Implement a sampling profiler
https://bugs.webkit.org/show_bug.cgi?id=151713
Reviewed by Filip Pizlo.
Source/JavaScriptCore:
This patch implements a sampling profiler for JavaScriptCore
that will be used in the Inspector UI. The implementation works as follows:
We queue the sampling profiler to run a task on a background
thread every 1ms. When the queued task executes, the sampling profiler
will pause the JSC execution thread and attempt to take a stack trace.
The sampling profiler does everything it can to be very careful
while taking this stack trace. Because it's reading arbitrary memory,
the sampling profiler must validate every pointer it reads from.
The sampling profiler tries to get an ExecutableBase for every call frame
it reads. It first tries to read the CodeBlock slot. It does this because
it can be 100% certain that a pointer is a CodeBlock while it's taking a
stack trace. But, not every call frame will have a CodeBlock. So we must read
the call frame's callee. For these stack traces where we read the callee, we
must verify the callee pointer, and the pointer traversal to an ExecutableBase,
on the main JSC execution thread, and not on the thread taking the stack
trace. We do this verification either before we run the marking phase in
GC, or when somebody asks the SamplingProfiler to materialize its data.
The SamplingProfiler must also be careful to not grab any locks while the JSC execution
thread is paused (this means it can't do anything that mallocs) because
that could cause a deadlock. Therefore, the sampling profiler grabs
locks for all data structures it consults before it pauses the JSC
execution thread.
* CMakeLists.txt:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters:
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/CodeBlock.h:
(JSC::CodeBlock::clearVisitWeaklyHasBeenCalled):
(JSC::CodeBlockSet::mark):
* dfg/DFGNodeType.h:
* heap/CodeBlockSet.cpp:
(JSC::CodeBlockSet::add):
(JSC::CodeBlockSet::promoteYoungCodeBlocks):
(JSC::CodeBlockSet::clearMarksForFullCollection):
(JSC::CodeBlockSet::lastChanceToFinalize):
(JSC::CodeBlockSet::deleteUnmarkedAndUnreferenced):
(JSC::CodeBlockSet::contains):
(JSC::CodeBlockSet::writeBarrierCurrentlyExecutingCodeBlocks):
(JSC::CodeBlockSet::remove): Deleted.
* heap/CodeBlockSet.h:
(JSC::CodeBlockSet::getLock):
(JSC::CodeBlockSet::iterate):
The sampling pofiler uses the heap's CodeBlockSet to validate
CodeBlock pointers. This data structure must now be under a lock
because we must be certain we're not pausing the JSC execution thread
while it's manipulating this data structure.
* heap/ConservativeRoots.cpp:
(JSC::ConservativeRoots::ConservativeRoots):
(JSC::ConservativeRoots::grow):
(JSC::ConservativeRoots::genericAddPointer):
(JSC::ConservativeRoots::genericAddSpan):
(JSC::ConservativeRoots::add):
(JSC::CompositeMarkHook::CompositeMarkHook):
(JSC::CompositeMarkHook::mark):
* heap/ConservativeRoots.h:
* heap/Heap.cpp:
(JSC::Heap::markRoots):
(JSC::Heap::visitHandleStack):
(JSC::Heap::visitSamplingProfiler):
(JSC::Heap::traceCodeBlocksAndJITStubRoutines):
(JSC::Heap::snapshotMarkedSpace):
* heap/Heap.h:
(JSC::Heap::structureIDTable):
(JSC::Heap::codeBlockSet):
* heap/MachineStackMarker.cpp:
(pthreadSignalHandlerSuspendResume):
(JSC::getCurrentPlatformThread):
(JSC::MachineThreads::MachineThreads):
(JSC::MachineThreads::~MachineThreads):
(JSC::MachineThreads::Thread::createForCurrentThread):
(JSC::MachineThreads::Thread::operator==):
(JSC::isThreadInList):
(JSC::MachineThreads::addCurrentThread):
(JSC::MachineThreads::machineThreadForCurrentThread):
(JSC::MachineThreads::removeThread):
(JSC::MachineThreads::gatherFromCurrentThread):
(JSC::MachineThreads::Thread::Thread):
(JSC::MachineThreads::Thread::~Thread):
(JSC::MachineThreads::Thread::suspend):
(JSC::MachineThreads::Thread::resume):
(JSC::MachineThreads::Thread::getRegisters):
(JSC::MachineThreads::Thread::Registers::stackPointer):
(JSC::MachineThreads::Thread::Registers::framePointer):
(JSC::MachineThreads::Thread::Registers::instructionPointer):
(JSC::MachineThreads::Thread::freeRegisters):
(JSC::MachineThreads::tryCopyOtherThreadStacks):
(JSC::pthreadSignalHandlerSuspendResume): Deleted.
(JSC::MachineThreads::Thread::operator!=): Deleted.
* heap/MachineStackMarker.h:
(JSC::MachineThreads::Thread::operator!=):
(JSC::MachineThreads::getLock):
(JSC::MachineThreads::threadsListHead):
We can now ask a MachineThreads::Thread for its frame pointer
and program counter on darwin and windows platforms. efl
and gtk implementations will happen in another patch.
* heap/MarkedBlockSet.h:
(JSC::MarkedBlockSet::getLock):
(JSC::MarkedBlockSet::add):
(JSC::MarkedBlockSet::remove):
(JSC::MarkedBlockSet::recomputeFilter):
(JSC::MarkedBlockSet::filter):
(JSC::MarkedBlockSet::set):
* heap/MarkedSpace.cpp:
(JSC::Free::Free):
(JSC::Free::operator()):
(JSC::FreeOrShrink::FreeOrShrink):
(JSC::FreeOrShrink::operator()):
(JSC::MarkedSpace::~MarkedSpace):
(JSC::MarkedSpace::isPagedOut):
(JSC::MarkedSpace::freeBlock):
(JSC::MarkedSpace::freeOrShrinkBlock):
(JSC::MarkedSpace::shrink):
* heap/MarkedSpace.h:
(JSC::MarkedSpace::forEachLiveCell):
(JSC::MarkedSpace::forEachDeadCell):
* interpreter/CallFrame.h:
(JSC::ExecState::calleeAsValue):
(JSC::ExecState::callee):
(JSC::ExecState::unsafeCallee):
(JSC::ExecState::codeBlock):
(JSC::ExecState::scope):
* jit/ExecutableAllocator.cpp:
(JSC::ExecutableAllocator::dumpProfile):
(JSC::ExecutableAllocator::getLock):
(JSC::ExecutableAllocator::isValidExecutableMemory):
* jit/ExecutableAllocator.h:
* jit/ExecutableAllocatorFixedVMPool.cpp:
(JSC::ExecutableAllocator::allocate):
(JSC::ExecutableAllocator::isValidExecutableMemory):
(JSC::ExecutableAllocator::getLock):
(JSC::ExecutableAllocator::committedByteCount):
The sampling profiler consults the ExecutableAllocator to check
if the frame pointer it reads is in executable allocated memory.
* jsc.cpp:
(GlobalObject::finishCreation):
(functionCheckModuleSyntax):
(functionStartSamplingProfiler):
(functionSamplingProfilerStackTraces):
* llint/LLIntPCRanges.h: Added.
(JSC::LLInt::isLLIntPC):
* offlineasm/asm.rb:
I added the ability to test whether the PC is executing
LLInt code because this code is not part of the memory
our executable allocator allocates.
* runtime/Executable.h:
(JSC::ExecutableBase::isModuleProgramExecutable):
(JSC::ExecutableBase::isExecutableType):
(JSC::ExecutableBase::isHostFunction):
* runtime/JSLock.cpp:
(JSC::JSLock::didAcquireLock):
(JSC::JSLock::unlock):
* runtime/Options.h:
* runtime/SamplingProfiler.cpp: Added.
(JSC::reportStats):
(JSC::FrameWalker::FrameWalker):
(JSC::FrameWalker::walk):
(JSC::FrameWalker::wasValidWalk):
(JSC::FrameWalker::advanceToParentFrame):
(JSC::FrameWalker::isAtTop):
(JSC::FrameWalker::resetAtMachineFrame):
(JSC::FrameWalker::isValidFramePointer):
(JSC::FrameWalker::isValidCodeBlock):
(JSC::FrameWalker::tryToGetExecutableFromCallee):
The FrameWalker class is used to walk the stack in a safe
manner. It doesn't do anything that would deadlock, and it
validates all pointers that it sees.
(JSC::SamplingProfiler::SamplingProfiler):
(JSC::SamplingProfiler::~SamplingProfiler):
(JSC::SamplingProfiler::visit):
(JSC::SamplingProfiler::shutdown):
(JSC::SamplingProfiler::start):
(JSC::SamplingProfiler::stop):
(JSC::SamplingProfiler::pause):
(JSC::SamplingProfiler::noticeCurrentThreadAsJSCExecutionThread):
(JSC::SamplingProfiler::dispatchIfNecessary):
(JSC::SamplingProfiler::dispatchFunction):
(JSC::SamplingProfiler::noticeJSLockAcquisition):
(JSC::SamplingProfiler::noticeVMEntry):
(JSC::SamplingProfiler::observeStackTrace):
(JSC::SamplingProfiler::clearData):
(JSC::displayName):
(JSC::startLine):
(JSC::startColumn):
(JSC::sourceID):
(JSC::url):
(JSC::SamplingProfiler::stacktracesAsJSON):
* runtime/SamplingProfiler.h: Added.
(JSC::SamplingProfiler::getLock):
(JSC::SamplingProfiler::setTimingInterval):
(JSC::SamplingProfiler::stackTraces):
* runtime/VM.cpp:
(JSC::VM::VM):
(JSC::VM::~VM):
(JSC::VM::setLastStackTop):
(JSC::VM::createContextGroup):
(JSC::VM::ensureWatchdog):
(JSC::VM::ensureSamplingProfiler):
(JSC::thunkGeneratorForIntrinsic):
* runtime/VM.h:
(JSC::VM::watchdog):
(JSC::VM::isSafeToRecurse):
(JSC::VM::lastStackTop):
(JSC::VM::scratchBufferForSize):
(JSC::VM::samplingProfiler):
(JSC::VM::setShouldRewriteConstAsVar):
(JSC::VM::setLastStackTop): Deleted.
* runtime/VMEntryScope.cpp:
(JSC::VMEntryScope::VMEntryScope):
* tests/stress/sampling-profiler: Added.
* tests/stress/sampling-profiler-anonymous-function.js: Added.
(foo):
(baz):
* tests/stress/sampling-profiler-basic.js: Added.
(bar):
(foo):
(nothing):
(top):
(jaz):
(kaz):
(checkInlining):
* tests/stress/sampling-profiler-deep-stack.js: Added.
(foo):
(hellaDeep):
(start):
* tests/stress/sampling-profiler-microtasks.js: Added.
(testResults):
(loop.jaz):
(loop):
* tests/stress/sampling-profiler/samplingProfiler.js: Added.
(assert):
(let.nodePrototype.makeChildIfNeeded):
(makeNode):
(updateCallingContextTree):
(doesTreeHaveStackTrace):
(makeTree):
(runTest):
(dumpTree):
* tools/JSDollarVMPrototype.cpp:
(JSC::JSDollarVMPrototype::isInObjectSpace):
(JSC::JSDollarVMPrototype::isInStorageSpace):
* yarr/YarrJIT.cpp:
(JSC::Yarr::YarrGenerator::generateEnter):
(JSC::Yarr::YarrGenerator::generateReturn):
(JSC::Yarr::YarrGenerator::YarrGenerator):
(JSC::Yarr::YarrGenerator::compile):
(JSC::Yarr::jitCompile):
We now have a boolean that's set to true when
we're executing a RegExp, and to false otherwise.
The boolean lives off of VM.
* CMakeLists.txt:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters:
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/CodeBlock.h:
(JSC::CodeBlock::clearVisitWeaklyHasBeenCalled):
(JSC::CodeBlockSet::mark):
* dfg/DFGNodeType.h:
* heap/CodeBlockSet.cpp:
(JSC::CodeBlockSet::add):
(JSC::CodeBlockSet::promoteYoungCodeBlocks):
(JSC::CodeBlockSet::clearMarksForFullCollection):
(JSC::CodeBlockSet::lastChanceToFinalize):
(JSC::CodeBlockSet::deleteUnmarkedAndUnreferenced):
(JSC::CodeBlockSet::contains):
(JSC::CodeBlockSet::writeBarrierCurrentlyExecutingCodeBlocks):
(JSC::CodeBlockSet::remove): Deleted.
* heap/CodeBlockSet.h:
(JSC::CodeBlockSet::getLock):
(JSC::CodeBlockSet::iterate):
* heap/ConservativeRoots.cpp:
(JSC::ConservativeRoots::ConservativeRoots):
(JSC::ConservativeRoots::genericAddPointer):
(JSC::ConservativeRoots::add):
(JSC::CompositeMarkHook::CompositeMarkHook):
(JSC::CompositeMarkHook::mark):
* heap/ConservativeRoots.h:
* heap/Heap.cpp:
(JSC::Heap::markRoots):
(JSC::Heap::visitHandleStack):
(JSC::Heap::visitSamplingProfiler):
(JSC::Heap::traceCodeBlocksAndJITStubRoutines):
* heap/Heap.h:
(JSC::Heap::structureIDTable):
(JSC::Heap::codeBlockSet):
* heap/HeapInlines.h:
(JSC::Heap::didFreeBlock):
(JSC::Heap::isPointerGCObject):
(JSC::Heap::isValueGCObject):
* heap/MachineStackMarker.cpp:
(pthreadSignalHandlerSuspendResume):
(JSC::getCurrentPlatformThread):
(JSC::MachineThreads::MachineThreads):
(JSC::MachineThreads::~MachineThreads):
(JSC::MachineThreads::Thread::createForCurrentThread):
(JSC::MachineThreads::Thread::operator==):
(JSC::isThreadInList):
(JSC::MachineThreads::addCurrentThread):
(JSC::MachineThreads::machineThreadForCurrentThread):
(JSC::MachineThreads::removeThread):
(JSC::MachineThreads::gatherFromCurrentThread):
(JSC::MachineThreads::Thread::Thread):
(JSC::MachineThreads::Thread::~Thread):
(JSC::MachineThreads::Thread::suspend):
(JSC::MachineThreads::Thread::resume):
(JSC::MachineThreads::Thread::getRegisters):
(JSC::MachineThreads::Thread::Registers::stackPointer):
(JSC::MachineThreads::Thread::Registers::framePointer):
(JSC::MachineThreads::Thread::Registers::instructionPointer):
(JSC::MachineThreads::Thread::freeRegisters):
(JSC::pthreadSignalHandlerSuspendResume): Deleted.
(JSC::MachineThreads::Thread::operator!=): Deleted.
* heap/MachineStackMarker.h:
(JSC::MachineThreads::Thread::operator!=):
(JSC::MachineThreads::getLock):
(JSC::MachineThreads::threadsListHead):
* heap/MarkedBlockSet.h:
* heap/MarkedSpace.cpp:
(JSC::Free::Free):
(JSC::Free::operator()):
(JSC::FreeOrShrink::FreeOrShrink):
(JSC::FreeOrShrink::operator()):
* interpreter/CallFrame.h:
(JSC::ExecState::calleeAsValue):
(JSC::ExecState::callee):
(JSC::ExecState::unsafeCallee):
(JSC::ExecState::codeBlock):
(JSC::ExecState::scope):
* jit/ExecutableAllocator.cpp:
(JSC::ExecutableAllocator::dumpProfile):
(JSC::ExecutableAllocator::getLock):
(JSC::ExecutableAllocator::isValidExecutableMemory):
* jit/ExecutableAllocator.h:
* jit/ExecutableAllocatorFixedVMPool.cpp:
(JSC::ExecutableAllocator::allocate):
(JSC::ExecutableAllocator::isValidExecutableMemory):
(JSC::ExecutableAllocator::getLock):
(JSC::ExecutableAllocator::committedByteCount):
* jsc.cpp:
(GlobalObject::finishCreation):
(functionCheckModuleSyntax):
(functionPlatformSupportsSamplingProfiler):
(functionStartSamplingProfiler):
(functionSamplingProfilerStackTraces):
* llint/LLIntPCRanges.h: Added.
(JSC::LLInt::isLLIntPC):
* offlineasm/asm.rb:
* runtime/Executable.h:
(JSC::ExecutableBase::isModuleProgramExecutable):
(JSC::ExecutableBase::isExecutableType):
(JSC::ExecutableBase::isHostFunction):
* runtime/JSLock.cpp:
(JSC::JSLock::didAcquireLock):
(JSC::JSLock::unlock):
* runtime/Options.h:
* runtime/SamplingProfiler.cpp: Added.
(JSC::reportStats):
(JSC::FrameWalker::FrameWalker):
(JSC::FrameWalker::walk):
(JSC::FrameWalker::wasValidWalk):
(JSC::FrameWalker::advanceToParentFrame):
(JSC::FrameWalker::isAtTop):
(JSC::FrameWalker::resetAtMachineFrame):
(JSC::FrameWalker::isValidFramePointer):
(JSC::FrameWalker::isValidCodeBlock):
(JSC::SamplingProfiler::SamplingProfiler):
(JSC::SamplingProfiler::~SamplingProfiler):
(JSC::SamplingProfiler::processUnverifiedStackTraces):
(JSC::SamplingProfiler::visit):
(JSC::SamplingProfiler::shutdown):
(JSC::SamplingProfiler::start):
(JSC::SamplingProfiler::stop):
(JSC::SamplingProfiler::pause):
(JSC::SamplingProfiler::noticeCurrentThreadAsJSCExecutionThread):
(JSC::SamplingProfiler::dispatchIfNecessary):
(JSC::SamplingProfiler::dispatchFunction):
(JSC::SamplingProfiler::noticeJSLockAcquisition):
(JSC::SamplingProfiler::noticeVMEntry):
(JSC::SamplingProfiler::clearData):
(JSC::displayName):
(JSC::SamplingProfiler::stacktracesAsJSON):
(WTF::printInternal):
* runtime/SamplingProfiler.h: Added.
(JSC::SamplingProfiler::StackFrame::StackFrame):
(JSC::SamplingProfiler::getLock):
(JSC::SamplingProfiler::setTimingInterval):
(JSC::SamplingProfiler::stackTraces):
* runtime/VM.cpp:
(JSC::VM::VM):
(JSC::VM::~VM):
(JSC::VM::setLastStackTop):
(JSC::VM::createContextGroup):
(JSC::VM::ensureWatchdog):
(JSC::VM::ensureSamplingProfiler):
(JSC::thunkGeneratorForIntrinsic):
* runtime/VM.h:
(JSC::VM::watchdog):
(JSC::VM::samplingProfiler):
(JSC::VM::isSafeToRecurse):
(JSC::VM::lastStackTop):
(JSC::VM::scratchBufferForSize):
(JSC::VM::setLastStackTop): Deleted.
* runtime/VMEntryScope.cpp:
(JSC::VMEntryScope::VMEntryScope):
* tests/stress/sampling-profiler: Added.
* tests/stress/sampling-profiler-anonymous-function.js: Added.
(platformSupportsSamplingProfiler.foo):
(platformSupportsSamplingProfiler.baz):
(platformSupportsSamplingProfiler):
* tests/stress/sampling-profiler-basic.js: Added.
(platformSupportsSamplingProfiler.bar):
(platformSupportsSamplingProfiler.foo):
(platformSupportsSamplingProfiler.nothing):
(platformSupportsSamplingProfiler.top):
(platformSupportsSamplingProfiler.jaz):
(platformSupportsSamplingProfiler.kaz):
(platformSupportsSamplingProfiler.checkInlining):
(platformSupportsSamplingProfiler):
* tests/stress/sampling-profiler-deep-stack.js: Added.
(platformSupportsSamplingProfiler.foo):
(platformSupportsSamplingProfiler.let.hellaDeep):
(platformSupportsSamplingProfiler.let.start):
(platformSupportsSamplingProfiler):
* tests/stress/sampling-profiler-microtasks.js: Added.
(platformSupportsSamplingProfiler.testResults):
(platformSupportsSamplingProfiler):
(platformSupportsSamplingProfiler.loop.jaz):
(platformSupportsSamplingProfiler.loop):
* tests/stress/sampling-profiler/samplingProfiler.js: Added.
(assert):
(let.nodePrototype.makeChildIfNeeded):
(makeNode):
(updateCallingContextTree):
(doesTreeHaveStackTrace):
(makeTree):
(runTest):
(dumpTree):
* yarr/YarrJIT.cpp:
(JSC::Yarr::YarrGenerator::generateEnter):
(JSC::Yarr::YarrGenerator::generateReturn):
(JSC::Yarr::YarrGenerator::YarrGenerator):
(JSC::Yarr::YarrGenerator::compile):
(JSC::Yarr::jitCompile):
Source/WTF:
* wtf/MetaAllocator.cpp:
(WTF::MetaAllocator::decrementPageOccupancy):
(WTF::MetaAllocator::isInAllocatedMemory):
(WTF::MetaAllocator::roundUp):
* wtf/MetaAllocator.h:
(WTF::MetaAllocator::getLock):
* wtf/Platform.h:
Tools:
* Scripts/run-jsc-stress-tests:
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@194840 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/heap/CodeBlockSet.cpp b/Source/JavaScriptCore/heap/CodeBlockSet.cpp
index 7c6cee2..0cfcd1f 100644
--- a/Source/JavaScriptCore/heap/CodeBlockSet.cpp
+++ b/Source/JavaScriptCore/heap/CodeBlockSet.cpp
@@ -45,28 +45,32 @@
void CodeBlockSet::add(CodeBlock* codeBlock)
{
+ LockHolder locker(&m_lock);
bool isNewEntry = m_newCodeBlocks.add(codeBlock).isNewEntry;
ASSERT_UNUSED(isNewEntry, isNewEntry);
}
-void CodeBlockSet::promoteYoungCodeBlocks()
+void CodeBlockSet::promoteYoungCodeBlocks(const LockHolder&)
{
+ ASSERT(m_lock.isLocked());
m_oldCodeBlocks.add(m_newCodeBlocks.begin(), m_newCodeBlocks.end());
m_newCodeBlocks.clear();
}
void CodeBlockSet::clearMarksForFullCollection()
{
+ LockHolder locker(&m_lock);
for (CodeBlock* codeBlock : m_oldCodeBlocks)
codeBlock->clearVisitWeaklyHasBeenCalled();
// We promote after we clear marks on the old generation CodeBlocks because
// none of the young generations CodeBlocks need to be cleared.
- promoteYoungCodeBlocks();
+ promoteYoungCodeBlocks(locker);
}
void CodeBlockSet::lastChanceToFinalize()
{
+ LockHolder locker(&m_lock);
for (CodeBlock* codeBlock : m_newCodeBlocks)
codeBlock->classInfo()->methodTable.destroy(codeBlock);
@@ -76,6 +80,7 @@
void CodeBlockSet::deleteUnmarkedAndUnreferenced(HeapOperation collectionType)
{
+ LockHolder locker(&m_lock);
HashSet<CodeBlock*>& set = collectionType == EdenCollection ? m_newCodeBlocks : m_oldCodeBlocks;
Vector<CodeBlock*> unmarked;
for (CodeBlock* codeBlock : set) {
@@ -91,21 +96,21 @@
// Any remaining young CodeBlocks are live and need to be promoted to the set of old CodeBlocks.
if (collectionType == EdenCollection)
- promoteYoungCodeBlocks();
+ promoteYoungCodeBlocks(locker);
}
-void CodeBlockSet::remove(CodeBlock* codeBlock)
+bool CodeBlockSet::contains(const LockHolder&, void* candidateCodeBlock)
{
- if (m_oldCodeBlocks.contains(codeBlock)) {
- m_oldCodeBlocks.remove(codeBlock);
- return;
- }
- ASSERT(m_newCodeBlocks.contains(codeBlock));
- m_newCodeBlocks.remove(codeBlock);
+ RELEASE_ASSERT(m_lock.isLocked());
+ CodeBlock* codeBlock = static_cast<CodeBlock*>(candidateCodeBlock);
+ if (!HashSet<CodeBlock*>::isValidValue(codeBlock))
+ return false;
+ return m_oldCodeBlocks.contains(codeBlock) || m_newCodeBlocks.contains(codeBlock) || m_currentlyExecuting.contains(codeBlock);
}
void CodeBlockSet::writeBarrierCurrentlyExecutingCodeBlocks(Heap* heap)
{
+ LockHolder locker(&m_lock);
if (verbose)
dataLog("Remembering ", m_currentlyExecuting.size(), " code blocks.\n");
for (CodeBlock* codeBlock : m_currentlyExecuting)
