Re: cnd_timedout returns immediately when built with MinGW

[Tim Rühsen]

Hi Bruno,

On 05.08.22 20:27, Bruno Haible wrote:
> Hi Tim,
>
> > I am at switching wget2 multithreading from C99+glthreads to C11
> > (threads.h).
>
> I hope that you have considered the Gnulib documentation on this topic:
> https://www.gnu.org/software/gnulib/manual/html_node/Choosing-a-multithreading-API.html

Thanks for the pointer. I used the gnulib API in the past and created 
API wrappers for libwget,
so that apps didn't need to use gnulib directly. Since Wget2 is the only 
app I know that uses libwget,
I recently decided to go with ISO C (C11) in the future and drop the 
libwget thread API completely.

The rationale was
- gnulib is C11, so the libwget code is
- less code = less maintenance
- the library code just uses the basic thread, condition and mutex API

I read that even the MS C compilers / libraries support ISO C thread 
nowadays,
so ISO C seems OK to me.

> > The tests work well on Linux (amd64) (Debian unstable/testing/stable,
> > Fedora 35, Arch, Alpine/muslc) with native builds (gcc or clang).
> >
> > But they completely fail when cross-building with MinGW64 (on Debian
> > bookworm).
>
> And what's the execution environment? Is it Windows or is it wine? wine is
> not supported; I've had enough work making it work on Windows.

Testing with wine, as I don't own a Windows license.
Have to carry a USB stick to a friend in order to test on real Windows 
(trying to avoid that).

And yeah, I can fully understand that wine isn't directly supported. It 
seems to be
a can of worms on it's own.

> Also, are you configuring with --enable-threads=windows? If yes, then
> it should work (on Windows). If not, then if the winpthreads library
> is found, it will be used; but since this library is broken, some of the
> tests will hang, crash, or fail. To avoid using this broken library,
> add this macro invocation to your configure.ac:
>    gl_AVOID_WINPTHREAD

'--enable-threads=windows' does not work with MinGW since 'threads.h' is 
not available via gnulib then.
MinGW also doesn't provide it. It's not 100% clear to me what this 
option actually does.

I'll use gl_AVOID_WINPTHREAD since there are reports from Windows users 
regarding multi-threading not working
as expected (using the gnulib API).

Thank you, I appreciate your help & hints !

Regards, Tim

> Bruno

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