hid

bool SpdController::read(void *buf, size_t len)
{
    if (!opened)
        return false;

    OVERLAPPED  op;
    ZeroMemory(&op, sizeof(op));
    op.hEvent = CreateEvent(nullptr, false, false, nullptr);
    DWORD dwBytesReturned = 0;
    ULONG dwError = NOERROR;
    dwError = ReadFile(hDevice, buf, len, &dwBytesReturned, &op) ? NOERROR : GetLastError();
    if (dwError == ERROR_IO_PENDING) {
        // Ждем завершения чтения
        dwError = GetOverlappedResultEx(nullptr, &op, &dwBytesReturned, 500, FALSE) ? NOERROR : GetLastError();
        if (dwError != NOERROR) {
            // Таймаут вылетел или совсем всё плохо
            CancelIo(hDevice);
            CloseHandle(op.hEvent);
            return false;
        } else {
            CloseHandle(op.hEvent);
            return true;
        }
    } else {
        CancelIo(hDevice);
        CloseHandle(op.hEvent);
        return false;
    }
}