getOrCreateApplicationEnvironment is main entrypoint to create
ApplicationEnvironment in production and compiler tests
It is subject to be called concurrently, that's why
APPLICATION_LOCK exists
ApplicationEnvironment itself hosts Application from idea-core
It is actually singleton, that is subject to be disposed, once all
operations referencing it completes
To properly dispose ApplicationEnvironment when there is no references
left, we maintain reference counter aka ourProjectCount
Originally, there was data-race caused by the fact, that ourProjectCount
was updated after publication of application
Linear, data-race occurs in following order
T1: getOrCreateApplicationEnvironment returns application
T2: Disposes its reference to application, causing ourProjectCount to
reach zero, and disposing application that is already available to T1
T1: Updates counter, but its application already disposed
Simon Ogorodnik
f2dee2bf85