@snakefoot your input please :)

So when people configure KeepFileOpen on limited NetCore-platforms then they will continue to have KeepFileOpen=false. Think this is very confusing, and still prefer to have ConcurrentWrites = false by default on NetCore-platforms, instead of all this guess-magic.

Still don't like the testing with exceptions. Also you need to catch a lot more. See also

if (ex is SecurityException || ex is UnauthorizedAccessException || ex is NotSupportedException || ex is NotImplementedException || ex is PlatformNotSupportedException)

So when people configure KeepFileOpen on limited NetCore-platforms then they will continue to have KeepFileOpen=false. Think this is very confusing, and still prefer to have ConcurrentWrites = false by default on NetCore-platforms, instead of all this guess-magic.

I tried to not change the current behavior (the fallback when there is no mutex), but only change the detection, which wasn't good enough.

If the fallback is not good, IMO that's another issue and maybe more for NLog 5.

Still don't like the testing with exceptions. Also you need to catch a lot more. See also

if (ex is SecurityException || ex is UnauthorizedAccessException || ex is NotSupportedException || ex is NotImplementedException || ex is PlatformNotSupportedException)

will fix that

Please make CreateSharableMutex() return null instead of creating a dummy Mutex-object.

And places where null is not acceptable (Ex. MutexMultiProcessFileAppender) then throw exception.

Please make CreateSharableMutex() return null instead of creating a dummy Mutex-object.

that's existing code. Just moved around.

Yes but now you have made the support-detection more advanced, and the fallback was invalid, and now the fallback is exercised even more.

Fair enough, will check that

Btw. Title of PR should be UWP (and not UPW)

WUPS!

@snakefoot please review, thanks!

Codecov Report

Merging #3079 into dev will increase coverage by 1%.
The diff coverage is 69%.

@@           Coverage Diff           @@
##             dev   #3079     +/-   ##
=======================================
+ Coverage     80%     80%     +1%     
=======================================
  Files        349     349             
  Lines      27519   28685   +1166     
  Branches    3653    3986    +333     
=======================================
+ Hits       21903   22977   +1074     
- Misses      4567    4634     +67     
- Partials    1049    1074     +25

@snakefoot thanks for your suggestions. Those are applied now. Please let me know if this is ready to merge :)

Looks good now. Still prefer just having global-mutex disabled by default for NetCore. Better performance and better compatibility. Maybe for NLog 5.0 ?

Looks good now. Still prefer just having global-mutex disabled by default for NetCore. Better performance and better compatibility. Maybe for NLog 5.0 ?

I think that's OK, but we have to double check the pro and cons for it