how to force send and recv data c++

this code sometimes hang the system on recv 
int CLTIUReadWrite::Read(  char *data, int nbytes)
{
    int nleft, nread;
    char *ptr2;

    ptr2 = data;

     nleft = nbytes;
        while (nleft > 0) {
        nread = read(m_Client->Socket, ptr2, nleft);
        if (nread < 0)
            return nread;
        else if (nread == 0)
            break;

        nleft -= nread;
        ptr2 += nread;
    }
    return (nbytes - nleft);
}
void CLTIUReadWrite::Write(  char *buff, int size)
{
	int h = m_Client->Write(( char*)buff,false,size);
	
	printf(" \n data write %i data actual %i \n ",h,size);
}