gskmempool

gskmempool — pooling memory allocators.

Synopsis

#define             GSK_MEM_POOL_FIXED_STATIC_INIT      (size)
#define             GSK_MEM_POOL_STATIC_INIT
                    GskMemPool;
                    GskMemPoolFixed;
void                gsk_mem_pool_construct              (GskMemPool *pool);
void                gsk_mem_pool_construct_with_scratch_buf
                                                        (GskMemPool *pool,
                                                         gpointer buffer,
                                                         gsize buffer_size);
gpointer            gsk_mem_pool_alloc                  (GskMemPool *pool,
                                                         gsize size);
gpointer            gsk_mem_pool_alloc0                 (GskMemPool *pool,
                                                         gsize size);
char *              gsk_mem_pool_strdup                 (GskMemPool *pool,
                                                         const char *str);
void                gsk_mem_pool_destruct               (GskMemPool *pool);
void                gsk_mem_pool_fixed_construct        (GskMemPoolFixed *pool,
                                                         gsize size);
gpointer            gsk_mem_pool_fixed_alloc            (GskMemPoolFixed *pool);
gpointer            gsk_mem_pool_fixed_alloc0           (GskMemPoolFixed *pool);
void                gsk_mem_pool_fixed_free             (GskMemPoolFixed *pool,
                                                         gpointer from_pool);
void                gsk_mem_pool_fixed_destruct         (GskMemPoolFixed *pool);

Description

GSK provides two pooling memory allocators. The first allocator is allocate-only, and can allocate blocks of variable size. The second allocator is alloc-and-free, but must allocate blocks of a fixed-size, which must be chosen when you construct the pool.

Both of these classes use the global allocator (g_new and g_free) as their underlying store.

These may only be accessed by one thread at a time: you should make sure to have a mutex to lock if multiple threads have access to the same mempool. I suspect the majority of use cases already must be mutex-protected for other reasons, but stronger evidence is welcome.

Details

GSK_MEM_POOL_FIXED_STATIC_INIT()

#define             GSK_MEM_POOL_FIXED_STATIC_INIT(size)

Initialize a fixed-length static mem-pool member-wise given its elements' size.

Example:

static GskMemPoolFixed request_pool = GSK_MEM_POOL_FIXED_STATIC_INIT(sizeof (Request));
...
Request *request = gsk_mem_pool_fixed_alloc (&request_pool);
...
gsk_mem_pool_fixed_free (request);

size :

the size of the mem-pool's elements.

GSK_MEM_POOL_STATIC_INIT

#define             GSK_MEM_POOL_STATIC_INIT

Initialize a fixed-length static mem-pool member-wise.

Example:

void foo ()
{
  GskMemPool mem_pool = GSK_MEM_POOL_STATIC_INIT;
  void *garbage = gsk_mem_pool_alloc (&mem_pool, 20);
  ...
  gsk_mem_pool_destruct (&mem_pool);
}


GskMemPool

typedef struct {
} GskMemPool;

A memory pool. It should be created on the stack or inside another object.


GskMemPoolFixed

typedef struct {
} GskMemPoolFixed;

A fixed-size memory pool. It should be created on the stack or inside another object.


gsk_mem_pool_construct ()

void                gsk_mem_pool_construct              (GskMemPool *pool);

Initialize the members of a mem-pool. (The memory for the mem-pool structure itself must be provided: either as a part of another structure or on the stack.)

pool :

the mem-pool to initialize.

gsk_mem_pool_construct_with_scratch_buf ()

void                gsk_mem_pool_construct_with_scratch_buf
                                                        (GskMemPool *pool,
                                                         gpointer buffer,
                                                         gsize buffer_size);

Initialize the members of a mem-pool, using a scratch-buffer that the user provides. (The caller is responsible for ensuring that the buffer exists long enough)

pool :

the mem-pool to initialize.

buffer :

the buffer to use.

buffer_size :

the number of bytes in buffer to use as storage.

gsk_mem_pool_alloc ()

gpointer            gsk_mem_pool_alloc                  (GskMemPool *pool,
                                                         gsize size);

Allocate memory from a pool, This function terminates the program if there is an out-of-memory condition.

pool :

area to allocate memory from.

size :

number of bytes to allocate.

Returns :

the slab of memory allocated from the pool.

gsk_mem_pool_alloc0 ()

gpointer            gsk_mem_pool_alloc0                 (GskMemPool *pool,
                                                         gsize size);

Allocate memory from a pool, and initializes it to 0. This function terminates the program if there is an out-of-memory condition.

pool :

area to allocate memory from.

size :

number of bytes to allocate.

Returns :

the slab of memory allocated from the pool.

gsk_mem_pool_strdup ()

char *              gsk_mem_pool_strdup                 (GskMemPool *pool,
                                                         const char *str);

Allocated space from the mem-pool to store the given string (including its terminal NUL character) and copy the string onto that buffer.

If str is NULL, then NULL is returned.

pool :

area to allocate memory from.

str :

a string to duplicate, or NULL.

Returns :

a copy of str, allocated from pool.

gsk_mem_pool_destruct ()

void                gsk_mem_pool_destruct               (GskMemPool *pool);

Destroy all chunk associated with the given mem-pool.

pool :

the pool to destroy.

gsk_mem_pool_fixed_construct ()

void                gsk_mem_pool_fixed_construct        (GskMemPoolFixed *pool,
                                                         gsize size);

Set up a fixed-size memory allocator for use.

pool :

the fixed-size memory pool to construct.

size :

size of the allocation to take from the mem-pool.

gsk_mem_pool_fixed_alloc ()

gpointer            gsk_mem_pool_fixed_alloc            (GskMemPoolFixed *pool);

Allocate a block of the Fixed-Pool's size.

pool :

the pool to allocate a block from.

Returns :

the allocated memory.

gsk_mem_pool_fixed_alloc0 ()

gpointer            gsk_mem_pool_fixed_alloc0           (GskMemPoolFixed *pool);

Allocate a block of the Fixed-Pool's size. Set its contents to 0.

pool :

the pool to allocate a block from.

Returns :

the allocated, zeroed memory.

gsk_mem_pool_fixed_free ()

void                gsk_mem_pool_fixed_free             (GskMemPoolFixed *pool,
                                                         gpointer from_pool);

Recycle some of the pool's memory back to it.

pool :

the pool to return memory to.

from_pool :

the memory to return to this pool. It must have been allocated from this pool.

gsk_mem_pool_fixed_destruct ()

void                gsk_mem_pool_fixed_destruct         (GskMemPoolFixed *pool);

Free all memory associated with this pool.

pool :

the pool to destroy.