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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.
*/
#include <inttypes.h>
#include <string.h>
#include <isc/astack.h>
#include <isc/atomic.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/types.h>
#include <isc/util.h>
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));
}
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