LLAppViewer's heap LLWatchdogTimeout might be destroyed very late -- as late
as in LLAppViewer's destructor. By that time, LLAppViewer::cleanup() has
already called LLSingletonBase::deleteAll(), destroying the LLWatchdog
LLSingleton instance.
But LLWatchdogTimeout isa LLWatchdogEntry, and ~LLWatchdogEntry() calls
stop(), and stop() tries to remove that instance from LLWatchdog, thus
inadvertently resurrecting the deleted LLWatchdog. Which is pointless because
the resurrected LLWatchdog has never heard of the LLWatchdogTimeout instance
trying to remove itself.
Defend LLWatchdogEntry::stop() against the case in which LLWatchdog has
already been deleted.
Make the LLError::Settings LLSingleton duplicate the file handle for stderr
(usually 2) on construction. Make its destructor restore the original target
for that file handle. Provide a getDupStderr() method to obtain the duplicate
file handle.
Move Settings declaration up to the top of the file so other code can
reference it.
Make RecordToFile (the Recorder subclass engaged by LLError::logToFile()),
instead of duplicating stderr's file handle itself, capture the duplicate
stderr file handle from Settings to revert stderr redirection on destruction.
Make RecordToStderr (the Recorder subclass engaged by LLError::logToStderr())
use fdopen() to create an LLFILE* targeting the duplicate file handle from
Settings. Write output to that instead of to stderr so logToStderr() continues
to provide output for the user instead of duplicating each line into the log
file.
Add ndof_dump_list() call, to enumerate available devices, when
ndof_init_first() returns failure.
Add "joystick" tags to existing LL_INFOS() (etc.) calls in
llviewerjoystick.cpp to make it easier to enable and disable such log
messages.
Add a specialized operator<<() function to log the contents of an NDOF_Device
struct. Add a couple LL_DEBUGS() calls for more visibility into library
operations.
Some of the libraries we use produce log output to stderr. Such output can be
informative, but is invisible unless you launch the viewer from a console. In
particular, it's invisible to anyone trying to diagnose a problem by reading
someone else's SecondLife.log file.
Make RecordToFile -- the Recorder subclass engaged by LLError::logToFile() --
redirect STDERR_FILENO to the newly-opened log file so that any subsequent
writes to stderr (or cerr, for that matter) will be captured in the log file.
But first duplicate the original stderr file handle, and restore it when
RecordToFile is destroyed. That way, output written to stderr during the final
moments of application shutdown should still appear on (console) stderr.
LLUniqueFile wraps an LLFILE* in a move-only class that closes the wrapped
LLFILE* on destruction. It provides conversion operators to permit idiomatic
usage as an LLFILE* value.
Since the consuming coroutine LLCoprocedurePool::coprocedureInvokerCoro() has
been observed to outlive the LLCoprocedurePool instance that owns the
CoprocQueue_t, closing that queue isn't enough to keep the coroutine from
crashing at shutdown: accessing a deleted CoprocQueue_t is fatal whether or
not it's been closed.
Make LLCoprocedurePool store a shared_ptr to a heap CoprocQueue_t instance,
and pass that shared_ptr by value to consuming coroutines. That way the
CoprocQueue_t instance is guaranteed to live as long as the last interested
party.
Instead of heap-allocating a CoroData instance per coroutine, storing the
pointer in a ptr_map and deleting it from the ptr_map once the
fiber_specific_ptr for that coroutine is cleaned up -- just declare a stack
instance on the top-level stack frame, the simplest C++ lifespan management.
Derive CoroData from LLInstanceTracker to detect potential name collisions and
to enumerate instances.
Continue registering each coroutine's CoroData instance in our
fiber_specific_ptr, but use a no-op deleter function.
Make ~LLCoros() directly pump the fiber scheduler a few times, instead of
having a special "LLApp" listener.
By the time "LLApp" listeners are notified that the app is quitting, the
mainloop is no longer running. Even though those listeners do things like
close work queues and inject exceptions into pending promises, any coroutines
waiting on those resources must regain control before they can notice and shut
down properly. Add a final "LLApp" listener that resumes ready coroutines a
few more times.
Make sure every other "LLApp" listener is positioned before that new one.
Add LLCoros::TempStatus instances around known suspension points so
printActiveCoroutines() can report what each suspended coroutine is waiting
for.
Similarly, sprinkle checkStop() calls at known suspension points.
Make LLApp::setStatus() post an event to a new LLEventPump "LLApp" with a
string corresponding to the status value being set, but only until
~LLEventPumps() -- since setStatus() also gets called very late in the
application's lifetime.
Make postAndSuspendSetup() (used by postAndSuspend(), suspendUntilEventOn(),
postAndSuspendWithTimeout(), suspendUntilEventOnWithTimeout()) add a listener
on the new "LLApp" LLEventPump that pushes the new LLCoros::Stopping exception
to the coroutine waiting on the LLCoros::Promise. Make it return the new
LLBoundListener along with the previous one.
Accordingly, make postAndSuspend() and postAndSuspendWithTimeout() store the
new LLBoundListener returned by postAndSuspendSetup() in a LLTempBoundListener
(as with the previous one) so it will automatically disconnect once the wait
is over.
Make each LLCoprocedurePool instance listen on "LLApp" with a listener that
closes the queue on which new work items are dispatched. Closing the queue
causes the waiting dispatch coroutine to terminate. Store the connection in an
LLTempBoundListener on the LLCoprocedurePool so it will disconnect
automatically on destruction.
Refactor the loop in coprocedureInvokerCoro() to instantiate TempStatus around
the suspending call.
Change a couple spammy LL_INFOS() calls to LL_DEBUGS(). Give all logging calls
in that module a "CoProcMgr" tag to make it straightforward to re-enable the
LL_DEBUGS() calls as desired.
Introduce LLCoros::Stop exception, with subclasses Stopping, Stopped and
Shutdown. Add LLCoros::checkStop(), intended to be called periodically by any
coroutine with nontrivial lifespan. It checks the LLApp status and, unless
isRunning(), throws one of these new exceptions.
Make LLCoros::toplevel() catch Stop specially and log forcible coroutine
termination.
Now that LLApp status matters even in a test program, introduce a trivial
LLTestApp subclass whose sole function is to make isRunning() true.
(LLApp::setStatus() is protected: only a subclass can call it.) Add LLTestApp
instances to lleventcoro_test.cpp and lllogin_test.cpp.
Make LLCoros::toplevel() accept parameters by value rather than by const
reference so we can continue using them even after context switches.
Make private LLCoros::get_CoroData() static. Given that we've observed some
coroutines living past LLCoros destruction, making the caller call
LLCoros::instance() is more dangerous than encapsulating it within a static
method -- since the encapsulated call can check LLCoros::wasDeleted() first
and do something reasonable instead. This also eliminates the need for both a
const and non-const overload.
Defend LLCoros::delete_CoroData() (cleanup function for fiber_specific_ptr for
CoroData, implicitly called after coroutine termination) against calls after
~LLCoros().
Add a status string to coroutine-local data, with LLCoro::setStatus(),
getStatus() and RAII class TempStatus.
Add an optional 'when' string argument to LLCoros::printActiveCoroutines().
Make ~LLCoros() print the coroutines still active at destruction.
~LLEventPumps() deletes every LLEventPump instance it created itself. However,
many classes themselves contain LLEventPump subclass instances. These are
registered with LLEventPumps without it managing their lifespan.
But LLEventPump::reset() frees the LLStandardSignal aka
boost::signals2::signal instance owned by the LLEventPump, perforce
disconnecting all current listeners and disabling the LLEventPump. Even though
the instance still exists, if someone subsequently calls post(), nothing will
happen -- which is better than control trying to reach a method of a deleted
object.
Having a map from std::string to a factory function returning LLEventPump* is
a cool idea, especially since you could statically populate such a map with
string literals and little lambdas.
Unfortunately, static initialization of any data is a bad idea when control
can reach consuming code before that module's static data are constructed.
Since LLEventPumps is already an LLSingleton, it's simple enough to make its
map non-static and initialize it in the constructor.
But another recent static factory-function map was introduced in
llleaplistener.cpp to support the LLLeapListener::newpump() operation. That
involves no LLSingletons.
Introduce LLEventPumps::make(name, tweak, type) to instantiate an LLEventPump
subclass of the specified type with specified (name, tweak) parameters.
Instances returned by make() are owned by LLEventPumps, as with obtain().
Introduce LLEventPumps::BadType exception for when the type string isn't
recognized.
LLEventPumps::obtain() can then simply call make() when the specified instance
name doesn't already exist. The configuration data used internally by obtain()
becomes { string instance name, string subclass name }. Although this too is
currently initialized in the LLEventPumps constructor, migrating it to a
configuration file would now be far more straightforward than before.
LLLeapListener::newpump(), too, can call LLEventPumps::make() with the
caller-specified type string. This eliminates that static factory map.
newpump() must catch BadType and report the error back to its invoker.
Given that the LLEventPump subclass instances returned by make() are owned by
LLEventPumps rather than LLLeapListener, there is no further need for the
LLLeapListener::mEventPumps ptr_map, which was used only to manage lifetime.
Also remove LLLeapListener's "killpump" operation since LLEventPumps provides
no corresponding functionality.
Although this is legal, apparently there was a bug in the C++11 standard (to
which gcc 4.8 conforms) that was subsequently fixed in the standard (and thus
in gcc 4.9). Thanks Henri Beauchamp.
No one uses LLEventQueue to defer posted events until the next mainloop tick
-- and with LLCoros moving to Boost.Fiber, cross-coroutine event posting works
that way anyway, making LLEventQueue pretty unnecessary.
The static RegisterFlush instance in llevents.cpp was used to call
LLEventPumps::flush() once per mainloop tick, which in turn called flush() on
every registered LLEventPump. But the only reason for that mechanism was to
support LLEventQueue. In fact, when LLEventMailDrop overrode its flush()
method for something quite different, it was startling to find that the new
flush() override was being called once per frame -- which caused at least one
fairly mysterious bug. Remove RegisterFlush. Both LLEventPumps::flush() and
LLEventPump::flush() remain for now, though intended usage is unclear.
Eliminating LLEventQueue means we must at least repurpose
LLEventPumps::mQueueNames, a map intended to make LLEventPumps::obtain()
instantiate an LLEventQueue rather than the default LLEventPump. Replace it
with mFactories, a map from desired instance name to a callable returning
LLEventPump*. New map initialization syntax plus lambda support allows us to
populate that map at compile time with little lambdas returning the correct
subclass instance.
Similarly, LLLeapListener::newpump() used to check the ["type"] entry in the
LLSD request specifically for "LLEventQueue". Introduce another such map in
llleaplistener.cpp for potential future extensibility.
Eliminate the LLEventQueue-specific test.
Overriding virtual LLEventPump::flush() for the semantic of discarding
LLEventMailDrop's queued events turns out not to be such a great idea, because
LLEventPumps::flush(), which calls every registered LLEventPump's flush()
method, is called every mainloop tick. The first time we hit a use case in
which we expected LLEventMailDrop to hold queued events across a mainloop tick,
we were baffled that they were never delivered.
Moving that logic to a separate method specific to LLEventMailDrop resolves
that problem. Naming it discard() clarifies its intended functionality.
The LLEventMailDrop used to communicate with the Vivox coroutine is a member
of LLVivoxVoiceClient. We don't need to keep looking it up by its string name
in LLEventPumps.
LLEventLogProxy can be introduced to serve as a logging proxy for an existing
LLEventPump subclass instance. Access through the LLEventLogProxy will be
logged; access directly to the underlying LLEventPump will not.
LLEventLogProxyFor<LLEventPumpSubclass> functions as a drop-in replacement for
the original LLEventPumpSubclass instance. It internally instantiates
LLEventPumpSubclass and serves as a proxy for that instance.
Add unit tests for LLEventMailDrop and LLEventLogProxyFor<LLEventMailDrop>,
both "plain" (events only) and via lleventcoro.h synchronization.
passed to postAndSuspendsetup().
The requestPump is optional, and the function varies its behavior depending on
whether that parameter is empty or meaningful. But it unconditionally uses the
replyPump. Passing an empty LLEventPumpOrPumpName caused mysterious crashes.
Add llassert_always_msg() to make the coding error explicit in such a case.
Also streamline access to meaningful requestPump and replyPump by temporarily
caching the bound LLEventPump reference.
LLEventDetail::visit_and_connect() promised special treatment for the
specific case when an LLEventPump::listen() listener was composed of (possibly
nested) boost::bind() objects storing boost::weak_ptr values -- specifically
boost::bind() rather than std::bind or lambdas, specifically boost::weak_ptr
rather than std::weak_ptr.
Outside of self-tests, it does not appear that anyone actually uses that
support.
There is good reason not to: it's a silent side effect of a complicated
compile-time inspection that could be silently derailed by use of std::bind()
or a lambda or a std::weak_ptr. Can you be sure you've engaged that promise?
How?
A more robust guarantee can be achieved by storing an LLTempBoundConnection in
the transient object itself. When the object is destroyed, the listener is
disconnected. Normal C++ rules around object destruction guarantee it. This
idiom is widely used.
There are a couple good reasons to remove the visit_and_connect() machinery:
* boost::bind() and boost::weak_ptr do not constitute the wave of the future.
Preferring those constructs to lambdas and std::weak_ptr penalizes new code,
whether by silently failing or by discouraging use of modern idioms.
* The visit_and_connect() machinery was always complicated, and apparently
never very robust. Most of its promised features have been commented out
over the years. Making the code base simpler, clearer and more maintainable
is always a useful effect.
LLEventDetail::visit_and_connect() was also used by the four
LLNotificationChannelBase::connectMumble() methods. Streamline those as well.
Of course, remove related test code.
llsd::array(), as one might suspect, takes an arbitrary number of arguments of
arbitrary convertible types and returns an LLSD::Array constructed from those
elements. This supercedes the older LLSDArray class.
llsd::map() takes an even number of arguments paired as (LLSD::String,
arbitrary convertible type) and returns an LLSD::Map constructed from those
(key, value) pairs. This supercedes the older LLSDMap class.
These two functions not only have a simpler API -- arbitrary function
arguments rather than an (arg list)(arg list) sequence -- but also
specifically return a final LLSD object, rather than needing conversion to
LLSD from the LLSDArray or LLSDMap object.
Also support LLSD == LLSD and LLSD != LLSD comparisons, using llsd_equals()
with default exact-float-equality semantics.
Nat Goodspeed