pools.c File Reference

Data Structures
struct	free_atom_t
Defines
#define	DEFAULT_BLOCK_SIZE   8192
Functions
void	init_pool (pool_t *pool, int atom_size)
	initializes a pool
void	expand_pool (pool_t *pool)
	expands a pool when requested
void	return_to_pool (pool_t *pool, void *a)
	returns atom back to its pool
void *	take_from_pool (pool_t *pool)
	takes new atom from a pool
Variables
pool_t	data_pool
	pool for data atoms
pool_t	data_pool_ex
	pool for extended data atoms

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Define Documentation

#define DEFAULT_BLOCK_SIZE   8192

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Function Documentation

void init_pool	(	pool_t *	pool,
		int	atom_size
	)

Parameters:

pool	pool to initialize
atom_size	size of atom in bytes

Initializes a pool by setting size of atoms and maximal size of the pool. Initially the pool has no any allocated atoms. Aom will be allocated during the first request to take an atom.

{
  static int id = 0;
  pool->id      = ++id;
  pool->atom_size  = atom_size;
  pool->block_size    = DEFAULT_BLOCK_SIZE;
  pool->free_block_atoms = 0;
  pool->free_atom  = NULL;
  pool->free_block    = NULL;
  pool->first_atom    = NULL;

  #ifdef DEBUG_POOL
    printf( "<POOL> Create pool %d (size=%d)\n",
       pool->id, atom_size );
  #endif //DEBUG_POOL
}

void expand_pool

(

pool_t *

pool

)

Parameters:

pool	pool to be expanded

Assumes that both the list and the block of free free atoms are empty and allocates a new block.

{
  pool->first_atom = ALLOC( pool->atom_size * pool->block_size );
  pool->free_block = pool->first_atom;

#ifdef DEBUG_CLEAR_FREED_MEM
  memset( pool->first_atom, 0xFF, pool->atom_size * pool->block_size );
#endif //DEBUG_CLEAR_FREE_MEM


  #ifdef SAFEMODE
    assert( pool->free_block );
  #endif //SAFEMODE

  pool->free_block_atoms = pool->block_size;

  #ifdef DEBUG_POOL
    printf( "<POOL> Expand pool %d by %d bytes (%d atoms)\n",
       pool->id, pool->atom_size*pool->block_size,pool->block_size );
  #endif //DEBUG_POOL

  #ifdef ADVANCED
    stats_free += pool->block_size;
    stats_allocs--; // do not count pool allocs
  #endif //ADVANCED
}

void return_to_pool	(	pool_t *	pool,
		void *	a
	)

Parameters:

pool	pool that will accept the atom
a	atom to be returned

Returns atom to the pool. The function assumes that the atom size is the same as the pool's atom size. Returned atoms are attached to the list and never to the block.

{
  //printf("!");
  #ifdef DEBUG_ATOM
  printf("<ATOM> -[%08x]\n",(int)a);
  #endif //DEBUG_ATOM

  #ifdef DEBUG_RUNTIME_ATOMS
  if( running_compiled_code )
    {
      outter( TEXT("<RUNTIME> free "), -1 );
      dump_atom_address( a );
      //dump_atom( a, 1 );
      outter( TEXT("\n"), -1 );
    }
  #endif
  #ifdef DEBUG_COMPILETIME_ATOMS
  if( compiling_code )
    {
      outter( TEXT("<COMPILETIME> free "), -1 );
      dump_atom_address( a );
      //dump_atom( a, 1 );
      outter( TEXT("\n"), -1 );
    }
  #endif

#ifdef DEBUG_CLEAR_FREED_MEM
  memset( a, 0xFF, pool->atom_size );
#endif //DEBUG_CLEAR_FREE_MEM

  free_atom_t* b = a;
  b->next = pool->free_atom;
  pool->free_atom = b;

  //printf("delete %x\n",(int)b);

  //*((void**)a) = pool->free_atom;
  //pool->free_atom = a;

}

void * take_from_pool

(

pool_t *

pool

)

Parameters:

pool	pool from which to allocate atom

Returns:

new atom from the pool

Takes atom from the pool. First attempts to take it from the list. If empty it takes from the block. If it is empty too then expands the pool with a new fresh block and takes atom from it.

{
  // take atom from the list
  free_atom_t* new = pool->free_atom;
  //printf(",");
  if( new )
    { // there is free atom in the list
      //printf("alloc  %x (next free is %x)\n",(int)new,(int)new->next);
      pool->free_atom = new->next;
    }
  else
    { // take atom from the block
      if( !pool->free_block ) expand_pool( pool );

      new = (free_atom_t*)((char*)pool->free_block + (-- pool->free_block_atoms)*pool->atom_size);
      if( pool->free_block_atoms == 0 )
   pool->free_block = NULL;
    }

  #ifdef DEBUG_ATOM
  printf( "<ATOM> +[%08x]\n",(int)new );
  #endif //ATOM

  #ifdef DEBUG_RUNTIME_ATOMS
  if( running_compiled_code )
    {
      outter( TEXT("<RUNTIME> alloc"), -1 );
      dump_atom_address( (atom_t)new );
      outter( TEXT("\n"), -1 );
    }
  #endif
  #ifdef DEBUG_COMPILETIME_ATOMS
  if( compiling_code )
    {
      outter( TEXT("<COMPILETIME> alloc"), -1 );
      dump_atom_address( (atom_t)new );
      outter( TEXT("\n"), -1 );
    }
  #endif

  return new;
}

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Variable Documentation

pool_t data_pool

pool_t data_pool_ex