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.
A shocking number of LLSingleton subclasses had public constructors -- and in
several instances, were being explicitly instantiated independently of the
LLSingleton machinery. This breaks the new LLSingleton dependency-tracking
machinery. It seems only fair that if you say you want an LLSingleton, there
should only be ONE INSTANCE!
Introduce LLSINGLETON() and LLSINGLETON_EMPTY_CTOR() macros. These handle the
friend class LLSingleton<whatevah>;
and explicitly declare a private nullary constructor.
To try to enforce the LLSINGLETON() convention, introduce a new pure virtual
LLSingleton method you_must_use_LLSINGLETON_macro() which is, as you might
suspect, defined by the macro. If you declare an LLSingleton subclass without
using LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() in the class body, you can't
instantiate the subclass for lack of a you_must_use_LLSINGLETON_macro()
implementation -- which will hopefully remind the coder.
Trawl through ALL LLSingleton subclass definitions, sprinkling in
LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() as appropriate. Remove all explicit
constructor declarations, public or private, along with relevant 'friend class
LLSingleton<myself>' declarations. Where destructors are declared, move them
into private section as well. Where the constructor was inline but nontrivial,
move out of class body.
Fix several LLSingleton abuses revealed by making ctors/dtors private:
LLGlobalEconomy was both an LLSingleton and the base class for
LLRegionEconomy, a non-LLSingleton. (Therefore every LLRegionEconomy instance
contained another instance of the LLGlobalEconomy "singleton.") Extract
LLBaseEconomy; LLGlobalEconomy is now a trivial subclass of that.
LLRegionEconomy, as you might suspect, now derives from LLBaseEconomy.
LLToolGrab, an LLSingleton, was also explicitly instantiated by
LLToolCompGun's constructor. Extract LLToolGrabBase, explicitly instantiated,
with trivial subclass LLToolGrab, the LLSingleton instance.
(WARNING: LLToolGrabBase methods have an unnerving tendency to go after
LLToolGrab::getInstance(). I DO NOT KNOW what should be the relationship
between the instance in LLToolCompGun and the LLToolGrab singleton instance.)
LLGridManager declared a variant constructor accepting (const std::string&),
with the comment:
// initialize with an explicity grid file for testing.
As there is no evidence of this being called from anywhere, delete it.
LLChicletBar's constructor accepted an optional (const LLSD&). As the LLSD
parameter wasn't used, and as there is no evidence of it being passed from
anywhere, delete the parameter.
LLViewerWindow::shutdownViews() was checking LLNavigationBar::
instanceExists(), then deleting its getInstance() pointer -- leaving a
dangling LLSingleton instance pointer, a land mine if any subsequent code
should attempt to reference it. Use deleteSingleton() instead.
~LLAppViewer() was calling LLViewerEventRecorder::instance() and then
explicitly calling ~LLViewerEventRecorder() on that instance -- leaving the
LLSingleton instance pointer pointing to an allocated-but-destroyed instance.
Use deleteSingleton() instead.
The stack we maintain of which LLSingletons are currently initializing only
makes sense when associated with a particular C++ call stack. But each
coroutine introduces another C++ call stack!
Move the initializing stack from function-static storage to
LLSingletonBase::MasterList. Make it a map keyed by llcoro::id. Each coro then
has a stack of its own.
This introduces more dependencies on the MasterList singleton, requiring
additional LLSingleton_manage_master workarounds.
Specifically, add DEBUG logging to the code that maintains the stack of
LLSingletons currently being initialized. This involves passing
LLSingletonBase's constructor the name of LLSingleton's template parameter
subclass, since during that constructor typeid(*this).name() will only produce
"LLSingletonBase".
Also add logdebugs() and oktolog() helper functions.
LLSingleton explicitly supports circular dependencies: initialization
performed during an LLSingleton subclass's initSingleton() method may
recursively call that same subclass's getInstance() method. On the other hand,
circularity from a subclass constructor cannot be permitted, else
getInstance() would have to return a partially-constructed object.
Our dependency tracking circularity check initially forbade both. Loosen it to
permit references from within initSingleton().
Part of LLError's logging infrastructure is implemented with an LLSingleton.
Therefore, attempts to log from within LLSingleton machinery could potentially
go south if LLError's LLSingleton is not yet initialized.
Introduce LLError::is_available() in llerrorcontrol.h and llerror.cpp.
Make LLSingletonBase::logwarns() and logerrs() consult LLError::is_available()
before attempting to use LL_WARNS or LL_ERRS, respectively.
Moreover, make all LLSingleton internal logging use logwarns() and logerrs()
instead of directly engaging LL_ERRS or LL_WARNS.
Introduce LLSingleton::cleanupSingleton() canonical method as the place to put
any subclass cleanup logic that might take nontrivial realtime or throw an
exception. Neither is appropriate in a destructor.
Track all extant LLSingleton subclass instances on a master list, which
permits adding LLSingletonBase::cleanupAll() and deleteAll() methods.
Also notice when any LLSingleton subclass constructor (or initSingleton()
method) calls instance() or getInstance() for another LLSingleton, and capture
that other LLSingleton instance as a dependency of the first. This permits
cleanupAll() and deleteAll() to perform a dependency sort on the master list,
thus cleaning up (or deleting) leaf LLSingletons AFTER the LLSingletons that
depend on them.
Make C++ runtime's final static destructor call LLSingletonBase::deleteAll()
instead of deleting individual LLSingleton instances in arbitrary order.
Eliminate "llerror.h" from llsingleton.h, a longstanding TODO.
Remove evil getIfExists() method, used by no one.
Remove evil destroyed() method, used in exactly three places -- one of which
is a test. Replace with equally evil instanceExists() method, which is used
EVERYWHERE -- sigh.
made fast timer stack thread local
added LLThreadLocalSingleton
made LLThreadLocalPointer obey pointer rules for const
added LLThreadLocalSingletonPointer for fast thread local pointers
* Removed check_curl_code and check_curl_multi_code from the global namespace.
* Added comments documenting which thread the public methods of LLProxy should be called from.
* Corrected grammar in LLSingleton.h
* Fixed a buffer scope problem in llpacketring.cpp.
Nat Goodspeed