Crash if React instance is destroyed while an async storage operation is in progress

[zholobov]

https://github.com/Microsoft/react-native-windows/blob/8bc676281c3f8a2bc8e783654e608c0e489ed5b1/ReactWindows/ReactNative/Modules/Storage/AsyncStorageModule.cs#L322

Any _mutex.Release() (or any other code using _mutex) will crash with ObjectDisposedException if React instance was disposed meanwhile and _mutex.Dispose() was called. This is possible since _mutex.Release() calls are done in continuations that can be executed after the disposal.

[reseul]

@zholobov I think @psivaram is fixing this these days

[zholobov]

@reseul oh, checked with him, thanks! Cool - he may want to use this work item to justify a PR here.

[matthargett]

I have PR #1888 that I believe resolves this issue. I need to respond to the existing feedback, but please let me know if there's something else I need to do there.

We are not investing in new features or lower priority bug fixes on vCurrent. The bulk of investment is now in vNext as we prepare to make that the default choice. If this issue is still relevant on the vNext implementation please open a vNext issue. If this issue is of significant severity for a vCurrent app and vNext is not an option, re-open with justification.