GetLastError() (with and without debugger)

[Pedro Lamarão]

I apologize for my previous post; I mistakenly pressed the send message
keyboard shortcut.


Em sex., 12 de ago. de 2022 às 06:22, Manuel Bleichenbacher <
manuel.bleichenbacher at gmail.com> escreveu:


> This is incorrect. WriteFile() indicates an error, but GetLastError()
> returns 0 (= NO_ERROR). Could it be that the debugger calls another Windows
> API function between those two functions, resetting the last error?
>
> In my project that's a major issue. Since the software behaves incorrectly
> with the debugger, the software can no longer be debugged. This doesn't
> just affect it when debugging this particular piece of code but anytime
> this code is run in a debugging session.
>


As far as I know, GetLastError and WSAGetLastError are getter-like
functions for effectively thread local data.
It is safe to call Windows API functions from inside the same process but
another thread.

The effect you are observing cannot be simply that of the JVM or the
debugger is calling Windows API from some thread.
This effect must be that of the JVM or the debugger calling Windows API
from inside your program's thread.

If either the JVM or the debugger is indeed "hijacking" program threads to
call into Windows API functions,
this would be a blocker to using panama-based bindings to do anything
useful with Windows API.
It would be impossible to drive Windows API or Windows Sockets correctly.
Overlapped I/O, for example, relies on GetLastError to distinguish between
various non-error conditions.

-- 
Pedro Lamarão
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.org/pipermail/panama-dev/attachments/20220812/aab6a603/attachment.htm>