ushm_buffer.h

/*
 * =============================================================================
 * File        : ushm_buffer.h
 * Author      : Leandro Martins dos Santos
 * Description : Functions and constants declarations for handling buffers
 *               in the user shared memory.
 * =============================================================================
 */

#ifndef USHM_BUFFER_H
#define USHM_BUFFER_H

// Buffer definitions
////////////////////////////////////////////////////////////////////////////////////////
// Constants
#define INT_SHIFT       2   // sizeof(int) == 2^2
#define DOUBLE_SHIFT    3   // sizeof(double) == 2^3
////////////////////////////////////////////////////////////////////////////////////////
// User defined
#define USHM_BASE_ADDR    4000  // Base Address
#define USHM_BUFF_SIZE    1000
#define MAX_FRAME_NUMEL   20

////////////////////////////////////////////////////////////////////////////////////////
#include <stdbool.h>

////////////////////////////////////////////////////////////////////////////////////////
typedef union {
    double d;
    int i;
} Point;


int init_buffer(char *types, Point *ptr_arr[], size_t *frame_bytesize, void *base_memory);

size_t get_frame_len(char *types);

void set_aligned_pointer(Point *ptr_arr[], int idx, void **next_free_memory, size_t size);
bool is_aligned(void* addr, size_t alignment);
void* align_addr(void *addr, size_t alignment);

int update_buffer(char *types, Point *ptr_arr[], size_t size);
void update_addr(Point *ptr_arr[], int idx, size_t size);

void write_double(Point *ptr_arr[], int idx , size_t size, double value);
void write_int(Point *ptr_arr[], int idx, size_t size, int value);
void write_frame(char *types, Point *ptr_arr[], size_t size, Point values[]);

void test_write_buffer(char *frame_types, Point *ptr_arr[], size_t size);
void test_print_buffer(char *frame_types, Point *ptr_arr[], size_t size);

////////////////////////////////////////////////////////////////////////////////////////

#endif // USHM_BUFFER_H