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-rw-r--r--lib/isc/stats.c203
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diff --git a/lib/isc/stats.c b/lib/isc/stats.c
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+++ b/lib/isc/stats.c
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+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+#include <string.h>
+
+#include <isc/atomic.h>
+#include <isc/buffer.h>
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/refcount.h>
+#include <isc/stats.h>
+#include <isc/util.h>
+
+#define ISC_STATS_MAGIC ISC_MAGIC('S', 't', 'a', 't')
+#define ISC_STATS_VALID(x) ISC_MAGIC_VALID(x, ISC_STATS_MAGIC)
+
+#if defined(_WIN32) && !defined(_WIN64)
+typedef atomic_int_fast32_t isc__atomic_statcounter_t;
+#else /* if defined(_WIN32) && !defined(_WIN64) */
+typedef atomic_int_fast64_t isc__atomic_statcounter_t;
+#endif /* if defined(_WIN32) && !defined(_WIN64) */
+
+struct isc_stats {
+ unsigned int magic;
+ isc_mem_t *mctx;
+ isc_refcount_t references;
+ int ncounters;
+ isc__atomic_statcounter_t *counters;
+};
+
+static isc_result_t
+create_stats(isc_mem_t *mctx, int ncounters, isc_stats_t **statsp) {
+ isc_stats_t *stats;
+ size_t counters_alloc_size;
+
+ REQUIRE(statsp != NULL && *statsp == NULL);
+
+ stats = isc_mem_get(mctx, sizeof(*stats));
+ counters_alloc_size = sizeof(isc__atomic_statcounter_t) * ncounters;
+ stats->counters = isc_mem_get(mctx, counters_alloc_size);
+ isc_refcount_init(&stats->references, 1);
+ for (int i = 0; i < ncounters; i++) {
+ atomic_init(&stats->counters[i], 0);
+ }
+ stats->mctx = NULL;
+ isc_mem_attach(mctx, &stats->mctx);
+ stats->ncounters = ncounters;
+ stats->magic = ISC_STATS_MAGIC;
+ *statsp = stats;
+
+ return (ISC_R_SUCCESS);
+}
+
+void
+isc_stats_attach(isc_stats_t *stats, isc_stats_t **statsp) {
+ REQUIRE(ISC_STATS_VALID(stats));
+ REQUIRE(statsp != NULL && *statsp == NULL);
+
+ isc_refcount_increment(&stats->references);
+ *statsp = stats;
+}
+
+void
+isc_stats_detach(isc_stats_t **statsp) {
+ isc_stats_t *stats;
+
+ REQUIRE(statsp != NULL && ISC_STATS_VALID(*statsp));
+
+ stats = *statsp;
+ *statsp = NULL;
+
+ if (isc_refcount_decrement(&stats->references) == 1) {
+ isc_refcount_destroy(&stats->references);
+ isc_mem_put(stats->mctx, stats->counters,
+ sizeof(isc__atomic_statcounter_t) *
+ stats->ncounters);
+ isc_mem_putanddetach(&stats->mctx, stats, sizeof(*stats));
+ }
+}
+
+int
+isc_stats_ncounters(isc_stats_t *stats) {
+ REQUIRE(ISC_STATS_VALID(stats));
+
+ return (stats->ncounters);
+}
+
+isc_result_t
+isc_stats_create(isc_mem_t *mctx, isc_stats_t **statsp, int ncounters) {
+ REQUIRE(statsp != NULL && *statsp == NULL);
+
+ return (create_stats(mctx, ncounters, statsp));
+}
+
+void
+isc_stats_increment(isc_stats_t *stats, isc_statscounter_t counter) {
+ REQUIRE(ISC_STATS_VALID(stats));
+ REQUIRE(counter < stats->ncounters);
+
+ atomic_fetch_add_relaxed(&stats->counters[counter], 1);
+}
+
+void
+isc_stats_decrement(isc_stats_t *stats, isc_statscounter_t counter) {
+ REQUIRE(ISC_STATS_VALID(stats));
+ REQUIRE(counter < stats->ncounters);
+ atomic_fetch_sub_release(&stats->counters[counter], 1);
+}
+
+void
+isc_stats_dump(isc_stats_t *stats, isc_stats_dumper_t dump_fn, void *arg,
+ unsigned int options) {
+ int i;
+
+ REQUIRE(ISC_STATS_VALID(stats));
+
+ for (i = 0; i < stats->ncounters; i++) {
+ uint32_t counter = atomic_load_acquire(&stats->counters[i]);
+ if ((options & ISC_STATSDUMP_VERBOSE) == 0 && counter == 0) {
+ continue;
+ }
+ dump_fn((isc_statscounter_t)i, counter, arg);
+ }
+}
+
+void
+isc_stats_set(isc_stats_t *stats, uint64_t val, isc_statscounter_t counter) {
+ REQUIRE(ISC_STATS_VALID(stats));
+ REQUIRE(counter < stats->ncounters);
+
+ atomic_store_release(&stats->counters[counter], val);
+}
+
+void
+isc_stats_update_if_greater(isc_stats_t *stats, isc_statscounter_t counter,
+ isc_statscounter_t value) {
+ REQUIRE(ISC_STATS_VALID(stats));
+ REQUIRE(counter < stats->ncounters);
+
+ isc_statscounter_t curr_value =
+ atomic_load_acquire(&stats->counters[counter]);
+ do {
+ if (curr_value >= value) {
+ break;
+ }
+ } while (!atomic_compare_exchange_weak_acq_rel(
+ &stats->counters[counter], &curr_value, value));
+}
+
+isc_statscounter_t
+isc_stats_get_counter(isc_stats_t *stats, isc_statscounter_t counter) {
+ REQUIRE(ISC_STATS_VALID(stats));
+ REQUIRE(counter < stats->ncounters);
+
+ return (atomic_load_acquire(&stats->counters[counter]));
+}
+
+void
+isc_stats_resize(isc_stats_t **statsp, int ncounters) {
+ isc_stats_t *stats;
+ size_t counters_alloc_size;
+ isc__atomic_statcounter_t *newcounters;
+
+ REQUIRE(statsp != NULL && *statsp != NULL);
+ REQUIRE(ISC_STATS_VALID(*statsp));
+ REQUIRE(ncounters > 0);
+
+ stats = *statsp;
+ if (stats->ncounters >= ncounters) {
+ /* We already have enough counters. */
+ return;
+ }
+
+ /* Grow number of counters. */
+ counters_alloc_size = sizeof(isc__atomic_statcounter_t) * ncounters;
+ newcounters = isc_mem_get(stats->mctx, counters_alloc_size);
+ for (int i = 0; i < ncounters; i++) {
+ atomic_init(&newcounters[i], 0);
+ }
+ for (int i = 0; i < stats->ncounters; i++) {
+ uint32_t counter = atomic_load_acquire(&stats->counters[i]);
+ atomic_store_release(&newcounters[i], counter);
+ }
+ isc_mem_put(stats->mctx, stats->counters,
+ sizeof(isc__atomic_statcounter_t) * stats->ncounters);
+ stats->counters = newcounters;
+ stats->ncounters = ncounters;
+}