1 /* $NetBSD: counter.h,v 1.1.1.2 2014/12/10 03:34:44 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2014 Internet Systems Consortium, Inc. ("ISC") 5 * 6 * Permission to use, copy, modify, and/or distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 11 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 12 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 13 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 14 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 15 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 16 * PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #ifndef ISC_COUNTER_H 20 #define ISC_COUNTER_H 1 21 22 /***** 23 ***** Module Info 24 *****/ 25 26 /*! \file isc/counter.h 27 * 28 * \brief The isc_counter_t object is a simplified version of the 29 * isc_quota_t object; it tracks the consumption of limited 30 * resources, returning an error condition when the quota is 31 * exceeded. However, unlike isc_quota_t, attaching and detaching 32 * from a counter object does not increment or decrement the counter. 33 */ 34 35 /*** 36 *** Imports. 37 ***/ 38 39 #include <isc/lang.h> 40 #include <isc/mutex.h> 41 #include <isc/types.h> 42 43 /***** 44 ***** Types. 45 *****/ 46 47 ISC_LANG_BEGINDECLS 48 49 isc_result_t 50 isc_counter_create(isc_mem_t *mctx, int limit, isc_counter_t **counterp); 51 /*%< 52 * Allocate and initialize a counter object. 53 */ 54 55 isc_result_t 56 isc_counter_increment(isc_counter_t *counter); 57 /*%< 58 * Increment the counter. 59 * 60 * If the counter limit is nonzero and has been reached, then 61 * return ISC_R_QUOTA, otherwise ISC_R_SUCCESS. (The counter is 62 * incremented regardless of return value.) 63 */ 64 65 unsigned int 66 isc_counter_used(isc_counter_t *counter); 67 /*%< 68 * Return the current counter value. 69 */ 70 71 void 72 isc_counter_setlimit(isc_counter_t *counter, int limit); 73 /*%< 74 * Set the counter limit. 75 */ 76 77 void 78 isc_counter_attach(isc_counter_t *source, isc_counter_t **targetp); 79 /*%< 80 * Attach to a counter object, increasing its reference counter. 81 */ 82 83 void 84 isc_counter_detach(isc_counter_t **counterp); 85 /*%< 86 * Detach (and destroy if reference counter has dropped to zero) 87 * a counter object. 88 */ 89 90 ISC_LANG_ENDDECLS 91 92 #endif /* ISC_COUNTER_H */ 93