resource.h revision 290001 
1/*
2 * Copyright (C) 2004-2008  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000, 2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: resource.h,v 1.13 2008/07/11 23:47:09 tbox Exp $ */
19
20#ifndef ISC_RESOURCE_H
21#define ISC_RESOURCE_H 1
22
23/*! \file isc/resource.h */
24
25#include <isc/lang.h>
26#include <isc/types.h>
27
28#define ISC_RESOURCE_UNLIMITED ((isc_resourcevalue_t)ISC_UINT64_MAX)
29
30ISC_LANG_BEGINDECLS
31
32isc_result_t
33isc_resource_setlimit(isc_resource_t resource, isc_resourcevalue_t value);
34/*%<
35 * Set the maximum limit for a system resource.
36 *
37 * Notes:
38 *\li	If 'value' exceeds the maximum possible on the operating system,
39 *	it is silently limited to that maximum -- or to "infinity", if
40 *	the operating system has that concept.  #ISC_RESOURCE_UNLIMITED
41 *	can be used to explicitly ask for the maximum.
42 *
43 * Requires:
44 *\li	'resource' is a valid member of the isc_resource_t enumeration.
45 *
46 * Returns:
47 *\li	#ISC_R_SUCCESS	Success.
48 *\li	#ISC_R_NOTIMPLEMENTED	'resource' is not a type known by the OS.
49 *\li	#ISC_R_NOPERM	The calling process did not have adequate permission
50 *			to change the resource limit.
51 */
52
53isc_result_t
54isc_resource_getlimit(isc_resource_t resource, isc_resourcevalue_t *value);
55/*%<
56 * Get the maximum limit for a system resource.
57 *
58 * Notes:
59 *\li	'value' is set to the maximum limit.
60 *
61 *\li	#ISC_RESOURCE_UNLIMITED is the maximum value of isc_resourcevalue_t.
62 *
63 *\li	On many (all?) Unix systems, RLIM_INFINITY is a valid value that is
64 *	significantly less than #ISC_RESOURCE_UNLIMITED, but which in practice
65 *	behaves the same.
66 *
67 *\li	The current ISC libdns configuration file parser assigns a value
68 *	of ISC_UINT32_MAX for a size_spec of "unlimited" and ISC_UNIT32_MAX - 1
69 *	for "default", the latter of which is supposed to represent "the
70 *	limit that was in force when the server started".  Since these are
71 *	valid values in the middle of the range of isc_resourcevalue_t,
72 *	there is the possibility for confusion over what exactly those
73 *	particular values are supposed to represent in a particular context --
74 *	discrete integral values or generalized concepts.
75 *
76 * Requires:
77 *\li	'resource' is a valid member of the isc_resource_t enumeration.
78 *
79 * Returns:
80 *\li	#ISC_R_SUCCESS		Success.
81 *\li	#ISC_R_NOTIMPLEMENTED	'resource' is not a type known by the OS.
82 */
83
84isc_result_t
85isc_resource_getcurlimit(isc_resource_t resource, isc_resourcevalue_t *value);
86/*%<
87 * Same as isc_resource_getlimit(), but returns the current (soft) limit.
88 *
89 * Returns:
90 *\li	#ISC_R_SUCCESS		Success.
91 *\li	#ISC_R_NOTIMPLEMENTED	'resource' is not a type known by the OS.
92 */
93
94ISC_LANG_ENDDECLS
95
96#endif /* ISC_RESOURCE_H */
97
98