/*
 * call-seq:
 *
 *      io.kgio_write(str)   -> nil
 *
 * Returns nil when the write completes.
 *
 * This may block and call any method defined to +kgio_wait_writable+
 * for the class.
 */
static VALUE kgio_write(VALUE io, VALUE str)
{
        return my_write(io, str, 1);
}