/* $NetBSD: astack.c,v 1.1.4.2 2024/02/29 11:38:59 martin Exp $ */ /* * 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. */ #include #include #include #include #include #include #include #include struct isc_astack { isc_mem_t *mctx; size_t size; size_t pos; isc_mutex_t lock; uintptr_t nodes[]; }; isc_astack_t * isc_astack_new(isc_mem_t *mctx, size_t size) { isc_astack_t *stack = isc_mem_get( mctx, sizeof(isc_astack_t) + size * sizeof(uintptr_t)); *stack = (isc_astack_t){ .size = size, }; isc_mem_attach(mctx, &stack->mctx); memset(stack->nodes, 0, size * sizeof(uintptr_t)); isc_mutex_init(&stack->lock); return (stack); } bool isc_astack_trypush(isc_astack_t *stack, void *obj) { if (!isc_mutex_trylock(&stack->lock)) { if (stack->pos >= stack->size) { UNLOCK(&stack->lock); return (false); } stack->nodes[stack->pos++] = (uintptr_t)obj; UNLOCK(&stack->lock); return (true); } else { return (false); } } void * isc_astack_pop(isc_astack_t *stack) { LOCK(&stack->lock); uintptr_t rv; if (stack->pos == 0) { rv = 0; } else { rv = stack->nodes[--stack->pos]; } UNLOCK(&stack->lock); return ((void *)rv); } void isc_astack_destroy(isc_astack_t *stack) { LOCK(&stack->lock); REQUIRE(stack->pos == 0); UNLOCK(&stack->lock); isc_mutex_destroy(&stack->lock); isc_mem_putanddetach(&stack->mctx, stack, sizeof(struct isc_astack) + stack->size * sizeof(uintptr_t)); }