Created attachment 446938 [details] STP136Crashes Since STP 136 I've been seeing one off crashes on forums.swift.org. The tab will crash, reload, and then work fine. It either occurs on one of the heap helper threads or directly in JSC execution itself. I've attached all of the crashes since 136 released. Here are the typical stacks: 0 JavaScriptCore 0x3d0b6fbf8 JSC::JSFinalObject::visitChildren(JSC::JSCell*, JSC::SlotVisitor&) + 1128 1 JavaScriptCore 0x3d145b76b JSC::SlotVisitor::drain(WTF::MonotonicTime)::$_3::operator()(JSC::MarkStackArray&) const + 251 2 JavaScriptCore 0x3d1458c72 JSC::SlotVisitor::drain(WTF::MonotonicTime) + 178 3 JavaScriptCore 0x3d145978d JSC::SlotVisitor::drainFromShared(JSC::SlotVisitor::SharedDrainMode, WTF::MonotonicTime) + 1597 4 JavaScriptCore 0x3d1430f44 WTF::SharedTaskFunctor<void (), JSC::Heap::runBeginPhase(JSC::GCConductor)::$_18>::run() + 148 5 JavaScriptCore 0x3d1c8d06c WTF::ParallelHelperClient::runTask(WTF::RefPtr<WTF::SharedTask<void ()>, WTF::RawPtrTraits<WTF::SharedTask<void ()> >, WTF::DefaultRefDerefTraits<WTF::SharedTask<void ()> > > const&) + 44 6 JavaScriptCore 0x3d1c8dc66 WTF::ParallelHelperPool::Thread::work() + 22 7 JavaScriptCore 0x3d1c6246a WTF::Detail::CallableWrapper<WTF::AutomaticThread::start(WTF::AbstractLocker const&)::$_0, void>::call() + 490 8 JavaScriptCore 0x3d1caa88d WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*) + 157 9 JavaScriptCore 0x3d0aa0e89 WTF::wtfThreadEntryPoint(void*) + 9 10 libsystem_pthread.dylib 0x7ff80082d514 _pthread_start + 125 11 libsystem_pthread.dylib 0x7ff80082902f thread_start + 15 Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 JavaScriptCore 0x500b69034 operationGetByVal + 1028 1 ??? 0x53193abbb330 ??? 2 ??? 0x53193a94afc0 ??? 3 ??? 0x53193a94ec66 ??? 4 ??? 0x53193a8b02db ??? 5 ??? 0x53193ac86f94 ??? 6 ??? 0x53193aef4118 ??? 7 JavaScriptCore 0x500e64beb llint_entry + 117268 8 JavaScriptCore 0x500e64beb llint_entry + 117268 9 JavaScriptCore 0x500e64beb llint_entry + 117268 10 ??? 0x53193ad30cc9 ??? 11 ??? 0x53193a8c21e6 ??? 12 JavaScriptCore 0x500e64beb llint_entry + 117268 13 JavaScriptCore 0x500e64beb llint_entry + 117268 14 JavaScriptCore 0x500e64beb llint_entry + 117268 15 JavaScriptCore 0x500e64beb llint_entry + 117268 16 ??? 0x53193af93131 ??? 17 ??? 0x53193afdb285 ??? 18 ??? 0x53193a9b895e ??? 19 ??? 0x53193a9e8bf8 ??? 20 ??? 0x53193aa97ebc ??? 21 ??? 0x53193af98b10 ??? 22 ??? 0x53193afbf3dc ??? 23 ??? 0x53193a824757 ??? 24 JavaScriptCore 0x500e64c70 llint_entry + 117401 25 ??? 0x53193af8c9eb ??? 26 ??? 0x53193afbe50a ??? 27 JavaScriptCore 0x500e64c70 llint_entry + 117401 28 JavaScriptCore 0x500e64c70 llint_entry + 117401 29 JavaScriptCore 0x500e47fd6 vmEntryToJavaScript + 216 30 JavaScriptCore 0x501520945 JSC::Interpreter::executeCall(JSC::JSGlobalObject*, JSC::JSObject*, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 485 31 JavaScriptCore 0x50177fefe JSC::profiledCall(JSC::JSGlobalObject*, JSC::ProfilingReason, JSC::JSValue, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) + 174 32 WebCore 0x50b1f36e0 WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext&, WebCore::Event&) + 2432 33 WebCore 0x50b54050c WebCore::EventTarget::innerInvokeEventListeners(WebCore::Event&, WTF::Vector<WTF::RefPtr<WebCore::RegisteredEventListener, WTF::RawPtrTraits<WebCore::RegisteredEventListener>, WTF::DefaultRefDerefTraits<WebCore::RegisteredEventListener> >, 1ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>, WebCore::EventTarget::EventInvokePhase) + 428 34 WebCore 0x50b53fd56 WebCore::EventTarget::fireEventListeners(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) + 630 35 WebCore 0x50b53fab4 WebCore::EventTarget::dispatchEvent(WebCore::Event&) + 228 36 WebCore 0x50c2e879c WebCore::XMLHttpRequest::dispatchEvent(WebCore::Event&) + 300 37 WebCore 0x50c2e3d77 WebCore::XMLHttpRequestProgressEventThrottle::dispatchProgressEvent(WTF::AtomString const&) + 423 38 WebCore 0x50a174e2b WebCore::XMLHttpRequest::callReadyStateChangeListener() + 411 39 WebCore 0x50c2e3b51 WebCore::XMLHttpRequest::changeState(WebCore::XMLHttpRequest::State) + 225 40 WebCore 0x50c2e78e7 WebCore::XMLHttpRequest::didFinishLoading(WTF::ObjectIdentifier<WebCore::ResourceLoader>) + 519 41 WebCore 0x50b9f27ed WebCore::DocumentThreadableLoader::didFinishLoading(WTF::ObjectIdentifier<WebCore::ResourceLoader>) + 541 42 WebCore 0x50ba7f55f WebCore::CachedResource::checkNotify(WebCore::NetworkLoadMetrics const&) + 95 43 WebCore 0x50ba7dd89 WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*, WebCore::NetworkLoadMetrics const&) + 409 44 WebCore 0x50ba4f3cd WebCore::SubresourceLoader::didFinishLoading(WebCore::NetworkLoadMetrics const&) + 989 45 WebKit 0x502ad6d3c WebKit::WebResourceLoader::didFinishResourceLoad(WebCore::NetworkLoadMetrics const&) + 204 46 WebKit 0x502c5e39d WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) + 333 47 WebKit 0x5024ea418 IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 634 48 WebKit 0x5024ecad1 WTF::Detail::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_11, void>::call() + 187 49 JavaScriptCore 0x501c93c3f WTF::RunLoop::performWork() + 447 50 JavaScriptCore 0x501c9472a WTF::RunLoop::performWork(void*) + 26 51 CoreFoundation 0x7ff8008f484d __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 52 CoreFoundation 0x7ff8008f47b5 __CFRunLoopDoSource0 + 180 53 CoreFoundation 0x7ff8008f4534 __CFRunLoopDoSources0 + 242 54 CoreFoundation 0x7ff8008f2f6b __CFRunLoopRun + 893 55 CoreFoundation 0x7ff8008f252d CFRunLoopRunSpecific + 563 56 Foundation 0x7ff80175a75e -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 216 57 Foundation 0x7ff8017e52c3 -[NSRunLoop(NSRunLoop) run] + 76 58 libxpc.dylib 0x7ff80057b233 _xpc_objc_main + 825 59 libxpc.dylib 0x7ff80057ac22 xpc_main + 99 60 WebKit 0x50267d9de WebKit::XPCServiceMain(int, char const**) + 85 61 dyld 0x11481c4fe start + 462
Nice! Multiple crash signatures are likely expected for this kind of bug.
<rdar://problem/86420006>
Internal JSC team couldn't reproduce. Please file a new crash report if you continue to see this on new STP builds.