How read serial port with ZwReadFile?

Ryuji Kawaida 61

Now, I am trying to read the serial port with ZwReadFile.

For read serial port I use ZwCreateFile and put as property FILE_SYNCHRONOUS_IO_ALERT.
ZwReadFile returns values following:

What is mean this bytes?
Where find information about FILE_SYNCHRONOUS_IO_ALERT?

Reference:
https://www.codeproject.com/Messages/3591090/Re-What-is-the-effect-of-FILE-SYNCHRONOUS-IO-ALERT.aspx

Pavel A 431 Reputation points

2021-06-03T00:04:30.197+00:00

The picture "101000-bytes.png" in your post is not visible.

This is the first result from Google:
https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntifs/nf-ntifs-ntcreatefile

TL;DR FILE_SYNCHRONOUS_IO_ALERT causes waits on synchronous I/O be alertable.
And FILE_SYNCHRONOUS_IO_NONALERT causes these waits to be non-alertable.
Explanation of alerts IIRC can be found in the Windows Internals book.

--pa

Your answer