Bug 180337 - Frequent crashes in WorkerCacheStorageConnection
Summary: Frequent crashes in WorkerCacheStorageConnection
Status: RESOLVED DUPLICATE of bug 180304
Alias: None
Product: WebKit
Classification: Unclassified
Component: WebCore Misc. (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-12-03 14:43 PST by Chris Dumez
Modified: 2017-12-04 10:14 PST (History)
3 users (show)

See Also:

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Description Chris Dumez 2017-12-03 14:43:30 PST 
I see frequent crashes in DOMCacheEngine when running the tests locally:

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x00000000bbadbeef
Exception Note:        EXC_CORPSE_NOTIFY

Termination Signal:    Segmentation fault: 11
Termination Reason:    Namespace SIGNAL, Code 0xb
Terminating Process:   exc handler [0]

VM Regions Near 0xbbadbeef:
--> 
    __TEXT                 000000010ee69000-000000010ee6b000 [    8K] r-x/rwx SM=COW  /Volumes/VOLUME/*/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent.Development

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.JavaScriptCore      	0x00000005d42681e4 WTFCrash + 36 (Assertions.cpp:273)
1   com.apple.WebCore             	0x00000005c7d6c188 WTF::Deque<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >, 0ul>::checkValidity() const + 168 (Deque.h:250)
2   com.apple.WebCore             	0x00000005c7d6e73f void WTF::Deque<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >, 0ul>::append<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> > >(std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >&&) + 47 (Deque.h:455)
3   com.apple.WebCore             	0x00000005c7d6e705 WTF::Deque<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >, 0ul>::append(std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >&&) + 37 (Deque.h:87)
4   com.apple.WebCore             	0x00000005c7d626fb WTF::MessageQueue<WebCore::WorkerRunLoop::Task>::append(std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >) + 75 (MessageQueue.h:97)
5   com.apple.WebCore             	0x00000005c7d5fac4 WebCore::WorkerRunLoop::postTaskForMode(WebCore::ScriptExecutionContext::Task&&, WTF::String const&) + 356 (WorkerRunLoop.cpp:252)
6   com.apple.WebCore             	0x00000005c7db6b99 WebCore::ServiceWorkerThreadProxy::postTaskForModeToWorkerGlobalScope(WebCore::ScriptExecutionContext::Task&&, WTF::String const&) + 73 (ServiceWorkerThreadProxy.cpp:68)
7   com.apple.WebCore             	0x00000005c5f2a75b WebCore::WorkerCacheStorageConnection::doRemove(unsigned long long, unsigned long long)::$_37::operator()()::'lambda'(WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&)::operator()(WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&) + 283 (WorkerCacheStorageConnection.cpp:137)
8   com.apple.WebCore             	0x00000005c5f2a584 WTF::Function<void (WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&)>::CallableWrapper<WebCore::WorkerCacheStorageConnection::doRemove(unsigned long long, unsigned long long)::$_37::operator()()::'lambda'(WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&)>::call(WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&) + 52 (Function.h:101)
9   com.apple.WebCore             	0x00000005c5eed6ee WTF::Function<void (WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&)>::operator()(WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&) const + 158 (Function.h:56)
10  com.apple.WebCore             	0x00000005c5eed455 WebCore::CacheStorageConnection::openOrRemoveCompleted(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&) + 85
11  com.apple.WebKit              	0x00000005c0805845 WebCore::CacheStorageConnection::removeCompleted(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&) + 37 (CacheStorageConnection.h:62)
12  com.apple.WebKit              	0x00000005c0805810 WebKit::WebCacheStorageConnection::removeCompleted(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&) + 48 (WebCacheStorageConnection.cpp:107)
13  com.apple.WebKit              	0x00000005c0812060 void IPC::callMemberFunctionImpl<WebKit::WebCacheStorageConnection, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&), std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> >, 0ul, 1ul>(WebKit::WebCacheStorageConnection*, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&), std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> >&&, std::__1::integer_sequence<unsigned long, 0ul, 1ul>) + 192 (HandleMessage.h:41)
14  com.apple.WebKit              	0x00000005c0810940 void IPC::callMemberFunction<WebKit::WebCacheStorageConnection, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&), std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> >, std::__1::integer_sequence<unsigned long, 0ul, 1ul> >(std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> >&&, WebKit::WebCacheStorageConnection*, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&)) + 96 (HandleMessage.h:47)
15  com.apple.WebKit              	0x00000005c08100b8 void IPC::handleMessage<Messages::WebCacheStorageConnection::RemoveCompleted, WebKit::WebCacheStorageConnection, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&)>(IPC::Decoder&, WebKit::WebCacheStorageConnection*, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheIdentifierOperationResult, WebCore::DOMCacheEngine::Error> const&)) + 280
16  com.apple.WebKit              	0x00000005c080fb0d WebKit::WebCacheStorageConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 237 (WebCacheStorageConnectionMessageReceiver.cpp:48)
17  com.apple.WebKit              	0x00000005c0817eca WebKit::WebCacheStorageProvider::process(IPC::Connection&, IPC::Decoder&) + 90 (WebCacheStorageProvider.cpp:56)
18  com.apple.WebKit              	0x00000005c03af7bc WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 812 (NetworkProcessConnection.cpp:94)
19  com.apple.WebKit              	0x00000005c013b333 IPC::Connection::dispatchMessage(IPC::Decoder&) + 51 (Connection.cpp:902)
20  com.apple.WebKit              	0x00000005c0130918 IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 712
21  com.apple.WebKit              	0x00000005c013b93a IPC::Connection::dispatchOneMessage() + 1530 (Connection.cpp:959)
22  com.apple.WebKit              	0x00000005c0153c1d IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_14::operator()() + 29 (Connection.cpp:896)
23  com.apple.WebKit              	0x00000005c0153b79 WTF::Function<void ()>::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_14>::call() + 25 (Function.h:101)
24  com.apple.JavaScriptCore      	0x00000005d42810db WTF::Function<void ()>::operator()() const + 139 (Function.h:56)
25  com.apple.JavaScriptCore      	0x00000005d42c82d3 WTF::RunLoop::performWork() + 211 (RunLoop.cpp:107)
26  com.apple.JavaScriptCore      	0x00000005d42c8b54 WTF::RunLoop::performWork(void*) + 36 (RunLoopCF.cpp:38)
27  com.apple.CoreFoundation      	0x00007fff36aaa5a1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
28  com.apple.CoreFoundation      	0x00007fff36b6435c __CFRunLoopDoSource0 + 108
29  com.apple.CoreFoundation      	0x00007fff36a8d040 __CFRunLoopDoSources0 + 208
30  com.apple.CoreFoundation      	0x00007fff36a8c4bd __CFRunLoopRun + 1293
31  com.apple.CoreFoundation      	0x00007fff36a8bd23 CFRunLoopRunSpecific + 483
32  com.apple.HIToolbox           	0x00007fff35da3e26 RunCurrentEventLoopInMode + 286
33  com.apple.HIToolbox           	0x00007fff35da3b96 ReceiveNextEventCommon + 613
34  com.apple.HIToolbox           	0x00007fff35da3914 _BlockUntilNextEventMatchingListInModeWithFilter + 64
35  com.apple.AppKit              	0x00007fff3406ef5f _DPSNextEvent + 2085
36  com.apple.AppKit              	0x00007fff34804b4c -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 3044
37  com.apple.AppKit              	0x00007fff34063d6d -[NSApplication run] + 764
38  com.apple.AppKit              	0x00007fff34032f1a NSApplicationMain + 804
39  libxpc.dylib                  	0x00007fff5e71342f _xpc_objc_main + 580
40  libxpc.dylib                  	0x00007fff5e712082 xpc_main + 417
41  com.apple.WebKit.WebContent   	0x000000010ee6a13b main + 1195 (XPCServiceMain.mm:148)
42  libdyld.dylib                 	0x00007fff5e446115 start + 1
Comment 1 Chris Dumez 2017-12-03 14:56:35 PST 
Probably same root cause:
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.JavaScriptCore      	0x000000013c2681e4 WTFCrash + 36 (Assertions.cpp:273)
1   com.apple.WebCore             	0x000000012fd6c188 WTF::Deque<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >, 0ul>::checkValidity() const + 168 (Deque.h:250)
2   com.apple.WebCore             	0x000000012fd6e73f void WTF::Deque<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >, 0ul>::append<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> > >(std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >&&) + 47 (Deque.h:455)
3   com.apple.WebCore             	0x000000012fd6e705 WTF::Deque<std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >, 0ul>::append(std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >&&) + 37 (Deque.h:87)
4   com.apple.WebCore             	0x000000012fd626fb WTF::MessageQueue<WebCore::WorkerRunLoop::Task>::append(std::__1::unique_ptr<WebCore::WorkerRunLoop::Task, std::__1::default_delete<WebCore::WorkerRunLoop::Task> >) + 75 (MessageQueue.h:97)
5   com.apple.WebCore             	0x000000012fd5fac4 WebCore::WorkerRunLoop::postTaskForMode(WebCore::ScriptExecutionContext::Task&&, WTF::String const&) + 356 (WorkerRunLoop.cpp:252)
6   com.apple.WebCore             	0x000000012fdb6b99 WebCore::ServiceWorkerThreadProxy::postTaskForModeToWorkerGlobalScope(WebCore::ScriptExecutionContext::Task&&, WTF::String const&) + 73 (ServiceWorkerThreadProxy.cpp:68)
7   com.apple.WebCore             	0x000000012df2bf90 WebCore::WorkerCacheStorageConnection::doRetrieveCaches(unsigned long long, WTF::String const&, unsigned long long)::$_38::operator()()::'lambda'(WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&)::operator()(WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&) + 352 (WorkerCacheStorageConnection.cpp:158)
8   com.apple.WebCore             	0x000000012df2bd84 WTF::Function<void (WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&)>::CallableWrapper<WebCore::WorkerCacheStorageConnection::doRetrieveCaches(unsigned long long, WTF::String const&, unsigned long long)::$_38::operator()()::'lambda'(WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&)>::call(WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&) + 52 (Function.h:101)
9   com.apple.WebCore             	0x000000012deeda0e WTF::Function<void (WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&)>::operator()(WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&) const + 158 (Function.h:56)
10  com.apple.WebCore             	0x000000012deed77d WebCore::CacheStorageConnection::updateCaches(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&) + 93
11  com.apple.WebKit              	0x000000012880588d WebKit::WebCacheStorageConnection::updateCaches(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&) + 61 (WebCacheStorageConnection.cpp:112)
12  com.apple.WebKit              	0x0000000128814d50 void IPC::callMemberFunctionImpl<WebKit::WebCacheStorageConnection, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&), std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error> >, 0ul, 1ul>(WebKit::WebCacheStorageConnection*, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&), std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error> >&&, std::__1::integer_sequence<unsigned long, 0ul, 1ul>) + 192 (HandleMessage.h:41)
13  com.apple.WebKit              	0x0000000128812100 void IPC::callMemberFunction<WebKit::WebCacheStorageConnection, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&), std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error> >, std::__1::integer_sequence<unsigned long, 0ul, 1ul> >(std::__1::tuple<unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error> >&&, WebKit::WebCacheStorageConnection*, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&)) + 96 (HandleMessage.h:47)
14  com.apple.WebKit              	0x00000001288101fc void IPC::handleMessage<Messages::WebCacheStorageConnection::UpdateCaches, WebKit::WebCacheStorageConnection, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&)>(IPC::Decoder&, WebKit::WebCacheStorageConnection*, void (WebKit::WebCacheStorageConnection::*)(unsigned long long, WTF::Expected<WebCore::DOMCacheEngine::CacheInfos, WebCore::DOMCacheEngine::Error>&&)) + 284 (HandleMessage.h:127)
15  com.apple.WebKit              	0x000000012880fb90 WebKit::WebCacheStorageConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 368 (WebCacheStorageConnectionMessageReceiver.cpp:52)
16  com.apple.WebKit              	0x0000000128817eca WebKit::WebCacheStorageProvider::process(IPC::Connection&, IPC::Decoder&) + 90 (WebCacheStorageProvider.cpp:56)
17  com.apple.WebKit              	0x00000001283af7bc WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 812 (NetworkProcessConnection.cpp:94)
18  com.apple.WebKit              	0x000000012813b333 IPC::Connection::dispatchMessage(IPC::Decoder&) + 51 (Connection.cpp:902)
19  com.apple.WebKit              	0x0000000128130918 IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 712
20  com.apple.WebKit              	0x000000012813b93a IPC::Connection::dispatchOneMessage() + 1530 (Connection.cpp:959)
21  com.apple.WebKit              	0x0000000128153c1d IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_14::operator()() + 29 (Connection.cpp:896)
22  com.apple.WebKit              	0x0000000128153b79 WTF::Function<void ()>::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_14>::call() + 25 (Function.h:101)
23  com.apple.JavaScriptCore      	0x000000013c2810db WTF::Function<void ()>::operator()() const + 139 (Function.h:56)
24  com.apple.JavaScriptCore      	0x000000013c2c82d3 WTF::RunLoop::performWork() + 211 (RunLoop.cpp:107)
25  com.apple.JavaScriptCore      	0x000000013c2c8b54 WTF::RunLoop::performWork(void*) + 36 (RunLoopCF.cpp:38)
26  com.apple.CoreFoundation      	0x00007fff36aaa5a1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
27  com.apple.CoreFoundation      	0x00007fff36b6435c __CFRunLoopDoSource0 + 108
28  com.apple.CoreFoundation      	0x00007fff36a8d040 __CFRunLoopDoSources0 + 208
29  com.apple.CoreFoundation      	0x00007fff36a8c4bd __CFRunLoopRun + 1293
30  com.apple.CoreFoundation      	0x00007fff36a8bd23 CFRunLoopRunSpecific + 483
31  com.apple.HIToolbox           	0x00007fff35da3e26 RunCurrentEventLoopInMode + 286
32  com.apple.HIToolbox           	0x00007fff35da3b96 ReceiveNextEventCommon + 613
33  com.apple.HIToolbox           	0x00007fff35da3914 _BlockUntilNextEventMatchingListInModeWithFilter + 64
34  com.apple.AppKit              	0x00007fff3406ef5f _DPSNextEvent + 2085
35  com.apple.AppKit              	0x00007fff34804b4c -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 3044
36  com.apple.AppKit              	0x00007fff34063d6d -[NSApplication run] + 764
37  com.apple.AppKit              	0x00007fff34032f1a NSApplicationMain + 804
38  libxpc.dylib                  	0x00007fff5e71342f _xpc_objc_main + 580
39  libxpc.dylib                  	0x00007fff5e712082 xpc_main + 417
40  com.apple.WebKit.WebContent   	0x000000010d36813b main + 1195 (XPCServiceMain.mm:148)
41  libdyld.dylib                 	0x00007fff5e446115 start + 1
Comment 2 Chris Dumez 2017-12-03 14:59:05 PST 
My bet is that WorkerCacheStorageConnection::m_proxy is dead. It is a WorkerLoaderProxy&, nothing seems to keep it alive?
Comment 4 Chris Dumez 2017-12-03 15:05:27 PST 
Looks like it causes http/tests/workers/service/service-worker-clear.html to flakily time out.
Comment 5 youenn fablet 2017-12-03 20:57:47 PST 
I believe this is a dupe of https://bugs.webkit.org/show_bug.cgi?id=180304.
Let's finalize 180304 and see whether this crash is still happening.
Comment 6 Chris Dumez 2017-12-04 10:14:07 PST 

*** This bug has been marked as a duplicate of bug 180304 ***