/*
 * Copyright (c) 1999-2006 Christophe Fillot.
 * E-mail: cf@utc.fr
 *
 * mempool.h: Simple Memory Pools.
 */

#ifndef __MEMPOOL_H__
#define __MEMPOOL_H__  1

#include <sys/types.h>
#include <sys/time.h>
#include <pthread.h>

#include "utils.h"

/* Memory Pool "Fixed" Flag */
#define MEMPOOL_FIXED  1

/* Dummy value used to check if a memory block is invalid */
#define MEMBLOCK_TAG  0xdeadbeef

typedef struct memblock memblock_t;
typedef struct mempool mempool_t;

/* Memory block */
struct memblock {
   int tag;                  /* MEMBLOCK_TAG if block is valid */
   size_t block_size;        /* Block size (without header) */
   memblock_t *next,*prev;   /* Double linked list pointers */
   mempool_t *pool;          /* Pool which contains this block */
   m_uint64_t data[0];       /* Memory block itself */
};

/* Memory Pool */
struct mempool {
   memblock_t *block_list;   /* Double-linked block list */
   pthread_mutex_t lock;     /* Mutex for managing pool */
   char *name;               /* Name of this pool */
   int flags;                /* Flags */
   int nr_blocks;            /* Number of blocks in this pool */
   size_t total_size;        /* Total bytes allocated */
   size_t max_size;          /* Maximum memory */
};

/* Lock and unlock access to a memory pool */
#define MEMPOOL_LOCK(mp)    pthread_mutex_lock(&(mp)->lock)
#define MEMPOOL_UNLOCK(mp)  pthread_mutex_unlock(&(mp)->lock)

/* Callback function for use with mp_foreach */
typedef void (*mp_foreach_cbk)(memblock_t *block,void *user_arg);

/* Execute an action for each block in specified pool */
static inline void mp_foreach(mempool_t *pool,mp_foreach_cbk cbk,void *arg)
{
   memblock_t *mb;

   for(mb=pool->block_list;mb;mb=mb->next)
      cbk(mb,arg);
}

/* Allocate a new block in specified pool */
void *mp_alloc(mempool_t *pool,size_t size);

/* Allocate a new block which will not be zeroed */
void *mp_alloc_n0(mempool_t *pool,size_t size);

/* Reallocate a block */
void *mp_realloc(void *addr,size_t new_size);

/* Allocate a new memory block and copy data into it */
void *mp_dup(mempool_t *pool,void *data,size_t size);

/* Duplicate specified string and insert it in a memory pool */
char *mp_strdup(mempool_t *pool,char *str);

/* Free block at specified address */
int mp_free(void *addr);

/* Free block at specified address and clean pointer */
int mp_free_ptr(void *addr);

/* Free all blocks of specified pool */
void mp_free_all_blocks(mempool_t *pool);

/* Free specified memory pool */
void mp_free_pool(mempool_t *pool);

/* Create a new pool in a fixed memory area */
mempool_t *mp_create_fixed_pool(mempool_t *mp,char *name);

/* Create a new pool */
mempool_t *mp_create_pool(char *name);

#endif