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77ec2a6c22
The isc_counter_create() doesn't need the return value (it was always ISC_R_SUCCESS), use the macros to implement the reference counting, little style cleanup, and expand the unit test.
95 lines
2.2 KiB
C
95 lines
2.2 KiB
C
/*
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* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
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*
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* SPDX-License-Identifier: MPL-2.0
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, you can obtain one at https://mozilla.org/MPL/2.0/.
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*
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* See the COPYRIGHT file distributed with this work for additional
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* information regarding copyright ownership.
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*/
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/*! \file */
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#include <stdbool.h>
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#include <stddef.h>
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#include <isc/atomic.h>
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#include <isc/counter.h>
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#include <isc/magic.h>
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#include <isc/mem.h>
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#include <isc/refcount.h>
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#include <isc/util.h>
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#define COUNTER_MAGIC ISC_MAGIC('C', 'n', 't', 'r')
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#define VALID_COUNTER(r) ISC_MAGIC_VALID(r, COUNTER_MAGIC)
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struct isc_counter {
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unsigned int magic;
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isc_mem_t *mctx;
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isc_refcount_t references;
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atomic_uint_fast32_t limit;
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atomic_uint_fast32_t used;
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};
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void
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isc_counter_create(isc_mem_t *mctx, int limit, isc_counter_t **counterp) {
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REQUIRE(counterp != NULL && *counterp == NULL);
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isc_counter_t *counter = isc_mem_get(mctx, sizeof(*counter));
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*counter = (isc_counter_t){
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.magic = COUNTER_MAGIC,
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.references = 1,
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.limit = limit,
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};
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isc_mem_attach(mctx, &counter->mctx);
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*counterp = counter;
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}
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isc_result_t
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isc_counter_increment(isc_counter_t *counter) {
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uint_fast32_t used = atomic_fetch_add_relaxed(&counter->used, 1) + 1;
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uint_fast32_t limit = atomic_load_acquire(&counter->limit);
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if (limit != 0 && used >= limit) {
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return ISC_R_QUOTA;
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}
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return ISC_R_SUCCESS;
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}
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unsigned int
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isc_counter_used(isc_counter_t *counter) {
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REQUIRE(VALID_COUNTER(counter));
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return atomic_load_relaxed(&counter->used);
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}
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void
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isc_counter_setlimit(isc_counter_t *counter, int limit) {
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REQUIRE(VALID_COUNTER(counter));
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atomic_store_release(&counter->limit, limit);
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}
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unsigned int
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isc_counter_getlimit(isc_counter_t *counter) {
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REQUIRE(VALID_COUNTER(counter));
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return atomic_load_acquire(&counter->limit);
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}
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static void
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isc__counter_destroy(isc_counter_t *counter) {
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REQUIRE(VALID_COUNTER(counter));
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isc_refcount_destroy(&counter->references);
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counter->magic = 0;
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isc_mem_putanddetach(&counter->mctx, counter, sizeof(*counter));
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}
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ISC_REFCOUNT_IMPL(isc_counter, isc__counter_destroy);
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