Provide support for setting JSC options in {N} applications
mbektchiev opened this issue · comments
Is your feature request related to a problem? Please describe.
JSC has literally hundreds of options that can be used to control behavior and/or expose internal APIs. Currently there's no way to specify them in a {N} application while the Android runtime allows for tweaking its V8 engine's optionsapp/package.json. We'd like to have parity and allow users to control them.
Describe the solution you'd like
Read and respect the options written in the ios.jscFlags variable in app/package.json
Additional context
- Many options' values have effect only during JSC's initialization phase, that's why a runtime interface seems unnecessary for now although it exists in C++ and can also be considered.
- This feature replaces #732 as it will bring more control and flexibility.
- All currently supported options by iOS runtime's version of WebKit are listed in JSC_OPTIONS macro definition in Options.h
With the current implementation you can set the JSC options by passing ios.jscFlags list of options in the following format "--=" separated by space. Here's an example how to set dumpOptions(dumps JSC options (0 = None, 1 = Overridden only, 2 = All, 3 = Verbose)):
{
"ios": {
"jscFlags": "--dumpOptions=2"
}
}If dumpOptions is set to 2, when starting the application through xCode, it should dump the values of all JSC options in the Target Output:
All JSC options:
validateOptions=false
dumpOptions=2 (default: 0)
configFile=""
useLLInt=true
useJIT=false (default: true)
useBaselineJIT=true
useDFGJIT=true
useRegExpJIT=true
useDOMJIT=true
reportMustSucceedExecutableAllocations=false
maxPerThreadStackUsage=4194304
softReservedZoneSize=131072
reservedZoneSize=65536
crashIfCantAllocateJITMemory=false
jitMemoryReservationSize=0
useSeparatedWXHeap=false
forceCodeBlockLiveness=false
forceICFailure=false
repatchCountForCoolDown=8
initialCoolDownCount=20
repatchBufferingCountdown=8
dumpGeneratedBytecodes=false
dumpBytecodeLivenessResults=false
validateBytecode=false
forceDebuggerBytecodeGeneration=false
dumpBytecodesBeforeGeneratorification=false
useFunctionDotArguments=true
useTailCalls=true
optimizeRecursiveTailCalls=true
alwaysUseShadowChicken=false
shadowChickenLogSize=1000
shadowChickenMaxTailDeletedFramesSize=128
dumpDisassembly=false
asyncDisassembly=false
dumpDFGDisassembly=false
dumpFTLDisassembly=false
dumpAllDFGNodes=false
bytecodeRangeToJITCompile=<null>
bytecodeRangeToDFGCompile=<null>
bytecodeRangeToFTLCompile=<null>
jitWhitelist=""
dfgWhitelist=""
ftlWhitelist=""
dumpSourceAtDFGTime=false
dumpBytecodeAtDFGTime=false
dumpGraphAfterParsing=false
dumpGraphAtEachPhase=false
dumpDFGGraphAtEachPhase=false
dumpDFGFTLGraphAtEachPhase=false
dumpB3GraphAtEachPhase=false
dumpAirGraphAtEachPhase=false
verboseDFGBytecodeParsing=false
safepointBeforeEachPhase=true
verboseCompilation=false
verboseFTLCompilation=false
logCompilationChanges=false
useProbeOSRExit=false
printEachOSRExit=false
validateGraph=false
validateGraphAtEachPhase=false
verboseValidationFailure=false
verboseOSR=false
verboseDFGOSRExit=false
verboseFTLOSRExit=false
verboseCallLink=false
verboseCompilationQueue=false
reportCompileTimes=false
reportBaselineCompileTimes=false
reportDFGCompileTimes=false
reportFTLCompileTimes=false
reportTotalCompileTimes=false
reportParseTimes=false
reportBytecodeCompileTimes=false
verboseExitProfile=false
verboseCFA=false
verboseDFGFailure=false
verboseFTLToJSThunk=false
verboseFTLFailure=false
alwaysComputeHash=false
testTheFTL=false
verboseSanitizeStack=false
useGenerationalGC=true
useConcurrentBarriers=true
useConcurrentGC=true
collectContinuously=false
collectContinuouslyPeriodMS=1
forceFencedBarrier=false
verboseVisitRace=false
optimizeParallelSlotVisitorsForStoppedMutator=false
largeHeapSize=33554432
smallHeapSize=1048576
smallHeapRAMFraction=0.8 (default: 0.25)
smallHeapGrowthFactor=2
mediumHeapRAMFraction=0.9 (default: 0.5)
mediumHeapGrowthFactor=1.5
largeHeapGrowthFactor=1.24
miniVMHeapGrowthFactor=1.27
criticalGCMemoryThreshold=0.8
minimumMutatorUtilization=0
maximumMutatorUtilization=0.6 (default: 0.7)
epsilonMutatorUtilization=0.01
concurrentGCMaxHeadroom=1.4 (default: 1.5)
concurrentGCPeriodMS=2
useStochasticMutatorScheduler=false (default: true)
minimumGCPauseMS=1 (default: 0.3)
gcPauseScale=0.3
gcIncrementBytes=10000
gcIncrementMaxBytes=100000
gcIncrementScale=0
scribbleFreeCells=false
sizeClassProgression=1.4
largeAllocationCutoff=100000
dumpSizeClasses=false
useBumpAllocator=true
stealEmptyBlocksFromOtherAllocators=true
tradeDestructorBlocks=true
eagerlyUpdateTopCallFrame=false
useOSREntryToDFG=true
useOSREntryToFTL=true
useFTLJIT=false (default: true)
useFTLTBAA=true
validateFTLOSRExitLiveness=false
defaultB3OptLevel=2
b3AlwaysFailsBeforeCompile=false
b3AlwaysFailsBeforeLink=false
ftlCrashes=false
clobberAllRegsInFTLICSlowPath=true
enableJITDebugAssertions=true
useAccessInlining=true
maxAccessVariantListSize=8
usePolyvariantDevirtualization=true
usePolymorphicAccessInlining=true
usePolymorphicCallInlining=true
usePolymorphicCallInliningForNonStubStatus=false
maxPolymorphicCallVariantListSize=15
maxPolymorphicCallVariantListSizeForTopTier=5
maxPolymorphicCallVariantListSizeForWebAssemblyToJS=5
maxPolymorphicCallVariantsForInlining=5
frequentCallThreshold=2
minimumCallToKnownRate=0.51
createPreHeaders=true
useMovHintRemoval=true
usePutStackSinking=true
useObjectAllocationSinking=true
useArityFixupInlining=true
logExecutableAllocation=false
useConcurrentJIT=true
numberOfDFGCompilerThreads=2
numberOfFTLCompilerThreads=1
priorityDeltaOfDFGCompilerThreads=0
priorityDeltaOfFTLCompilerThreads=0
priorityDeltaOfWasmCompilerThreads=0
useProfiler=false
disassembleBaselineForProfiler=true
useArchitectureSpecificOptimizations=true
breakOnThrow=false
maximumOptimizationCandidateInstructionCount=100000
maximumFunctionForCallInlineCandidateInstructionCount=190
maximumFunctionForClosureCallInlineCandidateInstructionCount=100
maximumFunctionForConstructInlineCandidateInstructionCount=100
maximumFTLCandidateInstructionCount=20000
maximumInliningDepth=5
maximumInliningRecursion=2
maximumInliningCallerSize=10000
maximumVarargsForInlining=100
usePolyvariantCallInlining=true
usePolyvariantByIdInlining=true
useMaximalFlushInsertionPhase=false
maximumBinaryStringSwitchCaseLength=50
maximumBinaryStringSwitchTotalLength=2000
jitPolicyScale=1
forceEagerCompilation=false
thresholdForJITAfterWarmUp=500
thresholdForJITSoon=100
thresholdForOptimizeAfterWarmUp=1000
thresholdForOptimizeAfterLongWarmUp=1000
thresholdForOptimizeSoon=1000
executionCounterIncrementForLoop=1
executionCounterIncrementForEntry=15
thresholdForFTLOptimizeAfterWarmUp=100000
thresholdForFTLOptimizeSoon=1000
ftlTierUpCounterIncrementForLoop=1
ftlTierUpCounterIncrementForReturn=15
ftlOSREntryFailureCountForReoptimization=15
ftlOSREntryRetryThreshold=100
evalThresholdMultiplier=10
maximumEvalCacheableSourceLength=256
randomizeExecutionCountsBetweenCheckpoints=false
maximumExecutionCountsBetweenCheckpointsForBaseline=1000
maximumExecutionCountsBetweenCheckpointsForUpperTiers=50000
likelyToTakeSlowCaseMinimumCount=20
couldTakeSlowCaseMinimumCount=10
osrExitCountForReoptimization=100
osrExitCountForReoptimizationFromLoop=5
reoptimizationRetryCounterMax=21 (default: 0)
minimumOptimizationDelay=1
maximumOptimizationDelay=5
desiredProfileLivenessRate=0.75
desiredProfileFullnessRate=0.35
doubleVoteRatioForDoubleFormat=2
structureCheckVoteRatioForHoisting=1
checkArrayVoteRatioForHoisting=1
maximumDirectCallStackSize=200
minimumNumberOfScansBetweenRebalance=100
numberOfGCMarkers=8
useParallelMarkingConstraintSolver=true
opaqueRootMergeThreshold=1000
minHeapUtilization=0.8
minMarkedBlockUtilization=0.9
slowPathAllocsBetweenGCs=0
percentCPUPerMBForFullTimer=0.0003125
percentCPUPerMBForEdenTimer=0.0025
collectionTimerMaxPercentCPU=0.05
forceWeakRandomSeed=false
forcedWeakRandomSeed=0
useZombieMode=false
useImmortalObjects=false
sweepSynchronously=false
maxSingleAllocationSize=0
logGC=None
useGC=true
gcAtEnd=false
forceGCSlowPaths=false
gcMaxHeapSize=0
forceRAMSize=0
recordGCPauseTimes=false
logHeapStatisticsAtExit=false
forceCodeBlockToJettisonDueToOldAge=false
useEagerCodeBlockJettisonTiming=false
useTypeProfiler=false
useControlFlowProfiler=false
useSamplingProfiler=false
sampleInterval=1000
collectSamplingProfilerDataForJSCShell=false
samplingProfilerTopFunctionsCount=12
samplingProfilerTopBytecodesCount=40
samplingProfilerPath=""
sampleCCode=false
alwaysGeneratePCToCodeOriginMap=false
verifyHeap=false
numberOfGCCyclesToRecordForVerification=3
exceptionStackTraceLimit=100
defaultErrorStackTraceLimit=100
useExceptionFuzz=false
fireExceptionFuzzAt=0
validateDFGExceptionHandling=true (default: false)
dumpSimulatedThrows=false
validateExceptionChecks=false
unexpectedExceptionStackTraceLimit=100
useExecutableAllocationFuzz=false
fireExecutableAllocationFuzzAt=0
fireExecutableAllocationFuzzAtOrAfter=0
verboseExecutableAllocationFuzz=false
useOSRExitFuzz=false
fireOSRExitFuzzAtStatic=0
fireOSRExitFuzzAt=0
fireOSRExitFuzzAtOrAfter=0
logPhaseTimes=false
rareBlockPenalty=0.001
airLinearScanVerbose=false
airLinearScanSpillsEverything=false
airForceBriggsAllocator=false
airForceIRCAllocator=false
airRandomizeRegs=false
coalesceSpillSlots=true
logAirRegisterPressure=false
useB3TailDup=true
maxB3TailDupBlockSize=3
maxB3TailDupBlockSuccessors=3
useDollarVM=false
functionOverrides=""
useSigillCrashAnalyzer=true (default: false)
watchdog=0
usePollingTraps=false
useMachForExceptions=false (default: true)
useICStats=false
prototypeHitCountForLLIntCaching=2
dumpCompiledRegExpPatterns=false
dumpModuleRecord=false
dumpModuleLoadingState=false
exposeInternalModuleLoader=false
useSuperSampler=false
useSourceProviderCache=true
useCodeCache=true
useWebAssembly=false (default: true)
enableSpectreMitigations=true
enableSpectreGadgets=false
usePoisoning=true
zeroStackFrame=false
useAsyncIterator=true
failToCompileWebAssemblyCode=false
webAssemblyPartialCompileLimit=5000
webAssemblyBBQOptimizationLevel=1
webAssemblyOMGOptimizationLevel=2
useBBQTierUpChecks=true
webAssemblyOMGTierUpCount=5000
webAssemblyLoopDecrement=15
webAssemblyFunctionEntryDecrement=1
useWebAssemblyFastMemory=false
logWebAssemblyMemory=false
webAssemblyFastMemoryRedzonePages=128
crashIfWebAssemblyCantFastMemory=false
maxNumWebAssemblyFastMemories=4
useFastTLSForWasmContext=false (default: true)
useWebAssemblyStreamingApi=false
useCallICsForWebAssemblyToJSCalls=true
useEagerWebAssemblyModuleHashing=false
useObjectRestSpread=true
useBigInt=false
useIntlNumberFormatToParts=false
useIntlPluralRules=false
useArrayAllocationProfiling=true
forcePolyProto=false
forceMiniVMMode=false
useTracePoints=false
Seems that options apply (tried with logGC) but can't see any log in terminal or Console app, only if I open the project in Xcode. Where is expected to see the output of these options?
Automation tests should be added after merging #1093