The comment indicates that calling LLSingletonBase::deleteAll() is optional
because the LLSingleton machinery implicitly calls that during final
static-object cleanup. That is no longer true.
The recent LLSingleton work added a hook that would run during the C++
runtime's final destruction of static objects. When the LAST LLSingleton in
any module was destroyed, its destructor would call
LLSingletonBase::deleteAll(). That mechanism was intended to permit an
application consuming LLSingletons to skip making an explicit deleteAll()
call, knowing that all instantiated LLSingleton instances would eventually be
cleaned up anyway.
However -- experience proves that kicking off deleteAll() processing during
the C++ runtime's final cleanup is too late. Too much has already been
destroyed. That call tends to cause more shutdown crashes than it resolves.
This commit deletes that whole mechanism. Going forward, if you want to clean
up LLSingleton instances, you must explicitly call
LLSingletonBase::deleteAll() during the application lifetime. If you don't,
LLSingleton instances will simply be leaked -- which might be okay,
considering the application is terminating anyway.
The logging subsystem depends on two different LLSingletons for some reason.
It turns out to be very difficult to completely avoid executing any logging
calls after the LLSingletonBase::deleteAll(), but we really don't want to
resurrect those LLSingletons so late in the run for a couple stragglers.
Introduce LLSingleton::wasDeleted() query method, and use it in logging
subsystem to simply bypass last-millisecond logging requests.
The LLSingletonBase::deleteAll() call late in LLAppViewer::cleanup() deletes
the LLSingleton(s) used by the logging machinery, among other things. Attempting
further logging after that call (such as our cheery "Goodbye!") has the
unfortunate effect of attempting to resurrect the deleted LLSingleton(s). Move
"Goodbye!" to just *before* the call.
Also, given that call, the manual references to a couple specific LLSingletons
in ~LLAppViewer() are (a) unnecessary and (b) cause attempted resurrection.
Eliminate both.
Ansariel