Function doio_loop

net/basic_socket.h:112–122

#define DOIO_ONCE(iocb, waitcb) doio_once(LAMBDA(iocb), LAMBDA(waitcb))

template <typename IOCB, typename STEP> __FORCE_INLINE__
ssize_t doio_loop(IOCB iocb, STEP step) {
    ssize_t ret, n = 0;
    do {
        ret = iocb();
        if (ret <  0) return ret; // error
        if (ret == 0) break;  // EOF
        n += ret;
    } while (step(ret, n));
    return n;
}

struct BufStep {
    void*& buf;