Summary:
There was an interesting problem in Flipper which I encountered. On closing our app we would deadlock. This was happening when joining the Flipper thread.
Upon investigation I found that it happened only when Flipper was not connected to the app. And digging in I found that it's because we are continually trying to connect the `FlipperClient` to the Flipper app when there is no connection. This works great, but it continues even if you have asked Flipper to terminate. So this meant that the `EventBase` never gets chance to shutdown, as it keeps getting new work to do.
The fix is to add a flag to `FlipperConnectionManagerImpl` to say if the conection is started or not. Then, if it's not started and we get a request to retry connection, then we will fail it.
Reviewed By: jknoxville
Differential Revision: D18780622
fbshipit-source-id: cce82cbb5c54e6d92ea16644c8a247bd2578ae26
d37c64c329