Rename CONCURRENT_JIT/ConcurrentJIT to CONCURRENT_JS/ConcurrentJS
https://bugs.webkit.org/show_bug.cgi?id=164791

Reviewed by Geoffrey Garen.
        
Source/JavaScriptCore:

Just renaming.

* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/ArrayProfile.cpp:
(JSC::ArrayProfile::computeUpdatedPrediction):
(JSC::ArrayProfile::briefDescription):
(JSC::ArrayProfile::briefDescriptionWithoutUpdating):
* bytecode/ArrayProfile.h:
(JSC::ArrayProfile::observedArrayModes):
(JSC::ArrayProfile::mayInterceptIndexedAccesses):
(JSC::ArrayProfile::mayStoreToHole):
(JSC::ArrayProfile::outOfBounds):
(JSC::ArrayProfile::usesOriginalArrayStructures):
* bytecode/CallLinkStatus.cpp:
(JSC::CallLinkStatus::computeFromLLInt):
(JSC::CallLinkStatus::computeFor):
(JSC::CallLinkStatus::computeExitSiteData):
(JSC::CallLinkStatus::computeFromCallLinkInfo):
(JSC::CallLinkStatus::computeDFGStatuses):
* bytecode/CallLinkStatus.h:
* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::dumpValueProfiling):
(JSC::CodeBlock::dumpArrayProfiling):
(JSC::CodeBlock::finishCreation):
(JSC::CodeBlock::setConstantRegisters):
(JSC::CodeBlock::getStubInfoMap):
(JSC::CodeBlock::getCallLinkInfoMap):
(JSC::CodeBlock::getByValInfoMap):
(JSC::CodeBlock::addStubInfo):
(JSC::CodeBlock::addByValInfo):
(JSC::CodeBlock::addCallLinkInfo):
(JSC::CodeBlock::resetJITData):
(JSC::CodeBlock::shrinkToFit):
(JSC::CodeBlock::getArrayProfile):
(JSC::CodeBlock::addArrayProfile):
(JSC::CodeBlock::getOrAddArrayProfile):
(JSC::CodeBlock::updateAllPredictionsAndCountLiveness):
(JSC::CodeBlock::updateAllArrayPredictions):
(JSC::CodeBlock::nameForRegister):
(JSC::CodeBlock::livenessAnalysisSlow):
* bytecode/CodeBlock.h:
(JSC::CodeBlock::setJITCode):
(JSC::CodeBlock::valueProfilePredictionForBytecodeOffset):
(JSC::CodeBlock::addFrequentExitSite):
(JSC::CodeBlock::hasExitSite):
(JSC::CodeBlock::livenessAnalysis):
* bytecode/DFGExitProfile.cpp:
(JSC::DFG::ExitProfile::add):
(JSC::DFG::ExitProfile::hasExitSite):
(JSC::DFG::QueryableExitProfile::initialize):
* bytecode/DFGExitProfile.h:
(JSC::DFG::ExitProfile::hasExitSite):
* bytecode/GetByIdStatus.cpp:
(JSC::GetByIdStatus::hasExitSite):
(JSC::GetByIdStatus::computeFor):
(JSC::GetByIdStatus::computeForStubInfo):
(JSC::GetByIdStatus::computeForStubInfoWithoutExitSiteFeedback):
* bytecode/GetByIdStatus.h:
* bytecode/LazyOperandValueProfile.cpp:
(JSC::CompressedLazyOperandValueProfileHolder::computeUpdatedPredictions):
(JSC::CompressedLazyOperandValueProfileHolder::add):
(JSC::LazyOperandValueProfileParser::initialize):
(JSC::LazyOperandValueProfileParser::prediction):
* bytecode/LazyOperandValueProfile.h:
* bytecode/MethodOfGettingAValueProfile.cpp:
(JSC::MethodOfGettingAValueProfile::emitReportValue):
* bytecode/PutByIdStatus.cpp:
(JSC::PutByIdStatus::hasExitSite):
(JSC::PutByIdStatus::computeFor):
(JSC::PutByIdStatus::computeForStubInfo):
* bytecode/PutByIdStatus.h:
* bytecode/StructureStubClearingWatchpoint.cpp:
(JSC::StructureStubClearingWatchpoint::fireInternal):
* bytecode/ValueProfile.h:
(JSC::ValueProfileBase::briefDescription):
(JSC::ValueProfileBase::computeUpdatedPrediction):
* dfg/DFGArrayMode.cpp:
(JSC::DFG::ArrayMode::fromObserved):
* dfg/DFGArrayMode.h:
(JSC::DFG::ArrayMode::withSpeculationFromProfile):
(JSC::DFG::ArrayMode::withProfile):
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::injectLazyOperandSpeculation):
(JSC::DFG::ByteCodeParser::getPredictionWithoutOSRExit):
(JSC::DFG::ByteCodeParser::getArrayMode):
(JSC::DFG::ByteCodeParser::handleInlining):
(JSC::DFG::ByteCodeParser::parseBlock):
(JSC::DFG::ByteCodeParser::InlineStackEntry::InlineStackEntry):
* dfg/DFGDriver.cpp:
(JSC::DFG::compileImpl):
* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
(JSC::DFG::FixupPhase::attemptToMakeGetArrayLength):
* dfg/DFGGraph.cpp:
(JSC::DFG::Graph::tryGetConstantClosureVar):
* dfg/DFGObjectAllocationSinkingPhase.cpp:
* dfg/DFGPredictionInjectionPhase.cpp:
(JSC::DFG::PredictionInjectionPhase::run):
* ftl/FTLLowerDFGToB3.cpp:
(JSC::FTL::DFG::LowerDFGToB3::compileMaterializeCreateActivation):
* ftl/FTLOperations.cpp:
(JSC::FTL::operationMaterializeObjectInOSR):
* heap/Heap.cpp:
(JSC::Heap::addToRememberedSet):
* jit/JIT.cpp:
(JSC::JIT::compileWithoutLinking):
* jit/JITInlines.h:
(JSC::JIT::chooseArrayMode):
* jit/JITOperations.cpp:
(JSC::tryGetByValOptimize):
* jit/JITPropertyAccess.cpp:
(JSC::JIT::privateCompileGetByValWithCachedId):
(JSC::JIT::privateCompilePutByValWithCachedId):
* jit/JITWorklist.cpp:
(JSC::JITWorklist::compileLater):
(JSC::JITWorklist::compileNow):
* jit/Repatch.cpp:
(JSC::repatchGetByID):
(JSC::repatchPutByID):
* llint/LLIntSlowPaths.cpp:
(JSC::LLInt::setupGetByIdPrototypeCache):
(JSC::LLInt::LLINT_SLOW_PATH_DECL):
(JSC::LLInt::setUpCall):
* profiler/ProfilerBytecodeSequence.cpp:
(JSC::Profiler::BytecodeSequence::BytecodeSequence):
* runtime/CommonSlowPaths.cpp:
(JSC::SLOW_PATH_DECL):
* runtime/CommonSlowPaths.h:
(JSC::CommonSlowPaths::tryCachePutToScopeGlobal):
(JSC::CommonSlowPaths::tryCacheGetFromScopeGlobal):
* runtime/ConcurrentJITLock.h: Removed.
* runtime/ConcurrentJSLock.h: Copied from Source/JavaScriptCore/runtime/ConcurrentJITLock.h.
(JSC::ConcurrentJSLockerBase::ConcurrentJSLockerBase):
(JSC::ConcurrentJSLockerBase::~ConcurrentJSLockerBase):
(JSC::GCSafeConcurrentJSLocker::GCSafeConcurrentJSLocker):
(JSC::GCSafeConcurrentJSLocker::~GCSafeConcurrentJSLocker):
(JSC::ConcurrentJSLocker::ConcurrentJSLocker):
(JSC::ConcurrentJITLockerBase::ConcurrentJITLockerBase): Deleted.
(JSC::ConcurrentJITLockerBase::~ConcurrentJITLockerBase): Deleted.
(JSC::ConcurrentJITLockerBase::unlockEarly): Deleted.
(JSC::GCSafeConcurrentJITLocker::GCSafeConcurrentJITLocker): Deleted.
(JSC::GCSafeConcurrentJITLocker::~GCSafeConcurrentJITLocker): Deleted.
(JSC::ConcurrentJITLocker::ConcurrentJITLocker): Deleted.
* runtime/InferredType.cpp:
(JSC::InferredType::canWatch):
(JSC::InferredType::addWatchpoint):
(JSC::InferredType::willStoreValueSlow):
(JSC::InferredType::makeTopSlow):
(JSC::InferredType::set):
(JSC::InferredType::removeStructure):
* runtime/InferredType.h:
* runtime/InferredTypeTable.cpp:
(JSC::InferredTypeTable::visitChildren):
(JSC::InferredTypeTable::get):
(JSC::InferredTypeTable::willStoreValue):
(JSC::InferredTypeTable::makeTop):
* runtime/InferredTypeTable.h:
* runtime/JSEnvironmentRecord.cpp:
(JSC::JSEnvironmentRecord::heapSnapshot):
* runtime/JSGlobalObject.cpp:
(JSC::JSGlobalObject::addGlobalVar):
(JSC::JSGlobalObject::addStaticGlobals):
* runtime/JSLexicalEnvironment.cpp:
(JSC::JSLexicalEnvironment::getOwnNonIndexPropertyNames):
* runtime/JSObject.cpp:
(JSC::JSObject::deleteProperty):
(JSC::JSObject::shiftButterflyAfterFlattening):
* runtime/JSObject.h:
* runtime/JSObjectInlines.h:
(JSC::JSObject::putDirectWithoutTransition):
(JSC::JSObject::putDirectInternal):
* runtime/JSScope.cpp:
(JSC::abstractAccess):
(JSC::JSScope::collectClosureVariablesUnderTDZ):
* runtime/JSSegmentedVariableObject.cpp:
(JSC::JSSegmentedVariableObject::findVariableIndex):
(JSC::JSSegmentedVariableObject::addVariables):
(JSC::JSSegmentedVariableObject::heapSnapshot):
* runtime/JSSegmentedVariableObject.h:
* runtime/JSSymbolTableObject.cpp:
(JSC::JSSymbolTableObject::getOwnNonIndexPropertyNames):
* runtime/JSSymbolTableObject.h:
(JSC::symbolTableGet):
(JSC::symbolTablePut):
* runtime/Options.cpp:
(JSC::recomputeDependentOptions):
* runtime/Options.h:
* runtime/ProgramExecutable.cpp:
(JSC::ProgramExecutable::initializeGlobalProperties):
* runtime/RegExp.cpp:
(JSC::RegExp::compile):
(JSC::RegExp::matchConcurrently):
(JSC::RegExp::compileMatchOnly):
(JSC::RegExp::deleteCode):
* runtime/RegExp.h:
* runtime/Structure.cpp:
(JSC::Structure::materializePropertyTable):
(JSC::Structure::addPropertyTransitionToExistingStructureConcurrently):
(JSC::Structure::addNewPropertyTransition):
(JSC::Structure::takePropertyTableOrCloneIfPinned):
(JSC::Structure::nonPropertyTransition):
(JSC::Structure::flattenDictionaryStructure):
(JSC::Structure::ensurePropertyReplacementWatchpointSet):
(JSC::Structure::add):
(JSC::Structure::remove):
(JSC::Structure::visitChildren):
* runtime/Structure.h:
* runtime/StructureInlines.h:
(JSC::Structure::propertyReplacementWatchpointSet):
(JSC::Structure::add):
(JSC::Structure::remove):
* runtime/SymbolTable.cpp:
(JSC::SymbolTable::visitChildren):
(JSC::SymbolTable::localToEntry):
(JSC::SymbolTable::entryFor):
(JSC::SymbolTable::prepareForTypeProfiling):
(JSC::SymbolTable::uniqueIDForVariable):
(JSC::SymbolTable::uniqueIDForOffset):
(JSC::SymbolTable::globalTypeSetForOffset):
(JSC::SymbolTable::globalTypeSetForVariable):
* runtime/SymbolTable.h:
* runtime/TypeSet.cpp:
(JSC::TypeSet::addTypeInformation):
(JSC::TypeSet::invalidateCache):
* runtime/TypeSet.h:
(JSC::TypeSet::structureSet):
* runtime/VM.h:
* runtime/WriteBarrierInlines.h:
(JSC::WriteBarrierBase<T>::set):
(JSC::WriteBarrierBase<Unknown>::set):
* yarr/YarrInterpreter.cpp:
(JSC::Yarr::ByteCompiler::compile):
(JSC::Yarr::byteCompile):
* yarr/YarrInterpreter.h:
(JSC::Yarr::BytecodePattern::BytecodePattern):

Source/WTF:

Both the concurrent GC and the concurrent JIT rely on concurrency support in fundamental
JSC runtime components like JSValue. So, the thing that guards it should be a "feature"
called CONCURRENT_JS not CONCURRENT_JIT.

* wtf/Platform.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@208761 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index 77c1d86..a50a2ba 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,246 @@
+2016-11-15  Filip Pizlo  <fpizlo@apple.com>
+
+        Rename CONCURRENT_JIT/ConcurrentJIT to CONCURRENT_JS/ConcurrentJS
+        https://bugs.webkit.org/show_bug.cgi?id=164791
+
+        Reviewed by Geoffrey Garen.
+        
+        Just renaming.
+
+        * JavaScriptCore.xcodeproj/project.pbxproj:
+        * bytecode/ArrayProfile.cpp:
+        (JSC::ArrayProfile::computeUpdatedPrediction):
+        (JSC::ArrayProfile::briefDescription):
+        (JSC::ArrayProfile::briefDescriptionWithoutUpdating):
+        * bytecode/ArrayProfile.h:
+        (JSC::ArrayProfile::observedArrayModes):
+        (JSC::ArrayProfile::mayInterceptIndexedAccesses):
+        (JSC::ArrayProfile::mayStoreToHole):
+        (JSC::ArrayProfile::outOfBounds):
+        (JSC::ArrayProfile::usesOriginalArrayStructures):
+        * bytecode/CallLinkStatus.cpp:
+        (JSC::CallLinkStatus::computeFromLLInt):
+        (JSC::CallLinkStatus::computeFor):
+        (JSC::CallLinkStatus::computeExitSiteData):
+        (JSC::CallLinkStatus::computeFromCallLinkInfo):
+        (JSC::CallLinkStatus::computeDFGStatuses):
+        * bytecode/CallLinkStatus.h:
+        * bytecode/CodeBlock.cpp:
+        (JSC::CodeBlock::dumpValueProfiling):
+        (JSC::CodeBlock::dumpArrayProfiling):
+        (JSC::CodeBlock::finishCreation):
+        (JSC::CodeBlock::setConstantRegisters):
+        (JSC::CodeBlock::getStubInfoMap):
+        (JSC::CodeBlock::getCallLinkInfoMap):
+        (JSC::CodeBlock::getByValInfoMap):
+        (JSC::CodeBlock::addStubInfo):
+        (JSC::CodeBlock::addByValInfo):
+        (JSC::CodeBlock::addCallLinkInfo):
+        (JSC::CodeBlock::resetJITData):
+        (JSC::CodeBlock::shrinkToFit):
+        (JSC::CodeBlock::getArrayProfile):
+        (JSC::CodeBlock::addArrayProfile):
+        (JSC::CodeBlock::getOrAddArrayProfile):
+        (JSC::CodeBlock::updateAllPredictionsAndCountLiveness):
+        (JSC::CodeBlock::updateAllArrayPredictions):
+        (JSC::CodeBlock::nameForRegister):
+        (JSC::CodeBlock::livenessAnalysisSlow):
+        * bytecode/CodeBlock.h:
+        (JSC::CodeBlock::setJITCode):
+        (JSC::CodeBlock::valueProfilePredictionForBytecodeOffset):
+        (JSC::CodeBlock::addFrequentExitSite):
+        (JSC::CodeBlock::hasExitSite):
+        (JSC::CodeBlock::livenessAnalysis):
+        * bytecode/DFGExitProfile.cpp:
+        (JSC::DFG::ExitProfile::add):
+        (JSC::DFG::ExitProfile::hasExitSite):
+        (JSC::DFG::QueryableExitProfile::initialize):
+        * bytecode/DFGExitProfile.h:
+        (JSC::DFG::ExitProfile::hasExitSite):
+        * bytecode/GetByIdStatus.cpp:
+        (JSC::GetByIdStatus::hasExitSite):
+        (JSC::GetByIdStatus::computeFor):
+        (JSC::GetByIdStatus::computeForStubInfo):
+        (JSC::GetByIdStatus::computeForStubInfoWithoutExitSiteFeedback):
+        * bytecode/GetByIdStatus.h:
+        * bytecode/LazyOperandValueProfile.cpp:
+        (JSC::CompressedLazyOperandValueProfileHolder::computeUpdatedPredictions):
+        (JSC::CompressedLazyOperandValueProfileHolder::add):
+        (JSC::LazyOperandValueProfileParser::initialize):
+        (JSC::LazyOperandValueProfileParser::prediction):
+        * bytecode/LazyOperandValueProfile.h:
+        * bytecode/MethodOfGettingAValueProfile.cpp:
+        (JSC::MethodOfGettingAValueProfile::emitReportValue):
+        * bytecode/PutByIdStatus.cpp:
+        (JSC::PutByIdStatus::hasExitSite):
+        (JSC::PutByIdStatus::computeFor):
+        (JSC::PutByIdStatus::computeForStubInfo):
+        * bytecode/PutByIdStatus.h:
+        * bytecode/StructureStubClearingWatchpoint.cpp:
+        (JSC::StructureStubClearingWatchpoint::fireInternal):
+        * bytecode/ValueProfile.h:
+        (JSC::ValueProfileBase::briefDescription):
+        (JSC::ValueProfileBase::computeUpdatedPrediction):
+        * dfg/DFGArrayMode.cpp:
+        (JSC::DFG::ArrayMode::fromObserved):
+        * dfg/DFGArrayMode.h:
+        (JSC::DFG::ArrayMode::withSpeculationFromProfile):
+        (JSC::DFG::ArrayMode::withProfile):
+        * dfg/DFGByteCodeParser.cpp:
+        (JSC::DFG::ByteCodeParser::injectLazyOperandSpeculation):
+        (JSC::DFG::ByteCodeParser::getPredictionWithoutOSRExit):
+        (JSC::DFG::ByteCodeParser::getArrayMode):
+        (JSC::DFG::ByteCodeParser::handleInlining):
+        (JSC::DFG::ByteCodeParser::parseBlock):
+        (JSC::DFG::ByteCodeParser::InlineStackEntry::InlineStackEntry):
+        * dfg/DFGDriver.cpp:
+        (JSC::DFG::compileImpl):
+        * dfg/DFGFixupPhase.cpp:
+        (JSC::DFG::FixupPhase::fixupNode):
+        (JSC::DFG::FixupPhase::attemptToMakeGetArrayLength):
+        * dfg/DFGGraph.cpp:
+        (JSC::DFG::Graph::tryGetConstantClosureVar):
+        * dfg/DFGObjectAllocationSinkingPhase.cpp:
+        * dfg/DFGPredictionInjectionPhase.cpp:
+        (JSC::DFG::PredictionInjectionPhase::run):
+        * ftl/FTLLowerDFGToB3.cpp:
+        (JSC::FTL::DFG::LowerDFGToB3::compileMaterializeCreateActivation):
+        * ftl/FTLOperations.cpp:
+        (JSC::FTL::operationMaterializeObjectInOSR):
+        * heap/Heap.cpp:
+        (JSC::Heap::addToRememberedSet):
+        * jit/JIT.cpp:
+        (JSC::JIT::compileWithoutLinking):
+        * jit/JITInlines.h:
+        (JSC::JIT::chooseArrayMode):
+        * jit/JITOperations.cpp:
+        (JSC::tryGetByValOptimize):
+        * jit/JITPropertyAccess.cpp:
+        (JSC::JIT::privateCompileGetByValWithCachedId):
+        (JSC::JIT::privateCompilePutByValWithCachedId):
+        * jit/JITWorklist.cpp:
+        (JSC::JITWorklist::compileLater):
+        (JSC::JITWorklist::compileNow):
+        * jit/Repatch.cpp:
+        (JSC::repatchGetByID):
+        (JSC::repatchPutByID):
+        * llint/LLIntSlowPaths.cpp:
+        (JSC::LLInt::setupGetByIdPrototypeCache):
+        (JSC::LLInt::LLINT_SLOW_PATH_DECL):
+        (JSC::LLInt::setUpCall):
+        * profiler/ProfilerBytecodeSequence.cpp:
+        (JSC::Profiler::BytecodeSequence::BytecodeSequence):
+        * runtime/CommonSlowPaths.cpp:
+        (JSC::SLOW_PATH_DECL):
+        * runtime/CommonSlowPaths.h:
+        (JSC::CommonSlowPaths::tryCachePutToScopeGlobal):
+        (JSC::CommonSlowPaths::tryCacheGetFromScopeGlobal):
+        * runtime/ConcurrentJITLock.h: Removed.
+        * runtime/ConcurrentJSLock.h: Copied from Source/JavaScriptCore/runtime/ConcurrentJITLock.h.
+        (JSC::ConcurrentJSLockerBase::ConcurrentJSLockerBase):
+        (JSC::ConcurrentJSLockerBase::~ConcurrentJSLockerBase):
+        (JSC::GCSafeConcurrentJSLocker::GCSafeConcurrentJSLocker):
+        (JSC::GCSafeConcurrentJSLocker::~GCSafeConcurrentJSLocker):
+        (JSC::ConcurrentJSLocker::ConcurrentJSLocker):
+        (JSC::ConcurrentJITLockerBase::ConcurrentJITLockerBase): Deleted.
+        (JSC::ConcurrentJITLockerBase::~ConcurrentJITLockerBase): Deleted.
+        (JSC::ConcurrentJITLockerBase::unlockEarly): Deleted.
+        (JSC::GCSafeConcurrentJITLocker::GCSafeConcurrentJITLocker): Deleted.
+        (JSC::GCSafeConcurrentJITLocker::~GCSafeConcurrentJITLocker): Deleted.
+        (JSC::ConcurrentJITLocker::ConcurrentJITLocker): Deleted.
+        * runtime/InferredType.cpp:
+        (JSC::InferredType::canWatch):
+        (JSC::InferredType::addWatchpoint):
+        (JSC::InferredType::willStoreValueSlow):
+        (JSC::InferredType::makeTopSlow):
+        (JSC::InferredType::set):
+        (JSC::InferredType::removeStructure):
+        * runtime/InferredType.h:
+        * runtime/InferredTypeTable.cpp:
+        (JSC::InferredTypeTable::visitChildren):
+        (JSC::InferredTypeTable::get):
+        (JSC::InferredTypeTable::willStoreValue):
+        (JSC::InferredTypeTable::makeTop):
+        * runtime/InferredTypeTable.h:
+        * runtime/JSEnvironmentRecord.cpp:
+        (JSC::JSEnvironmentRecord::heapSnapshot):
+        * runtime/JSGlobalObject.cpp:
+        (JSC::JSGlobalObject::addGlobalVar):
+        (JSC::JSGlobalObject::addStaticGlobals):
+        * runtime/JSLexicalEnvironment.cpp:
+        (JSC::JSLexicalEnvironment::getOwnNonIndexPropertyNames):
+        * runtime/JSObject.cpp:
+        (JSC::JSObject::deleteProperty):
+        (JSC::JSObject::shiftButterflyAfterFlattening):
+        * runtime/JSObject.h:
+        * runtime/JSObjectInlines.h:
+        (JSC::JSObject::putDirectWithoutTransition):
+        (JSC::JSObject::putDirectInternal):
+        * runtime/JSScope.cpp:
+        (JSC::abstractAccess):
+        (JSC::JSScope::collectClosureVariablesUnderTDZ):
+        * runtime/JSSegmentedVariableObject.cpp:
+        (JSC::JSSegmentedVariableObject::findVariableIndex):
+        (JSC::JSSegmentedVariableObject::addVariables):
+        (JSC::JSSegmentedVariableObject::heapSnapshot):
+        * runtime/JSSegmentedVariableObject.h:
+        * runtime/JSSymbolTableObject.cpp:
+        (JSC::JSSymbolTableObject::getOwnNonIndexPropertyNames):
+        * runtime/JSSymbolTableObject.h:
+        (JSC::symbolTableGet):
+        (JSC::symbolTablePut):
+        * runtime/Options.cpp:
+        (JSC::recomputeDependentOptions):
+        * runtime/Options.h:
+        * runtime/ProgramExecutable.cpp:
+        (JSC::ProgramExecutable::initializeGlobalProperties):
+        * runtime/RegExp.cpp:
+        (JSC::RegExp::compile):
+        (JSC::RegExp::matchConcurrently):
+        (JSC::RegExp::compileMatchOnly):
+        (JSC::RegExp::deleteCode):
+        * runtime/RegExp.h:
+        * runtime/Structure.cpp:
+        (JSC::Structure::materializePropertyTable):
+        (JSC::Structure::addPropertyTransitionToExistingStructureConcurrently):
+        (JSC::Structure::addNewPropertyTransition):
+        (JSC::Structure::takePropertyTableOrCloneIfPinned):
+        (JSC::Structure::nonPropertyTransition):
+        (JSC::Structure::flattenDictionaryStructure):
+        (JSC::Structure::ensurePropertyReplacementWatchpointSet):
+        (JSC::Structure::add):
+        (JSC::Structure::remove):
+        (JSC::Structure::visitChildren):
+        * runtime/Structure.h:
+        * runtime/StructureInlines.h:
+        (JSC::Structure::propertyReplacementWatchpointSet):
+        (JSC::Structure::add):
+        (JSC::Structure::remove):
+        * runtime/SymbolTable.cpp:
+        (JSC::SymbolTable::visitChildren):
+        (JSC::SymbolTable::localToEntry):
+        (JSC::SymbolTable::entryFor):
+        (JSC::SymbolTable::prepareForTypeProfiling):
+        (JSC::SymbolTable::uniqueIDForVariable):
+        (JSC::SymbolTable::uniqueIDForOffset):
+        (JSC::SymbolTable::globalTypeSetForOffset):
+        (JSC::SymbolTable::globalTypeSetForVariable):
+        * runtime/SymbolTable.h:
+        * runtime/TypeSet.cpp:
+        (JSC::TypeSet::addTypeInformation):
+        (JSC::TypeSet::invalidateCache):
+        * runtime/TypeSet.h:
+        (JSC::TypeSet::structureSet):
+        * runtime/VM.h:
+        * runtime/WriteBarrierInlines.h:
+        (JSC::WriteBarrierBase<T>::set):
+        (JSC::WriteBarrierBase<Unknown>::set):
+        * yarr/YarrInterpreter.cpp:
+        (JSC::Yarr::ByteCompiler::compile):
+        (JSC::Yarr::byteCompile):
+        * yarr/YarrInterpreter.h:
+        (JSC::Yarr::BytecodePattern::BytecodePattern):
+
 2016-11-15  Joseph Pecoraro  <pecoraro@apple.com>
 
         Web Inspector: Remove unused and untested Page.setTouchEmulationEnabled command
diff --git a/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj b/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
index cb8339e..8308c7d 100644
--- a/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
+++ b/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
@@ -743,7 +743,7 @@
 		0FDB2CCA173DA523007B3C1B /* FTLValueFromBlock.h in Headers */ = {isa = PBXBuildFile; fileRef = 0FDB2CC8173DA51E007B3C1B /* FTLValueFromBlock.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		0FDB2CE7174830A2007B3C1B /* DFGWorklist.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0FDB2CE5174830A2007B3C1B /* DFGWorklist.cpp */; };
 		0FDB2CE8174830A2007B3C1B /* DFGWorklist.h in Headers */ = {isa = PBXBuildFile; fileRef = 0FDB2CE6174830A2007B3C1B /* DFGWorklist.h */; };
-		0FDB2CEA174896C7007B3C1B /* ConcurrentJITLock.h in Headers */ = {isa = PBXBuildFile; fileRef = 0FDB2CE9174896C7007B3C1B /* ConcurrentJITLock.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		0FDB2CEA174896C7007B3C1B /* ConcurrentJSLock.h in Headers */ = {isa = PBXBuildFile; fileRef = 0FDB2CE9174896C7007B3C1B /* ConcurrentJSLock.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		0FDDBFB51666EED800C55FEF /* DFGVariableAccessDataDump.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0FDDBFB21666EED500C55FEF /* DFGVariableAccessDataDump.cpp */; };
 		0FDDBFB61666EEDA00C55FEF /* DFGVariableAccessDataDump.h in Headers */ = {isa = PBXBuildFile; fileRef = 0FDDBFB31666EED500C55FEF /* DFGVariableAccessDataDump.h */; };
 		0FDF67D21D9C6D27001B9825 /* B3Kind.h in Headers */ = {isa = PBXBuildFile; fileRef = 0FDF67D11D9C6086001B9825 /* B3Kind.h */; };
@@ -3157,7 +3157,7 @@
 		0FDB2CC8173DA51E007B3C1B /* FTLValueFromBlock.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; name = FTLValueFromBlock.h; path = ftl/FTLValueFromBlock.h; sourceTree = "<group>"; };
 		0FDB2CE5174830A2007B3C1B /* DFGWorklist.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = DFGWorklist.cpp; path = dfg/DFGWorklist.cpp; sourceTree = "<group>"; };
 		0FDB2CE6174830A2007B3C1B /* DFGWorklist.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = DFGWorklist.h; path = dfg/DFGWorklist.h; sourceTree = "<group>"; };
-		0FDB2CE9174896C7007B3C1B /* ConcurrentJITLock.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ConcurrentJITLock.h; sourceTree = "<group>"; };
+		0FDB2CE9174896C7007B3C1B /* ConcurrentJSLock.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ConcurrentJSLock.h; sourceTree = "<group>"; };
 		0FDDBFB21666EED500C55FEF /* DFGVariableAccessDataDump.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = DFGVariableAccessDataDump.cpp; path = dfg/DFGVariableAccessDataDump.cpp; sourceTree = "<group>"; };
 		0FDDBFB31666EED500C55FEF /* DFGVariableAccessDataDump.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = DFGVariableAccessDataDump.h; path = dfg/DFGVariableAccessDataDump.h; sourceTree = "<group>"; };
 		0FDF67D01D9C6086001B9825 /* B3Kind.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = B3Kind.cpp; path = b3/B3Kind.cpp; sourceTree = "<group>"; };
@@ -6113,7 +6113,7 @@
 				A7E5A3A61797432D00E893C0 /* CompilationResult.h */,
 				969A09220ED1E09C00F1F681 /* Completion.cpp */,
 				F5BB2BC5030F772101FCFE1D /* Completion.h */,
-				0FDB2CE9174896C7007B3C1B /* ConcurrentJITLock.h */,
+				0FDB2CE9174896C7007B3C1B /* ConcurrentJSLock.h */,
 				A5B6A74C18C6DBA600F11E91 /* ConsoleClient.cpp */,
 				A53CE08918BC21C300BEDF76 /* ConsoleClient.h */,
 				A55714BC1CD8048E0004D2C6 /* ConsoleObject.cpp */,
@@ -7875,7 +7875,7 @@
 				A7E5A3A81797432D00E893C0 /* CompilationResult.h in Headers */,
 				BC18C3F40E16F5CD00B34460 /* Completion.h in Headers */,
 				0F6FC751196110A800E1D02D /* ComplexGetStatus.h in Headers */,
-				0FDB2CEA174896C7007B3C1B /* ConcurrentJITLock.h in Headers */,
+				0FDB2CEA174896C7007B3C1B /* ConcurrentJSLock.h in Headers */,
 				BC18C3F50E16F5CD00B34460 /* config.h in Headers */,
 				144836E7132DA7BE005BE785 /* ConservativeRoots.h in Headers */,
 				A53CE08A18BC21C300BEDF76 /* ConsoleClient.h in Headers */,
diff --git a/Source/JavaScriptCore/bytecode/ArrayProfile.cpp b/Source/JavaScriptCore/bytecode/ArrayProfile.cpp
index b8ade22..3146b18 100644
--- a/Source/JavaScriptCore/bytecode/ArrayProfile.cpp
+++ b/Source/JavaScriptCore/bytecode/ArrayProfile.cpp
@@ -94,7 +94,7 @@
         out.print(comma, "Float64ArrayMode");
 }
 
-void ArrayProfile::computeUpdatedPrediction(const ConcurrentJITLocker& locker, CodeBlock* codeBlock)
+void ArrayProfile::computeUpdatedPrediction(const ConcurrentJSLocker& locker, CodeBlock* codeBlock)
 {
     if (!m_lastSeenStructureID)
         return;
@@ -104,7 +104,7 @@
     m_lastSeenStructureID = 0;
 }
 
-void ArrayProfile::computeUpdatedPrediction(const ConcurrentJITLocker&, CodeBlock* codeBlock, Structure* lastSeenStructure)
+void ArrayProfile::computeUpdatedPrediction(const ConcurrentJSLocker&, CodeBlock* codeBlock, Structure* lastSeenStructure)
 {
     m_observedArrayModes |= arrayModeFromStructure(lastSeenStructure);
     
@@ -122,13 +122,13 @@
         m_usesOriginalArrayStructures = false;
 }
 
-CString ArrayProfile::briefDescription(const ConcurrentJITLocker& locker, CodeBlock* codeBlock)
+CString ArrayProfile::briefDescription(const ConcurrentJSLocker& locker, CodeBlock* codeBlock)
 {
     computeUpdatedPrediction(locker, codeBlock);
     return briefDescriptionWithoutUpdating(locker);
 }
 
-CString ArrayProfile::briefDescriptionWithoutUpdating(const ConcurrentJITLocker&)
+CString ArrayProfile::briefDescriptionWithoutUpdating(const ConcurrentJSLocker&)
 {
     StringPrintStream out;
     
diff --git a/Source/JavaScriptCore/bytecode/ArrayProfile.h b/Source/JavaScriptCore/bytecode/ArrayProfile.h
index 2f2ac59..279906d 100644
--- a/Source/JavaScriptCore/bytecode/ArrayProfile.h
+++ b/Source/JavaScriptCore/bytecode/ArrayProfile.h
@@ -25,7 +25,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "JSArray.h"
 #include "Structure.h"
 #include <wtf/SegmentedVector.h>
@@ -216,19 +216,19 @@
         m_lastSeenStructureID = structure->id();
     }
     
-    void computeUpdatedPrediction(const ConcurrentJITLocker&, CodeBlock*);
-    void computeUpdatedPrediction(const ConcurrentJITLocker&, CodeBlock*, Structure* lastSeenStructure);
+    void computeUpdatedPrediction(const ConcurrentJSLocker&, CodeBlock*);
+    void computeUpdatedPrediction(const ConcurrentJSLocker&, CodeBlock*, Structure* lastSeenStructure);
     
-    ArrayModes observedArrayModes(const ConcurrentJITLocker&) const { return m_observedArrayModes; }
-    bool mayInterceptIndexedAccesses(const ConcurrentJITLocker&) const { return m_mayInterceptIndexedAccesses; }
+    ArrayModes observedArrayModes(const ConcurrentJSLocker&) const { return m_observedArrayModes; }
+    bool mayInterceptIndexedAccesses(const ConcurrentJSLocker&) const { return m_mayInterceptIndexedAccesses; }
     
-    bool mayStoreToHole(const ConcurrentJITLocker&) const { return m_mayStoreToHole; }
-    bool outOfBounds(const ConcurrentJITLocker&) const { return m_outOfBounds; }
+    bool mayStoreToHole(const ConcurrentJSLocker&) const { return m_mayStoreToHole; }
+    bool outOfBounds(const ConcurrentJSLocker&) const { return m_outOfBounds; }
     
-    bool usesOriginalArrayStructures(const ConcurrentJITLocker&) const { return m_usesOriginalArrayStructures; }
+    bool usesOriginalArrayStructures(const ConcurrentJSLocker&) const { return m_usesOriginalArrayStructures; }
     
-    CString briefDescription(const ConcurrentJITLocker&, CodeBlock*);
-    CString briefDescriptionWithoutUpdating(const ConcurrentJITLocker&);
+    CString briefDescription(const ConcurrentJSLocker&, CodeBlock*);
+    CString briefDescriptionWithoutUpdating(const ConcurrentJSLocker&);
     
 private:
     friend class LLIntOffsetsExtractor;
diff --git a/Source/JavaScriptCore/bytecode/CallLinkStatus.cpp b/Source/JavaScriptCore/bytecode/CallLinkStatus.cpp
index faaf711..cbc555d 100644
--- a/Source/JavaScriptCore/bytecode/CallLinkStatus.cpp
+++ b/Source/JavaScriptCore/bytecode/CallLinkStatus.cpp
@@ -52,7 +52,7 @@
     m_variants.append(CallVariant(value.asCell()));
 }
 
-CallLinkStatus CallLinkStatus::computeFromLLInt(const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
+CallLinkStatus CallLinkStatus::computeFromLLInt(const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
 {
     UNUSED_PARAM(profiledBlock);
     UNUSED_PARAM(bytecodeIndex);
@@ -81,7 +81,7 @@
 CallLinkStatus CallLinkStatus::computeFor(
     CodeBlock* profiledBlock, unsigned bytecodeIndex, const CallLinkInfoMap& map)
 {
-    ConcurrentJITLocker locker(profiledBlock->m_lock);
+    ConcurrentJSLocker locker(profiledBlock->m_lock);
     
     UNUSED_PARAM(profiledBlock);
     UNUSED_PARAM(bytecodeIndex);
@@ -103,7 +103,7 @@
 }
 
 CallLinkStatus::ExitSiteData CallLinkStatus::computeExitSiteData(
-    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
+    const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
 {
     ExitSiteData exitSiteData;
     
@@ -124,7 +124,7 @@
 
 #if ENABLE(JIT)
 CallLinkStatus CallLinkStatus::computeFor(
-    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, CallLinkInfo& callLinkInfo)
+    const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, CallLinkInfo& callLinkInfo)
 {
     // We don't really need this, but anytime we have to debug this code, it becomes indispensable.
     UNUSED_PARAM(profiledBlock);
@@ -135,7 +135,7 @@
 }
 
 CallLinkStatus CallLinkStatus::computeFromCallLinkInfo(
-    const ConcurrentJITLocker&, CallLinkInfo& callLinkInfo)
+    const ConcurrentJSLocker&, CallLinkInfo& callLinkInfo)
 {
     if (callLinkInfo.clearedByGC())
         return takesSlowPath();
@@ -228,7 +228,7 @@
 }
 
 CallLinkStatus CallLinkStatus::computeFor(
-    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, CallLinkInfo& callLinkInfo,
+    const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, CallLinkInfo& callLinkInfo,
     ExitSiteData exitSiteData)
 {
     CallLinkStatus result = computeFor(locker, profiledBlock, callLinkInfo);
@@ -277,13 +277,13 @@
             baselineCodeBlockForOriginAndBaselineCodeBlock(codeOrigin, baselineCodeBlock);
         ExitSiteData exitSiteData;
         {
-            ConcurrentJITLocker locker(currentBaseline->m_lock);
+            ConcurrentJSLocker locker(currentBaseline->m_lock);
             exitSiteData = computeExitSiteData(
                 locker, currentBaseline, codeOrigin.bytecodeIndex);
         }
         
         {
-            ConcurrentJITLocker locker(dfgCodeBlock->m_lock);
+            ConcurrentJSLocker locker(dfgCodeBlock->m_lock);
             map.add(info.codeOrigin(), computeFor(locker, dfgCodeBlock, info, exitSiteData));
         }
     }
diff --git a/Source/JavaScriptCore/bytecode/CallLinkStatus.h b/Source/JavaScriptCore/bytecode/CallLinkStatus.h
index fe471594..353deaa 100644
--- a/Source/JavaScriptCore/bytecode/CallLinkStatus.h
+++ b/Source/JavaScriptCore/bytecode/CallLinkStatus.h
@@ -29,7 +29,7 @@
 #include "CallVariant.h"
 #include "CodeOrigin.h"
 #include "CodeSpecializationKind.h"
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "ExitingJITType.h"
 #include "Intrinsic.h"
 #include "JSCJSValue.h"
@@ -70,14 +70,14 @@
         bool takesSlowPath { false };
         bool badFunction { false };
     };
-    static ExitSiteData computeExitSiteData(const ConcurrentJITLocker&, CodeBlock*, unsigned bytecodeIndex);
+    static ExitSiteData computeExitSiteData(const ConcurrentJSLocker&, CodeBlock*, unsigned bytecodeIndex);
     
 #if ENABLE(JIT)
     // Computes the status assuming that we never took slow path and never previously
     // exited.
-    static CallLinkStatus computeFor(const ConcurrentJITLocker&, CodeBlock*, CallLinkInfo&);
+    static CallLinkStatus computeFor(const ConcurrentJSLocker&, CodeBlock*, CallLinkInfo&);
     static CallLinkStatus computeFor(
-        const ConcurrentJITLocker&, CodeBlock*, CallLinkInfo&, ExitSiteData);
+        const ConcurrentJSLocker&, CodeBlock*, CallLinkInfo&, ExitSiteData);
 #endif
     
     typedef HashMap<CodeOrigin, CallLinkStatus, CodeOriginApproximateHash> ContextMap;
@@ -118,10 +118,10 @@
 private:
     void makeClosureCall();
     
-    static CallLinkStatus computeFromLLInt(const ConcurrentJITLocker&, CodeBlock*, unsigned bytecodeIndex);
+    static CallLinkStatus computeFromLLInt(const ConcurrentJSLocker&, CodeBlock*, unsigned bytecodeIndex);
 #if ENABLE(JIT)
     static CallLinkStatus computeFromCallLinkInfo(
-        const ConcurrentJITLocker&, CallLinkInfo&);
+        const ConcurrentJSLocker&, CallLinkInfo&);
 #endif
     
     CallVariantList m_variants;
diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.cpp b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
index 30ab028..fbd8549 100644
--- a/Source/JavaScriptCore/bytecode/CodeBlock.cpp
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
@@ -679,7 +679,7 @@
 
 void CodeBlock::dumpValueProfiling(PrintStream& out, const Instruction*& it, bool& hasPrintedProfiling)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     ++it;
     CString description = it->u.profile->briefDescription(locker);
@@ -691,7 +691,7 @@
 
 void CodeBlock::dumpArrayProfiling(PrintStream& out, const Instruction*& it, bool& hasPrintedProfiling)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     ++it;
     if (!it->u.arrayProfile)
@@ -1964,7 +1964,7 @@
     if (UnlinkedModuleProgramCodeBlock* unlinkedModuleProgramCodeBlock = jsDynamicCast<UnlinkedModuleProgramCodeBlock*>(unlinkedCodeBlock)) {
         SymbolTable* clonedSymbolTable = jsCast<ModuleProgramExecutable*>(ownerExecutable)->moduleEnvironmentSymbolTable();
         if (m_vm->typeProfiler()) {
-            ConcurrentJITLocker locker(clonedSymbolTable->m_lock);
+            ConcurrentJSLocker locker(clonedSymbolTable->m_lock);
             clonedSymbolTable->prepareForTypeProfiling(locker);
         }
         replaceConstant(unlinkedModuleProgramCodeBlock->moduleEnvironmentSymbolTableConstantRegisterOffset(), clonedSymbolTable);
@@ -2219,7 +2219,7 @@
                     int symbolTableIndex = pc[5].u.operand;
                     SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
                     const Identifier& ident = identifier(pc[2].u.operand);
-                    ConcurrentJITLocker locker(symbolTable->m_lock);
+                    ConcurrentJSLocker locker(symbolTable->m_lock);
                     auto iter = symbolTable->find(locker, ident.impl());
                     ASSERT(iter != symbolTable->end(locker));
                     iter->value.prepareToWatch();
@@ -2275,7 +2275,7 @@
 
                 UniquedStringImpl* impl = (op.type == ModuleVar) ? op.importedName.get() : ident.impl();
                 if (symbolTable) {
-                    ConcurrentJITLocker locker(symbolTable->m_lock);
+                    ConcurrentJSLocker locker(symbolTable->m_lock);
                     // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
                     symbolTable->prepareForTypeProfiling(locker);
                     globalVariableID = symbolTable->uniqueIDForVariable(locker, impl, vm);
@@ -2289,7 +2289,7 @@
                 int symbolTableIndex = pc[2].u.operand;
                 SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
                 const Identifier& ident = identifier(pc[4].u.operand);
-                ConcurrentJITLocker locker(symbolTable->m_lock);
+                ConcurrentJSLocker locker(symbolTable->m_lock);
                 // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
                 globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), vm);
                 globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), vm);
@@ -2457,7 +2457,7 @@
         if (!constant.isEmpty()) {
             if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(constant)) {
                 if (hasTypeProfiler) {
-                    ConcurrentJITLocker locker(symbolTable->m_lock);
+                    ConcurrentJSLocker locker(symbolTable->m_lock);
                     symbolTable->prepareForTypeProfiling(locker);
                 }
 
@@ -2973,7 +2973,7 @@
 #endif
 }
 
-void CodeBlock::getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result)
+void CodeBlock::getStubInfoMap(const ConcurrentJSLocker&, StubInfoMap& result)
 {
 #if ENABLE(JIT)
     if (JITCode::isJIT(jitType()))
@@ -2985,11 +2985,11 @@
 
 void CodeBlock::getStubInfoMap(StubInfoMap& result)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     getStubInfoMap(locker, result);
 }
 
-void CodeBlock::getCallLinkInfoMap(const ConcurrentJITLocker&, CallLinkInfoMap& result)
+void CodeBlock::getCallLinkInfoMap(const ConcurrentJSLocker&, CallLinkInfoMap& result)
 {
 #if ENABLE(JIT)
     if (JITCode::isJIT(jitType()))
@@ -3001,11 +3001,11 @@
 
 void CodeBlock::getCallLinkInfoMap(CallLinkInfoMap& result)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     getCallLinkInfoMap(locker, result);
 }
 
-void CodeBlock::getByValInfoMap(const ConcurrentJITLocker&, ByValInfoMap& result)
+void CodeBlock::getByValInfoMap(const ConcurrentJSLocker&, ByValInfoMap& result)
 {
 #if ENABLE(JIT)
     if (JITCode::isJIT(jitType())) {
@@ -3019,14 +3019,14 @@
 
 void CodeBlock::getByValInfoMap(ByValInfoMap& result)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     getByValInfoMap(locker, result);
 }
 
 #if ENABLE(JIT)
 StructureStubInfo* CodeBlock::addStubInfo(AccessType accessType)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return m_stubInfos.add(accessType);
 }
 
@@ -3061,13 +3061,13 @@
 
 ByValInfo* CodeBlock::addByValInfo()
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return m_byValInfos.add();
 }
 
 CallLinkInfo* CodeBlock::addCallLinkInfo()
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return m_callLinkInfos.add();
 }
 
@@ -3083,7 +3083,7 @@
 void CodeBlock::resetJITData()
 {
     RELEASE_ASSERT(!JITCode::isJIT(jitType()));
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     // We can clear these because no other thread will have references to any stub infos, call
     // link infos, or by val infos if we don't have JIT code. Attempts to query these data
@@ -3313,7 +3313,7 @@
 
 void CodeBlock::shrinkToFit(ShrinkMode shrinkMode)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
 
     m_rareCaseProfiles.shrinkToFit();
     
@@ -3975,7 +3975,7 @@
 }
 #endif
 
-ArrayProfile* CodeBlock::getArrayProfile(const ConcurrentJITLocker&, unsigned bytecodeOffset)
+ArrayProfile* CodeBlock::getArrayProfile(const ConcurrentJSLocker&, unsigned bytecodeOffset)
 {
     for (unsigned i = 0; i < m_arrayProfiles.size(); ++i) {
         if (m_arrayProfiles[i].bytecodeOffset() == bytecodeOffset)
@@ -3986,11 +3986,11 @@
 
 ArrayProfile* CodeBlock::getArrayProfile(unsigned bytecodeOffset)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return getArrayProfile(locker, bytecodeOffset);
 }
 
-ArrayProfile* CodeBlock::addArrayProfile(const ConcurrentJITLocker&, unsigned bytecodeOffset)
+ArrayProfile* CodeBlock::addArrayProfile(const ConcurrentJSLocker&, unsigned bytecodeOffset)
 {
     m_arrayProfiles.append(ArrayProfile(bytecodeOffset));
     return &m_arrayProfiles.last();
@@ -3998,11 +3998,11 @@
 
 ArrayProfile* CodeBlock::addArrayProfile(unsigned bytecodeOffset)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return addArrayProfile(locker, bytecodeOffset);
 }
 
-ArrayProfile* CodeBlock::getOrAddArrayProfile(const ConcurrentJITLocker& locker, unsigned bytecodeOffset)
+ArrayProfile* CodeBlock::getOrAddArrayProfile(const ConcurrentJSLocker& locker, unsigned bytecodeOffset)
 {
     ArrayProfile* result = getArrayProfile(locker, bytecodeOffset);
     if (result)
@@ -4012,7 +4012,7 @@
 
 ArrayProfile* CodeBlock::getOrAddArrayProfile(unsigned bytecodeOffset)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return getOrAddArrayProfile(locker, bytecodeOffset);
 }
 
@@ -4042,7 +4042,7 @@
 
 void CodeBlock::updateAllPredictionsAndCountLiveness(unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     numberOfLiveNonArgumentValueProfiles = 0;
     numberOfSamplesInProfiles = 0; // If this divided by ValueProfile::numberOfBuckets equals numberOfValueProfiles() then value profiles are full.
@@ -4074,7 +4074,7 @@
 
 void CodeBlock::updateAllArrayPredictions()
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     for (unsigned i = m_arrayProfiles.size(); i--;)
         m_arrayProfiles[i].computeUpdatedPrediction(locker, this);
@@ -4284,7 +4284,7 @@
         if (m_constantRegisters[i].get().isEmpty())
             continue;
         if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(m_constantRegisters[i].get())) {
-            ConcurrentJITLocker locker(symbolTable->m_lock);
+            ConcurrentJSLocker locker(symbolTable->m_lock);
             auto end = symbolTable->end(locker);
             for (auto ptr = symbolTable->begin(locker); ptr != end; ++ptr) {
                 if (ptr->value.varOffset() == VarOffset(virtualRegister)) {
@@ -4636,7 +4636,7 @@
 {
     std::unique_ptr<BytecodeLivenessAnalysis> analysis = std::make_unique<BytecodeLivenessAnalysis>(this);
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         if (!m_livenessAnalysis)
             m_livenessAnalysis = WTFMove(analysis);
         return *m_livenessAnalysis;
diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.h b/Source/JavaScriptCore/bytecode/CodeBlock.h
index c180f56..819834b 100644
--- a/Source/JavaScriptCore/bytecode/CodeBlock.h
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.h
@@ -38,7 +38,7 @@
 #include "CodeOrigin.h"
 #include "CodeType.h"
 #include "CompactJITCodeMap.h"
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "DFGCommon.h"
 #include "DFGExitProfile.h"
 #include "DeferredCompilationCallback.h"
@@ -235,13 +235,13 @@
 
     Optional<unsigned> bytecodeOffsetFromCallSiteIndex(CallSiteIndex);
 
-    void getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result);
+    void getStubInfoMap(const ConcurrentJSLocker&, StubInfoMap& result);
     void getStubInfoMap(StubInfoMap& result);
     
-    void getCallLinkInfoMap(const ConcurrentJITLocker&, CallLinkInfoMap& result);
+    void getCallLinkInfoMap(const ConcurrentJSLocker&, CallLinkInfoMap& result);
     void getCallLinkInfoMap(CallLinkInfoMap& result);
 
-    void getByValInfoMap(const ConcurrentJITLocker&, ByValInfoMap& result);
+    void getByValInfoMap(const ConcurrentJSLocker&, ByValInfoMap& result);
     void getByValInfoMap(ByValInfoMap& result);
     
 #if ENABLE(JIT)
@@ -322,7 +322,7 @@
     {
         ASSERT(heap()->isDeferred());
         heap()->reportExtraMemoryAllocated(code->size());
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         WTF::storeStoreFence(); // This is probably not needed because the lock will also do something similar, but it's good to be paranoid.
         m_jitCode = code;
     }
@@ -413,7 +413,7 @@
     unsigned numberOfValueProfiles() { return m_valueProfiles.size(); }
     ValueProfile* valueProfile(int index) { return &m_valueProfiles[index]; }
     ValueProfile* valueProfileForBytecodeOffset(int bytecodeOffset);
-    SpeculatedType valueProfilePredictionForBytecodeOffset(const ConcurrentJITLocker& locker, int bytecodeOffset)
+    SpeculatedType valueProfilePredictionForBytecodeOffset(const ConcurrentJSLocker& locker, int bytecodeOffset)
     {
         if (ValueProfile* valueProfile = valueProfileForBytecodeOffset(bytecodeOffset))
             return valueProfile->computeUpdatedPrediction(locker);
@@ -459,11 +459,11 @@
 
     unsigned numberOfArrayProfiles() const { return m_arrayProfiles.size(); }
     const ArrayProfileVector& arrayProfiles() { return m_arrayProfiles; }
-    ArrayProfile* addArrayProfile(const ConcurrentJITLocker&, unsigned bytecodeOffset);
+    ArrayProfile* addArrayProfile(const ConcurrentJSLocker&, unsigned bytecodeOffset);
     ArrayProfile* addArrayProfile(unsigned bytecodeOffset);
-    ArrayProfile* getArrayProfile(const ConcurrentJITLocker&, unsigned bytecodeOffset);
+    ArrayProfile* getArrayProfile(const ConcurrentJSLocker&, unsigned bytecodeOffset);
     ArrayProfile* getArrayProfile(unsigned bytecodeOffset);
-    ArrayProfile* getOrAddArrayProfile(const ConcurrentJITLocker&, unsigned bytecodeOffset);
+    ArrayProfile* getOrAddArrayProfile(const ConcurrentJSLocker&, unsigned bytecodeOffset);
     ArrayProfile* getOrAddArrayProfile(unsigned bytecodeOffset);
 
     // Exception handling support
@@ -497,17 +497,17 @@
     bool addFrequentExitSite(const DFG::FrequentExitSite& site)
     {
         ASSERT(JITCode::isBaselineCode(jitType()));
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return m_exitProfile.add(locker, this, site);
     }
 
-    bool hasExitSite(const ConcurrentJITLocker& locker, const DFG::FrequentExitSite& site) const
+    bool hasExitSite(const ConcurrentJSLocker& locker, const DFG::FrequentExitSite& site) const
     {
         return m_exitProfile.hasExitSite(locker, site);
     }
     bool hasExitSite(const DFG::FrequentExitSite& site) const
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return hasExitSite(locker, site);
     }
 
@@ -591,7 +591,7 @@
     BytecodeLivenessAnalysis& livenessAnalysis()
     {
         {
-            ConcurrentJITLocker locker(m_lock);
+            ConcurrentJSLocker locker(m_lock);
             if (!!m_livenessAnalysis)
                 return *m_livenessAnalysis;
         }
@@ -834,7 +834,7 @@
     // Another exception to the rules is that the GC can do whatever it wants
     // without holding any locks, because the GC is guaranteed to wait until any
     // concurrent compilation threads finish what they're doing.
-    mutable ConcurrentJITLock m_lock;
+    mutable ConcurrentJSLock m_lock;
 
     Atomic<bool> m_visitWeaklyHasBeenCalled;
 
diff --git a/Source/JavaScriptCore/bytecode/DFGExitProfile.cpp b/Source/JavaScriptCore/bytecode/DFGExitProfile.cpp
index 67b9852..64fe9a3 100644
--- a/Source/JavaScriptCore/bytecode/DFGExitProfile.cpp
+++ b/Source/JavaScriptCore/bytecode/DFGExitProfile.cpp
@@ -41,7 +41,7 @@
 ExitProfile::ExitProfile() { }
 ExitProfile::~ExitProfile() { }
 
-bool ExitProfile::add(const ConcurrentJITLocker&, CodeBlock* owner, const FrequentExitSite& site)
+bool ExitProfile::add(const ConcurrentJSLocker&, CodeBlock* owner, const FrequentExitSite& site)
 {
     ASSERT(site.jitType() != ExitFromAnything);
 
@@ -85,7 +85,7 @@
     return result;
 }
 
-bool ExitProfile::hasExitSite(const ConcurrentJITLocker&, const FrequentExitSite& site) const
+bool ExitProfile::hasExitSite(const ConcurrentJSLocker&, const FrequentExitSite& site) const
 {
     if (!m_frequentExitSites)
         return false;
@@ -100,7 +100,7 @@
 QueryableExitProfile::QueryableExitProfile() { }
 QueryableExitProfile::~QueryableExitProfile() { }
 
-void QueryableExitProfile::initialize(const ConcurrentJITLocker&, const ExitProfile& profile)
+void QueryableExitProfile::initialize(const ConcurrentJSLocker&, const ExitProfile& profile)
 {
     if (!profile.m_frequentExitSites)
         return;
diff --git a/Source/JavaScriptCore/bytecode/DFGExitProfile.h b/Source/JavaScriptCore/bytecode/DFGExitProfile.h
index 8f37276..337e3ec 100644
--- a/Source/JavaScriptCore/bytecode/DFGExitProfile.h
+++ b/Source/JavaScriptCore/bytecode/DFGExitProfile.h
@@ -27,7 +27,7 @@
 
 #if ENABLE(DFG_JIT)
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "ExitKind.h"
 #include "ExitingJITType.h"
 #include <wtf/HashSet.h>
@@ -160,7 +160,7 @@
     // be called a fixed number of times per recompilation. Recompilation is
     // rare to begin with, and implies doing O(n) operations on the CodeBlock
     // anyway.
-    bool add(const ConcurrentJITLocker&, CodeBlock* owner, const FrequentExitSite&);
+    bool add(const ConcurrentJSLocker&, CodeBlock* owner, const FrequentExitSite&);
     
     // Get the frequent exit sites for a bytecode index. This is O(n), and is
     // meant to only be used from debugging/profiling code.
@@ -170,12 +170,12 @@
     // in the compiler. It should be strictly cheaper than building a
     // QueryableExitProfile, if you really expect this to be called infrequently
     // and you believe that there are few exit sites.
-    bool hasExitSite(const ConcurrentJITLocker&, const FrequentExitSite&) const;
-    bool hasExitSite(const ConcurrentJITLocker& locker, ExitKind kind) const
+    bool hasExitSite(const ConcurrentJSLocker&, const FrequentExitSite&) const;
+    bool hasExitSite(const ConcurrentJSLocker& locker, ExitKind kind) const
     {
         return hasExitSite(locker, FrequentExitSite(kind));
     }
-    bool hasExitSite(const ConcurrentJITLocker& locker, unsigned bytecodeIndex, ExitKind kind) const
+    bool hasExitSite(const ConcurrentJSLocker& locker, unsigned bytecodeIndex, ExitKind kind) const
     {
         return hasExitSite(locker, FrequentExitSite(bytecodeIndex, kind));
     }
@@ -191,7 +191,7 @@
     QueryableExitProfile();
     ~QueryableExitProfile();
     
-    void initialize(const ConcurrentJITLocker&, const ExitProfile&);
+    void initialize(const ConcurrentJSLocker&, const ExitProfile&);
 
     bool hasExitSite(const FrequentExitSite& site) const
     {
diff --git a/Source/JavaScriptCore/bytecode/GetByIdStatus.cpp b/Source/JavaScriptCore/bytecode/GetByIdStatus.cpp
index 18c1c7e..a6c458c 100644
--- a/Source/JavaScriptCore/bytecode/GetByIdStatus.cpp
+++ b/Source/JavaScriptCore/bytecode/GetByIdStatus.cpp
@@ -62,7 +62,7 @@
 }
 
 #if ENABLE(DFG_JIT)
-bool GetByIdStatus::hasExitSite(const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
+bool GetByIdStatus::hasExitSite(const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
 {
     return profiledBlock->hasExitSite(locker, DFG::FrequentExitSite(bytecodeIndex, BadCache))
         || profiledBlock->hasExitSite(locker, DFG::FrequentExitSite(bytecodeIndex, BadConstantCache));
@@ -109,7 +109,7 @@
 
 GetByIdStatus GetByIdStatus::computeFor(CodeBlock* profiledBlock, StubInfoMap& map, unsigned bytecodeIndex, UniquedStringImpl* uid)
 {
-    ConcurrentJITLocker locker(profiledBlock->m_lock);
+    ConcurrentJSLocker locker(profiledBlock->m_lock);
 
     GetByIdStatus result;
 
@@ -132,7 +132,7 @@
 }
 
 #if ENABLE(DFG_JIT)
-GetByIdStatus GetByIdStatus::computeForStubInfo(const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo, CodeOrigin codeOrigin, UniquedStringImpl* uid)
+GetByIdStatus GetByIdStatus::computeForStubInfo(const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo, CodeOrigin codeOrigin, UniquedStringImpl* uid)
 {
     GetByIdStatus result = GetByIdStatus::computeForStubInfoWithoutExitSiteFeedback(
         locker, profiledBlock, stubInfo, uid,
@@ -146,7 +146,7 @@
 
 #if ENABLE(JIT)
 GetByIdStatus GetByIdStatus::computeForStubInfoWithoutExitSiteFeedback(
-    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo, UniquedStringImpl* uid,
+    const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo, UniquedStringImpl* uid,
     CallLinkStatus::ExitSiteData callExitSiteData)
 {
     if (!stubInfo || !stubInfo->everConsidered)
@@ -298,14 +298,14 @@
     if (dfgBlock) {
         CallLinkStatus::ExitSiteData exitSiteData;
         {
-            ConcurrentJITLocker locker(profiledBlock->m_lock);
+            ConcurrentJSLocker locker(profiledBlock->m_lock);
             exitSiteData = CallLinkStatus::computeExitSiteData(
                 locker, profiledBlock, codeOrigin.bytecodeIndex);
         }
         
         GetByIdStatus result;
         {
-            ConcurrentJITLocker locker(dfgBlock->m_lock);
+            ConcurrentJSLocker locker(dfgBlock->m_lock);
             result = computeForStubInfoWithoutExitSiteFeedback(
                 locker, dfgBlock, dfgMap.get(codeOrigin), uid, exitSiteData);
         }
@@ -314,7 +314,7 @@
             return result;
     
         {
-            ConcurrentJITLocker locker(profiledBlock->m_lock);
+            ConcurrentJSLocker locker(profiledBlock->m_lock);
             if (hasExitSite(locker, profiledBlock, codeOrigin.bytecodeIndex))
                 return GetByIdStatus(TakesSlowPath, true);
         }
diff --git a/Source/JavaScriptCore/bytecode/GetByIdStatus.h b/Source/JavaScriptCore/bytecode/GetByIdStatus.h
index 02b0d26..e8aad89 100644
--- a/Source/JavaScriptCore/bytecode/GetByIdStatus.h
+++ b/Source/JavaScriptCore/bytecode/GetByIdStatus.h
@@ -27,7 +27,7 @@
 
 #include "CallLinkStatus.h"
 #include "CodeOrigin.h"
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "ExitingJITType.h"
 #include "GetByIdVariant.h"
 
@@ -75,7 +75,7 @@
     static GetByIdStatus computeFor(CodeBlock* baselineBlock, CodeBlock* dfgBlock, StubInfoMap& baselineMap, StubInfoMap& dfgMap, CodeOrigin, UniquedStringImpl* uid);
 
 #if ENABLE(DFG_JIT)
-    static GetByIdStatus computeForStubInfo(const ConcurrentJITLocker&, CodeBlock* baselineBlock, StructureStubInfo*, CodeOrigin, UniquedStringImpl* uid);
+    static GetByIdStatus computeForStubInfo(const ConcurrentJSLocker&, CodeBlock* baselineBlock, StructureStubInfo*, CodeOrigin, UniquedStringImpl* uid);
 #endif
 
     State state() const { return m_state; }
@@ -102,11 +102,11 @@
     
 private:
 #if ENABLE(DFG_JIT)
-    static bool hasExitSite(const ConcurrentJITLocker&, CodeBlock*, unsigned bytecodeIndex);
+    static bool hasExitSite(const ConcurrentJSLocker&, CodeBlock*, unsigned bytecodeIndex);
 #endif
 #if ENABLE(JIT)
     static GetByIdStatus computeForStubInfoWithoutExitSiteFeedback(
-        const ConcurrentJITLocker&, CodeBlock* profiledBlock, StructureStubInfo*,
+        const ConcurrentJSLocker&, CodeBlock* profiledBlock, StructureStubInfo*,
         UniquedStringImpl* uid, CallLinkStatus::ExitSiteData);
 #endif
     static GetByIdStatus computeFromLLInt(CodeBlock*, unsigned bytecodeIndex, UniquedStringImpl* uid);
diff --git a/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.cpp b/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.cpp
index de654db..0929d6f 100644
--- a/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.cpp
+++ b/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.cpp
@@ -33,7 +33,7 @@
 CompressedLazyOperandValueProfileHolder::CompressedLazyOperandValueProfileHolder() { }
 CompressedLazyOperandValueProfileHolder::~CompressedLazyOperandValueProfileHolder() { }
 
-void CompressedLazyOperandValueProfileHolder::computeUpdatedPredictions(const ConcurrentJITLocker& locker)
+void CompressedLazyOperandValueProfileHolder::computeUpdatedPredictions(const ConcurrentJSLocker& locker)
 {
     if (!m_data)
         return;
@@ -43,7 +43,7 @@
 }
 
 LazyOperandValueProfile* CompressedLazyOperandValueProfileHolder::add(
-    const ConcurrentJITLocker&, const LazyOperandValueProfileKey& key)
+    const ConcurrentJSLocker&, const LazyOperandValueProfileKey& key)
 {
     if (!m_data)
         m_data = std::make_unique<LazyOperandValueProfile::List>();
@@ -62,7 +62,7 @@
 LazyOperandValueProfileParser::~LazyOperandValueProfileParser() { }
 
 void LazyOperandValueProfileParser::initialize(
-    const ConcurrentJITLocker&, CompressedLazyOperandValueProfileHolder& holder)
+    const ConcurrentJSLocker&, CompressedLazyOperandValueProfileHolder& holder)
 {
     ASSERT(m_map.isEmpty());
     
@@ -87,7 +87,7 @@
 }
 
 SpeculatedType LazyOperandValueProfileParser::prediction(
-    const ConcurrentJITLocker& locker, const LazyOperandValueProfileKey& key) const
+    const ConcurrentJSLocker& locker, const LazyOperandValueProfileKey& key) const
 {
     LazyOperandValueProfile* profile = getIfPresent(key);
     if (!profile)
diff --git a/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.h b/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.h
index 05e6a88..9c3b068 100644
--- a/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.h
+++ b/Source/JavaScriptCore/bytecode/LazyOperandValueProfile.h
@@ -25,7 +25,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "ValueProfile.h"
 #include "VirtualRegister.h"
 #include <wtf/HashMap.h>
@@ -152,10 +152,10 @@
     CompressedLazyOperandValueProfileHolder();
     ~CompressedLazyOperandValueProfileHolder();
     
-    void computeUpdatedPredictions(const ConcurrentJITLocker&);
+    void computeUpdatedPredictions(const ConcurrentJSLocker&);
     
     LazyOperandValueProfile* add(
-        const ConcurrentJITLocker&, const LazyOperandValueProfileKey& key);
+        const ConcurrentJSLocker&, const LazyOperandValueProfileKey& key);
     
 private:
     friend class LazyOperandValueProfileParser;
@@ -169,13 +169,13 @@
     ~LazyOperandValueProfileParser();
     
     void initialize(
-        const ConcurrentJITLocker&, CompressedLazyOperandValueProfileHolder& holder);
+        const ConcurrentJSLocker&, CompressedLazyOperandValueProfileHolder& holder);
     
     LazyOperandValueProfile* getIfPresent(
         const LazyOperandValueProfileKey& key) const;
     
     SpeculatedType prediction(
-        const ConcurrentJITLocker&, const LazyOperandValueProfileKey& key) const;
+        const ConcurrentJSLocker&, const LazyOperandValueProfileKey& key) const;
 private:
     HashMap<LazyOperandValueProfileKey, LazyOperandValueProfile*> m_map;
 };
diff --git a/Source/JavaScriptCore/bytecode/MethodOfGettingAValueProfile.cpp b/Source/JavaScriptCore/bytecode/MethodOfGettingAValueProfile.cpp
index 0795009..f479e5f 100644
--- a/Source/JavaScriptCore/bytecode/MethodOfGettingAValueProfile.cpp
+++ b/Source/JavaScriptCore/bytecode/MethodOfGettingAValueProfile.cpp
@@ -59,7 +59,7 @@
     case LazyOperand: {
         LazyOperandValueProfileKey key(u.lazyOperand.bytecodeOffset, VirtualRegister(u.lazyOperand.operand));
         
-        ConcurrentJITLocker locker(u.lazyOperand.codeBlock->m_lock);
+        ConcurrentJSLocker locker(u.lazyOperand.codeBlock->m_lock);
         LazyOperandValueProfile* profile =
             u.lazyOperand.codeBlock->lazyOperandValueProfiles().add(locker, key);
         jit.storeValue(regs, profile->specFailBucket(0));
diff --git a/Source/JavaScriptCore/bytecode/PutByIdStatus.cpp b/Source/JavaScriptCore/bytecode/PutByIdStatus.cpp
index 43feef5..fc0a472 100644
--- a/Source/JavaScriptCore/bytecode/PutByIdStatus.cpp
+++ b/Source/JavaScriptCore/bytecode/PutByIdStatus.cpp
@@ -54,7 +54,7 @@
 }
 
 #if ENABLE(DFG_JIT)
-bool PutByIdStatus::hasExitSite(const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
+bool PutByIdStatus::hasExitSite(const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, unsigned bytecodeIndex)
 {
     return profiledBlock->hasExitSite(locker, DFG::FrequentExitSite(bytecodeIndex, BadCache))
         || profiledBlock->hasExitSite(locker, DFG::FrequentExitSite(bytecodeIndex, BadConstantCache));
@@ -110,7 +110,7 @@
 
 PutByIdStatus PutByIdStatus::computeFor(CodeBlock* profiledBlock, StubInfoMap& map, unsigned bytecodeIndex, UniquedStringImpl* uid)
 {
-    ConcurrentJITLocker locker(profiledBlock->m_lock);
+    ConcurrentJSLocker locker(profiledBlock->m_lock);
     
     UNUSED_PARAM(profiledBlock);
     UNUSED_PARAM(bytecodeIndex);
@@ -134,7 +134,7 @@
 }
 
 #if ENABLE(JIT)
-PutByIdStatus PutByIdStatus::computeForStubInfo(const ConcurrentJITLocker& locker, CodeBlock* baselineBlock, StructureStubInfo* stubInfo, CodeOrigin codeOrigin, UniquedStringImpl* uid)
+PutByIdStatus PutByIdStatus::computeForStubInfo(const ConcurrentJSLocker& locker, CodeBlock* baselineBlock, StructureStubInfo* stubInfo, CodeOrigin codeOrigin, UniquedStringImpl* uid)
 {
     return computeForStubInfo(
         locker, baselineBlock, stubInfo, uid,
@@ -142,7 +142,7 @@
 }
 
 PutByIdStatus PutByIdStatus::computeForStubInfo(
-    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
+    const ConcurrentJSLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
     UniquedStringImpl* uid, CallLinkStatus::ExitSiteData callExitSiteData)
 {
     if (!stubInfo || !stubInfo->everConsidered)
@@ -266,7 +266,7 @@
     if (dfgBlock) {
         CallLinkStatus::ExitSiteData exitSiteData;
         {
-            ConcurrentJITLocker locker(baselineBlock->m_lock);
+            ConcurrentJSLocker locker(baselineBlock->m_lock);
             if (hasExitSite(locker, baselineBlock, codeOrigin.bytecodeIndex))
                 return PutByIdStatus(TakesSlowPath);
             exitSiteData = CallLinkStatus::computeExitSiteData(
@@ -275,7 +275,7 @@
             
         PutByIdStatus result;
         {
-            ConcurrentJITLocker locker(dfgBlock->m_lock);
+            ConcurrentJSLocker locker(dfgBlock->m_lock);
             result = computeForStubInfo(
                 locker, dfgBlock, dfgMap.get(codeOrigin), uid, exitSiteData);
         }
diff --git a/Source/JavaScriptCore/bytecode/PutByIdStatus.h b/Source/JavaScriptCore/bytecode/PutByIdStatus.h
index 89d28e9..1dd95cd 100644
--- a/Source/JavaScriptCore/bytecode/PutByIdStatus.h
+++ b/Source/JavaScriptCore/bytecode/PutByIdStatus.h
@@ -77,7 +77,7 @@
     static PutByIdStatus computeFor(CodeBlock* baselineBlock, CodeBlock* dfgBlock, StubInfoMap& baselineMap, StubInfoMap& dfgMap, CodeOrigin, UniquedStringImpl* uid);
 
 #if ENABLE(JIT)
-    static PutByIdStatus computeForStubInfo(const ConcurrentJITLocker&, CodeBlock* baselineBlock, StructureStubInfo*, CodeOrigin, UniquedStringImpl* uid);
+    static PutByIdStatus computeForStubInfo(const ConcurrentJSLocker&, CodeBlock* baselineBlock, StructureStubInfo*, CodeOrigin, UniquedStringImpl* uid);
 #endif
     
     State state() const { return m_state; }
@@ -97,11 +97,11 @@
     
 private:
 #if ENABLE(DFG_JIT)
-    static bool hasExitSite(const ConcurrentJITLocker&, CodeBlock*, unsigned bytecodeIndex);
+    static bool hasExitSite(const ConcurrentJSLocker&, CodeBlock*, unsigned bytecodeIndex);
 #endif
 #if ENABLE(JIT)
     static PutByIdStatus computeForStubInfo(
-        const ConcurrentJITLocker&, CodeBlock*, StructureStubInfo*, UniquedStringImpl* uid,
+        const ConcurrentJSLocker&, CodeBlock*, StructureStubInfo*, UniquedStringImpl* uid,
         CallLinkStatus::ExitSiteData);
 #endif
     static PutByIdStatus computeFromLLInt(CodeBlock*, unsigned bytecodeIndex, UniquedStringImpl* uid);
diff --git a/Source/JavaScriptCore/bytecode/StructureStubClearingWatchpoint.cpp b/Source/JavaScriptCore/bytecode/StructureStubClearingWatchpoint.cpp
index a8ad6c9..f27e507 100644
--- a/Source/JavaScriptCore/bytecode/StructureStubClearingWatchpoint.cpp
+++ b/Source/JavaScriptCore/bytecode/StructureStubClearingWatchpoint.cpp
@@ -54,7 +54,7 @@
         // This will implicitly cause my own demise: stub reset removes all watchpoints.
         // That works, because deleting a watchpoint removes it from the set's list, and
         // the set's list traversal for firing is robust against the set changing.
-        ConcurrentJITLocker locker(m_holder.codeBlock()->m_lock);
+        ConcurrentJSLocker locker(m_holder.codeBlock()->m_lock);
         m_holder.stubInfo()->reset(m_holder.codeBlock());
         return;
     }
diff --git a/Source/JavaScriptCore/bytecode/ValueProfile.h b/Source/JavaScriptCore/bytecode/ValueProfile.h
index d5a6f74..8724eb4 100644
--- a/Source/JavaScriptCore/bytecode/ValueProfile.h
+++ b/Source/JavaScriptCore/bytecode/ValueProfile.h
@@ -28,7 +28,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "Heap.h"
 #include "JSArray.h"
 #include "SpeculatedType.h"
@@ -106,7 +106,7 @@
         return false;
     }
     
-    CString briefDescription(const ConcurrentJITLocker& locker)
+    CString briefDescription(const ConcurrentJSLocker& locker)
     {
         computeUpdatedPrediction(locker);
         
@@ -134,7 +134,7 @@
     
     // Updates the prediction and returns the new one. Never call this from any thread
     // that isn't executing the code.
-    SpeculatedType computeUpdatedPrediction(const ConcurrentJITLocker&)
+    SpeculatedType computeUpdatedPrediction(const ConcurrentJSLocker&)
     {
         for (unsigned i = 0; i < totalNumberOfBuckets; ++i) {
             JSValue value = JSValue::decode(m_buckets[i]);
diff --git a/Source/JavaScriptCore/dfg/DFGArrayMode.cpp b/Source/JavaScriptCore/dfg/DFGArrayMode.cpp
index 92c97f2..7778bb3 100644
--- a/Source/JavaScriptCore/dfg/DFGArrayMode.cpp
+++ b/Source/JavaScriptCore/dfg/DFGArrayMode.cpp
@@ -35,7 +35,7 @@
 
 namespace JSC { namespace DFG {
 
-ArrayMode ArrayMode::fromObserved(const ConcurrentJITLocker& locker, ArrayProfile* profile, Array::Action action, bool makeSafe)
+ArrayMode ArrayMode::fromObserved(const ConcurrentJSLocker& locker, ArrayProfile* profile, Array::Action action, bool makeSafe)
 {
     Array::Class nonArray;
     if (profile->usesOriginalArrayStructures(locker))
diff --git a/Source/JavaScriptCore/dfg/DFGArrayMode.h b/Source/JavaScriptCore/dfg/DFGArrayMode.h
index 3d9efd5..45e1d5a 100644
--- a/Source/JavaScriptCore/dfg/DFGArrayMode.h
+++ b/Source/JavaScriptCore/dfg/DFGArrayMode.h
@@ -168,7 +168,7 @@
         return ArrayMode(word);
     }
     
-    static ArrayMode fromObserved(const ConcurrentJITLocker&, ArrayProfile*, Array::Action, bool makeSafe);
+    static ArrayMode fromObserved(const ConcurrentJSLocker&, ArrayProfile*, Array::Action, bool makeSafe);
     
     ArrayMode withSpeculation(Array::Speculation speculation) const
     {
@@ -180,7 +180,7 @@
         return ArrayMode(type(), arrayClass, speculation(), conversion());
     }
     
-    ArrayMode withSpeculationFromProfile(const ConcurrentJITLocker& locker, ArrayProfile* profile, bool makeSafe) const
+    ArrayMode withSpeculationFromProfile(const ConcurrentJSLocker& locker, ArrayProfile* profile, bool makeSafe) const
     {
         Array::Speculation mySpeculation;
 
@@ -194,7 +194,7 @@
         return withSpeculation(mySpeculation);
     }
     
-    ArrayMode withProfile(const ConcurrentJITLocker& locker, ArrayProfile* profile, bool makeSafe) const
+    ArrayMode withProfile(const ConcurrentJSLocker& locker, ArrayProfile* profile, bool makeSafe) const
     {
         Array::Class myArrayClass;
 
diff --git a/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp b/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
index e7a8314..2de6db0 100644
--- a/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
+++ b/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
@@ -407,7 +407,7 @@
     {
         ASSERT(node->op() == GetLocal);
         ASSERT(node->origin.semantic.bytecodeIndex == m_currentIndex);
-        ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+        ConcurrentJSLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
         LazyOperandValueProfileKey key(m_currentIndex, node->local());
         SpeculatedType prediction = m_inlineStackTop->m_lazyOperands.prediction(locker, key);
         node->variableAccessData()->predict(prediction);
@@ -852,7 +852,7 @@
     {
         SpeculatedType prediction;
         {
-            ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+            ConcurrentJSLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
             prediction = m_inlineStackTop->m_profiledBlock->valueProfilePredictionForBytecodeOffset(locker, bytecodeIndex);
         }
 
@@ -891,7 +891,7 @@
 
             bytecodeIndex = codeOrigin->bytecodeIndex;
             CodeBlock* profiledBlock = stack->m_profiledBlock;
-            ConcurrentJITLocker locker(profiledBlock->m_lock);
+            ConcurrentJSLocker locker(profiledBlock->m_lock);
             return profiledBlock->valueProfilePredictionForBytecodeOffset(locker, bytecodeIndex);
         }
 
@@ -928,7 +928,7 @@
     
     ArrayMode getArrayMode(ArrayProfile* profile, Array::Action action)
     {
-        ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+        ConcurrentJSLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
         profile->computeUpdatedPrediction(locker, m_inlineStackTop->m_profiledBlock);
         bool makeSafe = profile->outOfBounds(locker);
         return ArrayMode::fromObserved(locker, profile, action, makeSafe);
@@ -1883,7 +1883,7 @@
                         // arguments received inside the callee. But that probably won't matter for most
                         // calls.
                         if (codeBlock && argument < static_cast<unsigned>(codeBlock->numParameters())) {
-                            ConcurrentJITLocker locker(codeBlock->m_lock);
+                            ConcurrentJSLocker locker(codeBlock->m_lock);
                             if (ValueProfile* profile = codeBlock->valueProfileForArgument(argument))
                                 variable->predict(profile->computeUpdatedPrediction(locker));
                         }
@@ -4261,7 +4261,7 @@
             GetByIdStatus getByIdStatus;
             unsigned identifierNumber = 0;
             {
-                ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+                ConcurrentJSLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
                 ByValInfo* byValInfo = m_inlineStackTop->m_byValInfos.get(CodeOrigin(currentCodeOrigin().bytecodeIndex));
                 // FIXME: When the bytecode is not compiled in the baseline JIT, byValInfo becomes null.
                 // At that time, there is no information.
@@ -4319,7 +4319,7 @@
                 unsigned identifierNumber = std::numeric_limits<unsigned>::max();
                 PutByIdStatus putByIdStatus;
                 {
-                    ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+                    ConcurrentJSLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
                     ByValInfo* byValInfo = m_inlineStackTop->m_byValInfos.get(CodeOrigin(currentCodeOrigin().bytecodeIndex));
                     // FIXME: When the bytecode is not compiled in the baseline JIT, byValInfo becomes null.
                     // At that time, there is no information.
@@ -4945,7 +4945,7 @@
             WatchpointSet* watchpoints = 0;
             uintptr_t operand;
             {
-                ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+                ConcurrentJSLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
                 if (resolveType == GlobalVar || resolveType == GlobalVarWithVarInjectionChecks || resolveType == GlobalLexicalVar || resolveType == GlobalLexicalVarWithVarInjectionChecks)
                     watchpoints = currentInstruction[5].u.watchpointSet;
                 else if (resolveType != UnresolvedProperty && resolveType != UnresolvedPropertyWithVarInjectionChecks)
@@ -4991,7 +4991,7 @@
                 ScopeOffset offset;
                 JSSegmentedVariableObject* scopeObject = jsCast<JSSegmentedVariableObject*>(JSScope::constantScopeForCodeBlock(resolveType, m_inlineStackTop->m_codeBlock));
                 {
-                    ConcurrentJITLocker locker(scopeObject->symbolTable()->m_lock);
+                    ConcurrentJSLocker locker(scopeObject->symbolTable()->m_lock);
                     SymbolTableEntry entry = scopeObject->symbolTable()->get(locker, uid);
                     watchpointSet = entry.watchpointSet();
                     offset = entry.scopeOffset();
@@ -5114,7 +5114,7 @@
             WatchpointSet* watchpoints = nullptr;
             uintptr_t operand;
             {
-                ConcurrentJITLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
+                ConcurrentJSLocker locker(m_inlineStackTop->m_profiledBlock->m_lock);
                 if (resolveType == GlobalVar || resolveType == GlobalVarWithVarInjectionChecks || resolveType == LocalClosureVar || resolveType == GlobalLexicalVar || resolveType == GlobalLexicalVarWithVarInjectionChecks)
                     watchpoints = currentInstruction[5].u.watchpointSet;
                 else if (resolveType != UnresolvedProperty && resolveType != UnresolvedPropertyWithVarInjectionChecks)
@@ -5552,7 +5552,7 @@
     , m_caller(byteCodeParser->m_inlineStackTop)
 {
     {
-        ConcurrentJITLocker locker(m_profiledBlock->m_lock);
+        ConcurrentJSLocker locker(m_profiledBlock->m_lock);
         m_lazyOperands.initialize(locker, m_profiledBlock->lazyOperandValueProfiles());
         m_exitProfile.initialize(locker, profiledBlock->exitProfile());
         
diff --git a/Source/JavaScriptCore/dfg/DFGDriver.cpp b/Source/JavaScriptCore/dfg/DFGDriver.cpp
index 14cd0d0..74c98ca 100644
--- a/Source/JavaScriptCore/dfg/DFGDriver.cpp
+++ b/Source/JavaScriptCore/dfg/DFGDriver.cpp
@@ -100,7 +100,7 @@
         new Plan(codeBlock, profiledDFGCodeBlock, mode, osrEntryBytecodeIndex, mustHandleValues));
     
     plan->callback = callback;
-    if (Options::useConcurrentJIT()) {
+    if (Options::useConcurrentJS()) {
         Worklist& worklist = ensureGlobalWorklistFor(mode);
         if (logCompilationChanges(mode))
             dataLog("Deferring DFG compilation of ", *codeBlock, " with queue length ", worklist.queueLength(), ".\n");
diff --git a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
index b15f00f..3fb4a26 100644
--- a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
@@ -1577,7 +1577,7 @@
             } else if (typeSet->doesTypeConformTo(TypeObject)) {
                 StructureSet set;
                 {
-                    ConcurrentJITLocker locker(typeSet->m_lock);
+                    ConcurrentJSLocker locker(typeSet->m_lock);
                     set = typeSet->structureSet(locker);
                 }
                 if (!set.isEmpty()) {
@@ -2659,7 +2659,7 @@
             profiledBlock->getArrayProfile(node->origin.semantic.bytecodeIndex);
         ArrayMode arrayMode = ArrayMode(Array::SelectUsingPredictions);
         if (arrayProfile) {
-            ConcurrentJITLocker locker(profiledBlock->m_lock);
+            ConcurrentJSLocker locker(profiledBlock->m_lock);
             arrayProfile->computeUpdatedPrediction(locker, profiledBlock);
             arrayMode = ArrayMode::fromObserved(locker, arrayProfile, Array::Read, false);
             if (arrayMode.type() == Array::Unprofiled) {
diff --git a/Source/JavaScriptCore/dfg/DFGGraph.cpp b/Source/JavaScriptCore/dfg/DFGGraph.cpp
index a29b86d..f9f8e4c 100644
--- a/Source/JavaScriptCore/dfg/DFGGraph.cpp
+++ b/Source/JavaScriptCore/dfg/DFGGraph.cpp
@@ -1323,7 +1323,7 @@
     JSValue value;
     WatchpointSet* set;
     {
-        ConcurrentJITLocker locker(symbolTable->m_lock);
+        ConcurrentJSLocker locker(symbolTable->m_lock);
         
         SymbolTableEntry* entry = symbolTable->entryFor(locker, offset);
         if (!entry)
diff --git a/Source/JavaScriptCore/dfg/DFGObjectAllocationSinkingPhase.cpp b/Source/JavaScriptCore/dfg/DFGObjectAllocationSinkingPhase.cpp
index a1b8393..a752f00 100644
--- a/Source/JavaScriptCore/dfg/DFGObjectAllocationSinkingPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGObjectAllocationSinkingPhase.cpp
@@ -865,7 +865,7 @@
             writes.add(ActivationScopePLoc, LazyNode(node->child1().node()));
             {
                 SymbolTable* symbolTable = node->castOperand<SymbolTable*>();
-                ConcurrentJITLocker locker(symbolTable->m_lock);
+                ConcurrentJSLocker locker(symbolTable->m_lock);
                 LazyNode initialValue(m_graph.freeze(node->initializationValueForActivation()));
                 for (auto iter = symbolTable->begin(locker), end = symbolTable->end(locker); iter != end; ++iter) {
                     writes.add(
diff --git a/Source/JavaScriptCore/dfg/DFGPredictionInjectionPhase.cpp b/Source/JavaScriptCore/dfg/DFGPredictionInjectionPhase.cpp
index 89aaa5b..27fb903 100644
--- a/Source/JavaScriptCore/dfg/DFGPredictionInjectionPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGPredictionInjectionPhase.cpp
@@ -49,7 +49,7 @@
         
         ASSERT(codeBlock()->numParameters() >= 1);
         {
-            ConcurrentJITLocker locker(profiledBlock()->m_lock);
+            ConcurrentJSLocker locker(profiledBlock()->m_lock);
             
             for (size_t arg = 0; arg < static_cast<size_t>(codeBlock()->numParameters()); ++arg) {
                 ValueProfile* profile = profiledBlock()->valueProfileForArgument(arg);
diff --git a/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp b/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
index f1dd18a..f17acc9 100644
--- a/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
+++ b/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
@@ -8388,7 +8388,7 @@
 
         if (validationEnabled()) {
             // Validate to make sure every slot in the scope has one value.
-            ConcurrentJITLocker locker(table->m_lock);
+            ConcurrentJSLocker locker(table->m_lock);
             for (auto iter = table->begin(locker), end = table->end(locker); iter != end; ++iter) {
                 bool found = false;
                 for (unsigned i = 0; i < data.m_properties.size(); ++i) {
diff --git a/Source/JavaScriptCore/ftl/FTLOperations.cpp b/Source/JavaScriptCore/ftl/FTLOperations.cpp
index d747524..467f517 100644
--- a/Source/JavaScriptCore/ftl/FTLOperations.cpp
+++ b/Source/JavaScriptCore/ftl/FTLOperations.cpp
@@ -214,7 +214,7 @@
 
         if (validationEnabled()) {
             // Validate to make sure every slot in the scope has one value.
-            ConcurrentJITLocker locker(table->m_lock);
+            ConcurrentJSLocker locker(table->m_lock);
             for (auto iter = table->begin(locker), end = table->end(locker); iter != end; ++iter) {
                 bool found = false;
                 for (unsigned i = materialization->properties().size(); i--;) {
diff --git a/Source/JavaScriptCore/heap/Heap.cpp b/Source/JavaScriptCore/heap/Heap.cpp
index 9611892..b528307 100644
--- a/Source/JavaScriptCore/heap/Heap.cpp
+++ b/Source/JavaScriptCore/heap/Heap.cpp
@@ -987,7 +987,7 @@
 void Heap::addToRememberedSet(const JSCell* cell)
 {
     ASSERT(cell);
-    ASSERT(!Options::useConcurrentJIT() || !isCompilationThread());
+    ASSERT(!Options::useConcurrentJS() || !isCompilationThread());
     if (!Heap::isMarkedConcurrently(cell)) {
         // During a full collection a store into an unmarked object that had surivived past
         // collections will manifest as a store to an unmarked black object. If the object gets
diff --git a/Source/JavaScriptCore/jit/JIT.cpp b/Source/JavaScriptCore/jit/JIT.cpp
index f4c5f29..c2acfb3 100644
--- a/Source/JavaScriptCore/jit/JIT.cpp
+++ b/Source/JavaScriptCore/jit/JIT.cpp
@@ -525,7 +525,7 @@
         before = monotonicallyIncreasingTimeMS();
     
     {
-        ConcurrentJITLocker locker(m_codeBlock->m_lock);
+        ConcurrentJSLocker locker(m_codeBlock->m_lock);
         m_instructions = m_codeBlock->instructions().clone();
     }
 
diff --git a/Source/JavaScriptCore/jit/JITInlines.h b/Source/JavaScriptCore/jit/JITInlines.h
index 0877249..eade9af 100644
--- a/Source/JavaScriptCore/jit/JITInlines.h
+++ b/Source/JavaScriptCore/jit/JITInlines.h
@@ -1021,7 +1021,7 @@
 
 inline JITArrayMode JIT::chooseArrayMode(ArrayProfile* profile)
 {
-    ConcurrentJITLocker locker(m_codeBlock->m_lock);
+    ConcurrentJSLocker locker(m_codeBlock->m_lock);
     profile->computeUpdatedPrediction(locker, m_codeBlock);
     ArrayModes arrayModes = profile->observedArrayModes(locker);
     if (arrayProfileSaw(arrayModes, DoubleShape))
diff --git a/Source/JavaScriptCore/jit/JITOperations.cpp b/Source/JavaScriptCore/jit/JITOperations.cpp
index 843dda9..e8ca4e2 100644
--- a/Source/JavaScriptCore/jit/JITOperations.cpp
+++ b/Source/JavaScriptCore/jit/JITOperations.cpp
@@ -610,7 +610,7 @@
             JITArrayMode arrayMode = jitArrayModeForStructure(structure);
             if (jitArrayModePermitsPut(arrayMode) && arrayMode != byValInfo->arrayMode) {
                 CodeBlock* codeBlock = exec->codeBlock();
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
                 byValInfo->arrayProfile->computeUpdatedPrediction(locker, codeBlock, structure);
 
                 JIT::compilePutByVal(&vm, exec->codeBlock(), byValInfo, returnAddress, arrayMode);
@@ -638,7 +638,7 @@
                 }
             } else {
                 CodeBlock* codeBlock = exec->codeBlock();
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
                 byValInfo->seen = true;
                 byValInfo->cachedId = propertyName;
                 if (subscript.isSymbol())
@@ -694,7 +694,7 @@
             JITArrayMode arrayMode = jitArrayModeForStructure(structure);
             if (jitArrayModePermitsPut(arrayMode) && arrayMode != byValInfo->arrayMode) {
                 CodeBlock* codeBlock = exec->codeBlock();
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
                 byValInfo->arrayProfile->computeUpdatedPrediction(locker, codeBlock, structure);
 
                 JIT::compileDirectPutByVal(&vm, exec->codeBlock(), byValInfo, returnAddress, arrayMode);
@@ -720,7 +720,7 @@
                 }
             } else {
                 CodeBlock* codeBlock = exec->codeBlock();
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
                 byValInfo->seen = true;
                 byValInfo->cachedId = propertyName;
                 if (subscript.isSymbol())
@@ -1743,7 +1743,7 @@
                 // If we reached this case, we got an interesting array mode we did not expect when we compiled.
                 // Let's update the profile to do better next time.
                 CodeBlock* codeBlock = exec->codeBlock();
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
                 byValInfo->arrayProfile->computeUpdatedPrediction(locker, codeBlock, structure);
 
                 JIT::compileGetByVal(&vm, exec->codeBlock(), byValInfo, returnAddress, arrayMode);
@@ -1771,7 +1771,7 @@
                 }
             } else {
                 CodeBlock* codeBlock = exec->codeBlock();
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
                 byValInfo->seen = true;
                 byValInfo->cachedId = propertyName;
                 if (subscript.isSymbol())
diff --git a/Source/JavaScriptCore/jit/JITPropertyAccess.cpp b/Source/JavaScriptCore/jit/JITPropertyAccess.cpp
index 891e582..7ea1e20 100644
--- a/Source/JavaScriptCore/jit/JITPropertyAccess.cpp
+++ b/Source/JavaScriptCore/jit/JITPropertyAccess.cpp
@@ -1324,7 +1324,7 @@
 
     JITGetByIdGenerator gen = emitGetByValWithCachedId(byValInfo, currentInstruction, propertyName, fastDoneCase, slowDoneCase, slowCases);
 
-    ConcurrentJITLocker locker(m_codeBlock->m_lock);
+    ConcurrentJSLocker locker(m_codeBlock->m_lock);
     LinkBuffer patchBuffer(*m_vm, *this, m_codeBlock);
     patchBuffer.link(slowCases, CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(returnAddress.value())).labelAtOffset(byValInfo->returnAddressToSlowPath));
     patchBuffer.link(fastDoneCase, byValInfo->badTypeJump.labelAtOffset(byValInfo->badTypeJumpToDone));
@@ -1415,7 +1415,7 @@
 
     JITPutByIdGenerator gen = emitPutByValWithCachedId(byValInfo, currentInstruction, putKind, propertyName, doneCases, slowCases);
 
-    ConcurrentJITLocker locker(m_codeBlock->m_lock);
+    ConcurrentJSLocker locker(m_codeBlock->m_lock);
     LinkBuffer patchBuffer(*m_vm, *this, m_codeBlock);
     patchBuffer.link(slowCases, CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(returnAddress.value())).labelAtOffset(byValInfo->returnAddressToSlowPath));
     patchBuffer.link(doneCases, byValInfo->badTypeJump.labelAtOffset(byValInfo->badTypeJumpToDone));
diff --git a/Source/JavaScriptCore/jit/JITWorklist.cpp b/Source/JavaScriptCore/jit/JITWorklist.cpp
index 2c22da3..71c139f 100644
--- a/Source/JavaScriptCore/jit/JITWorklist.cpp
+++ b/Source/JavaScriptCore/jit/JITWorklist.cpp
@@ -229,7 +229,7 @@
         return;
     }
     
-    if (!Options::useConcurrentJIT()) {
+    if (!Options::useConcurrentJS()) {
         Plan::compileNow(codeBlock);
         return;
     }
@@ -284,7 +284,7 @@
     }
     
     if (isPlanned) {
-        RELEASE_ASSERT(Options::useConcurrentJIT());
+        RELEASE_ASSERT(Options::useConcurrentJS());
         // This is expensive, but probably good enough.
         completeAllForVM(*codeBlock->vm());
     }
diff --git a/Source/JavaScriptCore/jit/Repatch.cpp b/Source/JavaScriptCore/jit/Repatch.cpp
index baa5b7d..b2c3a5f 100644
--- a/Source/JavaScriptCore/jit/Repatch.cpp
+++ b/Source/JavaScriptCore/jit/Repatch.cpp
@@ -319,7 +319,7 @@
 void repatchGetByID(ExecState* exec, JSValue baseValue, const Identifier& propertyName, const PropertySlot& slot, StructureStubInfo& stubInfo, GetByIDKind kind)
 {
     SuperSamplerScope superSamplerScope(false);
-    GCSafeConcurrentJITLocker locker(exec->codeBlock()->m_lock, exec->vm().heap);
+    GCSafeConcurrentJSLocker locker(exec->codeBlock()->m_lock, exec->vm().heap);
     
     if (tryCacheGetByID(exec, baseValue, propertyName, slot, stubInfo, kind) == GiveUpOnCache)
         ftlThunkAwareRepatchCall(exec->codeBlock(), stubInfo.slowPathCallLocation(), appropriateGenericGetByIdFunction(kind));
@@ -473,7 +473,7 @@
 void repatchPutByID(ExecState* exec, JSValue baseValue, Structure* structure, const Identifier& propertyName, const PutPropertySlot& slot, StructureStubInfo& stubInfo, PutKind putKind)
 {
     SuperSamplerScope superSamplerScope(false);
-    GCSafeConcurrentJITLocker locker(exec->codeBlock()->m_lock, exec->vm().heap);
+    GCSafeConcurrentJSLocker locker(exec->codeBlock()->m_lock, exec->vm().heap);
     
     if (tryCachePutByID(exec, baseValue, structure, propertyName, slot, stubInfo, putKind) == GiveUpOnCache)
         ftlThunkAwareRepatchCall(exec->codeBlock(), stubInfo.slowPathCallLocation(), appropriateGenericPutByIdFunction(slot, putKind));
diff --git a/Source/JavaScriptCore/llint/LLIntSlowPaths.cpp b/Source/JavaScriptCore/llint/LLIntSlowPaths.cpp
index 68ae154..c593408 100644
--- a/Source/JavaScriptCore/llint/LLIntSlowPaths.cpp
+++ b/Source/JavaScriptCore/llint/LLIntSlowPaths.cpp
@@ -627,7 +627,7 @@
     }
     ASSERT((offset == invalidOffset) == slot.isUnset());
 
-    ConcurrentJITLocker locker(codeBlock->m_lock);
+    ConcurrentJSLocker locker(codeBlock->m_lock);
 
     if (slot.isUnset()) {
         pc[0].u.opcode = LLInt::getOpcode(op_get_by_id_unset);
@@ -675,7 +675,7 @@
             if (structure->propertyAccessesAreCacheable()) {
                 vm.heap.writeBarrier(codeBlock);
                 
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
 
                 pc[4].u.structureID = structure->id();
                 pc[5].u.operand = slot.cachedOffset();
@@ -748,7 +748,7 @@
             vm.heap.writeBarrier(codeBlock);
             
             if (slot.type() == PutPropertySlot::NewProperty) {
-                GCSafeConcurrentJITLocker locker(codeBlock->m_lock, vm.heap);
+                GCSafeConcurrentJSLocker locker(codeBlock->m_lock, vm.heap);
             
                 if (!structure->isDictionary() && structure->previousID()->outOfLineCapacity() == structure->outOfLineCapacity()) {
                     ASSERT(structure->previousID()->transitionWatchpointSetHasBeenInvalidated());
@@ -1335,7 +1335,7 @@
     if (!LLINT_ALWAYS_ACCESS_SLOW && callLinkInfo) {
         CodeBlock* callerCodeBlock = exec->codeBlock();
 
-        ConcurrentJITLocker locker(callerCodeBlock->m_lock);
+        ConcurrentJSLocker locker(callerCodeBlock->m_lock);
         
         if (callLinkInfo->isOnList())
             callLinkInfo->remove();
diff --git a/Source/JavaScriptCore/profiler/ProfilerBytecodeSequence.cpp b/Source/JavaScriptCore/profiler/ProfilerBytecodeSequence.cpp
index f5759d0..0470a37 100644
--- a/Source/JavaScriptCore/profiler/ProfilerBytecodeSequence.cpp
+++ b/Source/JavaScriptCore/profiler/ProfilerBytecodeSequence.cpp
@@ -40,7 +40,7 @@
     StringPrintStream out;
     
     for (unsigned i = 0; i < codeBlock->numberOfArgumentValueProfiles(); ++i) {
-        ConcurrentJITLocker locker(codeBlock->m_lock);
+        ConcurrentJSLocker locker(codeBlock->m_lock);
         CString description = codeBlock->valueProfileForArgument(i)->briefDescription(locker);
         if (!description.length())
             continue;
diff --git a/Source/JavaScriptCore/runtime/CommonSlowPaths.cpp b/Source/JavaScriptCore/runtime/CommonSlowPaths.cpp
index 4806a30..f63ed57 100644
--- a/Source/JavaScriptCore/runtime/CommonSlowPaths.cpp
+++ b/Source/JavaScriptCore/runtime/CommonSlowPaths.cpp
@@ -826,7 +826,7 @@
         if (resolvedScope->isGlobalObject()) {
             JSGlobalObject* globalObject = jsCast<JSGlobalObject*>(resolvedScope);
             if (globalObject->hasProperty(exec, ident)) {
-                ConcurrentJITLocker locker(exec->codeBlock()->m_lock);
+                ConcurrentJSLocker locker(exec->codeBlock()->m_lock);
                 if (resolveType == UnresolvedProperty)
                     pc[4].u.operand = GlobalProperty;
                 else
@@ -836,7 +836,7 @@
             }
         } else if (resolvedScope->isGlobalLexicalEnvironment()) {
             JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(resolvedScope);
-            ConcurrentJITLocker locker(exec->codeBlock()->m_lock);
+            ConcurrentJSLocker locker(exec->codeBlock()->m_lock);
             if (resolveType == UnresolvedProperty)
                 pc[4].u.operand = GlobalLexicalVar;
             else
diff --git a/Source/JavaScriptCore/runtime/CommonSlowPaths.h b/Source/JavaScriptCore/runtime/CommonSlowPaths.h
index 9eed6f1..f7daabb 100644
--- a/Source/JavaScriptCore/runtime/CommonSlowPaths.h
+++ b/Source/JavaScriptCore/runtime/CommonSlowPaths.h
@@ -106,7 +106,7 @@
             ResolveType newResolveType = resolveType == UnresolvedProperty ? GlobalProperty : GlobalPropertyWithVarInjectionChecks;
             resolveType = newResolveType;
             getPutInfo = GetPutInfo(getPutInfo.resolveMode(), newResolveType, getPutInfo.initializationMode());
-            ConcurrentJITLocker locker(codeBlock->m_lock);
+            ConcurrentJSLocker locker(codeBlock->m_lock);
             pc[4].u.operand = getPutInfo.operand();
         } else if (scope->isGlobalLexicalEnvironment()) {
             JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(scope);
@@ -114,7 +114,7 @@
             pc[4].u.operand = GetPutInfo(getPutInfo.resolveMode(), newResolveType, getPutInfo.initializationMode()).operand();
             SymbolTableEntry entry = globalLexicalEnvironment->symbolTable()->get(ident.impl());
             ASSERT(!entry.isNull());
-            ConcurrentJITLocker locker(codeBlock->m_lock);
+            ConcurrentJSLocker locker(codeBlock->m_lock);
             pc[5].u.watchpointSet = entry.watchpointSet();
             pc[6].u.pointer = static_cast<void*>(globalLexicalEnvironment->variableAt(entry.scopeOffset()).slot());
         }
@@ -134,7 +134,7 @@
         
         scope->structure()->didCachePropertyReplacement(exec->vm(), slot.cachedOffset());
 
-        ConcurrentJITLocker locker(codeBlock->m_lock);
+        ConcurrentJSLocker locker(codeBlock->m_lock);
         pc[5].u.structure.set(exec->vm(), codeBlock, scope->structure());
         pc[6].u.operand = slot.cachedOffset();
     }
@@ -150,14 +150,14 @@
         if (scope->isGlobalObject()) {
             ResolveType newResolveType = resolveType == UnresolvedProperty ? GlobalProperty : GlobalPropertyWithVarInjectionChecks;
             resolveType = newResolveType; // Allow below caching mechanism to kick in.
-            ConcurrentJITLocker locker(exec->codeBlock()->m_lock);
+            ConcurrentJSLocker locker(exec->codeBlock()->m_lock);
             pc[4].u.operand = GetPutInfo(getPutInfo.resolveMode(), newResolveType, getPutInfo.initializationMode()).operand();
         } else if (scope->isGlobalLexicalEnvironment()) {
             JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(scope);
             ResolveType newResolveType = resolveType == UnresolvedProperty ? GlobalLexicalVar : GlobalLexicalVarWithVarInjectionChecks;
             SymbolTableEntry entry = globalLexicalEnvironment->symbolTable()->get(ident.impl());
             ASSERT(!entry.isNull());
-            ConcurrentJITLocker locker(exec->codeBlock()->m_lock);
+            ConcurrentJSLocker locker(exec->codeBlock()->m_lock);
             pc[4].u.operand = GetPutInfo(getPutInfo.resolveMode(), newResolveType, getPutInfo.initializationMode()).operand();
             pc[5].u.watchpointSet = entry.watchpointSet();
             pc[6].u.pointer = static_cast<void*>(globalLexicalEnvironment->variableAt(entry.scopeOffset()).slot());
@@ -170,7 +170,7 @@
             CodeBlock* codeBlock = exec->codeBlock();
             Structure* structure = scope->structure(vm);
             {
-                ConcurrentJITLocker locker(codeBlock->m_lock);
+                ConcurrentJSLocker locker(codeBlock->m_lock);
                 pc[5].u.structure.set(exec->vm(), codeBlock, structure);
                 pc[6].u.operand = slot.cachedOffset();
             }
diff --git a/Source/JavaScriptCore/runtime/ConcurrentJITLock.h b/Source/JavaScriptCore/runtime/ConcurrentJSLock.h
similarity index 62%
rename from Source/JavaScriptCore/runtime/ConcurrentJITLock.h
rename to Source/JavaScriptCore/runtime/ConcurrentJSLock.h
index bfb7ec9..9811a38 100644
--- a/Source/JavaScriptCore/runtime/ConcurrentJITLock.h
+++ b/Source/JavaScriptCore/runtime/ConcurrentJSLock.h
@@ -32,32 +32,32 @@
 
 namespace JSC {
 
-#if ENABLE(CONCURRENT_JIT)
-typedef Lock ConcurrentJITLock;
-typedef LockHolder ConcurrentJITLockerImpl;
+#if ENABLE(CONCURRENT_JS)
+typedef Lock ConcurrentJSLock;
+typedef LockHolder ConcurrentJSLockerImpl;
 #else
-typedef NoLock ConcurrentJITLock;
-typedef NoLockLocker ConcurrentJITLockerImpl;
+typedef NoLock ConcurrentJSLock;
+typedef NoLockLocker ConcurrentJSLockerImpl;
 #endif
 
-class ConcurrentJITLockerBase {
-    WTF_MAKE_NONCOPYABLE(ConcurrentJITLockerBase);
+class ConcurrentJSLockerBase {
+    WTF_MAKE_NONCOPYABLE(ConcurrentJSLockerBase);
 public:
-    explicit ConcurrentJITLockerBase(ConcurrentJITLock& lockable)
+    explicit ConcurrentJSLockerBase(ConcurrentJSLock& lockable)
         : m_locker(&lockable)
     {
     }
-    explicit ConcurrentJITLockerBase(ConcurrentJITLock* lockable)
+    explicit ConcurrentJSLockerBase(ConcurrentJSLock* lockable)
         : m_locker(lockable)
     {
     }
 
-    explicit ConcurrentJITLockerBase(NoLockingNecessaryTag)
+    explicit ConcurrentJSLockerBase(NoLockingNecessaryTag)
         : m_locker(NoLockingNecessary)
     {
     }
 
-    ~ConcurrentJITLockerBase()
+    ~ConcurrentJSLockerBase()
     {
     }
     
@@ -67,24 +67,24 @@
     }
 
 private:
-    ConcurrentJITLockerImpl m_locker;
+    ConcurrentJSLockerImpl m_locker;
 };
 
-class GCSafeConcurrentJITLocker : public ConcurrentJITLockerBase {
+class GCSafeConcurrentJSLocker : public ConcurrentJSLockerBase {
 public:
-    GCSafeConcurrentJITLocker(ConcurrentJITLock& lockable, Heap& heap)
-        : ConcurrentJITLockerBase(lockable)
+    GCSafeConcurrentJSLocker(ConcurrentJSLock& lockable, Heap& heap)
+        : ConcurrentJSLockerBase(lockable)
         , m_deferGC(heap)
     {
     }
 
-    GCSafeConcurrentJITLocker(ConcurrentJITLock* lockable, Heap& heap)
-        : ConcurrentJITLockerBase(lockable)
+    GCSafeConcurrentJSLocker(ConcurrentJSLock* lockable, Heap& heap)
+        : ConcurrentJSLockerBase(lockable)
         , m_deferGC(heap)
     {
     }
 
-    ~GCSafeConcurrentJITLocker()
+    ~GCSafeConcurrentJSLocker()
     {
         // We have to unlock early due to the destruction order of base
         // vs. derived classes. If we didn't, then we would destroy the 
@@ -97,35 +97,35 @@
     DeferGC m_deferGC;
 };
 
-class ConcurrentJITLocker : public ConcurrentJITLockerBase {
+class ConcurrentJSLocker : public ConcurrentJSLockerBase {
 public:
-    ConcurrentJITLocker(ConcurrentJITLock& lockable)
-        : ConcurrentJITLockerBase(lockable)
-#if ENABLE(CONCURRENT_JIT) && !defined(NDEBUG)
+    ConcurrentJSLocker(ConcurrentJSLock& lockable)
+        : ConcurrentJSLockerBase(lockable)
+#if ENABLE(CONCURRENT_JS) && !defined(NDEBUG)
         , m_disallowGC(InPlace)
 #endif
     {
     }
 
-    ConcurrentJITLocker(ConcurrentJITLock* lockable)
-        : ConcurrentJITLockerBase(lockable)
-#if ENABLE(CONCURRENT_JIT) && !defined(NDEBUG)
+    ConcurrentJSLocker(ConcurrentJSLock* lockable)
+        : ConcurrentJSLockerBase(lockable)
+#if ENABLE(CONCURRENT_JS) && !defined(NDEBUG)
         , m_disallowGC(InPlace)
 #endif
     {
     }
 
-    ConcurrentJITLocker(NoLockingNecessaryTag)
-        : ConcurrentJITLockerBase(NoLockingNecessary)
-#if ENABLE(CONCURRENT_JIT) && !defined(NDEBUG)
+    ConcurrentJSLocker(NoLockingNecessaryTag)
+        : ConcurrentJSLockerBase(NoLockingNecessary)
+#if ENABLE(CONCURRENT_JS) && !defined(NDEBUG)
         , m_disallowGC(Nullopt)
 #endif
     {
     }
     
-    ConcurrentJITLocker(int) = delete;
+    ConcurrentJSLocker(int) = delete;
 
-#if ENABLE(CONCURRENT_JIT) && !defined(NDEBUG)
+#if ENABLE(CONCURRENT_JS) && !defined(NDEBUG)
 private:
     Optional<DisallowGC> m_disallowGC;
 #endif
diff --git a/Source/JavaScriptCore/runtime/InferredType.cpp b/Source/JavaScriptCore/runtime/InferredType.cpp
index d1a3249..e1ef0c0 100644
--- a/Source/JavaScriptCore/runtime/InferredType.cpp
+++ b/Source/JavaScriptCore/runtime/InferredType.cpp
@@ -366,7 +366,7 @@
 {
 }
 
-bool InferredType::canWatch(const ConcurrentJITLocker& locker, const Descriptor& expected)
+bool InferredType::canWatch(const ConcurrentJSLocker& locker, const Descriptor& expected)
 {
     if (expected.kind() == Top)
         return false;
@@ -376,11 +376,11 @@
 
 bool InferredType::canWatch(const Descriptor& expected)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return canWatch(locker, expected);
 }
 
-void InferredType::addWatchpoint(const ConcurrentJITLocker& locker, Watchpoint* watchpoint)
+void InferredType::addWatchpoint(const ConcurrentJSLocker& locker, Watchpoint* watchpoint)
 {
     RELEASE_ASSERT(descriptor(locker).kind() != Top);
 
@@ -389,7 +389,7 @@
 
 void InferredType::addWatchpoint(Watchpoint* watchpoint)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     addWatchpoint(locker, watchpoint);
 }
 
@@ -404,7 +404,7 @@
     Descriptor myType;
     bool result;
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         oldType = descriptor(locker);
         myType = Descriptor::forValue(value);
 
@@ -427,7 +427,7 @@
 {
     Descriptor oldType;
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         oldType = descriptor(locker);
         if (!set(locker, vm, Top))
             return;
@@ -437,11 +437,11 @@
     m_watchpointSet.fireAll(vm, detail);
 }
 
-bool InferredType::set(const ConcurrentJITLocker& locker, VM& vm, Descriptor newDescriptor)
+bool InferredType::set(const ConcurrentJSLocker& locker, VM& vm, Descriptor newDescriptor)
 {
     // We will trigger write barriers while holding our lock. Currently, write barriers don't GC, but that
     // could change. If it does, we don't want to deadlock. Note that we could have used
-    // GCSafeConcurrentJITLocker in the caller, but the caller is on a fast path so maybe that wouldn't be
+    // GCSafeConcurrentJSLocker in the caller, but the caller is on a fast path so maybe that wouldn't be
     // a good idea.
     DeferGCForAWhile deferGC(vm.heap);
     
@@ -506,7 +506,7 @@
     Descriptor oldDescriptor;
     Descriptor newDescriptor;
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         oldDescriptor = descriptor(locker);
         newDescriptor = oldDescriptor;
         newDescriptor.removeStructure();
diff --git a/Source/JavaScriptCore/runtime/InferredType.h b/Source/JavaScriptCore/runtime/InferredType.h
index ddf244e..f60a9af 100644
--- a/Source/JavaScriptCore/runtime/InferredType.h
+++ b/Source/JavaScriptCore/runtime/InferredType.h
@@ -25,7 +25,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "JSCell.h"
 #include "PropertyName.h"
 #include "PutByIdFlags.h"
@@ -173,24 +173,24 @@
         Structure* m_structure;
     };
 
-    ConcurrentJITLock& lock() const { return m_lock; }
+    ConcurrentJSLock& lock() const { return m_lock; }
 
     Descriptor descriptorMainThread() const
     {
         return Descriptor(m_kind, m_structure ? m_structure->structure() : nullptr);
     }
     
-    Descriptor descriptor(const ConcurrentJITLocker&) const
+    Descriptor descriptor(const ConcurrentJSLocker&) const
     {
         return descriptorMainThread();
     }
     Descriptor descriptor() const
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return descriptor(locker);
     }
     
-    Kind kind(const ConcurrentJITLocker& locker) const { return descriptor(locker).kind(); }
+    Kind kind(const ConcurrentJSLocker& locker) const { return descriptor(locker).kind(); }
 
     bool isTop() const { return m_kind == Top; }
     bool isRelevant() const { return m_kind != Top; }
@@ -214,10 +214,10 @@
 
     // Returns true if it currently makes sense to watch this InferredType for this descriptor. Note that
     // this will always return false for Top.
-    bool canWatch(const ConcurrentJITLocker&, const Descriptor&);
+    bool canWatch(const ConcurrentJSLocker&, const Descriptor&);
     bool canWatch(const Descriptor&);
     
-    void addWatchpoint(const ConcurrentJITLocker&, Watchpoint*);
+    void addWatchpoint(const ConcurrentJSLocker&, Watchpoint*);
     void addWatchpoint(Watchpoint*);
 
     void dump(PrintStream&) const;
@@ -231,11 +231,11 @@
 
     // Helper for willStoreValueSlow() and makeTopSlow(). This returns true if we should fire the
     // watchpoint set.
-    bool set(const ConcurrentJITLocker&, VM&, Descriptor);
+    bool set(const ConcurrentJSLocker&, VM&, Descriptor);
     
     void removeStructure();
 
-    mutable ConcurrentJITLock m_lock;
+    mutable ConcurrentJSLock m_lock;
     
     Kind m_kind { Bottom };
 
diff --git a/Source/JavaScriptCore/runtime/InferredTypeTable.cpp b/Source/JavaScriptCore/runtime/InferredTypeTable.cpp
index f769368..95563e4 100644
--- a/Source/JavaScriptCore/runtime/InferredTypeTable.cpp
+++ b/Source/JavaScriptCore/runtime/InferredTypeTable.cpp
@@ -54,7 +54,7 @@
 {
     InferredTypeTable* inferredTypeTable = jsCast<InferredTypeTable*>(cell);
 
-    ConcurrentJITLocker locker(inferredTypeTable->m_lock);
+    ConcurrentJSLocker locker(inferredTypeTable->m_lock);
     
     for (auto& entry : inferredTypeTable->m_table) {
         if (!entry.value)
@@ -66,7 +66,7 @@
     }
 }
 
-InferredType* InferredTypeTable::get(const ConcurrentJITLocker&, UniquedStringImpl* uid)
+InferredType* InferredTypeTable::get(const ConcurrentJSLocker&, UniquedStringImpl* uid)
 {
     auto iter = m_table.find(uid);
     if (iter == m_table.end() || !iter->value)
@@ -83,7 +83,7 @@
 
 InferredType* InferredTypeTable::get(UniquedStringImpl* uid)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     return get(locker, uid);
 }
 
@@ -111,7 +111,7 @@
 
     TableType::AddResult result;
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         result = m_table.add(propertyName.uid(), WriteBarrier<InferredType>());
     }
     if (result.isNewEntry) {
@@ -143,7 +143,7 @@
 
     TableType::AddResult result;
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         result = m_table.add(propertyName.uid(), WriteBarrier<InferredType>());
     }
     if (!result.iterator->value)
diff --git a/Source/JavaScriptCore/runtime/InferredTypeTable.h b/Source/JavaScriptCore/runtime/InferredTypeTable.h
index db69eb4..6b4515f 100644
--- a/Source/JavaScriptCore/runtime/InferredTypeTable.h
+++ b/Source/JavaScriptCore/runtime/InferredTypeTable.h
@@ -55,13 +55,13 @@
 
     DECLARE_INFO;
 
-    ConcurrentJITLock& lock() { return m_lock; }
+    ConcurrentJSLock& lock() { return m_lock; }
 
     bool isEmpty() const { return m_table.isEmpty(); }
 
     // Get the current inferred type. Returns nullptr for both Top and Bottom. Null means Bottom if the
     // owning Structure doesn't know about the property.
-    InferredType* get(const ConcurrentJITLocker&, UniquedStringImpl*);
+    InferredType* get(const ConcurrentJSLocker&, UniquedStringImpl*);
     InferredType* get(UniquedStringImpl*);
     InferredType* get(PropertyName);
 
@@ -103,7 +103,7 @@
 
     // We only grab this lock when we're doing modifications on the main thread, or reads on the compiler
     // thread. The compiler thread is not allowed to do modifications.
-    ConcurrentJITLock m_lock;
+    ConcurrentJSLock m_lock;
 };
 
 } // namespace JSC
diff --git a/Source/JavaScriptCore/runtime/JSEnvironmentRecord.cpp b/Source/JavaScriptCore/runtime/JSEnvironmentRecord.cpp
index 923cd49..8807c42 100644
--- a/Source/JavaScriptCore/runtime/JSEnvironmentRecord.cpp
+++ b/Source/JavaScriptCore/runtime/JSEnvironmentRecord.cpp
@@ -49,7 +49,7 @@
     JSEnvironmentRecord* thisObject = jsCast<JSEnvironmentRecord*>(cell);
     Base::heapSnapshot(cell, builder);
 
-    ConcurrentJITLocker locker(thisObject->symbolTable()->m_lock);
+    ConcurrentJSLocker locker(thisObject->symbolTable()->m_lock);
     SymbolTable::Map::iterator end = thisObject->symbolTable()->end(locker);
     for (SymbolTable::Map::iterator it = thisObject->symbolTable()->begin(locker); it != end; ++it) {
         SymbolTableEntry::Fast entry = it->value;
diff --git a/Source/JavaScriptCore/runtime/JSGlobalObject.cpp b/Source/JavaScriptCore/runtime/JSGlobalObject.cpp
index d6878aa..6199c63 100644
--- a/Source/JavaScriptCore/runtime/JSGlobalObject.cpp
+++ b/Source/JavaScriptCore/runtime/JSGlobalObject.cpp
@@ -960,7 +960,7 @@
 
 void JSGlobalObject::addGlobalVar(const Identifier& ident)
 {
-    ConcurrentJITLocker locker(symbolTable()->m_lock);
+    ConcurrentJSLocker locker(symbolTable()->m_lock);
     SymbolTableEntry entry = symbolTable()->get(locker, ident.impl());
     if (!entry.isNull())
         return;
@@ -1283,7 +1283,7 @@
         WatchpointSet* watchpointSet = nullptr;
         WriteBarrierBase<Unknown>* variable = nullptr;
         {
-            ConcurrentJITLocker locker(symbolTable()->m_lock);
+            ConcurrentJSLocker locker(symbolTable()->m_lock);
             ScopeOffset offset = symbolTable()->takeNextScopeOffset(locker);
             RELEASE_ASSERT(offset = startOffset + i);
             SymbolTableEntry newEntry(VarOffset(offset), global.attributes);
diff --git a/Source/JavaScriptCore/runtime/JSLexicalEnvironment.cpp b/Source/JavaScriptCore/runtime/JSLexicalEnvironment.cpp
index dc923ac..436d6f2 100644
--- a/Source/JavaScriptCore/runtime/JSLexicalEnvironment.cpp
+++ b/Source/JavaScriptCore/runtime/JSLexicalEnvironment.cpp
@@ -44,7 +44,7 @@
     JSLexicalEnvironment* thisObject = jsCast<JSLexicalEnvironment*>(object);
 
     {
-        ConcurrentJITLocker locker(thisObject->symbolTable()->m_lock);
+        ConcurrentJSLocker locker(thisObject->symbolTable()->m_lock);
         SymbolTable::Map::iterator end = thisObject->symbolTable()->end(locker);
         for (SymbolTable::Map::iterator it = thisObject->symbolTable()->begin(locker); it != end; ++it) {
             if (it->value.getAttributes() & DontEnum && !mode.includeDontEnumProperties())
diff --git a/Source/JavaScriptCore/runtime/JSObject.cpp b/Source/JavaScriptCore/runtime/JSObject.cpp
index 946e941..d1e0731 100644
--- a/Source/JavaScriptCore/runtime/JSObject.cpp
+++ b/Source/JavaScriptCore/runtime/JSObject.cpp
@@ -1554,7 +1554,7 @@
 
         PropertyOffset offset;
         if (structure->isUncacheableDictionary())
-            offset = structure->removePropertyWithoutTransition(vm, propertyName, [] (const ConcurrentJITLocker&, PropertyOffset) { });
+            offset = structure->removePropertyWithoutTransition(vm, propertyName, [] (const ConcurrentJSLocker&, PropertyOffset) { });
         else
             thisObject->setStructure(vm, Structure::removePropertyTransition(vm, structure, propertyName, offset));
 
@@ -3189,7 +3189,7 @@
         vm, Structure::toCacheableDictionaryTransition(vm, structure(vm), &deferredWatchpointFire));
 }
 
-void JSObject::shiftButterflyAfterFlattening(const GCSafeConcurrentJITLocker&, VM& vm, Structure* structure, size_t outOfLineCapacityAfter)
+void JSObject::shiftButterflyAfterFlattening(const GCSafeConcurrentJSLocker&, VM& vm, Structure* structure, size_t outOfLineCapacityAfter)
 {
     // This could interleave visitChildren because some old structure could have been a non
     // dictionary structure. We have to be crazy careful. But, we are guaranteed to be holding
diff --git a/Source/JavaScriptCore/runtime/JSObject.h b/Source/JavaScriptCore/runtime/JSObject.h
index b4097a4..2996866 100644
--- a/Source/JavaScriptCore/runtime/JSObject.h
+++ b/Source/JavaScriptCore/runtime/JSObject.h
@@ -758,7 +758,7 @@
     {
         structure(vm)->flattenDictionaryStructure(vm, this);
     }
-    void shiftButterflyAfterFlattening(const GCSafeConcurrentJITLocker&, VM&, Structure* structure, size_t outOfLineCapacityAfter);
+    void shiftButterflyAfterFlattening(const GCSafeConcurrentJSLocker&, VM&, Structure* structure, size_t outOfLineCapacityAfter);
 
     JSGlobalObject* globalObject() const
     {
diff --git a/Source/JavaScriptCore/runtime/JSObjectInlines.h b/Source/JavaScriptCore/runtime/JSObjectInlines.h
index ae7693e..179bcf8 100644
--- a/Source/JavaScriptCore/runtime/JSObjectInlines.h
+++ b/Source/JavaScriptCore/runtime/JSObjectInlines.h
@@ -167,7 +167,7 @@
     unsigned oldOutOfLineCapacity = structure->outOfLineCapacity();
     structure->addPropertyWithoutTransition(
         vm, propertyName, attributes,
-        [&] (const GCSafeConcurrentJITLocker&, PropertyOffset offset) {
+        [&] (const GCSafeConcurrentJSLocker&, PropertyOffset offset) {
             if (structure->outOfLineCapacity() != oldOutOfLineCapacity) {
                 butterfly = allocateMoreOutOfLineStorage(vm, oldOutOfLineCapacity, structure->outOfLineCapacity());
                 WTF::storeStoreFence();
@@ -266,7 +266,7 @@
         unsigned oldOutOfLineCapacity = structure->outOfLineCapacity();
         offset = structure->addPropertyWithoutTransition(
             vm, propertyName, attributes,
-            [&] (const GCSafeConcurrentJITLocker&, PropertyOffset offset) {
+            [&] (const GCSafeConcurrentJSLocker&, PropertyOffset offset) {
                 Butterfly* butterfly = this->butterfly();
                 if (structure->outOfLineCapacity() != oldOutOfLineCapacity) {
                     butterfly = allocateMoreOutOfLineStorage(vm, oldOutOfLineCapacity, structure->outOfLineCapacity());
diff --git a/Source/JavaScriptCore/runtime/JSScope.cpp b/Source/JavaScriptCore/runtime/JSScope.cpp
index b0125e7..c4c749f 100644
--- a/Source/JavaScriptCore/runtime/JSScope.cpp
+++ b/Source/JavaScriptCore/runtime/JSScope.cpp
@@ -59,7 +59,7 @@
 
         SymbolTable* symbolTable = lexicalEnvironment->symbolTable();
         {
-            ConcurrentJITLocker locker(symbolTable->m_lock);
+            ConcurrentJSLocker locker(symbolTable->m_lock);
             auto iter = symbolTable->find(locker, ident.impl());
             if (iter != symbolTable->end(locker)) {
                 SymbolTableEntry& entry = iter->value;
@@ -83,7 +83,7 @@
                 JSModuleRecord* importedRecord = resolution.moduleRecord;
                 JSModuleEnvironment* importedEnvironment = importedRecord->moduleEnvironment();
                 SymbolTable* symbolTable = importedEnvironment->symbolTable();
-                ConcurrentJITLocker locker(symbolTable->m_lock);
+                ConcurrentJSLocker locker(symbolTable->m_lock);
                 auto iter = symbolTable->find(locker, resolution.localName.impl());
                 ASSERT(iter != symbolTable->end(locker));
                 SymbolTableEntry& entry = iter->value;
@@ -101,7 +101,7 @@
     if (scope->isGlobalLexicalEnvironment()) {
         JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(scope);
         SymbolTable* symbolTable = globalLexicalEnvironment->symbolTable();
-        ConcurrentJITLocker locker(symbolTable->m_lock);
+        ConcurrentJSLocker locker(symbolTable->m_lock);
         auto iter = symbolTable->find(locker, ident.impl());
         if (iter != symbolTable->end(locker)) {
             SymbolTableEntry& entry = iter->value;
@@ -134,7 +134,7 @@
         JSGlobalObject* globalObject = jsCast<JSGlobalObject*>(scope);
         {
             SymbolTable* symbolTable = globalObject->symbolTable();
-            ConcurrentJITLocker locker(symbolTable->m_lock);
+            ConcurrentJSLocker locker(symbolTable->m_lock);
             auto iter = symbolTable->find(locker, ident.impl());
             if (iter != symbolTable->end(locker)) {
                 SymbolTableEntry& entry = iter->value;
@@ -277,7 +277,7 @@
 
         SymbolTable* symbolTable = jsCast<JSSymbolTableObject*>(scope)->symbolTable();
         ASSERT(symbolTable->scopeType() == SymbolTable::ScopeType::LexicalScope || symbolTable->scopeType() == SymbolTable::ScopeType::CatchScope);
-        ConcurrentJITLocker locker(symbolTable->m_lock);
+        ConcurrentJSLocker locker(symbolTable->m_lock);
         for (auto end = symbolTable->end(locker), iter = symbolTable->begin(locker); iter != end; ++iter)
             result.add(iter->key);
     }
diff --git a/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.cpp b/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.cpp
index 9d5bdf5..49c4c94 100644
--- a/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.cpp
+++ b/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.cpp
@@ -36,7 +36,7 @@
 
 ScopeOffset JSSegmentedVariableObject::findVariableIndex(void* variableAddress)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     for (unsigned i = m_variables.size(); i--;) {
         if (&m_variables[i] != variableAddress)
@@ -49,7 +49,7 @@
 
 ScopeOffset JSSegmentedVariableObject::addVariables(unsigned numberOfVariablesToAdd, JSValue initialValue)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     size_t oldSize = m_variables.size();
     m_variables.grow(oldSize + numberOfVariablesToAdd);
@@ -75,7 +75,7 @@
     JSSegmentedVariableObject* thisObject = jsCast<JSSegmentedVariableObject*>(cell);
     Base::heapSnapshot(cell, builder);
 
-    ConcurrentJITLocker locker(thisObject->symbolTable()->m_lock);
+    ConcurrentJSLocker locker(thisObject->symbolTable()->m_lock);
     SymbolTable::Map::iterator end = thisObject->symbolTable()->end(locker);
     for (SymbolTable::Map::iterator it = thisObject->symbolTable()->begin(locker); it != end; ++it) {
         SymbolTableEntry::Fast entry = it->value;
diff --git a/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.h b/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.h
index 0f2e7ca..0d4a815 100644
--- a/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.h
+++ b/Source/JavaScriptCore/runtime/JSSegmentedVariableObject.h
@@ -28,7 +28,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "JSObject.h"
 #include "JSSymbolTableObject.h"
 #include "SymbolTable.h"
@@ -97,7 +97,7 @@
     }
     
     SegmentedVector<WriteBarrier<Unknown>, 16> m_variables;
-    ConcurrentJITLock m_lock;
+    ConcurrentJSLock m_lock;
 };
 
 } // namespace JSC
diff --git a/Source/JavaScriptCore/runtime/JSSymbolTableObject.cpp b/Source/JavaScriptCore/runtime/JSSymbolTableObject.cpp
index fc8c92e..efbc191 100644
--- a/Source/JavaScriptCore/runtime/JSSymbolTableObject.cpp
+++ b/Source/JavaScriptCore/runtime/JSSymbolTableObject.cpp
@@ -57,7 +57,7 @@
 {
     JSSymbolTableObject* thisObject = jsCast<JSSymbolTableObject*>(object);
     {
-        ConcurrentJITLocker locker(thisObject->symbolTable()->m_lock);
+        ConcurrentJSLocker locker(thisObject->symbolTable()->m_lock);
         SymbolTable::Map::iterator end = thisObject->symbolTable()->end(locker);
         for (SymbolTable::Map::iterator it = thisObject->symbolTable()->begin(locker); it != end; ++it) {
             if (!(it->value.getAttributes() & DontEnum) || mode.includeDontEnumProperties()) {
diff --git a/Source/JavaScriptCore/runtime/JSSymbolTableObject.h b/Source/JavaScriptCore/runtime/JSSymbolTableObject.h
index 8a299e5..366b5a0 100644
--- a/Source/JavaScriptCore/runtime/JSSymbolTableObject.h
+++ b/Source/JavaScriptCore/runtime/JSSymbolTableObject.h
@@ -81,7 +81,7 @@
     SymbolTableObjectType* object, PropertyName propertyName, PropertySlot& slot)
 {
     SymbolTable& symbolTable = *object->symbolTable();
-    ConcurrentJITLocker locker(symbolTable.m_lock);
+    ConcurrentJSLocker locker(symbolTable.m_lock);
     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
     if (iter == symbolTable.end(locker))
         return false;
@@ -102,7 +102,7 @@
     SymbolTableObjectType* object, PropertyName propertyName, PropertyDescriptor& descriptor)
 {
     SymbolTable& symbolTable = *object->symbolTable();
-    ConcurrentJITLocker locker(symbolTable.m_lock);
+    ConcurrentJSLocker locker(symbolTable.m_lock);
     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
     if (iter == symbolTable.end(locker))
         return false;
@@ -124,7 +124,7 @@
     bool& slotIsWriteable)
 {
     SymbolTable& symbolTable = *object->symbolTable();
-    ConcurrentJITLocker locker(symbolTable.m_lock);
+    ConcurrentJSLocker locker(symbolTable.m_lock);
     SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
     if (iter == symbolTable.end(locker))
         return false;
@@ -174,7 +174,7 @@
         SymbolTable& symbolTable = *object->symbolTable();
         // FIXME: This is very suspicious. We shouldn't need a GC-safe lock here.
         // https://bugs.webkit.org/show_bug.cgi?id=134601
-        GCSafeConcurrentJITLocker locker(symbolTable.m_lock, vm.heap);
+        GCSafeConcurrentJSLocker locker(symbolTable.m_lock, vm.heap);
         SymbolTable::Map::iterator iter = symbolTable.find(locker, propertyName.uid());
         if (iter == symbolTable.end(locker))
             return false;
diff --git a/Source/JavaScriptCore/runtime/Options.cpp b/Source/JavaScriptCore/runtime/Options.cpp
index 4508b7b..88d70ca8 100644
--- a/Source/JavaScriptCore/runtime/Options.cpp
+++ b/Source/JavaScriptCore/runtime/Options.cpp
@@ -317,8 +317,8 @@
 #if !ENABLE(YARR_JIT)
     Options::useRegExpJIT() = false;
 #endif
-#if !ENABLE(CONCURRENT_JIT)
-    Options::useConcurrentJIT() = false;
+#if !ENABLE(CONCURRENT_JS)
+    Options::useConcurrentJS() = false;
 #endif
 #if !ENABLE(DFG_JIT)
     Options::useDFGJIT() = false;
@@ -370,7 +370,7 @@
         Options::thresholdForFTLOptimizeAfterWarmUp() = 20;
         Options::thresholdForFTLOptimizeSoon() = 20;
         Options::maximumEvalCacheableSourceLength() = 150000;
-        Options::useConcurrentJIT() = false;
+        Options::useConcurrentJS() = false;
     }
     if (Options::useMaximalFlushInsertionPhase()) {
         Options::useOSREntryToDFG() = false;
diff --git a/Source/JavaScriptCore/runtime/Options.h b/Source/JavaScriptCore/runtime/Options.h
index 7c3e941..15beb22 100644
--- a/Source/JavaScriptCore/runtime/Options.h
+++ b/Source/JavaScriptCore/runtime/Options.h
@@ -233,7 +233,7 @@
     v(bool, useObjectAllocationSinking, true, Normal, nullptr) \
     v(bool, logExecutableAllocation, false, Normal, nullptr) \
     \
-    v(bool, useConcurrentJIT, true, Normal, "allows the DFG / FTL compilation in threads other than the executing JS thread") \
+    v(bool, useConcurrentJS, true, Normal, "allows the DFG / FTL compilation in threads other than the executing JS thread") \
     v(unsigned, numberOfDFGCompilerThreads, computeNumberOfWorkerThreads(2, 2) - 1, Normal, nullptr) \
     v(unsigned, numberOfFTLCompilerThreads, computeNumberOfWorkerThreads(8, 2) - 1, Normal, nullptr) \
     v(int32, priorityDeltaOfDFGCompilerThreads, computePriorityDeltaOfWorkerThreads(-1, 0), Normal, nullptr) \
@@ -431,7 +431,7 @@
     v(enablePolymorphicCallInlining, usePolymorphicCallInlining, SameOption) \
     v(enableMovHintRemoval, useMovHintRemoval, SameOption) \
     v(enableObjectAllocationSinking, useObjectAllocationSinking, SameOption) \
-    v(enableConcurrentJIT, useConcurrentJIT, SameOption) \
+    v(enableConcurrentJS, useConcurrentJS, SameOption) \
     v(enableProfiler, useProfiler, SameOption) \
     v(enableArchitectureSpecificOptimizations, useArchitectureSpecificOptimizations, SameOption) \
     v(enablePolyvariantCallInlining, usePolyvariantCallInlining, SameOption) \
diff --git a/Source/JavaScriptCore/runtime/ProgramExecutable.cpp b/Source/JavaScriptCore/runtime/ProgramExecutable.cpp
index c77fa61..f874f17 100644
--- a/Source/JavaScriptCore/runtime/ProgramExecutable.cpp
+++ b/Source/JavaScriptCore/runtime/ProgramExecutable.cpp
@@ -153,7 +153,7 @@
     {
         JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(globalObject->globalScope());
         SymbolTable* symbolTable = globalLexicalEnvironment->symbolTable();
-        ConcurrentJITLocker locker(symbolTable->m_lock);
+        ConcurrentJSLocker locker(symbolTable->m_lock);
         for (auto& entry : lexicalDeclarations) {
             if (UNLIKELY(entry.value.isConst() && !vm.globalConstRedeclarationShouldThrow() && !isStrictMode())) {
                 if (symbolTable->contains(locker, entry.key.get()))
diff --git a/Source/JavaScriptCore/runtime/RegExp.cpp b/Source/JavaScriptCore/runtime/RegExp.cpp
index 9939704..a372360 100644
--- a/Source/JavaScriptCore/runtime/RegExp.cpp
+++ b/Source/JavaScriptCore/runtime/RegExp.cpp
@@ -262,7 +262,7 @@
 
 void RegExp::compile(VM* vm, Yarr::YarrCharSize charSize)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     Yarr::YarrPattern pattern(m_patternString, m_flags, &m_constructionError, vm->stackLimit());
     if (m_constructionError) {
@@ -304,7 +304,7 @@
 bool RegExp::matchConcurrently(
     VM& vm, const String& s, unsigned startOffset, int& position, Vector<int>& ovector)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
 
     if (!hasCodeFor(s.is8Bit() ? Yarr::Char8 : Yarr::Char16))
         return false;
@@ -315,7 +315,7 @@
 
 void RegExp::compileMatchOnly(VM* vm, Yarr::YarrCharSize charSize)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     Yarr::YarrPattern pattern(m_patternString, m_flags, &m_constructionError, vm->stackLimit());
     if (m_constructionError) {
@@ -356,7 +356,7 @@
 
 bool RegExp::matchConcurrently(VM& vm, const String& s, unsigned startOffset, MatchResult& result)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
 
     if (!hasMatchOnlyCodeFor(s.is8Bit() ? Yarr::Char8 : Yarr::Char16))
         return false;
@@ -367,7 +367,7 @@
 
 void RegExp::deleteCode()
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     if (!hasCode())
         return;
diff --git a/Source/JavaScriptCore/runtime/RegExp.h b/Source/JavaScriptCore/runtime/RegExp.h
index 996571f..bbe93f5 100644
--- a/Source/JavaScriptCore/runtime/RegExp.h
+++ b/Source/JavaScriptCore/runtime/RegExp.h
@@ -21,7 +21,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "ExecutableAllocator.h"
 #include "MatchResult.h"
 #include "RegExpKey.h"
@@ -142,7 +142,7 @@
     unsigned m_rtMatchCallCount;
     unsigned m_rtMatchFoundCount;
 #endif
-    ConcurrentJITLock m_lock;
+    ConcurrentJSLock m_lock;
 
 #if ENABLE(YARR_JIT)
     Yarr::YarrCodeBlock m_regExpJITCode;
diff --git a/Source/JavaScriptCore/runtime/Structure.cpp b/Source/JavaScriptCore/runtime/Structure.cpp
index 428de5f..5a97f4a 100644
--- a/Source/JavaScriptCore/runtime/Structure.cpp
+++ b/Source/JavaScriptCore/runtime/Structure.cpp
@@ -337,7 +337,7 @@
     // Must hold the lock on this structure, since we will be modifying this structure's
     // property map. We don't want getConcurrently() to see the property map in a half-baked
     // state.
-    GCSafeConcurrentJITLocker locker(m_lock, vm.heap);
+    GCSafeConcurrentJSLocker locker(m_lock, vm.heap);
     if (setPropertyTable)
         this->setPropertyTable(vm, table);
 
@@ -380,7 +380,7 @@
 
 Structure* Structure::addPropertyTransitionToExistingStructureConcurrently(Structure* structure, UniquedStringImpl* uid, unsigned attributes, PropertyOffset& offset)
 {
-    ConcurrentJITLocker locker(structure->m_lock);
+    ConcurrentJSLocker locker(structure->m_lock);
     return addPropertyTransitionToExistingStructureImpl(structure, uid, attributes, offset);
 }
 
@@ -478,7 +478,7 @@
 
     checkOffset(transition->m_offset, transition->inlineCapacity());
     {
-        ConcurrentJITLocker locker(structure->m_lock);
+        ConcurrentJSLocker locker(structure->m_lock);
         structure->m_transitionTable.add(vm, transition);
     }
     transition->checkOffsetConsistency();
@@ -597,7 +597,7 @@
     if (result) {
         if (isPinnedPropertyTable())
             return result->copy(vm, result->size() + 1);
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         setPropertyTable(vm, nullptr);
         return result;
     }
@@ -668,7 +668,7 @@
     if (structure->isDictionary())
         transition->pin(vm, transition->ensurePropertyTable(vm));
     else {
-        ConcurrentJITLocker locker(structure->m_lock);
+        ConcurrentJSLocker locker(structure->m_lock);
         structure->m_transitionTable.add(vm, transition);
     }
 
@@ -719,7 +719,7 @@
     checkOffsetConsistency();
     ASSERT(isDictionary());
     
-    GCSafeConcurrentJITLocker locker(m_lock, vm.heap);
+    GCSafeConcurrentJSLocker locker(m_lock, vm.heap);
 
     size_t beforeOutOfLineCapacity = this->outOfLineCapacity();
     if (isUncacheableDictionary()) {
@@ -803,7 +803,7 @@
     
     if (!hasRareData())
         allocateRareData(vm);
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     StructureRareData* rareData = this->rareData();
     if (!rareData->m_replacementWatchpointSets) {
         rareData->m_replacementWatchpointSets =
@@ -943,12 +943,12 @@
 
 PropertyOffset Structure::add(VM& vm, PropertyName propertyName, unsigned attributes)
 {
-    return add(vm, propertyName, attributes, [] (const GCSafeConcurrentJITLocker&, PropertyOffset) { });
+    return add(vm, propertyName, attributes, [] (const GCSafeConcurrentJSLocker&, PropertyOffset) { });
 }
 
 PropertyOffset Structure::remove(PropertyName propertyName)
 {
-    return remove(propertyName, [] (const ConcurrentJITLocker&, PropertyOffset) { });
+    return remove(propertyName, [] (const ConcurrentJSLocker&, PropertyOffset) { });
 }
 
 void Structure::getPropertyNamesFromStructure(VM& vm, PropertyNameArray& propertyNames, EnumerationMode mode)
@@ -1023,7 +1023,7 @@
 
     JSCell::visitChildren(thisObject, visitor);
     
-    ConcurrentJITLocker locker(thisObject->m_lock);
+    ConcurrentJSLocker locker(thisObject->m_lock);
     
     visitor.append(&thisObject->m_globalObject);
     if (!thisObject->isObject())
diff --git a/Source/JavaScriptCore/runtime/Structure.h b/Source/JavaScriptCore/runtime/Structure.h
index 1a2f1ba..36fb34a 100644
--- a/Source/JavaScriptCore/runtime/Structure.h
+++ b/Source/JavaScriptCore/runtime/Structure.h
@@ -26,7 +26,7 @@
 #pragma once
 
 #include "ClassInfo.h"
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "IndexingType.h"
 #include "InferredTypeTable.h"
 #include "JSCJSValue.h"
@@ -581,7 +581,7 @@
     
     static void dumpContextHeader(PrintStream&);
     
-    ConcurrentJITLock& lock() { return m_lock; }
+    ConcurrentJSLock& lock() { return m_lock; }
     
     DECLARE_EXPORT_INFO;
 
@@ -760,7 +760,7 @@
 
     uint8_t m_inlineCapacity;
     
-    ConcurrentJITLock m_lock;
+    ConcurrentJSLock m_lock;
     
     uint32_t m_bitField;
 };
diff --git a/Source/JavaScriptCore/runtime/StructureInlines.h b/Source/JavaScriptCore/runtime/StructureInlines.h
index 4a0b670..1dba9c7 100644
--- a/Source/JavaScriptCore/runtime/StructureInlines.h
+++ b/Source/JavaScriptCore/runtime/StructureInlines.h
@@ -233,7 +233,7 @@
 
 inline WatchpointSet* Structure::propertyReplacementWatchpointSet(PropertyOffset offset)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     if (!hasRareData())
         return nullptr;
     WTF::loadLoadFence();
@@ -290,7 +290,7 @@
 {
     PropertyTable* table = ensurePropertyTable(vm);
 
-    GCSafeConcurrentJITLocker locker(m_lock, vm.heap);
+    GCSafeConcurrentJSLocker locker(m_lock, vm.heap);
     
     setPropertyTable(vm, table);
     
@@ -315,7 +315,7 @@
 template<typename Func>
 inline PropertyOffset Structure::remove(PropertyName propertyName, const Func& func)
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     
     checkConsistency();
 
diff --git a/Source/JavaScriptCore/runtime/SymbolTable.cpp b/Source/JavaScriptCore/runtime/SymbolTable.cpp
index a127301..7596f4a 100644
--- a/Source/JavaScriptCore/runtime/SymbolTable.cpp
+++ b/Source/JavaScriptCore/runtime/SymbolTable.cpp
@@ -108,11 +108,11 @@
         visitor.append(&thisSymbolTable->m_rareData->m_codeBlock);
     
     // Save some memory. This is O(n) to rebuild and we do so on the fly.
-    ConcurrentJITLocker locker(thisSymbolTable->m_lock);
+    ConcurrentJSLocker locker(thisSymbolTable->m_lock);
     thisSymbolTable->m_localToEntry = nullptr;
 }
 
-const SymbolTable::LocalToEntryVec& SymbolTable::localToEntry(const ConcurrentJITLocker&)
+const SymbolTable::LocalToEntryVec& SymbolTable::localToEntry(const ConcurrentJSLocker&)
 {
     if (UNLIKELY(!m_localToEntry)) {
         unsigned size = 0;
@@ -133,7 +133,7 @@
     return *m_localToEntry;
 }
 
-SymbolTableEntry* SymbolTable::entryFor(const ConcurrentJITLocker& locker, ScopeOffset offset)
+SymbolTableEntry* SymbolTable::entryFor(const ConcurrentJSLocker& locker, ScopeOffset offset)
 {
     auto& toEntryVector = localToEntry(locker);
     if (offset.offset() >= toEntryVector.size())
@@ -190,7 +190,7 @@
     return result;
 }
 
-void SymbolTable::prepareForTypeProfiling(const ConcurrentJITLocker&)
+void SymbolTable::prepareForTypeProfiling(const ConcurrentJSLocker&)
 {
     if (m_rareData)
         return;
@@ -220,7 +220,7 @@
     m_rareData->m_codeBlock.set(*codeBlock->vm(), this, codeBlock);
 }
 
-GlobalVariableID SymbolTable::uniqueIDForVariable(const ConcurrentJITLocker&, UniquedStringImpl* key, VM& vm)
+GlobalVariableID SymbolTable::uniqueIDForVariable(const ConcurrentJSLocker&, UniquedStringImpl* key, VM& vm)
 {
     RELEASE_ASSERT(m_rareData);
 
@@ -239,7 +239,7 @@
     return id;
 }
 
-GlobalVariableID SymbolTable::uniqueIDForOffset(const ConcurrentJITLocker& locker, VarOffset offset, VM& vm)
+GlobalVariableID SymbolTable::uniqueIDForOffset(const ConcurrentJSLocker& locker, VarOffset offset, VM& vm)
 {
     RELEASE_ASSERT(m_rareData);
 
@@ -251,7 +251,7 @@
     return uniqueIDForVariable(locker, iter->value.get(), vm);
 }
 
-RefPtr<TypeSet> SymbolTable::globalTypeSetForOffset(const ConcurrentJITLocker& locker, VarOffset offset, VM& vm)
+RefPtr<TypeSet> SymbolTable::globalTypeSetForOffset(const ConcurrentJSLocker& locker, VarOffset offset, VM& vm)
 {
     RELEASE_ASSERT(m_rareData);
 
@@ -265,7 +265,7 @@
     return globalTypeSetForVariable(locker, iter->value.get(), vm);
 }
 
-RefPtr<TypeSet> SymbolTable::globalTypeSetForVariable(const ConcurrentJITLocker& locker, UniquedStringImpl* key, VM& vm)
+RefPtr<TypeSet> SymbolTable::globalTypeSetForVariable(const ConcurrentJSLocker& locker, UniquedStringImpl* key, VM& vm)
 {
     RELEASE_ASSERT(m_rareData);
 
diff --git a/Source/JavaScriptCore/runtime/SymbolTable.h b/Source/JavaScriptCore/runtime/SymbolTable.h
index eebadf8..3183664 100644
--- a/Source/JavaScriptCore/runtime/SymbolTable.h
+++ b/Source/JavaScriptCore/runtime/SymbolTable.h
@@ -28,7 +28,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "ConstantMode.h"
 #include "InferredValue.h"
 #include "JSObject.h"
@@ -462,61 +462,61 @@
     }
 
     // You must hold the lock until after you're done with the iterator.
-    Map::iterator find(const ConcurrentJITLocker&, UniquedStringImpl* key)
+    Map::iterator find(const ConcurrentJSLocker&, UniquedStringImpl* key)
     {
         return m_map.find(key);
     }
     
-    Map::iterator find(const GCSafeConcurrentJITLocker&, UniquedStringImpl* key)
+    Map::iterator find(const GCSafeConcurrentJSLocker&, UniquedStringImpl* key)
     {
         return m_map.find(key);
     }
     
-    SymbolTableEntry get(const ConcurrentJITLocker&, UniquedStringImpl* key)
+    SymbolTableEntry get(const ConcurrentJSLocker&, UniquedStringImpl* key)
     {
         return m_map.get(key);
     }
     
     SymbolTableEntry get(UniquedStringImpl* key)
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return get(locker, key);
     }
     
-    SymbolTableEntry inlineGet(const ConcurrentJITLocker&, UniquedStringImpl* key)
+    SymbolTableEntry inlineGet(const ConcurrentJSLocker&, UniquedStringImpl* key)
     {
         return m_map.inlineGet(key);
     }
     
     SymbolTableEntry inlineGet(UniquedStringImpl* key)
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return inlineGet(locker, key);
     }
     
-    Map::iterator begin(const ConcurrentJITLocker&)
+    Map::iterator begin(const ConcurrentJSLocker&)
     {
         return m_map.begin();
     }
     
-    Map::iterator end(const ConcurrentJITLocker&)
+    Map::iterator end(const ConcurrentJSLocker&)
     {
         return m_map.end();
     }
     
-    Map::iterator end(const GCSafeConcurrentJITLocker&)
+    Map::iterator end(const GCSafeConcurrentJSLocker&)
     {
         return m_map.end();
     }
     
-    size_t size(const ConcurrentJITLocker&) const
+    size_t size(const ConcurrentJSLocker&) const
     {
         return m_map.size();
     }
     
     size_t size() const
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return size(locker);
     }
     
@@ -555,7 +555,7 @@
         return ScopeOffset(scopeSize());
     }
     
-    ScopeOffset takeNextScopeOffset(const ConcurrentJITLocker&)
+    ScopeOffset takeNextScopeOffset(const ConcurrentJSLocker&)
     {
         ScopeOffset result = nextScopeOffset();
         m_maxScopeOffset = result;
@@ -564,12 +564,12 @@
     
     ScopeOffset takeNextScopeOffset()
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return takeNextScopeOffset(locker);
     }
     
     template<typename Entry>
-    void add(const ConcurrentJITLocker&, UniquedStringImpl* key, Entry&& entry)
+    void add(const ConcurrentJSLocker&, UniquedStringImpl* key, Entry&& entry)
     {
         RELEASE_ASSERT(!m_localToEntry);
         didUseVarOffset(entry.varOffset());
@@ -580,12 +580,12 @@
     template<typename Entry>
     void add(UniquedStringImpl* key, Entry&& entry)
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         add(locker, key, std::forward<Entry>(entry));
     }
     
     template<typename Entry>
-    void set(const ConcurrentJITLocker&, UniquedStringImpl* key, Entry&& entry)
+    void set(const ConcurrentJSLocker&, UniquedStringImpl* key, Entry&& entry)
     {
         RELEASE_ASSERT(!m_localToEntry);
         didUseVarOffset(entry.varOffset());
@@ -595,18 +595,18 @@
     template<typename Entry>
     void set(UniquedStringImpl* key, Entry&& entry)
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         set(locker, key, std::forward<Entry>(entry));
     }
     
-    bool contains(const ConcurrentJITLocker&, UniquedStringImpl* key)
+    bool contains(const ConcurrentJSLocker&, UniquedStringImpl* key)
     {
         return m_map.contains(key);
     }
     
     bool contains(UniquedStringImpl* key)
     {
-        ConcurrentJITLocker locker(m_lock);
+        ConcurrentJSLocker locker(m_lock);
         return contains(locker, key);
     }
     
@@ -651,13 +651,13 @@
         return m_arguments.get();
     }
     
-    const LocalToEntryVec& localToEntry(const ConcurrentJITLocker&);
-    SymbolTableEntry* entryFor(const ConcurrentJITLocker&, ScopeOffset);
+    const LocalToEntryVec& localToEntry(const ConcurrentJSLocker&);
+    SymbolTableEntry* entryFor(const ConcurrentJSLocker&, ScopeOffset);
     
-    GlobalVariableID uniqueIDForVariable(const ConcurrentJITLocker&, UniquedStringImpl* key, VM&);
-    GlobalVariableID uniqueIDForOffset(const ConcurrentJITLocker&, VarOffset, VM&);
-    RefPtr<TypeSet> globalTypeSetForOffset(const ConcurrentJITLocker&, VarOffset, VM&);
-    RefPtr<TypeSet> globalTypeSetForVariable(const ConcurrentJITLocker&, UniquedStringImpl* key, VM&);
+    GlobalVariableID uniqueIDForVariable(const ConcurrentJSLocker&, UniquedStringImpl* key, VM&);
+    GlobalVariableID uniqueIDForOffset(const ConcurrentJSLocker&, VarOffset, VM&);
+    RefPtr<TypeSet> globalTypeSetForOffset(const ConcurrentJSLocker&, VarOffset, VM&);
+    RefPtr<TypeSet> globalTypeSetForVariable(const ConcurrentJSLocker&, UniquedStringImpl* key, VM&);
 
     bool usesNonStrictEval() const { return m_usesNonStrictEval; }
     void setUsesNonStrictEval(bool usesNonStrictEval) { m_usesNonStrictEval = usesNonStrictEval; }
@@ -677,7 +677,7 @@
 
     SymbolTable* cloneScopePart(VM&);
 
-    void prepareForTypeProfiling(const ConcurrentJITLocker&);
+    void prepareForTypeProfiling(const ConcurrentJSLocker&);
 
     CodeBlock* rareDataCodeBlock();
     void setRareDataCodeBlock(CodeBlock*);
@@ -715,7 +715,7 @@
     std::unique_ptr<LocalToEntryVec> m_localToEntry;
 
 public:
-    mutable ConcurrentJITLock m_lock;
+    mutable ConcurrentJSLock m_lock;
 };
 
 } // namespace JSC
diff --git a/Source/JavaScriptCore/runtime/TypeSet.cpp b/Source/JavaScriptCore/runtime/TypeSet.cpp
index c240ccb..1f638c0 100644
--- a/Source/JavaScriptCore/runtime/TypeSet.cpp
+++ b/Source/JavaScriptCore/runtime/TypeSet.cpp
@@ -49,7 +49,7 @@
     if (structure && newShape && !runtimeTypeIsPrimitive(type)) {
         if (!m_structureSet.contains(structure)) {
             {
-                ConcurrentJITLocker locker(m_lock);
+                ConcurrentJSLocker locker(m_lock);
                 m_structureSet.add(structure);
             }
             // Make one more pass making sure that: 
@@ -83,7 +83,7 @@
 
 void TypeSet::invalidateCache()
 {
-    ConcurrentJITLocker locker(m_lock);
+    ConcurrentJSLocker locker(m_lock);
     auto keepMarkedStructuresFilter = [] (Structure* structure) -> bool { return Heap::isMarked(structure); };
     m_structureSet.genericFilter(keepMarkedStructuresFilter);
 }
diff --git a/Source/JavaScriptCore/runtime/TypeSet.h b/Source/JavaScriptCore/runtime/TypeSet.h
index ca90a84..22f178d 100644
--- a/Source/JavaScriptCore/runtime/TypeSet.h
+++ b/Source/JavaScriptCore/runtime/TypeSet.h
@@ -25,7 +25,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "RuntimeType.h"
 #include "StructureSet.h"
 #include <wtf/HashSet.h>
@@ -97,9 +97,9 @@
     bool isEmpty() const { return m_seenTypes == TypeNothing; }
     bool doesTypeConformTo(RuntimeTypeMask test) const;
     RuntimeTypeMask seenTypes() const { return m_seenTypes; }
-    StructureSet structureSet(const ConcurrentJITLocker&) const { return m_structureSet; }
+    StructureSet structureSet(const ConcurrentJSLocker&) const { return m_structureSet; }
 
-    ConcurrentJITLock m_lock;
+    ConcurrentJSLock m_lock;
 private:
     bool m_isOverflown;
     RuntimeTypeMask m_seenTypes;
diff --git a/Source/JavaScriptCore/runtime/VM.h b/Source/JavaScriptCore/runtime/VM.h
index 28a9b63..d5c97be 100644
--- a/Source/JavaScriptCore/runtime/VM.h
+++ b/Source/JavaScriptCore/runtime/VM.h
@@ -29,7 +29,7 @@
 #pragma once
 
 #include "CallData.h"
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "ControlFlowProfiler.h"
 #include "DateInstanceCache.h"
 #include "ExceptionEventLocation.h"
@@ -557,7 +557,7 @@
     RefPtr<TypedArrayController> m_typedArrayController;
     RegExpCache* m_regExpCache;
     BumpPointerAllocator m_regExpAllocator;
-    ConcurrentJITLock m_regExpAllocatorLock;
+    ConcurrentJSLock m_regExpAllocatorLock;
 
     std::unique_ptr<HasOwnPropertyCache> m_hasOwnPropertyCache;
     ALWAYS_INLINE HasOwnPropertyCache* hasOwnPropertyCache() { return m_hasOwnPropertyCache.get(); }
diff --git a/Source/JavaScriptCore/runtime/WriteBarrierInlines.h b/Source/JavaScriptCore/runtime/WriteBarrierInlines.h
index 4bd2dd6..7d8d66f 100644
--- a/Source/JavaScriptCore/runtime/WriteBarrierInlines.h
+++ b/Source/JavaScriptCore/runtime/WriteBarrierInlines.h
@@ -34,7 +34,7 @@
 inline void WriteBarrierBase<T>::set(VM& vm, const JSCell* owner, T* value)
 {
     ASSERT(value);
-    ASSERT(!Options::useConcurrentJIT() || !isCompilationThread());
+    ASSERT(!Options::useConcurrentJS() || !isCompilationThread());
     validateCell(value);
     setEarlyValue(vm, owner, value);
 }
@@ -56,7 +56,7 @@
 
 inline void WriteBarrierBase<Unknown>::set(VM& vm, const JSCell* owner, JSValue value)
 {
-    ASSERT(!Options::useConcurrentJIT() || !isCompilationThread());
+    ASSERT(!Options::useConcurrentJS() || !isCompilationThread());
     m_value = JSValue::encode(value);
     vm.heap.writeBarrier(owner, value);
 }
diff --git a/Source/JavaScriptCore/yarr/YarrInterpreter.cpp b/Source/JavaScriptCore/yarr/YarrInterpreter.cpp
index 727ae3a..0a9fd82c 100644
--- a/Source/JavaScriptCore/yarr/YarrInterpreter.cpp
+++ b/Source/JavaScriptCore/yarr/YarrInterpreter.cpp
@@ -1588,7 +1588,7 @@
         m_currentAlternativeIndex = 0;
     }
 
-    std::unique_ptr<BytecodePattern> compile(BumpPointerAllocator* allocator, ConcurrentJITLock* lock)
+    std::unique_ptr<BytecodePattern> compile(BumpPointerAllocator* allocator, ConcurrentJSLock* lock)
     {
         regexBegin(m_pattern.m_numSubpatterns, m_pattern.m_body->m_callFrameSize, m_pattern.m_body->m_alternatives[0]->onceThrough());
         emitDisjunction(m_pattern.m_body);
@@ -2042,7 +2042,7 @@
     Vector<std::unique_ptr<ByteDisjunction>> m_allParenthesesInfo;
 };
 
-std::unique_ptr<BytecodePattern> byteCompile(YarrPattern& pattern, BumpPointerAllocator* allocator, ConcurrentJITLock* lock)
+std::unique_ptr<BytecodePattern> byteCompile(YarrPattern& pattern, BumpPointerAllocator* allocator, ConcurrentJSLock* lock)
 {
     return ByteCompiler(pattern).compile(allocator, lock);
 }
diff --git a/Source/JavaScriptCore/yarr/YarrInterpreter.h b/Source/JavaScriptCore/yarr/YarrInterpreter.h
index 28d3d51..b8ea350 100644
--- a/Source/JavaScriptCore/yarr/YarrInterpreter.h
+++ b/Source/JavaScriptCore/yarr/YarrInterpreter.h
@@ -25,7 +25,7 @@
 
 #pragma once
 
-#include "ConcurrentJITLock.h"
+#include "ConcurrentJSLock.h"
 #include "YarrPattern.h"
 
 namespace WTF {
@@ -337,7 +337,7 @@
 struct BytecodePattern {
     WTF_MAKE_FAST_ALLOCATED;
 public:
-    BytecodePattern(std::unique_ptr<ByteDisjunction> body, Vector<std::unique_ptr<ByteDisjunction>>& parenthesesInfoToAdopt, YarrPattern& pattern, BumpPointerAllocator* allocator, ConcurrentJITLock* lock)
+    BytecodePattern(std::unique_ptr<ByteDisjunction> body, Vector<std::unique_ptr<ByteDisjunction>>& parenthesesInfoToAdopt, YarrPattern& pattern, BumpPointerAllocator* allocator, ConcurrentJSLock* lock)
         : m_body(WTFMove(body))
         , m_flags(pattern.m_flags)
         , m_allocator(allocator)
@@ -370,7 +370,7 @@
     // Each BytecodePattern is associated with a RegExp, each RegExp is associated
     // with a VM.  Cache a pointer to out VM's m_regExpAllocator.
     BumpPointerAllocator* m_allocator;
-    ConcurrentJITLock* m_lock;
+    ConcurrentJSLock* m_lock;
 
     CharacterClass* newlineCharacterClass;
     CharacterClass* wordcharCharacterClass;
@@ -380,7 +380,7 @@
     Vector<std::unique_ptr<CharacterClass>> m_userCharacterClasses;
 };
 
-JS_EXPORT_PRIVATE std::unique_ptr<BytecodePattern> byteCompile(YarrPattern&, BumpPointerAllocator*, ConcurrentJITLock* = nullptr);
+JS_EXPORT_PRIVATE std::unique_ptr<BytecodePattern> byteCompile(YarrPattern&, BumpPointerAllocator*, ConcurrentJSLock* = nullptr);
 JS_EXPORT_PRIVATE unsigned interpret(BytecodePattern*, const String& input, unsigned start, unsigned* output);
 unsigned interpret(BytecodePattern*, const LChar* input, unsigned length, unsigned start, unsigned* output);
 unsigned interpret(BytecodePattern*, const UChar* input, unsigned length, unsigned start, unsigned* output);