68 lines
1.8 KiB
C
68 lines
1.8 KiB
C
// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
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/*
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* This file provides some functions to manage a pool of pre-allocated
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* objects. It also provides a method to reserve a pre-defined number
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* of objects for higher priorty requests. The allocations follow the
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* following rules:
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*
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* 1. An allocation will succeed at any priority if there is more than
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* the reserved number of objects free.
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* 2. Only high priority allocations will succeed when there are less
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* than the reserved number of objects free.
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* 3. When an allocation is freed it is always added to the high priority
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* pool if there are less than the reserved number of allocations
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* available.
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*
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* Copyright 2013-2014 IBM Corp.
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*/
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#include <pool.h>
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#include <string.h>
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#include <stdlib.h>
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#include <ccan/list/list.h>
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void* pool_get(struct pool *pool, enum pool_priority priority)
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{
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void *obj;
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if (!pool->free_count ||
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((pool->free_count <= pool->reserved) && priority == POOL_NORMAL))
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return NULL;
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pool->free_count--;
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obj = (void *) list_pop_(&pool->free_list, 0);
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assert(obj);
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memset(obj, 0, pool->obj_size);
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return obj;
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}
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void pool_free_object(struct pool *pool, void *obj)
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{
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pool->free_count++;
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list_add_tail(&pool->free_list,
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(struct list_node *) (obj));
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}
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int pool_init(struct pool *pool, size_t obj_size, int count, int reserved)
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{
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int i;
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if (obj_size < sizeof(struct list_node))
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obj_size = sizeof(struct list_node);
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assert(count >= reserved);
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pool->buf = malloc(obj_size*count);
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if (!pool->buf)
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return -1;
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pool->obj_size = obj_size;
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pool->free_count = count;
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pool->reserved = reserved;
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list_head_init(&pool->free_list);
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for(i = 0; i < count; i++)
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list_add_tail(&pool->free_list,
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(struct list_node *) (pool->buf + obj_size*i));
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return 0;
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}
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