset_t	old_table,
	vm_size_t	new_size);

/* Free a table */
extern void ipc_table_free(
	vm_size_t	size,
	vm_offset_t	table);

#define	it_entries_alloc(its)						\
	((ipc_entry_t)							\
	 ipc_table_alloc((its)->its_size * sizeof(struct ipc_entry)))

#define it_entries_reallocable(its)					\
	(((its)->its_size * sizeof(struct ipc_entry)) >= PAGE_SIZE)

#define	it_entries_realloc(its, table, nits)				\
	((ipc_entry_t)							\
	 ipc_table_realloc((its)->its_size * sizeof(struct ipc_entry),	\
			   (vm_offset_t)(table),			\
			   (nits)->its_size * sizeof(struct ipc_entry)))

#define	it_entries_free(its, table)					\
	ipc_table_free((its)->its_size * sizeof(struct ipc_entry),	\
		       (vm_offset_t)(table))

#define	it_dnrequests_alloc(its)					\
	((ipc_port_request_t)						\
	 ipc_table_alloc((its)->its_size *				\
			 sizeof(struct ipc_port_request)))

#define	it_dnrequests_free(its, table)					\
	ipc_table_free((its)->its_size *				\
		       sizeof(struct ipc_port_request),			\
		       (vm_offset_t)(table))

#endif	/* _IPC_IPC_TABLE_H_ */