1 /* $NetBSD: stats.c,v 1.9 2021/08/19 11:50:18 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 https://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 for (int i = 0; i < ncounters; i++) { 58 atomic_init(&stats->counters[i], 0); 59 } 60 stats->mctx = NULL; 61 isc_mem_attach(mctx, &stats->mctx); 62 stats->ncounters = ncounters; 63 stats->magic = ISC_STATS_MAGIC; 64 *statsp = stats; 65 66 return (ISC_R_SUCCESS); 67 } 68 69 void 70 isc_stats_attach(isc_stats_t *stats, isc_stats_t **statsp) { 71 REQUIRE(ISC_STATS_VALID(stats)); 72 REQUIRE(statsp != NULL && *statsp == NULL); 73 74 isc_refcount_increment(&stats->references); 75 *statsp = stats; 76 } 77 78 void 79 isc_stats_detach(isc_stats_t **statsp) { 80 isc_stats_t *stats; 81 82 REQUIRE(statsp != NULL && ISC_STATS_VALID(*statsp)); 83 84 stats = *statsp; 85 *statsp = NULL; 86 87 if (isc_refcount_decrement(&stats->references) == 1) { 88 isc_refcount_destroy(&stats->references); 89 isc_mem_put(stats->mctx, stats->counters, 90 sizeof(isc__atomic_statcounter_t) * 91 stats->ncounters); 92 isc_mem_putanddetach(&stats->mctx, stats, sizeof(*stats)); 93 } 94 } 95 96 int 97 isc_stats_ncounters(isc_stats_t *stats) { 98 REQUIRE(ISC_STATS_VALID(stats)); 99 100 return (stats->ncounters); 101 } 102 103 isc_result_t 104 isc_stats_create(isc_mem_t *mctx, isc_stats_t **statsp, int ncounters) { 105 REQUIRE(statsp != NULL && *statsp == NULL); 106 107 return (create_stats(mctx, ncounters, statsp)); 108 } 109 110 void 111 isc_stats_increment(isc_stats_t *stats, isc_statscounter_t counter) { 112 REQUIRE(ISC_STATS_VALID(stats)); 113 REQUIRE(counter < stats->ncounters); 114 115 atomic_fetch_add_relaxed(&stats->counters[counter], 1); 116 } 117 118 void 119 isc_stats_decrement(isc_stats_t *stats, isc_statscounter_t counter) { 120 REQUIRE(ISC_STATS_VALID(stats)); 121 REQUIRE(counter < stats->ncounters); 122 atomic_fetch_sub_release(&stats->counters[counter], 1); 123 } 124 125 void 126 isc_stats_dump(isc_stats_t *stats, isc_stats_dumper_t dump_fn, void *arg, 127 unsigned int options) { 128 int i; 129 130 REQUIRE(ISC_STATS_VALID(stats)); 131 132 for (i = 0; i < stats->ncounters; i++) { 133 uint32_t counter = atomic_load_acquire(&stats->counters[i]); 134 if ((options & ISC_STATSDUMP_VERBOSE) == 0 && counter == 0) { 135 continue; 136 } 137 dump_fn((isc_statscounter_t)i, counter, arg); 138 } 139 } 140 141 void 142 isc_stats_set(isc_stats_t *stats, uint64_t val, isc_statscounter_t counter) { 143 REQUIRE(ISC_STATS_VALID(stats)); 144 REQUIRE(counter < stats->ncounters); 145 146 atomic_store_release(&stats->counters[counter], val); 147 } 148 149 void 150 isc_stats_update_if_greater(isc_stats_t *stats, isc_statscounter_t counter, 151 isc_statscounter_t value) { 152 REQUIRE(ISC_STATS_VALID(stats)); 153 REQUIRE(counter < stats->ncounters); 154 155 isc_statscounter_t curr_value = 156 atomic_load_acquire(&stats->counters[counter]); 157 do { 158 if (curr_value >= value) { 159 break; 160 } 161 } while (!atomic_compare_exchange_weak_acq_rel( 162 &stats->counters[counter], &curr_value, value)); 163 } 164 165 isc_statscounter_t 166 isc_stats_get_counter(isc_stats_t *stats, isc_statscounter_t counter) { 167 REQUIRE(ISC_STATS_VALID(stats)); 168 REQUIRE(counter < stats->ncounters); 169 170 return (atomic_load_acquire(&stats->counters[counter])); 171 } 172