Combine: Move SqlEnvChange to shared and sync usage

[Wraith2]

As the title says. Makes SqlEnvChange shared and changes netfx to use the same logic as netcore which has better a better memory allocation profile. Later on after this and #1199 are merged the SqlEnvChange objects can be pooled which will further reduce allocations on reconnection and query.

[JRahnama]

@Wraith2 can you address the conflict that I can merge the code please?

[Wraith2]

merge conflicts and feedback fixed.

[JRahnama]

@Wraith2 the failures are consistent and only happening on netfx. could be checked here

[Wraith2]

I went through the original commits from corefx and I think I've found the problem and corrected it. I can't debug the DTC related tests locally though because I can't get DTC working (spent my friday night trying) so if this doesn't work either I'll need some help or we'll have to close and retry this another time.

[johnnypham]

I went through the original commits from corefx and I think I've found the problem and corrected it. I can't debug the DTC related tests locally though because I can't get DTC working (spent my friday night trying) so if this doesn't work either I'll need some help or we'll have to close and retry this another time.

What have you tried? Adding a firewall rule for msdtc.exe worked for me.

[Wraith2]

Firewall rules. security permissions in component services. process monitoring. various KB support suggestions. I'm not new to debugging windows stuff. Sadly it just doesn't work for me, no idea why at this point.
The CI seems to have passed so if I fix up that project conflict it should be ok to merge.

Review needed again

Review needed again

Review needed again

[johnnypham]

Have you tried "allow an app through windows firewall"? For the CI agent machines, simply adding a firewall rule didn't work but this additional change did.

[Wraith2]

Yes, even tried with the firewall off. Didn't work. I'm not about to start uninstalling it to see if that helps so I'm just going to leave it alone for the moment. The CI will work for that test and the CI needs to pass before merge anyway so that'll be the coverage required.

I also removed a Debugger.Launch() from a test that got mistakenly merged in one of my other PR's.

[Wraith2]

The errors don't seem related. Could someone re-run the ci steps that failed?

[Wraith2]

What is blocking this PR please?

[cheenamalhotra]

@Wraith2

The last preview was the last window for pushing code changes and we've merged many changes. We are on code freeze and only bug fixes or test related changes are going to be merged till GA 4.0 is released. Our team is busy with security testing and other release related activities, we will merge when the time is right.

[Wraith2]

Ok, so where do I find that sort of information so I know what's going on? dotnet/runtime publish all this information about release dates code cutoffs etc, so do EFCore. Purely from the perspective of this PR there's no apparent reason that it missed an arbitrary deadline I couldn't see.

When I have been aware of deadlines like the 3.0 I've prepared code changes weeks in advance and still had the code skipped. I see nothing happening then sometimes something will get merged and then silence for weeks on end. From an external perspective there is no way to know why anything happens. I'm still hanging on here trying to collaborate and it's still frustrating and not changing.

[Wraith2]

This is another PR which I'm going to have to re-do because it's been open so long the rebase can't be done cleanly. There are errors around Server namespace types.