#include <iostream>
#include <sys/types.h>
#include <aio.h>
#include <fcntl.h>
#include <errno.h>
using namespace std;
const int SIZE_TO_READ = 100;
int main()
{
// open the file
int file = open("data.txt", O_RDONLY, 0);
if (file == -1)
{
cout << "Unable to open file!" << endl;
return 1;
}
// create the buffer
int* buffer = new int[SIZE_TO_READ]; //although the data is void
// create the control block structure
aiocb cb;
memset(&cb, 0, sizeof(aiocb));
cb.aio_nbytes = SIZE_TO_READ;
cb.aio_fildes = file;
cb.aio_offset = 0;
cb.aio_buf = buffer;
unsigned long long int sum(0);
// read!
while(1)
{
if (aio_read(&cb) == -1)
{
cout << "Unable to create request!" << endl;
close(file);
break;
}
for(int i=0; i<100; i++)
sum+ = (unsigned long long int)cb.aio_buf[i];
}
cout << "Request enqueued!" << endl;
// wait until the request has finished
while(aio_error(&cb) == EINPROGRESS)
{
cout << "Working..." << endl;
}
// success?
int numBytes = aio_return(&cb);
if (numBytes != -1)
{
cout << "Success!" << endl;
cout << "sum = " << sum << endl;
}
else
cout << "Error!" << endl;
// now clean up
delete[] buffer;
close(file);
return 0;
}
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