| 759 | } |
| 760 | |
| 761 | int HID_API_EXPORT HID_API_CALL hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds) |
| 762 | { |
| 763 | DWORD bytes_read = 0; |
| 764 | size_t copy_len = 0; |
| 765 | BOOL res; |
| 766 | |
| 767 | /* Copy the handle for convenience. */ |
| 768 | HANDLE ev = dev->ol.hEvent; |
| 769 | |
| 770 | if (!dev->read_pending) { |
| 771 | /* Start an Overlapped I/O read. */ |
| 772 | dev->read_pending = TRUE; |
| 773 | memset(dev->read_buf, 0, dev->input_report_length); |
| 774 | ResetEvent(ev); |
| 775 | res = ReadFile(dev->device_handle, dev->read_buf, (DWORD)dev->input_report_length, &bytes_read, &dev->ol); |
| 776 | |
| 777 | if (!res) { |
| 778 | if (GetLastError() != ERROR_IO_PENDING) { |
| 779 | /* ReadFile() has failed. |
| 780 | Clean up and return error. */ |
| 781 | CancelIo(dev->device_handle); |
| 782 | dev->read_pending = FALSE; |
| 783 | goto end_of_function; |
| 784 | } |
| 785 | } |
| 786 | } |
| 787 | |
| 788 | if (milliseconds >= 0) { |
| 789 | /* See if there is any data yet. */ |
| 790 | res = WaitForSingleObject(ev, milliseconds); |
| 791 | if (res != WAIT_OBJECT_0) { |
| 792 | /* There was no data this time. Return zero bytes available, |
| 793 | but leave the Overlapped I/O running. */ |
| 794 | return 0; |
| 795 | } |
| 796 | } |
| 797 | |
| 798 | /* Either WaitForSingleObject() told us that ReadFile has completed, or |
| 799 | we are in non-blocking mode. Get the number of bytes read. The actual |
| 800 | data has been copied to the data[] array which was passed to ReadFile(). */ |
| 801 | res = GetOverlappedResult(dev->device_handle, &dev->ol, &bytes_read, TRUE/*wait*/); |
| 802 | |
| 803 | /* Set pending back to false, even if GetOverlappedResult() returned error. */ |
| 804 | dev->read_pending = FALSE; |
| 805 | |
| 806 | if (res && bytes_read > 0) { |
| 807 | if (dev->read_buf[0] == 0x0) { |
| 808 | /* If report numbers aren't being used, but Windows sticks a report |
| 809 | number (0x0) on the beginning of the report anyway. To make this |
| 810 | work like the other platforms, and to make it work more like the |
| 811 | HID spec, we'll skip over this byte. */ |
| 812 | bytes_read--; |
| 813 | copy_len = length > bytes_read ? bytes_read : length; |
| 814 | memcpy(data, dev->read_buf+1, copy_len); |
| 815 | } |
| 816 | else { |
| 817 | /* Copy the whole buffer, report number and all. */ |
| 818 | copy_len = length > bytes_read ? bytes_read : length; |
no test coverage detected