1 /* $NetBSD: quota.h,v 1.4 2014/12/10 04:38:00 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (C) 2000, 2001 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* Id: quota.h,v 1.16 2007/06/19 23:47:18 tbox Exp */ 21 22 #ifndef ISC_QUOTA_H 23 #define ISC_QUOTA_H 1 24 25 /***** 26 ***** Module Info 27 *****/ 28 29 /*! \file isc/quota.h 30 * 31 * \brief The isc_quota_t object is a simple helper object for implementing 32 * quotas on things like the number of simultaneous connections to 33 * a server. It keeps track of the amount of quota in use, and 34 * encapsulates the locking necessary to allow multiple tasks to 35 * share a quota. 36 */ 37 38 /*** 39 *** Imports. 40 ***/ 41 42 #include <isc/lang.h> 43 #include <isc/mutex.h> 44 #include <isc/types.h> 45 46 /***** 47 ***** Types. 48 *****/ 49 50 ISC_LANG_BEGINDECLS 51 52 /*% isc_quota structure */ 53 struct isc_quota { 54 isc_mutex_t lock; /*%< Locked by lock. */ 55 int max; 56 int used; 57 int soft; 58 }; 59 60 isc_result_t 61 isc_quota_init(isc_quota_t *quota, int max); 62 /*%< 63 * Initialize a quota object. 64 * 65 * Returns: 66 * ISC_R_SUCCESS 67 * Other error Lock creation failed. 68 */ 69 70 void 71 isc_quota_destroy(isc_quota_t *quota); 72 /*%< 73 * Destroy a quota object. 74 */ 75 76 void 77 isc_quota_soft(isc_quota_t *quota, int soft); 78 /*%< 79 * Set a soft quota. 80 */ 81 82 void 83 isc_quota_max(isc_quota_t *quota, int max); 84 /*%< 85 * Re-set a maximum quota. 86 */ 87 88 isc_result_t 89 isc_quota_reserve(isc_quota_t *quota); 90 /*%< 91 * Attempt to reserve one unit of 'quota'. 92 * 93 * Returns: 94 * \li #ISC_R_SUCCESS Success 95 * \li #ISC_R_SOFTQUOTA Success soft quota reached 96 * \li #ISC_R_QUOTA Quota is full 97 */ 98 99 void 100 isc_quota_release(isc_quota_t *quota); 101 /*%< 102 * Release one unit of quota. 103 */ 104 105 isc_result_t 106 isc_quota_attach(isc_quota_t *quota, isc_quota_t **p); 107 /*%< 108 * Like isc_quota_reserve, and also attaches '*p' to the 109 * quota if successful (ISC_R_SUCCESS or ISC_R_SOFTQUOTA). 110 */ 111 112 void 113 isc_quota_detach(isc_quota_t **p); 114 /*%< 115 * Like isc_quota_release, and also detaches '*p' from the 116 * quota. 117 */ 118 119 ISC_LANG_ENDDECLS 120 121 #endif /* ISC_QUOTA_H */ 122