The observed crash was due to sharing a stateful global resource (the global
LLMessageSystem instance) between different tasks. Specifically, a coroutine
sets its mMessageReader one way, expecting that value to persist until it's
done with message parsing, but another coroutine sneaks in at a suspension
point and sets it differently.
Introduce LockMessageReader and LockMessageChecker classes, which must be
instantiated by a consumer of the resource. The constructor of each locks a
coroutine-aware mutex, so that for the lifetime of the lock object no other
coroutine can instantiate another.
Refactor the code so that LLMessageSystem::mMessageReader can only be modified
by LockMessageReader, not by direct assignment. mMessageReader is now an
instance of LLMessageReaderPointer, which supports dereferencing and
comparison but not assignment. Only LockMessageReader can change its value.
LockMessageReader addresses the use case in which the specific mMessageReader
value need only persist for the duration of a single method call. Add an
instance in LLMessageHandlerBridge::post().
LockMessageChecker is a subclass of LockMessageReader: both lock the same
mutex. LockMessageChecker addresses the use case in which the specific
mMessageReader value must persist across multiple method calls. Modify the
methods in question to require a LockMessageChecker instance. Provide
LockMessageChecker forwarding methods to facilitate calling the underlying
LLMessageSystem methods via the LockMessageChecker instance.
Add LockMessageChecker instances to LLAppViewer::idleNetwork(), a couple cases
in idle_startup() and LLMessageSystem::establishBidirectionalTrust().
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.
continued conversion to units system
made units perform type promotion correctly and preserve type in arithmetic
e.g. can now do LLVector3 in units
added typedefs for remaining common unit types, including implicits
consolidated most indra-specific constants in llcommon under indra_constants.h
fixed issues with operations on mixed unit types (implicit and explicit)
made LL_INFOS() style macros variadic in order to subsume other logging methods
such as ll_infos
added optional tag output to error recorders
The biggest things in this are Scalable Space Servers and Maint-Server-6
QAR-1209 : SSS
QAR-1295 : maint-server-6
Conflicts resolved by prospero:
C scripts/farm_distribute
C scripts/automated_build_scripts/build-linux.sh : resolved by
prospero, mostly kept the merge-right version in
the conflict, but there was one block of repeated
code from earlier that I removed.
C scripts/automated_build_scripts/build-mac.sh : kept merge-right
C indra/llcommon/llversionserver.h : svn revert
C indra/newsim/llsimparcel.h : kept *both*... working had "setArea",
merge-right had exportStream and importStream
C indra/newsim/llsimparcel.cpp : see llsimparcel.h
C indra/newsim/lltask.h : working had LLTask derived also from
LLScriptResourceConsumer, merge-right had LLTask
dervied also from LLAgentPosition. To resolve
conflict, derive from both.
C indra/newsim/lllslmanager.h : kept merge-right (had an added comment)
C indra/llmessage/llhttpnode.h : kept working (added the definition
of method LLHTTPNode::extendedResult)
C indra/lscript/lscript_execute_mono/llscriptexecutemono.cpp
C indra/lscript/lscript_execute_mono/llscriptexecutemono.h
: These two were resolved by si, in consultation with daveh
I also had to add the following stubs to
indra/newsim/tests/llgodkickutils_test.cpp in order to get it to
compile:
// LLScriptResourceConsumer interface methods in LLTask
LLScriptResource::LLScriptResource() { }
LLScriptResourcePool::LLScriptResourcePool() { }
LLScriptResourcePool LLScriptResourcePool::null;
LLScriptResourceConsumer::LLScriptResourceConsumer() { }
LLScriptResourcePool& LLScriptResourceConsumer::getScriptResourcePool() { return LLScriptResourcePool::null; }
const LLScriptResourcePool& LLScriptResourceConsumer::getScriptResourcePool() const { return LLScriptResourcePool::null; }
bool LLScriptResourceConsumer::switchScriptResourcePools(LLScriptResourcePool& new_pool) { return false; }
bool LLScriptResourceConsumer::canUseScriptResourcePool(const LLScriptResourcePool& resource_pool) { return false; }
bool LLScriptResourceConsumer::isInPool(const LLScriptResourcePool& resource_pool) { return false; }
void LLScriptResourceConsumer::setScriptResourcePool(LLScriptResourcePool& pool) { }
S32 LLTask::getUsedPublicURLs() const { return 0; }
void LLTask::setScriptResourcePool(LLScriptResourcePool& pool) { }
Ansariel