Allocpool

In bfdev allocpool is a mempool optimized for allocation, the struct is defined as follows:

struct bfdev_allocpool {
    void *block;
    size_t size;
    uintptr_t last;
    unsigned long count;
};

struct bfdev_allocpool {
    void *block;
    size_t size;
    uintptr_t last;
    unsigned long count;
};

The memory of the allocpool are available in the block field. The last field holds the current offset of memory. The count field holds the number of allocation.

Use the BFDEV_DEFINE_ALLOCPOOL(name, memory, size) macro to define an allocpool, and the bfdev_allocpool_init(allocpool, memory, size) call to initialize an allocpool object that has already been allocated.

/* define an int allocpool named foo using static array */
static char block[4096];
BFDEV_DEFINE_ALLOCPOOL(foo, block, sizeof(block));

/* initialize int allocpool named bar using malloc */
struct bfdev_allocpool bar;
void *block;

block = malloc(4096);
bfdev_allocpool_init(&bar, block, 4096);

/* define an int allocpool named foo using static array */
static char block[4096];
BFDEV_DEFINE_ALLOCPOOL(foo, block, sizeof(block));

/* initialize int allocpool named bar using malloc */
struct bfdev_allocpool bar;
void *block;

block = malloc(4096);
bfdev_allocpool_init(&bar, block, 4096);

Use the following functions to alloc and free in an allocpool:

bfdev_allocpool_alloc(allocpool, size, align) allocate an aligned memory block
bfdev_allocpool_free(allocpool, block) release any block of memory

The space occupied by the allocation pool grows linearly, free function will only release a reference count, when the count reaches zero, the space will be released uniformly.

int *foo;

foo = bfdev_allocpool_alloc(allocpool, 4, 0);
bfdev_allocpool_free(allocpool, foo);

int *foo;

foo = bfdev_allocpool_alloc(allocpool, 4, 0);
bfdev_allocpool_free(allocpool, foo);

Allocpool ​

Allocpool