create stack object with C (using block coding)

blockStack.m

#import <Foundation/Foundation.h>


typedef void(^block_t)(void);
typedef struct _stack {
	unsigned int _size;
	int _top;
	block_t *blocks;
} blockStack_t;
typedef void* stackRef;

// method functions
// declaration
stackRef create_stack(unsigned int size);
void stack_push_block(stackRef stack, block_t block);
void stack_pop_block(stackRef stack);
void stack_flush_block(stackRef stack);
void release_stack(stackRef stack);

// method functions
// definitions

stackRef create_stack(unsigned int size)
{
	blockStack_t *stack = (blockStack_t *)malloc(sizeof(blockStack_t));
	stack->_size = size;
	stack->_top = -1;
	stack->blocks = (block_t *)malloc(sizeof(block_t) * size);
	return (stackRef)stack;
}

void stack_push_block(stackRef stack, block_t block)
{
	blockStack_t *_stack = (blockStack_t *)stack;
	if(_stack->_top == _stack->_size - 1) return;
	_stack->_top += 1;
	*(_stack->blocks + _stack->_top) = block;
}

void stack_pop_block(stackRef stack) 
{
	blockStack_t *_stack = (blockStack_t *)stack;
	if(_stack->_top > -1) {
		(*(_stack->blocks + _stack->_top))();
		_stack->_top -= 1;
	}
}

void stack_flush_block(stackRef stack)
{
	blockStack_t *_stack = (blockStack_t *)stack;
	while(_stack->_top > -1) {
		(*(_stack->blocks + _stack->_top))();
		_stack->_top -= 1;
	}
}

void release_stack(stackRef stack)
{
	blockStack_t *_stack = (blockStack_t *)stack;
	free(_stack->blocks);
	free(_stack);
}

int main(int argc, char const *argv[])
{
	@autoreleasepool{
		stackRef s = create_stack(10);
		stack_push_block(s, ^(){NSLog(@"a");});
		stack_push_block(s, ^(){NSLog(@"b");});
		stack_push_block(s, ^(){NSLog(@"c");});
		stack_push_block(s, ^(){NSLog(@"d");});
		stack_pop_block(s);
		stack_push_block(s, ^(){NSLog(@"e");});
		stack_push_block(s, ^(){NSLog(@"f");});
		stack_push_block(s, ^(){NSLog(@"g");});
		stack_flush_block(s);
		release_stack(s);
	}
	return 0;
}

// 2013-06-05 00:03:41.374 blockStack[481:707] d
// 2013-06-05 00:03:41.376 blockStack[481:707] g
// 2013-06-05 00:03:41.376 blockStack[481:707] f
// 2013-06-05 00:03:41.376 blockStack[481:707] e
// 2013-06-05 00:03:41.377 blockStack[481:707] c
// 2013-06-05 00:03:41.377 blockStack[481:707] b
// 2013-06-05 00:03:41.377 blockStack[481:707] a
// [Finished in 0.0s]