1 /* $NetBSD: stats.c,v 1.7 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 /*! \file */ 15 16 #include <inttypes.h> 17 #include <string.h> 18 19 #include <isc/atomic.h> 20 #include <isc/buffer.h> 21 #include <isc/magic.h> 22 #include <isc/mem.h> 23 #include <isc/platform.h> 24 #include <isc/print.h> 25 #include <isc/refcount.h> 26 #include <isc/stats.h> 27 #include <isc/util.h> 28 29 #define ISC_STATS_MAGIC ISC_MAGIC('S', 't', 'a', 't') 30 #define ISC_STATS_VALID(x) ISC_MAGIC_VALID(x, ISC_STATS_MAGIC) 31 32 #if (defined(_WIN32) && !defined(_WIN64)) || !defined(_LP64) 33 typedef atomic_int_fast32_t isc__atomic_statcounter_t; 34 #else /* if defined(_WIN32) && !defined(_WIN64) */ 35 typedef atomic_int_fast64_t isc__atomic_statcounter_t; 36 #endif /* if defined(_WIN32) && !defined(_WIN64) */ 37 38 struct isc_stats { 39 unsigned int magic; 40 isc_mem_t *mctx; 41 isc_refcount_t references; 42 int ncounters; 43 isc__atomic_statcounter_t *counters; 44 }; 45 46 static isc_result_t 47 create_stats(isc_mem_t *mctx, int ncounters, isc_stats_t **statsp) { 48 isc_stats_t *stats; 49 size_t counters_alloc_size; 50 51 REQUIRE(statsp != NULL && *statsp == NULL); 52 53 stats = isc_mem_get(mctx, sizeof(*stats)); 54 counters_alloc_size = sizeof(isc__atomic_statcounter_t) * ncounters; 55 stats->counters = isc_mem_get(mctx, counters_alloc_size); 56 isc_refcount_init(&stats->references, 1); 57 memset(stats->counters, 0, counters_alloc_size); 58 stats->mctx = NULL; 59 isc_mem_attach(mctx, &stats->mctx); 60 stats->ncounters = ncounters; 61 stats->magic = ISC_STATS_MAGIC; 62 *statsp = stats; 63 64 return (ISC_R_SUCCESS); 65 } 66 67 void 68 isc_stats_attach(isc_stats_t *stats, isc_stats_t **statsp) { 69 REQUIRE(ISC_STATS_VALID(stats)); 70 REQUIRE(statsp != NULL && *statsp == NULL); 71 72 isc_refcount_increment(&stats->references); 73 *statsp = stats; 74 } 75 76 void 77 isc_stats_detach(isc_stats_t **statsp) { 78 isc_stats_t *stats; 79 80 REQUIRE(statsp != NULL && ISC_STATS_VALID(*statsp)); 81 82 stats = *statsp; 83 *statsp = NULL; 84 85 if (isc_refcount_decrement(&stats->references) == 1) { 86 isc_refcount_destroy(&stats->references); 87 isc_mem_put(stats->mctx, stats->counters, 88 sizeof(isc__atomic_statcounter_t) * 89 stats->ncounters); 90 isc_mem_putanddetach(&stats->mctx, stats, sizeof(*stats)); 91 } 92 } 93 94 int 95 isc_stats_ncounters(isc_stats_t *stats) { 96 REQUIRE(ISC_STATS_VALID(stats)); 97 98 return (stats->ncounters); 99 } 100 101 isc_result_t 102 isc_stats_create(isc_mem_t *mctx, isc_stats_t **statsp, int ncounters) { 103 REQUIRE(statsp != NULL && *statsp == NULL); 104 105 return (create_stats(mctx, ncounters, statsp)); 106 } 107 108 void 109 isc_stats_increment(isc_stats_t *stats, isc_statscounter_t counter) { 110 REQUIRE(ISC_STATS_VALID(stats)); 111 REQUIRE(counter < stats->ncounters); 112 113 atomic_fetch_add_relaxed(&stats->counters[counter], 1); 114 } 115 116 void 117 isc_stats_decrement(isc_stats_t *stats, isc_statscounter_t counter) { 118 REQUIRE(ISC_STATS_VALID(stats)); 119 REQUIRE(counter < stats->ncounters); 120 atomic_fetch_sub_release(&stats->counters[counter], 1); 121 } 122 123 void 124 isc_stats_dump(isc_stats_t *stats, isc_stats_dumper_t dump_fn, void *arg, 125 unsigned int options) { 126 int i; 127 128 REQUIRE(ISC_STATS_VALID(stats)); 129 130 for (i = 0; i < stats->ncounters; i++) { 131 uint32_t counter = atomic_load_acquire(&stats->counters[i]); 132 if ((options & ISC_STATSDUMP_VERBOSE) == 0 && counter == 0) { 133 continue; 134 } 135 dump_fn((isc_statscounter_t)i, counter, arg); 136 } 137 } 138 139 void 140 isc_stats_set(isc_stats_t *stats, uint64_t val, isc_statscounter_t counter) { 141 REQUIRE(ISC_STATS_VALID(stats)); 142 REQUIRE(counter < stats->ncounters); 143 144 atomic_store_release(&stats->counters[counter], val); 145 } 146 147 void 148 isc_stats_update_if_greater(isc_stats_t *stats, isc_statscounter_t counter, 149 isc_statscounter_t value) { 150 REQUIRE(ISC_STATS_VALID(stats)); 151 REQUIRE(counter < stats->ncounters); 152 153 isc_statscounter_t curr_value = 154 atomic_load_acquire(&stats->counters[counter]); 155 do { 156 if (curr_value >= value) { 157 break; 158 } 159 } while (!atomic_compare_exchange_weak_acq_rel( 160 &stats->counters[counter], &curr_value, value)); 161 } 162 163 isc_statscounter_t 164 isc_stats_get_counter(isc_stats_t *stats, isc_statscounter_t counter) { 165 REQUIRE(ISC_STATS_VALID(stats)); 166 REQUIRE(counter < stats->ncounters); 167 168 return (atomic_load_acquire(&stats->counters[counter])); 169 } 170