resource.h revision 1.4 
1/*	$NetBSD: resource.h,v 1.4 2020/05/24 19:46:26 christos Exp $	*/
2
3/*
4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5 *
6 * This Source Code Form is subject to the terms of the Mozilla Public
7 * License, v. 2.0. If a copy of the MPL was not distributed with this
8 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 *
10 * See the COPYRIGHT file distributed with this work for additional
11 * information regarding copyright ownership.
12 */
13
14#ifndef ISC_RESOURCE_H
15#define ISC_RESOURCE_H 1
16
17/*! \file isc/resource.h */
18
19#include <isc/lang.h>
20#include <isc/types.h>
21
22#define ISC_RESOURCE_UNLIMITED ((isc_resourcevalue_t)UINT64_MAX)
23
24ISC_LANG_BEGINDECLS
25
26isc_result_t
27isc_resource_setlimit(isc_resource_t resource, isc_resourcevalue_t value);
28/*%<
29 * Set the maximum limit for a system resource.
30 *
31 * Notes:
32 *\li	If 'value' exceeds the maximum possible on the operating system,
33 *	it is silently limited to that maximum -- or to "infinity", if
34 *	the operating system has that concept.  #ISC_RESOURCE_UNLIMITED
35 *	can be used to explicitly ask for the maximum.
36 *
37 * Requires:
38 *\li	'resource' is a valid member of the isc_resource_t enumeration.
39 *
40 * Returns:
41 *\li	#ISC_R_SUCCESS	Success.
42 *\li	#ISC_R_NOTIMPLEMENTED	'resource' is not a type known by the OS.
43 *\li	#ISC_R_NOPERM	The calling process did not have adequate permission
44 *			to change the resource limit.
45 */
46
47isc_result_t
48isc_resource_getlimit(isc_resource_t resource, isc_resourcevalue_t *value);
49/*%<
50 * Get the maximum limit for a system resource.
51 *
52 * Notes:
53 *\li	'value' is set to the maximum limit.
54 *
55 *\li	#ISC_RESOURCE_UNLIMITED is the maximum value of isc_resourcevalue_t.
56 *
57 *\li	On many (all?) Unix systems, RLIM_INFINITY is a valid value that is
58 *	significantly less than #ISC_RESOURCE_UNLIMITED, but which in practice
59 *	behaves the same.
60 *
61 *\li	The current ISC libdns configuration file parser assigns a value
62 *	of UINT32_MAX for a size_spec of "unlimited" and ISC_UNIT32_MAX - 1
63 *	for "default", the latter of which is supposed to represent "the
64 *	limit that was in force when the server started".  Since these are
65 *	valid values in the middle of the range of isc_resourcevalue_t,
66 *	there is the possibility for confusion over what exactly those
67 *	particular values are supposed to represent in a particular context --
68 *	discrete integral values or generalized concepts.
69 *
70 * Requires:
71 *\li	'resource' is a valid member of the isc_resource_t enumeration.
72 *
73 * Returns:
74 *\li	#ISC_R_SUCCESS		Success.
75 *\li	#ISC_R_NOTIMPLEMENTED	'resource' is not a type known by the OS.
76 */
77
78isc_result_t
79isc_resource_getcurlimit(isc_resource_t resource, isc_resourcevalue_t *value);
80/*%<
81 * Same as isc_resource_getlimit(), but returns the current (soft) limit.
82 *
83 * Returns:
84 *\li	#ISC_R_SUCCESS		Success.
85 *\li	#ISC_R_NOTIMPLEMENTED	'resource' is not a type known by the OS.
86 */
87
88ISC_LANG_ENDDECLS
89
90#endif /* ISC_RESOURCE_H */
91