|  | /* | 
|  | * Copyright (C) 2016-2021 Apple Inc. All rights reserved. | 
|  | * | 
|  | * Redistribution and use in source and binary forms, with or without | 
|  | * modification, are permitted provided that the following conditions | 
|  | * are met: | 
|  | * 1. Redistributions of source code must retain the above copyright | 
|  | *    notice, this list of conditions and the following disclaimer. | 
|  | * 2. Redistributions in binary form must reproduce the above copyright | 
|  | *    notice, this list of conditions and the following disclaimer in the | 
|  | *    documentation and/or other materials provided with the distribution. | 
|  | * | 
|  | * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY | 
|  | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | 
|  | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | 
|  | * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR | 
|  | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | 
|  | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | 
|  | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | 
|  | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY | 
|  | * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 
|  | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 
|  | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
|  | */ | 
|  |  | 
|  | #include "config.h" | 
|  | #include "SamplingProfiler.h" | 
|  |  | 
|  | #if ENABLE(SAMPLING_PROFILER) | 
|  |  | 
|  | #include "CodeBlock.h" | 
|  | #include "CodeBlockSet.h" | 
|  | #include "HeapIterationScope.h" | 
|  | #include "HeapUtil.h" | 
|  | #include "InlineCallFrame.h" | 
|  | #include "JSCInlines.h" | 
|  | #include "LLIntPCRanges.h" | 
|  | #include "MachineContext.h" | 
|  | #include "MarkedBlockInlines.h" | 
|  | #include "MarkedBlockSet.h" | 
|  | #include "NativeExecutable.h" | 
|  | #include "VM.h" | 
|  | #include "VMTrapsInlines.h" | 
|  | #include "WasmCallee.h" | 
|  | #include "WasmCalleeRegistry.h" | 
|  | #include "WasmCapabilities.h" | 
|  | #include <wtf/FilePrintStream.h> | 
|  | #include <wtf/HashSet.h> | 
|  | #include <wtf/RefPtr.h> | 
|  | #include <wtf/StackTrace.h> | 
|  | #include <wtf/text/StringBuilder.h> | 
|  |  | 
|  | namespace JSC { | 
|  |  | 
|  | static double sNumTotalStackTraces = 0; | 
|  | static double sNumTotalWalks = 0; | 
|  | static double sNumFailedWalks = 0; | 
|  | static const uint32_t sNumWalkReportingFrequency = 50; | 
|  | static const double sWalkErrorPercentage = .05; | 
|  | static constexpr bool sReportStatsOnlyWhenTheyreAboveThreshold = false; | 
|  | static constexpr bool sReportStats = false; | 
|  |  | 
|  | using FrameType = SamplingProfiler::FrameType; | 
|  | using UnprocessedStackFrame = SamplingProfiler::UnprocessedStackFrame; | 
|  |  | 
|  | ALWAYS_INLINE static void reportStats() | 
|  | { | 
|  | if (sReportStats && sNumTotalWalks && static_cast<uint64_t>(sNumTotalWalks) % sNumWalkReportingFrequency == 0) { | 
|  | if (!sReportStatsOnlyWhenTheyreAboveThreshold || (sNumFailedWalks / sNumTotalWalks > sWalkErrorPercentage)) { | 
|  | dataLogF("Num total walks: %llu. Failed walks percent: %lf\n", | 
|  | static_cast<unsigned long long>(sNumTotalWalks), sNumFailedWalks / sNumTotalWalks); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | class FrameWalker { | 
|  | public: | 
|  | FrameWalker(VM& vm, CallFrame* callFrame, const AbstractLocker& codeBlockSetLocker, const AbstractLocker& machineThreadsLocker) | 
|  | : m_vm(vm) | 
|  | , m_callFrame(callFrame) | 
|  | , m_entryFrame(vm.topEntryFrame) | 
|  | , m_codeBlockSetLocker(codeBlockSetLocker) | 
|  | , m_machineThreadsLocker(machineThreadsLocker) | 
|  | { | 
|  | } | 
|  |  | 
|  | SUPPRESS_ASAN | 
|  | size_t walk(Vector<UnprocessedStackFrame>& stackTrace, bool& didRunOutOfSpace) | 
|  | { | 
|  | if (sReportStats) | 
|  | sNumTotalWalks++; | 
|  | resetAtMachineFrame(); | 
|  | size_t maxStackTraceSize = stackTrace.size(); | 
|  | while (!isAtTop() && !m_bailingOut && m_depth < maxStackTraceSize) { | 
|  | recordJITFrame(stackTrace); | 
|  | advanceToParentFrame(); | 
|  | resetAtMachineFrame(); | 
|  | } | 
|  | didRunOutOfSpace = m_depth >= maxStackTraceSize && !isAtTop(); | 
|  | reportStats(); | 
|  | return m_depth; | 
|  | } | 
|  |  | 
|  | bool wasValidWalk() const | 
|  | { | 
|  | return !m_bailingOut; | 
|  | } | 
|  |  | 
|  | protected: | 
|  |  | 
|  | SUPPRESS_ASAN | 
|  | void recordJITFrame(Vector<UnprocessedStackFrame>& stackTrace) | 
|  | { | 
|  | CallSiteIndex callSiteIndex; | 
|  | CalleeBits unsafeCallee = m_callFrame->unsafeCallee(); | 
|  | CodeBlock* codeBlock = m_callFrame->unsafeCodeBlock(); | 
|  | if (unsafeCallee.isWasm()) | 
|  | codeBlock = nullptr; | 
|  | if (codeBlock) { | 
|  | ASSERT(isValidCodeBlock(codeBlock)); | 
|  | callSiteIndex = m_callFrame->unsafeCallSiteIndex(); | 
|  | } | 
|  | stackTrace[m_depth] = UnprocessedStackFrame(codeBlock, unsafeCallee, callSiteIndex); | 
|  | #if ENABLE(WEBASSEMBLY) | 
|  | if (Wasm::isSupported() && unsafeCallee.isWasm()) { | 
|  | assertIsHeld(Wasm::CalleeRegistry::singleton().getLock()); | 
|  | auto* wasmCallee = unsafeCallee.asWasmCallee(); | 
|  | if (Wasm::CalleeRegistry::singleton().isValidCallee(wasmCallee)) { | 
|  | // At this point, Wasm::Callee would be dying (ref count is 0), but its fields are still live. | 
|  | // And we can safely copy Wasm::IndexOrName even when any lock is held by suspended threads. | 
|  | stackTrace[m_depth].wasmIndexOrName = wasmCallee->indexOrName(); | 
|  | stackTrace[m_depth].wasmCompilationMode = wasmCallee->compilationMode(); | 
|  | } | 
|  | } | 
|  | #endif | 
|  | m_depth++; | 
|  | } | 
|  |  | 
|  | SUPPRESS_ASAN | 
|  | void advanceToParentFrame() | 
|  | { | 
|  | m_callFrame = m_callFrame->unsafeCallerFrame(m_entryFrame); | 
|  | } | 
|  |  | 
|  | bool isAtTop() const | 
|  | { | 
|  | return !m_callFrame; | 
|  | } | 
|  |  | 
|  | SUPPRESS_ASAN | 
|  | void resetAtMachineFrame() | 
|  | { | 
|  | if (isAtTop()) | 
|  | return; | 
|  |  | 
|  | if (!isValidFramePointer(m_callFrame)) { | 
|  | // Guard against pausing the process at weird program points. | 
|  | m_bailingOut = true; | 
|  | if (sReportStats) | 
|  | sNumFailedWalks++; | 
|  | return; | 
|  | } | 
|  |  | 
|  | CodeBlock* codeBlock = m_callFrame->unsafeCodeBlock(); | 
|  | if (!codeBlock || m_callFrame->unsafeCallee().isWasm()) | 
|  | return; | 
|  |  | 
|  | if (!isValidCodeBlock(codeBlock)) { | 
|  | m_bailingOut = true; | 
|  | if (sReportStats) | 
|  | sNumFailedWalks++; | 
|  | return; | 
|  | } | 
|  | } | 
|  |  | 
|  | bool isValidFramePointer(void* callFrame) | 
|  | { | 
|  | uint8_t* fpCast = bitwise_cast<uint8_t*>(callFrame); | 
|  | for (auto& thread : m_vm.heap.machineThreads().threads(m_machineThreadsLocker)) { | 
|  | uint8_t* stackBase = static_cast<uint8_t*>(thread->stack().origin()); | 
|  | uint8_t* stackLimit = static_cast<uint8_t*>(thread->stack().end()); | 
|  | RELEASE_ASSERT(stackBase); | 
|  | RELEASE_ASSERT(stackLimit); | 
|  | RELEASE_ASSERT(stackLimit <= stackBase); | 
|  | if (fpCast < stackBase && fpCast >= stackLimit) | 
|  | return true; | 
|  | } | 
|  | return false; | 
|  | } | 
|  |  | 
|  | bool isValidCodeBlock(CodeBlock* codeBlock) | 
|  | { | 
|  | if (!codeBlock) | 
|  | return false; | 
|  | bool result = m_vm.heap.codeBlockSet().contains(m_codeBlockSetLocker, codeBlock); | 
|  | return result; | 
|  | } | 
|  |  | 
|  | VM& m_vm; | 
|  | CallFrame* m_callFrame; | 
|  | EntryFrame* m_entryFrame; | 
|  | const AbstractLocker& m_codeBlockSetLocker; | 
|  | const AbstractLocker& m_machineThreadsLocker; | 
|  | bool m_bailingOut { false }; | 
|  | size_t m_depth { 0 }; | 
|  | }; | 
|  |  | 
|  | class CFrameWalker : public FrameWalker { | 
|  | public: | 
|  | typedef FrameWalker Base; | 
|  |  | 
|  | CFrameWalker(VM& vm, void* machineFrame, CallFrame* callFrame, const AbstractLocker& codeBlockSetLocker, const AbstractLocker& machineThreadsLocker) | 
|  | : Base(vm, callFrame, codeBlockSetLocker, machineThreadsLocker) | 
|  | , m_machineFrame(machineFrame) | 
|  | { | 
|  | } | 
|  |  | 
|  | size_t walk(Vector<UnprocessedStackFrame>& stackTrace, bool& didRunOutOfSpace) | 
|  | { | 
|  | if (sReportStats) | 
|  | sNumTotalWalks++; | 
|  | resetAtMachineFrame(); | 
|  | size_t maxStackTraceSize = stackTrace.size(); | 
|  | // The way the C walker decides if a frame it is about to trace is C or JS is by | 
|  | // ensuring m_callFrame points to some frame above the machineFrame. | 
|  | if (!isAtTop() && !m_bailingOut && m_machineFrame == m_callFrame) { | 
|  | recordJITFrame(stackTrace); | 
|  | Base::advanceToParentFrame(); | 
|  | resetAtMachineFrame(); | 
|  | } | 
|  |  | 
|  | while (!isAtTop() && !m_bailingOut && m_depth < maxStackTraceSize) { | 
|  | if (m_machineFrame >= m_callFrame) { | 
|  | // If we get to this state we probably have an invalid trace. | 
|  | m_bailingOut = true; | 
|  | break; | 
|  | } | 
|  |  | 
|  | if (isCFrame()) { | 
|  | RELEASE_ASSERT(!LLInt::isLLIntPC(frame()->callerFrame)); | 
|  | stackTrace[m_depth] = UnprocessedStackFrame(frame()->returnPC); | 
|  | m_depth++; | 
|  | } else | 
|  | recordJITFrame(stackTrace); | 
|  | advanceToParentFrame(); | 
|  | resetAtMachineFrame(); | 
|  | } | 
|  | didRunOutOfSpace = m_depth >= maxStackTraceSize && !isAtTop(); | 
|  | reportStats(); | 
|  | return m_depth; | 
|  | } | 
|  |  | 
|  | private: | 
|  |  | 
|  | bool isCFrame() | 
|  | { | 
|  | return frame()->callerFrame != m_callFrame; | 
|  | } | 
|  |  | 
|  | void advanceToParentFrame() | 
|  | { | 
|  | if (!isCFrame()) | 
|  | Base::advanceToParentFrame(); | 
|  | m_machineFrame = frame()->callerFrame; | 
|  | } | 
|  |  | 
|  | void resetAtMachineFrame() | 
|  | { | 
|  | if (!isValidFramePointer(m_machineFrame)) { | 
|  | // Guard against pausing the process at weird program points. | 
|  | m_bailingOut = true; | 
|  | if (sReportStats) | 
|  | sNumFailedWalks++; | 
|  | return; | 
|  | } | 
|  | Base::resetAtMachineFrame(); | 
|  | } | 
|  |  | 
|  | CallerFrameAndPC* frame() | 
|  | { | 
|  | return reinterpret_cast<CallerFrameAndPC*>(m_machineFrame); | 
|  | } | 
|  |  | 
|  | void* m_machineFrame; | 
|  | }; | 
|  |  | 
|  | SamplingProfiler::SamplingProfiler(VM& vm, Ref<Stopwatch>&& stopwatch) | 
|  | : m_isPaused(false) | 
|  | , m_isShutDown(false) | 
|  | , m_vm(vm) | 
|  | , m_weakRandom() | 
|  | , m_stopwatch(WTFMove(stopwatch)) | 
|  | , m_timingInterval(Seconds::fromMicroseconds(Options::sampleInterval())) | 
|  | { | 
|  | if (sReportStats) { | 
|  | sNumTotalWalks = 0; | 
|  | sNumFailedWalks = 0; | 
|  | } | 
|  |  | 
|  | m_currentFrames.grow(256); | 
|  | vm.heap.objectSpace().enablePreciseAllocationTracking(); | 
|  | } | 
|  |  | 
|  | SamplingProfiler::~SamplingProfiler() | 
|  | { | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::createThreadIfNecessary() | 
|  | { | 
|  | ASSERT(m_lock.isLocked()); | 
|  |  | 
|  | if (m_thread) | 
|  | return; | 
|  |  | 
|  | RefPtr<SamplingProfiler> profiler = this; | 
|  | m_thread = Thread::create("jsc.sampling-profiler.thread", [profiler] { | 
|  | profiler->timerLoop(); | 
|  | }); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::timerLoop() | 
|  | { | 
|  | while (true) { | 
|  | Seconds stackTraceProcessingTime = 0_s; | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | if (UNLIKELY(m_isShutDown)) | 
|  | return; | 
|  |  | 
|  | if (!m_isPaused && m_jscExecutionThread) | 
|  | takeSample(stackTraceProcessingTime); | 
|  |  | 
|  | m_lastTime = m_stopwatch->elapsedTime(); | 
|  | } | 
|  |  | 
|  | // Read section 6.2 of this paper for more elaboration of why we add a random | 
|  | // fluctuation here. The main idea is to prevent our timer from being in sync | 
|  | // with some system process such as a scheduled context switch. | 
|  | // http://plv.colorado.edu/papers/mytkowicz-pldi10.pdf | 
|  | double randomSignedNumber = (m_weakRandom.get() * 2.0) - 1.0; // A random number between [-1, 1). | 
|  | Seconds randomFluctuation = m_timingInterval * 0.2 * randomSignedNumber; | 
|  | WTF::sleep(m_timingInterval - std::min(m_timingInterval, stackTraceProcessingTime) + randomFluctuation); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::takeSample(Seconds& stackTraceProcessingTime) | 
|  | { | 
|  | ASSERT(m_lock.isLocked()); | 
|  | if (m_vm.entryScope) { | 
|  | Seconds nowTime = m_stopwatch->elapsedTime(); | 
|  |  | 
|  | Locker machineThreadsLocker { m_vm.heap.machineThreads().getLock() }; | 
|  | Locker codeBlockSetLocker { m_vm.heap.codeBlockSet().getLock() }; | 
|  | Locker executableAllocatorLocker { ExecutableAllocator::singleton().getLock() }; | 
|  | std::optional<LockHolder> wasmCalleesLocker; | 
|  | #if ENABLE(WEBASSEMBLY) | 
|  | if (Wasm::isSupported()) | 
|  | wasmCalleesLocker.emplace(Wasm::CalleeRegistry::singleton().getLock()); | 
|  | #endif | 
|  |  | 
|  | auto didSuspend = m_jscExecutionThread->suspend(); | 
|  | if (didSuspend) { | 
|  | // While the JSC thread is suspended, we can't do things like malloc because the JSC thread | 
|  | // may be holding the malloc lock. | 
|  | void* machineFrame; | 
|  | CallFrame* callFrame; | 
|  | void* machinePC; | 
|  | bool topFrameIsLLInt = false; | 
|  | void* llintPC; | 
|  | { | 
|  | PlatformRegisters registers; | 
|  | m_jscExecutionThread->getRegisters(registers); | 
|  | machineFrame = MachineContext::framePointer(registers); | 
|  | callFrame = static_cast<CallFrame*>(machineFrame); | 
|  | auto instructionPointer = MachineContext::instructionPointer(registers); | 
|  | if (instructionPointer) | 
|  | machinePC = instructionPointer->untaggedExecutableAddress(); | 
|  | else | 
|  | machinePC = nullptr; | 
|  | llintPC = removeCodePtrTag(MachineContext::llintInstructionPointer(registers)); | 
|  | assertIsNotTagged(machinePC); | 
|  | } | 
|  |  | 
|  | bool shouldAppendTopFrameAsCCode = false; | 
|  | // FIXME: Lets have a way of detecting when we're parsing code. | 
|  | // https://bugs.webkit.org/show_bug.cgi?id=152761 | 
|  | if (ExecutableAllocator::singleton().isValidExecutableMemory(executableAllocatorLocker, machinePC)) { | 
|  | if (m_vm.isExecutingInRegExpJIT) { | 
|  | // FIXME: We're executing a regexp. Lets gather more intersting data. | 
|  | // https://bugs.webkit.org/show_bug.cgi?id=152729 | 
|  | callFrame = m_vm.topCallFrame; // We need to do this or else we'd fail our backtrace validation b/c this isn't a JS frame. | 
|  | } | 
|  | } else if (LLInt::isLLIntPC(machinePC)) { | 
|  | topFrameIsLLInt = true; | 
|  | // We're okay to take a normal stack trace when the PC | 
|  | // is in LLInt code. | 
|  | } else { | 
|  | // We resort to topCallFrame to see if we can get anything | 
|  | // useful. We usually get here when we're executing C code. | 
|  | callFrame = m_vm.topCallFrame; | 
|  | if (Options::collectExtraSamplingProfilerData() && !Options::sampleCCode()) | 
|  | shouldAppendTopFrameAsCCode = true; | 
|  | } | 
|  |  | 
|  | size_t walkSize; | 
|  | bool wasValidWalk; | 
|  | bool didRunOutOfVectorSpace; | 
|  | if (Options::sampleCCode()) { | 
|  | CFrameWalker walker(m_vm, machineFrame, callFrame, codeBlockSetLocker, machineThreadsLocker); | 
|  | walkSize = walker.walk(m_currentFrames, didRunOutOfVectorSpace); | 
|  | wasValidWalk = walker.wasValidWalk(); | 
|  | } else { | 
|  | FrameWalker walker(m_vm, callFrame, codeBlockSetLocker, machineThreadsLocker); | 
|  | walkSize = walker.walk(m_currentFrames, didRunOutOfVectorSpace); | 
|  | wasValidWalk = walker.wasValidWalk(); | 
|  | } | 
|  |  | 
|  | m_jscExecutionThread->resume(); | 
|  |  | 
|  | auto startTime = MonotonicTime::now(); | 
|  | // We can now use data structures that malloc, and do other interesting things, again. | 
|  |  | 
|  | // FIXME: It'd be interesting to take data about the program's state when | 
|  | // we fail to take a stack trace: https://bugs.webkit.org/show_bug.cgi?id=152758 | 
|  | if (wasValidWalk && walkSize) { | 
|  | if (sReportStats) | 
|  | sNumTotalStackTraces++; | 
|  | Vector<UnprocessedStackFrame> stackTrace; | 
|  | stackTrace.reserveInitialCapacity(walkSize + !!shouldAppendTopFrameAsCCode); | 
|  | if (shouldAppendTopFrameAsCCode) | 
|  | stackTrace.uncheckedAppend(UnprocessedStackFrame { machinePC }); | 
|  | for (size_t i = 0; i < walkSize; i++) { | 
|  | UnprocessedStackFrame frame = m_currentFrames[i]; | 
|  | stackTrace.uncheckedAppend(frame); | 
|  | } | 
|  |  | 
|  | m_unprocessedStackTraces.append(UnprocessedStackTrace { nowTime, machinePC, topFrameIsLLInt, llintPC, WTFMove(stackTrace) }); | 
|  |  | 
|  | if (didRunOutOfVectorSpace) | 
|  | m_currentFrames.grow(m_currentFrames.size() * 1.25); | 
|  | } | 
|  |  | 
|  | auto endTime = MonotonicTime::now(); | 
|  | stackTraceProcessingTime = endTime - startTime; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | static ALWAYS_INLINE BytecodeIndex tryGetBytecodeIndex(unsigned llintPC, CodeBlock* codeBlock) | 
|  | { | 
|  | #if ENABLE(DFG_JIT) | 
|  | RELEASE_ASSERT(!codeBlock->hasCodeOrigins()); | 
|  | #endif | 
|  |  | 
|  | unsigned bytecodeOffset = llintPC; | 
|  | if (bytecodeOffset < codeBlock->instructionsSize()) | 
|  | return BytecodeIndex(bytecodeOffset); | 
|  | return BytecodeIndex(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::processUnverifiedStackTraces() | 
|  | { | 
|  | // This function needs to be called from the JSC execution thread. | 
|  | RELEASE_ASSERT(m_lock.isLocked()); | 
|  |  | 
|  | TinyBloomFilter filter = m_vm.heap.objectSpace().blocks().filter(); | 
|  |  | 
|  | for (UnprocessedStackTrace& unprocessedStackTrace : m_unprocessedStackTraces) { | 
|  | m_stackTraces.append(StackTrace()); | 
|  | StackTrace& stackTrace = m_stackTraces.last(); | 
|  | stackTrace.timestamp = unprocessedStackTrace.timestamp; | 
|  |  | 
|  | auto populateCodeLocation = [] (CodeBlock* codeBlock, JITType jitType, BytecodeIndex bytecodeIndex, StackFrame::CodeLocation& location) { | 
|  | if (bytecodeIndex.offset() < codeBlock->instructionsSize()) { | 
|  | int divot; | 
|  | int startOffset; | 
|  | int endOffset; | 
|  | codeBlock->expressionRangeForBytecodeIndex(bytecodeIndex, divot, startOffset, endOffset, | 
|  | location.lineNumber, location.columnNumber); | 
|  | location.bytecodeIndex = bytecodeIndex; | 
|  | } | 
|  | if (codeBlock->hasHash()) | 
|  | location.codeBlockHash = codeBlock->hash(); | 
|  | location.jitType = jitType; | 
|  | }; | 
|  |  | 
|  | auto appendCodeBlock = [&] (CodeBlock* codeBlock, JITType jitType, BytecodeIndex bytecodeIndex) { | 
|  | assertIsHeld(m_lock); | 
|  | stackTrace.frames.append(StackFrame(codeBlock->ownerExecutable())); | 
|  | m_liveCellPointers.add(codeBlock->ownerExecutable()); | 
|  | populateCodeLocation(codeBlock, jitType, bytecodeIndex, stackTrace.frames.last().semanticLocation); | 
|  | }; | 
|  |  | 
|  | auto appendEmptyFrame = [&] { | 
|  | stackTrace.frames.append(StackFrame()); | 
|  | }; | 
|  |  | 
|  | auto storeCalleeIntoLastFrame = [&] (UnprocessedStackFrame& unprocessedStackFrame) { | 
|  | assertIsHeld(m_lock); | 
|  | // Set the callee if it's a valid GC object. | 
|  | CalleeBits calleeBits = unprocessedStackFrame.unverifiedCallee; | 
|  | StackFrame& stackFrame = stackTrace.frames.last(); | 
|  | bool alreadyHasExecutable = !!stackFrame.executable; | 
|  | #if ENABLE(WEBASSEMBLY) | 
|  | if (calleeBits.isWasm()) { | 
|  | stackFrame.frameType = FrameType::Wasm; | 
|  | stackFrame.wasmIndexOrName = unprocessedStackFrame.wasmIndexOrName; | 
|  | stackFrame.wasmCompilationMode = unprocessedStackFrame.wasmCompilationMode; | 
|  | return; | 
|  | } | 
|  | #endif | 
|  |  | 
|  | JSValue callee = calleeBits.asCell(); | 
|  | if (!HeapUtil::isValueGCObject(m_vm.heap, filter, callee)) { | 
|  | if (!alreadyHasExecutable) | 
|  | stackFrame.frameType = FrameType::Unknown; | 
|  | return; | 
|  | } | 
|  |  | 
|  | JSCell* calleeCell = callee.asCell(); | 
|  | auto setFallbackFrameType = [&] { | 
|  | ASSERT(!alreadyHasExecutable); | 
|  | FrameType result = FrameType::Unknown; | 
|  | auto callData = getCallData(m_vm, calleeCell); | 
|  | if (callData.type == CallData::Type::Native) | 
|  | result = FrameType::Host; | 
|  |  | 
|  | stackFrame.frameType = result; | 
|  | }; | 
|  |  | 
|  | auto addCallee = [&] (JSObject* callee) { | 
|  | assertIsHeld(m_lock); | 
|  | stackFrame.callee = callee; | 
|  | m_liveCellPointers.add(callee); | 
|  | }; | 
|  |  | 
|  | if (calleeCell->type() != JSFunctionType) { | 
|  | if (JSObject* object = jsDynamicCast<JSObject*>(calleeCell->vm(), calleeCell)) | 
|  | addCallee(object); | 
|  |  | 
|  | if (!alreadyHasExecutable) | 
|  | setFallbackFrameType(); | 
|  |  | 
|  | return; | 
|  | } | 
|  |  | 
|  | addCallee(jsCast<JSFunction*>(calleeCell)); | 
|  |  | 
|  | if (alreadyHasExecutable) | 
|  | return; | 
|  |  | 
|  | ExecutableBase* executable = jsCast<JSFunction*>(calleeCell)->executable(); | 
|  | if (!executable) { | 
|  | setFallbackFrameType(); | 
|  | return; | 
|  | } | 
|  |  | 
|  | RELEASE_ASSERT(HeapUtil::isPointerGCObjectJSCell(m_vm.heap, filter, executable)); | 
|  | stackFrame.frameType = FrameType::Executable; | 
|  | stackFrame.executable = executable; | 
|  | m_liveCellPointers.add(executable); | 
|  | }; | 
|  |  | 
|  | auto appendCodeOrigin = [&] (CodeBlock* machineCodeBlock, CodeOrigin origin) { | 
|  | assertIsHeld(m_lock); | 
|  | size_t startIndex = stackTrace.frames.size(); // We want to change stack traces that we're about to append. | 
|  |  | 
|  | CodeOrigin machineOrigin; | 
|  | origin.walkUpInlineStack([&] (const CodeOrigin& codeOrigin) { | 
|  | machineOrigin = codeOrigin; | 
|  | auto* inlineCallFrame = codeOrigin.inlineCallFrame(); | 
|  | appendCodeBlock(inlineCallFrame ? inlineCallFrame->baselineCodeBlock.get() : machineCodeBlock, machineCodeBlock->jitType(), codeOrigin.bytecodeIndex()); | 
|  | }); | 
|  |  | 
|  | if (Options::collectExtraSamplingProfilerData()) { | 
|  | RELEASE_ASSERT(machineOrigin.isSet()); | 
|  | RELEASE_ASSERT(!machineOrigin.inlineCallFrame()); | 
|  |  | 
|  | StackFrame::CodeLocation machineLocation = stackTrace.frames.last().semanticLocation; | 
|  |  | 
|  | // We want to tell each inlined frame about the machine frame | 
|  | // they were inlined into. Currently, we only use this for dumping | 
|  | // output on the command line, but we could extend it to the web | 
|  | // inspector in the future if we find a need for it there. | 
|  | RELEASE_ASSERT(stackTrace.frames.size()); | 
|  | m_liveCellPointers.add(machineCodeBlock); | 
|  | for (size_t i = startIndex; i < stackTrace.frames.size() - 1; i++) | 
|  | stackTrace.frames[i].machineLocation = std::make_pair(machineLocation, machineCodeBlock); | 
|  | } | 
|  | }; | 
|  |  | 
|  | // Prepend the top-most inlined frame if needed and gather | 
|  | // location information about where the top frame is executing. | 
|  | size_t startIndex = 0; | 
|  | if (unprocessedStackTrace.frames.size() && !!unprocessedStackTrace.frames[0].verifiedCodeBlock) { | 
|  | CodeBlock* topCodeBlock = unprocessedStackTrace.frames[0].verifiedCodeBlock; | 
|  | if (unprocessedStackTrace.topFrameIsLLInt) { | 
|  | // We reuse LLInt CodeBlocks for the baseline JIT, so we need to check for both jit types. | 
|  | // This might also be false for various reasons (known and unknown), even though | 
|  | // it's super unlikely. One reason that this can be false is when we throw from a DFG frame, | 
|  | // and we end up having to unwind past an EntryFrame, we will end up executing | 
|  | // inside the LLInt's llint_handle_ucaught_exception. So we just protect against this | 
|  | // by ignoring it. | 
|  | BytecodeIndex bytecodeIndex = BytecodeIndex(0); | 
|  | if (topCodeBlock->jitType() == JITType::InterpreterThunk || topCodeBlock->jitType() == JITType::BaselineJIT) { | 
|  | unsigned bits = static_cast<unsigned>(bitwise_cast<uintptr_t>(unprocessedStackTrace.llintPC)); | 
|  | bytecodeIndex = tryGetBytecodeIndex(bits, topCodeBlock); | 
|  |  | 
|  | UNUSED_PARAM(bytecodeIndex); // FIXME: do something with this info for the web inspector: https://bugs.webkit.org/show_bug.cgi?id=153455 | 
|  |  | 
|  | appendCodeBlock(topCodeBlock, topCodeBlock->jitType(), bytecodeIndex); | 
|  | storeCalleeIntoLastFrame(unprocessedStackTrace.frames[0]); | 
|  | startIndex = 1; | 
|  | } | 
|  | } else { | 
|  | #if ENABLE(JIT) | 
|  | if (std::optional<CodeOrigin> codeOrigin = topCodeBlock->findPC(unprocessedStackTrace.topPC)) { | 
|  | appendCodeOrigin(topCodeBlock, *codeOrigin); | 
|  | storeCalleeIntoLastFrame(unprocessedStackTrace.frames[0]); | 
|  | startIndex = 1; | 
|  | } | 
|  | #endif | 
|  | UNUSED_PARAM(appendCodeOrigin); | 
|  | } | 
|  | } | 
|  |  | 
|  | for (size_t i = startIndex; i < unprocessedStackTrace.frames.size(); i++) { | 
|  | UnprocessedStackFrame& unprocessedStackFrame = unprocessedStackTrace.frames[i]; | 
|  | if (CodeBlock* codeBlock = unprocessedStackFrame.verifiedCodeBlock) { | 
|  | CallSiteIndex callSiteIndex = unprocessedStackFrame.callSiteIndex; | 
|  |  | 
|  | auto appendCodeBlockNoInlining = [&] { | 
|  | appendCodeBlock(codeBlock, codeBlock->jitType(), tryGetBytecodeIndex(callSiteIndex.bits(), codeBlock)); | 
|  | }; | 
|  |  | 
|  | #if ENABLE(DFG_JIT) | 
|  | if (codeBlock->hasCodeOrigins()) { | 
|  | if (codeBlock->canGetCodeOrigin(callSiteIndex)) | 
|  | appendCodeOrigin(codeBlock, codeBlock->codeOrigin(callSiteIndex)); | 
|  | else | 
|  | appendCodeBlock(codeBlock, codeBlock->jitType(), BytecodeIndex()); | 
|  | } else | 
|  | appendCodeBlockNoInlining(); | 
|  | #else | 
|  | appendCodeBlockNoInlining(); | 
|  | #endif | 
|  | } else if (unprocessedStackFrame.cCodePC) { | 
|  | appendEmptyFrame(); | 
|  | stackTrace.frames.last().cCodePC = unprocessedStackFrame.cCodePC; | 
|  | stackTrace.frames.last().frameType = FrameType::C; | 
|  | } else | 
|  | appendEmptyFrame(); | 
|  |  | 
|  | // Note that this is okay to do if we walked the inline stack because | 
|  | // the machine frame will be at the top of the processed stack trace. | 
|  | if (!unprocessedStackFrame.cCodePC) | 
|  | storeCalleeIntoLastFrame(unprocessedStackFrame); | 
|  | } | 
|  | } | 
|  |  | 
|  | m_unprocessedStackTraces.clear(); | 
|  | } | 
|  |  | 
|  | template<typename Visitor> | 
|  | void SamplingProfiler::visit(Visitor& visitor) | 
|  | { | 
|  | RELEASE_ASSERT(m_lock.isLocked()); | 
|  | for (JSCell* cell : m_liveCellPointers) | 
|  | visitor.appendUnbarriered(cell); | 
|  | } | 
|  |  | 
|  | template void SamplingProfiler::visit(AbstractSlotVisitor&); | 
|  | template void SamplingProfiler::visit(SlotVisitor&); | 
|  |  | 
|  | void SamplingProfiler::shutdown() | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | m_isShutDown = true; | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::start() | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | startWithLock(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::startWithLock() | 
|  | { | 
|  | ASSERT(m_lock.isLocked()); | 
|  | m_isPaused = false; | 
|  | createThreadIfNecessary(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::pause() | 
|  | { | 
|  | ASSERT(m_lock.isLocked()); | 
|  | m_isPaused = true; | 
|  | reportStats(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::noticeCurrentThreadAsJSCExecutionThreadWithLock() | 
|  | { | 
|  | ASSERT(m_lock.isLocked()); | 
|  | m_jscExecutionThread = &Thread::current(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::noticeCurrentThreadAsJSCExecutionThread() | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | noticeCurrentThreadAsJSCExecutionThreadWithLock(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::noticeJSLockAcquisition() | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | noticeCurrentThreadAsJSCExecutionThreadWithLock(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::noticeVMEntry() | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | ASSERT(m_vm.entryScope); | 
|  | noticeCurrentThreadAsJSCExecutionThreadWithLock(); | 
|  | m_lastTime = m_stopwatch->elapsedTime(); | 
|  | createThreadIfNecessary(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::clearData() | 
|  | { | 
|  | ASSERT(m_lock.isLocked()); | 
|  | m_stackTraces.clear(); | 
|  | m_liveCellPointers.clear(); | 
|  | m_unprocessedStackTraces.clear(); | 
|  | } | 
|  |  | 
|  | String SamplingProfiler::StackFrame::nameFromCallee(VM& vm) | 
|  | { | 
|  | if (!callee) | 
|  | return String(); | 
|  |  | 
|  | DeferTermination deferScope(vm); | 
|  | auto scope = DECLARE_CATCH_SCOPE(vm); | 
|  | JSGlobalObject* globalObject = callee->globalObject(vm); | 
|  | auto getPropertyIfPureOperation = [&] (const Identifier& ident) -> String { | 
|  | PropertySlot slot(callee, PropertySlot::InternalMethodType::VMInquiry, &vm); | 
|  | PropertyName propertyName(ident); | 
|  | bool hasProperty = callee->getPropertySlot(globalObject, propertyName, slot); | 
|  | scope.assertNoException(); | 
|  | if (hasProperty) { | 
|  | if (slot.isValue()) { | 
|  | JSValue nameValue = slot.getValue(globalObject, propertyName); | 
|  | if (isJSString(nameValue)) | 
|  | return asString(nameValue)->tryGetValue(); | 
|  | } | 
|  | } | 
|  | return String(); | 
|  | }; | 
|  |  | 
|  | String name = getPropertyIfPureOperation(vm.propertyNames->displayName); | 
|  | if (!name.isEmpty()) | 
|  | return name; | 
|  |  | 
|  | return getPropertyIfPureOperation(vm.propertyNames->name); | 
|  | } | 
|  |  | 
|  | String SamplingProfiler::StackFrame::displayName(VM& vm) | 
|  | { | 
|  | { | 
|  | String name = nameFromCallee(vm); | 
|  | if (!name.isEmpty()) | 
|  | return name; | 
|  | } | 
|  |  | 
|  | switch (frameType) { | 
|  | case FrameType::C: | 
|  | #if HAVE(DLADDR) | 
|  | if (frameType == FrameType::C) { | 
|  | auto demangled = WTF::StackTrace::demangle(const_cast<void*>(cCodePC)); | 
|  | if (demangled) | 
|  | return String(demangled->demangledName() ? demangled->demangledName() : demangled->mangledName()); | 
|  | WTF::dataLog("couldn't get a name"); | 
|  | } | 
|  | #endif | 
|  | return "(unknown C PC)"_s; | 
|  | case FrameType::Unknown: | 
|  | return "(unknown)"_s; | 
|  |  | 
|  | case FrameType::Host: | 
|  | return "(host)"_s; | 
|  |  | 
|  | case FrameType::Wasm: | 
|  | #if ENABLE(WEBASSEMBLY) | 
|  | if (wasmIndexOrName) | 
|  | return makeString(wasmIndexOrName.value()); | 
|  | #endif | 
|  | return "(wasm)"_s; | 
|  |  | 
|  | case FrameType::Executable: | 
|  | if (executable->isHostFunction()) | 
|  | return static_cast<NativeExecutable*>(executable)->name(); | 
|  |  | 
|  | if (executable->isFunctionExecutable()) | 
|  | return static_cast<FunctionExecutable*>(executable)->ecmaName().string(); | 
|  | if (executable->isProgramExecutable() || executable->isEvalExecutable()) | 
|  | return "(program)"_s; | 
|  | if (executable->isModuleProgramExecutable()) | 
|  | return "(module)"_s; | 
|  |  | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return String(); | 
|  | } | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return String(); | 
|  | } | 
|  |  | 
|  | String SamplingProfiler::StackFrame::displayNameForJSONTests(VM& vm) | 
|  | { | 
|  | { | 
|  | String name = nameFromCallee(vm); | 
|  | if (!name.isEmpty()) | 
|  | return name; | 
|  | } | 
|  |  | 
|  | switch (frameType) { | 
|  | case FrameType::Unknown: | 
|  | case FrameType::C: | 
|  | return "(unknown)"_s; | 
|  |  | 
|  | case FrameType::Host: | 
|  | return "(host)"_s; | 
|  |  | 
|  | case FrameType::Wasm: { | 
|  | #if ENABLE(WEBASSEMBLY) | 
|  | if (wasmIndexOrName) | 
|  | return makeString(wasmIndexOrName.value()); | 
|  | #endif | 
|  | return "(wasm)"_s; | 
|  | } | 
|  |  | 
|  | case FrameType::Executable: | 
|  | if (executable->isHostFunction()) | 
|  | return static_cast<NativeExecutable*>(executable)->name(); | 
|  |  | 
|  | if (executable->isFunctionExecutable()) { | 
|  | String result = static_cast<FunctionExecutable*>(executable)->ecmaName().string(); | 
|  | if (result.isEmpty()) | 
|  | return "(anonymous function)"_s; | 
|  | return result; | 
|  | } | 
|  | if (executable->isEvalExecutable()) | 
|  | return "(eval)"_s; | 
|  | if (executable->isProgramExecutable()) | 
|  | return "(program)"_s; | 
|  | if (executable->isModuleProgramExecutable()) | 
|  | return "(module)"_s; | 
|  |  | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return String(); | 
|  | } | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return String(); | 
|  | } | 
|  |  | 
|  | int SamplingProfiler::StackFrame::functionStartLine() | 
|  | { | 
|  | switch (frameType) { | 
|  | case FrameType::Unknown: | 
|  | case FrameType::Host: | 
|  | case FrameType::C: | 
|  | case FrameType::Wasm: | 
|  | return -1; | 
|  |  | 
|  | case FrameType::Executable: | 
|  | if (executable->isHostFunction()) | 
|  | return -1; | 
|  | return static_cast<ScriptExecutable*>(executable)->firstLine(); | 
|  | } | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | unsigned SamplingProfiler::StackFrame::functionStartColumn() | 
|  | { | 
|  | switch (frameType) { | 
|  | case FrameType::Unknown: | 
|  | case FrameType::Host: | 
|  | case FrameType::C: | 
|  | case FrameType::Wasm: | 
|  | return std::numeric_limits<unsigned>::max(); | 
|  |  | 
|  | case FrameType::Executable: | 
|  | if (executable->isHostFunction()) | 
|  | return std::numeric_limits<unsigned>::max(); | 
|  |  | 
|  | return static_cast<ScriptExecutable*>(executable)->startColumn(); | 
|  | } | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return std::numeric_limits<unsigned>::max(); | 
|  | } | 
|  |  | 
|  | intptr_t SamplingProfiler::StackFrame::sourceID() | 
|  | { | 
|  | switch (frameType) { | 
|  | case FrameType::Unknown: | 
|  | case FrameType::Host: | 
|  | case FrameType::C: | 
|  | case FrameType::Wasm: | 
|  | return -1; | 
|  |  | 
|  | case FrameType::Executable: | 
|  | if (executable->isHostFunction()) | 
|  | return -1; | 
|  |  | 
|  | return static_cast<ScriptExecutable*>(executable)->sourceID(); | 
|  | } | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | String SamplingProfiler::StackFrame::url() | 
|  | { | 
|  | switch (frameType) { | 
|  | case FrameType::Unknown: | 
|  | case FrameType::Host: | 
|  | case FrameType::C: | 
|  | case FrameType::Wasm: | 
|  | return emptyString(); | 
|  | case FrameType::Executable: | 
|  | if (executable->isHostFunction()) | 
|  | return emptyString(); | 
|  |  | 
|  | String url = static_cast<ScriptExecutable*>(executable)->sourceURL(); | 
|  | if (url.isEmpty()) | 
|  | return static_cast<ScriptExecutable*>(executable)->source().provider()->sourceURLDirective(); // Fall back to sourceURL directive. | 
|  | return url; | 
|  | } | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | return String(); | 
|  | } | 
|  |  | 
|  | Vector<SamplingProfiler::StackTrace> SamplingProfiler::releaseStackTraces() | 
|  | { | 
|  | ASSERT(m_lock.isLocked()); | 
|  | { | 
|  | HeapIterationScope heapIterationScope(m_vm.heap); | 
|  | processUnverifiedStackTraces(); | 
|  | } | 
|  |  | 
|  | Vector<StackTrace> result(WTFMove(m_stackTraces)); | 
|  | clearData(); | 
|  | return result; | 
|  | } | 
|  |  | 
|  | String SamplingProfiler::stackTracesAsJSON() | 
|  | { | 
|  | DeferGC deferGC(m_vm.heap); | 
|  | Locker locker { m_lock }; | 
|  |  | 
|  | { | 
|  | HeapIterationScope heapIterationScope(m_vm.heap); | 
|  | processUnverifiedStackTraces(); | 
|  | } | 
|  |  | 
|  | StringBuilder json; | 
|  | json.append('['); | 
|  |  | 
|  | bool loopedOnce = false; | 
|  | auto comma = [&] { | 
|  | if (loopedOnce) | 
|  | json.append(','); | 
|  | }; | 
|  | for (StackTrace& stackTrace : m_stackTraces) { | 
|  | comma(); | 
|  | json.append('['); | 
|  | loopedOnce = false; | 
|  | for (StackFrame& stackFrame : stackTrace.frames) { | 
|  | comma(); | 
|  | json.appendQuotedJSONString(stackFrame.displayNameForJSONTests(m_vm)); | 
|  | loopedOnce = true; | 
|  | } | 
|  | json.append(']'); | 
|  | loopedOnce = true; | 
|  | } | 
|  |  | 
|  | json.append(']'); | 
|  |  | 
|  | clearData(); | 
|  |  | 
|  | return json.toString(); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::registerForReportAtExit() | 
|  | { | 
|  | static Lock registrationLock; | 
|  | static HashSet<RefPtr<SamplingProfiler>>* profilesToReport; | 
|  |  | 
|  | Locker locker { registrationLock }; | 
|  |  | 
|  | if (!profilesToReport) { | 
|  | profilesToReport = new HashSet<RefPtr<SamplingProfiler>>(); | 
|  | atexit([]() { | 
|  | for (const auto& profile : *profilesToReport) | 
|  | profile->reportDataToOptionFile(); | 
|  | }); | 
|  | } | 
|  |  | 
|  | profilesToReport->add(adoptRef(this)); | 
|  | m_needsReportAtExit = true; | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::reportDataToOptionFile() | 
|  | { | 
|  | if (m_needsReportAtExit) { | 
|  | m_needsReportAtExit = false; | 
|  | JSLockHolder holder(m_vm); | 
|  | const char* path = Options::samplingProfilerPath(); | 
|  | StringPrintStream pathOut; | 
|  | pathOut.print(path, "/"); | 
|  | pathOut.print("JSCSampilingProfile-", reinterpret_cast<uintptr_t>(this), ".txt"); | 
|  | auto out = FilePrintStream::open(pathOut.toCString().data(), "w"); | 
|  | reportTopFunctions(*out); | 
|  | reportTopBytecodes(*out); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::reportTopFunctions() | 
|  | { | 
|  | reportTopFunctions(WTF::dataFile()); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::reportTopFunctions(PrintStream& out) | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | DeferGCForAWhile deferGC(m_vm.heap); | 
|  |  | 
|  | { | 
|  | HeapIterationScope heapIterationScope(m_vm.heap); | 
|  | processUnverifiedStackTraces(); | 
|  | } | 
|  |  | 
|  | size_t totalSamples = 0; | 
|  | HashMap<String, size_t> functionCounts; | 
|  | for (StackTrace& stackTrace : m_stackTraces) { | 
|  | if (!stackTrace.frames.size()) | 
|  | continue; | 
|  |  | 
|  | StackFrame& frame = stackTrace.frames.first(); | 
|  | String hash = ""_s; | 
|  | if (frame.semanticLocation.hasCodeBlockHash()) { | 
|  | StringPrintStream stream; | 
|  | frame.semanticLocation.codeBlockHash.dump(stream); | 
|  | hash = stream.toString(); | 
|  | } else | 
|  | hash = "<nil>"_s; | 
|  | auto frameDescription = makeString(frame.displayName(m_vm), '#', hash, ':', frame.sourceID()); | 
|  | functionCounts.add(frameDescription, 0).iterator->value++; | 
|  | totalSamples++; | 
|  | } | 
|  |  | 
|  | auto takeMax = [&] () -> std::pair<String, size_t> { | 
|  | String maxFrameDescription; | 
|  | size_t maxFrameCount = 0; | 
|  | for (const auto& entry : functionCounts) { | 
|  | if (entry.value > maxFrameCount) { | 
|  | maxFrameCount = entry.value; | 
|  | maxFrameDescription = entry.key; | 
|  | } | 
|  | } | 
|  | if (!maxFrameDescription.isEmpty()) | 
|  | functionCounts.remove(maxFrameDescription); | 
|  | return std::make_pair(maxFrameDescription, maxFrameCount); | 
|  | }; | 
|  |  | 
|  | if (Options::samplingProfilerTopFunctionsCount()) { | 
|  | out.println("\n\nSampling rate: ", m_timingInterval.microseconds(), " microseconds. Total samples: ", totalSamples); | 
|  | out.println("Top functions as <numSamples  'functionName#hash:sourceID'>"); | 
|  | for (size_t i = 0; i < Options::samplingProfilerTopFunctionsCount(); i++) { | 
|  | auto pair = takeMax(); | 
|  | if (pair.first.isEmpty()) | 
|  | break; | 
|  | out.printf("%6zu ", pair.second); | 
|  | out.println("   '", pair.first, "'"); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::reportTopBytecodes() | 
|  | { | 
|  | reportTopBytecodes(WTF::dataFile()); | 
|  | } | 
|  |  | 
|  | void SamplingProfiler::reportTopBytecodes(PrintStream& out) | 
|  | { | 
|  | Locker locker { m_lock }; | 
|  | DeferGCForAWhile deferGC(m_vm.heap); | 
|  |  | 
|  | { | 
|  | HeapIterationScope heapIterationScope(m_vm.heap); | 
|  | processUnverifiedStackTraces(); | 
|  | } | 
|  |  | 
|  | size_t totalSamples = 0; | 
|  | HashMap<String, size_t> bytecodeCounts; | 
|  | HashMap<String, size_t> tierCounts; | 
|  |  | 
|  | String llint = "LLInt"_s; | 
|  | String baseline = "Baseline"_s; | 
|  | String dfg = "DFG"_s; | 
|  | String ftl = "FTL"_s; | 
|  | String builtin = "js builtin"_s; | 
|  | String wasm = "Wasm"_s; | 
|  | String host = "Host"_s; | 
|  | String cpp = "C/C++"_s; | 
|  | String unknownFrame = "Unknown Frame"_s; | 
|  | String unknownExecutable = "Unknown Executable"_s; | 
|  |  | 
|  | auto forEachTier = [&] (auto func) { | 
|  | func(llint); | 
|  | func(baseline); | 
|  | func(dfg); | 
|  | func(ftl); | 
|  | func(builtin); | 
|  | func(wasm); | 
|  | func(host); | 
|  | func(cpp); | 
|  | func(unknownFrame); | 
|  | func(unknownExecutable); | 
|  | }; | 
|  |  | 
|  | for (StackTrace& stackTrace : m_stackTraces) { | 
|  | if (!stackTrace.frames.size()) | 
|  | continue; | 
|  |  | 
|  | auto descriptionForLocation = [&] (StackFrame::CodeLocation location, std::optional<Wasm::CompilationMode> wasmCompilationMode) -> String { | 
|  | String bytecodeIndex; | 
|  | String codeBlockHash; | 
|  | String jitType; | 
|  | if (location.hasBytecodeIndex()) | 
|  | bytecodeIndex = toString(location.bytecodeIndex); | 
|  | else | 
|  | bytecodeIndex = "<nil>"; | 
|  |  | 
|  | if (location.hasCodeBlockHash()) { | 
|  | StringPrintStream stream; | 
|  | location.codeBlockHash.dump(stream); | 
|  | codeBlockHash = stream.toString(); | 
|  | } else | 
|  | codeBlockHash = "<nil>"; | 
|  |  | 
|  | if (wasmCompilationMode) | 
|  | jitType = Wasm::makeString(wasmCompilationMode.value()); | 
|  | else | 
|  | jitType = JITCode::typeName(location.jitType); | 
|  |  | 
|  | return makeString("#", codeBlockHash, ":", jitType, ":", bytecodeIndex); | 
|  | }; | 
|  |  | 
|  | StackFrame& frame = stackTrace.frames.first(); | 
|  | auto frameDescription = makeString(frame.displayName(m_vm), descriptionForLocation(frame.semanticLocation, frame.wasmCompilationMode)); | 
|  | if (std::optional<std::pair<StackFrame::CodeLocation, CodeBlock*>> machineLocation = frame.machineLocation) { | 
|  | frameDescription = makeString(frameDescription, " <-- ", | 
|  | machineLocation->second->inferredName().data(), descriptionForLocation(machineLocation->first, std::nullopt)); | 
|  | } | 
|  | bytecodeCounts.add(frameDescription, 0).iterator->value++; | 
|  |  | 
|  | { | 
|  | String tierName; | 
|  | switch (frame.frameType) { | 
|  | case SamplingProfiler::FrameType::Executable: | 
|  | switch (frame.semanticLocation.jitType) { | 
|  | case JITType::HostCallThunk: | 
|  | tierName = host; | 
|  | break; | 
|  | case JITType::InterpreterThunk: | 
|  | tierName = llint; | 
|  | break; | 
|  | case JITType::BaselineJIT: | 
|  | tierName = baseline; | 
|  | break; | 
|  | case JITType::DFGJIT: | 
|  | tierName = dfg; | 
|  | break; | 
|  | case JITType::FTLJIT: | 
|  | tierName = ftl; | 
|  | break; | 
|  | default: | 
|  | tierName = unknownExecutable; | 
|  | break; | 
|  | } | 
|  |  | 
|  | if (frame.executable) { | 
|  | if (auto* executable = jsDynamicCast<FunctionExecutable*>(m_vm, frame.executable)) { | 
|  | if (executable->isBuiltinFunction()) | 
|  | tierCounts.add(builtin, 0).iterator->value++; | 
|  | } | 
|  | } | 
|  |  | 
|  | break; | 
|  | case SamplingProfiler::FrameType::Wasm: | 
|  | tierName = wasm; | 
|  | break; | 
|  | case SamplingProfiler::FrameType::Host: | 
|  | tierName = host; | 
|  | break; | 
|  | case SamplingProfiler::FrameType::C: | 
|  | tierName = cpp; | 
|  | break; | 
|  | case SamplingProfiler::FrameType::Unknown: | 
|  | tierName = unknownFrame; | 
|  | break; | 
|  | } | 
|  |  | 
|  | tierCounts.add(tierName, 0).iterator->value++; | 
|  | } | 
|  |  | 
|  | totalSamples++; | 
|  | } | 
|  |  | 
|  | auto takeMax = [&] () -> std::pair<String, size_t> { | 
|  | String maxFrameDescription; | 
|  | size_t maxFrameCount = 0; | 
|  | for (const auto& entry : bytecodeCounts) { | 
|  | if (entry.value > maxFrameCount) { | 
|  | maxFrameCount = entry.value; | 
|  | maxFrameDescription = entry.key; | 
|  | } | 
|  | } | 
|  | if (!maxFrameDescription.isEmpty()) | 
|  | bytecodeCounts.remove(maxFrameDescription); | 
|  | return std::make_pair(maxFrameDescription, maxFrameCount); | 
|  | }; | 
|  |  | 
|  | if (Options::samplingProfilerTopBytecodesCount()) { | 
|  | out.println("\n\nSampling rate: ", m_timingInterval.microseconds(), " microseconds. Total samples: ", totalSamples, "\n"); | 
|  |  | 
|  | out.println("Tier breakdown:"); | 
|  | out.println("-----------------------------------"); | 
|  | unsigned maxTierNameLength = 0; | 
|  | forEachTier([&] (String tier) { | 
|  | maxTierNameLength = std::max(maxTierNameLength, tier.length()); | 
|  | }); | 
|  | auto printTier = [&] (String tier) { | 
|  | size_t count = tierCounts.get(tier); | 
|  | if (!count && (tier == unknownFrame || tier == unknownExecutable)) | 
|  | return; | 
|  | out.print(tier, ": "); | 
|  | for (unsigned i = 0; i < maxTierNameLength + 2 - tier.length(); ++i) | 
|  | out.print(" "); | 
|  | out.printf("%6zu ", count); | 
|  | out.println(" (", (static_cast<double>(count) / static_cast<double>(totalSamples)) * 100, "%)"); | 
|  | }; | 
|  | forEachTier(printTier); | 
|  | out.println("\n"); | 
|  |  | 
|  | out.println("Hottest bytecodes as <numSamples   'functionName#hash:JITType:bytecodeIndex'>"); | 
|  | for (size_t i = 0; i < Options::samplingProfilerTopBytecodesCount(); i++) { | 
|  | auto pair = takeMax(); | 
|  | if (pair.first.isEmpty()) | 
|  | break; | 
|  | out.printf("%6zu ", pair.second); | 
|  | out.println("   '", pair.first, "'"); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | Thread* SamplingProfiler::thread() const | 
|  | { | 
|  | return m_thread.get(); | 
|  | } | 
|  |  | 
|  | } // namespace JSC | 
|  |  | 
|  | namespace WTF { | 
|  |  | 
|  | using namespace JSC; | 
|  |  | 
|  | void printInternal(PrintStream& out, SamplingProfiler::FrameType frameType) | 
|  | { | 
|  | switch (frameType) { | 
|  | case SamplingProfiler::FrameType::Executable: | 
|  | out.print("Executable"); | 
|  | break; | 
|  | case SamplingProfiler::FrameType::Wasm: | 
|  | out.print("Wasm"); | 
|  | break; | 
|  | case SamplingProfiler::FrameType::Host: | 
|  | out.print("Host"); | 
|  | break; | 
|  | case SamplingProfiler::FrameType::C: | 
|  | case SamplingProfiler::FrameType::Unknown: | 
|  | out.print("Unknown"); | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  | } // namespace WTF | 
|  |  | 
|  | #endif // ENABLE(SAMPLING_PROFILER) |