/*
 * Memory tester by Quintela.
 */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#define FILENAME "/tmp/testing_file"
/* Put here 2times your memory or less */
#define SIZE     (128 * 1024 * 1024) 


void error_string(char *msg)
{
        perror(msg);
        exit(EXIT_FAILURE);
}

int main(int argc, char * argv[])
{
        char *array;
        int i;
        int fd = open(FILENAME, O_RDWR | O_CREAT, 0666);
        if (fd == -1)
                error_string("Problems opening the file");

        if (lseek(fd, SIZE, SEEK_SET) != SIZE)
                error_string("Problems doing the lseek");

        if (write(fd,"\0",1) !=1)
                error_string("Problems writing");
 
        array = mmap(0, SIZE, PROT_WRITE, MAP_SHARED,fd,0);
        if (array == MAP_FAILED)
                error_string("The mmap has failed");
        
        for(i = 0; i < SIZE; i++) {
                array[i] = i;
        } 
        msync(array, SIZE, MS_SYNC);
        close(fd);
        exit(EXIT_SUCCESS);
}