FIX #2154 query virtualbox serially

[dgageot]

Signed-off-by: David Gageot david@gageot.net

[nathanleclaire]

Instead of complicating this code further and adding more provider-specific stuff in, we should just offload responsibility to the driver by throwing a sync.Mutex around calls to VBoxManage (have a PR for this in the wings). Otherwise folks (including us) will be more tempted write unsafe code in their drivers and expect the core to work around it.

I think a mutex around VBoxManage might let us take out the serial bit we have for virtualbox in our run-command-for-context bit as well, but we'll do one step at a time.

[dgageot]

Hey @nathanleclaire, closing this PR was a bit brutal. No offense taken though since I do really prefer your solution. However, since #2179 is not currently fixing this issue, I'm going to reopen this PR. Please consider it as a working quick and a bit dirty fix that gives you plenty of time to find a better fix.

[dgageot]

@nathanleclaire Please take a look at this updated PR.

[nathanleclaire]

This solution seems pretty reasonable. I have a few nits around style that I am thinking about making a PR to your repo for. Stay tuned.

[nathanleclaire]

I'm not sure that this persists RawDriver correctly on create. Can you confirm that it works for you?

[nathanleclaire]

dgageot#1

[dgageot]

@nathanleclaire Thanks for the improvements. PTAL

[nathanleclaire]

LGTM