mempool.h

/******************************************************************************
 * Copyright 2022 ETC Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************
 * This file is a part of EtcPal. For more information, go to:
 * https://github.com/ETCLabs/EtcPal
 ******************************************************************************/
 
/* etcpal/mempool.h: Fixed-size memory pools. */
 
#ifndef ETCPAL_MEMPOOL_H_
#define ETCPAL_MEMPOOL_H_
 
#include <stddef.h>
#include "etcpal/error.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
typedef struct EtcPalMempool EtcPalMempool;
 
struct EtcPalMempool
{
  EtcPalMempool* next;
};
 
typedef struct EtcPalMempoolDesc
{
  const size_t         elem_size;    
  const size_t         pool_size;    
  EtcPalMempool*       freelist;     
  EtcPalMempool* const list;         
  size_t               current_used; 
  void* const          pool;         
} EtcPalMempoolDesc;
 
#define ETCPAL_MEMPOOL_DECLARE(name) extern EtcPalMempoolDesc name##_pool_desc;
 
#define ETCPAL_MEMPOOL_DEFINE(name, type, size)                                     \
  type                     name##_pool[size];                                       \
  struct EtcPalMempool     name##_pool_list[size];                                  \
  struct EtcPalMempoolDesc name##_pool_desc = {sizeof(type),     /* elem_size */    \
                                               size,             /* pool_size */    \
                                               NULL,             /* freelist */     \
                                               name##_pool_list, /* list */         \
                                               0,                /* current_used */ \
                                               name##_pool /* pool */}
 
#define ETCPAL_MEMPOOL_DEFINE_ARRAY(name, type, array_size, pool_size)                      \
  type                     name##_pool[array_size][pool_size];                              \
  struct EtcPalMempool     name##_pool_list[pool_size];                                     \
  struct EtcPalMempoolDesc name##_pool_desc = {sizeof(type[array_size]), /* elem_size */    \
                                               pool_size,                /* pool_size */    \
                                               NULL,                     /* freelist */     \
                                               name##_pool_list,         /* list */         \
                                               0,                        /* current_used */ \
                                               name##_pool /* pool */}
 
#define etcpal_mempool_init(name) etcpal_mempool_init_priv(&name##_pool_desc)
 
#define etcpal_mempool_alloc(name) etcpal_mempool_alloc_priv(&name##_pool_desc)
 
#define etcpal_mempool_free(name, mem) etcpal_mempool_free_priv(&name##_pool_desc, mem)
 
#define etcpal_mempool_size(name) (name##_pool_desc.pool_size)
 
#define etcpal_mempool_used(name) etcpal_mempool_used_priv(&name##_pool_desc)
 
etcpal_error_t etcpal_mempool_init_priv(EtcPalMempoolDesc* desc);
void*          etcpal_mempool_alloc_priv(EtcPalMempoolDesc* desc);
void           etcpal_mempool_free_priv(EtcPalMempoolDesc* desc, void* elem);
size_t         etcpal_mempool_used_priv(EtcPalMempoolDesc* desc);
 
#ifdef __cplusplus
}
#endif
 
#endif /* ETCPAL_MEMPOOL_H_ */