contrib/bind-9.2.4rc7/lib/isc/include/isc/resource.h

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000, 2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and 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 1.4.2.1 2004/03/09 06:12:00 marka Exp $ */
  19
  20 #ifndef ISC_RESOURCE_H
  21 #define ISC_RESOURCE_H 1
  22
  23 #include <isc/lang.h>
  24 #include <isc/types.h>
  25
  26 #define ISC_RESOURCE_UNLIMITED ((isc_resourcevalue_t)ISC_UINT64_MAX)
  27
  28 ISC_LANG_BEGINDECLS
  29
  30 isc_result_t
  31 isc_resource_setlimit(isc_resource_t resource, isc_resourcevalue_t value);
  32 /*
  33  * Set the maximum limit for a system resource.
  34  *
  35  * Notes:
  36  *      If 'value' exceeds the maximum possible on the operating system,
  37  *      it is silently limited to that maximum -- or to "infinity", if
  38  *      the operating system has that concept.  ISC_RESOURCE_UNLIMITED
  39  *      can be used to explicitly ask for the maximum.
  40  *
  41  * Requires:
  42  *      'resource' is a valid member of the isc_resource_t enumeration.
  43  *
  44  * Returns:
  45  *      ISC_R_SUCCESS   Success.
  46  *      ISC_R_NOTIMPLEMENTED    'resource' is not a type known by the OS.
  47  *      ISC_R_NOPERM    The calling process did not have adequate permission
  48  *                      to change the resource limit.
  49  */
  50
  51 isc_result_t
  52 isc_resource_getlimit(isc_resource_t resource, isc_resourcevalue_t *value);
  53 /*
  54  * Get the maximum limit for a system resource.
  55  *
  56  * Notes:
  57  *      'value' is set to the maximum limit.
  58  *
  59  *      ISC_RESOURCE_UNLIMITED is the maximum value of isc_resourcevalue_t.
  60  *
  61  *      On many (all?) Unix systems, RLIM_INFINITY is a valid value that is
  62  *      significantly less than ISC_RESOURCE_UNLIMITED, but which in practice
  63  *      behaves the same.
  64  *
  65  *      The current ISC libdns configuration file parser assigns a value
  66  *      of ISC_UINT32_MAX for a size_spec of "unlimited" and ISC_UNIT32_MAX - 1
  67  *      for "default", the latter of which is supposed to represent "the
  68  *      limit that was in force when the server started".  Since these are
  69  *      valid values in the middle of the range of isc_resourcevalue_t,
  70  *      there is the possibility for confusion over what exactly those
  71  *      particular values are supposed to represent in a particular context --
  72  *      discrete integral values or generalized concepts.
  73  *
  74  * Requires:
  75  *      'resource' is a valid member of the isc_resource_t enumeration.
  76  *
  77  * Returns:
  78  *      ISC_R_SUCCESS           Success.
  79  *      ISC_R_NOTIMPLEMENTED    'resource' is not a type known by the OS.
  80  */
  81
  82 ISC_LANG_ENDDECLS
  83
  84 #endif /* ISC_RESOURCE_H */
  85