Bug 209684 – ASSERTION FAILED: m_wrapper on imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/ready-states/autoplay.html

• Component: Platform
• Status: RESOLVED FIXED

[Jason Lawrence]

Created attachment 394763 [details]
autoplay-crash-log

imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/ready-states/autoplay.html 

Description:
This test is flaky crashing on Mac Debug. The flaky crashes first appear in the visual history on 03/10/2020.

History:
https://results.webkit.org/?suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fready-states%2Fautoplay.html&platform=mac&style=debug&limit=50000

Crash log attached;
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.JavaScriptCore      	0x000000010a22dce0 WTFCrash + 16 (Assertions.cpp:309)
1   com.apple.WebCore             	0x0000000121ff747b WTFCrashWithInfo(int, char const*, char const*, int) + 27
2   com.apple.WebCore             	0x0000000124369528 WebCore::JSEventListener::ensureJSFunction(WebCore::ScriptExecutionContext&) const + 616 (JSEventListener.h:125)
3   com.apple.WebCore             	0x000000012436884b WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext&, WebCore::Event&) + 219 (JSEventListener.cpp:113)
4   com.apple.WebCore             	0x0000000124a25e4b WebCore::EventTarget::innerInvokeEventListeners(WebCore::Event&, WTF::Vector<WTF::RefPtr<WebCore::RegisteredEventListener, WTF::DumbPtrTraits<WebCore::RegisteredEventListener> >, 1ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>, WebCore::EventTarget::EventInvokePhase) + 1099 (EventTarget.cpp:326)
5   com.apple.WebCore             	0x0000000124a21ff2 WebCore::EventTarget::fireEventListeners(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) + 354 (EventTarget.cpp:257)
6   com.apple.WebCore             	0x0000000124aa6e4a WebCore::Node::handleLocalEvents(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) + 186 (Node.cpp:2365)
7   com.apple.WebCore             	0x0000000124a0d510 WebCore::EventContext::handleLocalEvents(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) const + 192 (EventContext.cpp:55)
8   com.apple.WebCore             	0x0000000124a0e02b WebCore::dispatchEventInDOM(WebCore::Event&, WebCore::EventPath const&) + 379 (EventDispatcher.cpp:101)
9   com.apple.WebCore             	0x0000000124a0db45 WebCore::EventDispatcher::dispatchEvent(WebCore::Node&, WebCore::Event&) + 581 (EventDispatcher.cpp:157)
10  com.apple.WebCore             	0x0000000124aa6e9d WebCore::Node::dispatchEvent(WebCore::Event&) + 29 (Node.cpp:2375)
11  com.apple.WebCore             	0x0000000124e6eb31 WebCore::HTMLMediaElement::dispatchEvent(WebCore::Event&) + 225 (HTMLMediaElement.cpp:5886)
12  com.apple.WebCore             	0x0000000124a44cd0 WebCore::MainThreadGenericEventQueue::dispatchOneEvent() + 608 (GenericEventQueue.cpp:73)
13  com.apple.WebCore             	0x0000000124a4b9e1 decltype(*(std::__1::forward<WebCore::MainThreadGenericEventQueue*&>(fp0)).*fp()) std::__1::__invoke<void (WebCore::MainThreadGenericEventQueue::*&)(), WebCore::MainThreadGenericEventQueue*&, void>(void (WebCore::MainThreadGenericEventQueue::*&&&)(), WebCore::MainThreadGenericEventQueue*&&&) + 113 (type_traits:4280)

[Radar WebKit Bug Importer]

<rdar://problem/60987285>

[Jason Lawrence]

I have marked this test as crashing while this issue is investigated.
https://trac.webkit.org/changeset/259143/webkit

[Alexey Proskuryakov]

Still crashing today (latest seen with r259201).

[Chris Dumez]

Media classes should really stop using those EventQueue classes and start using the HTML event loop. It would avoid such issues..

[Chris Dumez]

HTMLMediaElement has a single MainThreadGenericEventQueue data member: m_asyncEventQueue.

However, hasPendingActivity() already makes sure it does not have pending events:
bool HTMLMediaElement::hasPendingActivity() const
{
    return (hasAudio() && isPlaying()) || m_asyncEventQueue->hasPendingEvents() || m_playbackTargetIsWirelessQueue.hasPendingTasks() || m_creatingControls;
}

Therefore, it must be some other MainThreadGenericEventQueue which dispatches events on the HTMLMediaElement?

[Chris Dumez]

I have not been able to reproduce yet. If anybody is, please let me know how.

[Chris Dumez]

Created attachment 395047 [details]
Patch

[Darin Adler]

Comment on attachment 395047 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=395047&action=review

> Source/WebCore/dom/GenericEventQueue.h:59
> +    bool hasPendingActivityForGC() const;

Not loving this name. What is "activity for GC"? Maybe we mean "activity that should prevent GC"? Let's think about the words we would use to explain this.

[Chris Dumez]

Comment on attachment 395047 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=395047&action=review

>> Source/WebCore/dom/GenericEventQueue.h:59
>> +    bool hasPendingActivityForGC() const;
> 
> Not loving this name. What is "activity for GC"? Maybe we mean "activity that should prevent GC"? Let's think about the words we would use to explain this.

Would hasPendingActivity() be OK?

[Darin Adler]

(In reply to Darin Adler from comment #8)
> Let's think about the words we would use to explain this.

The words we would use to explain this to another person and maybe we can name the function better. (Don't hold up check-in looking for a better name, though.)

[Darin Adler]

Comment on attachment 395047 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=395047&action=review

>>> Source/WebCore/dom/GenericEventQueue.h:59
>>> +    bool hasPendingActivityForGC() const;
>> 
>> Not loving this name. What is "activity for GC"? Maybe we mean "activity that should prevent GC"? Let's think about the words we would use to explain this.
> 
> Would hasPendingActivity() be OK?

Probably.

[Chris Dumez]

(In reply to Darin Adler from comment #11)
> Comment on attachment 395047 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=395047&action=review
> 
> >>> Source/WebCore/dom/GenericEventQueue.h:59
> >>> +    bool hasPendingActivityForGC() const;
> >> 
> >> Not loving this name. What is "activity for GC"? Maybe we mean "activity that should prevent GC"? Let's think about the words we would use to explain this.
> > 
> > Would hasPendingActivity() be OK?
> 
> Probably.

This is only used for ActiveDOMObject::virtualHasPendingActivity() so it would at least be consistent.

[Chris Dumez]

Committed r259299: <https://trac.webkit.org/changeset/259299>

[Chris Dumez]

(In reply to Chris Dumez from comment #13)
> Committed r259299: <https://trac.webkit.org/changeset/259299>

Fixed name before landing.

[Chris Dumez]

There was a crash on the bot after my fix:
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.JavaScriptCore      	0x00000001c5edfc2e WTFCrash + 14 (Assertions.cpp:309)
1   com.apple.WebCore             	0x00000001a8fda47b WTFCrashWithInfo(int, char const*, char const*, int) + 27
2   com.apple.WebCore             	0x00000001ab36f83f WebCore::JSEventListener::ensureJSFunction(WebCore::ScriptExecutionContext&) const + 639 (JSEventListener.h:125)
3   com.apple.WebCore             	0x00000001ab36ebad WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext&, WebCore::Event&) + 205 (JSEventListener.cpp:113)
4   com.apple.WebCore             	0x00000001aba313a7 WebCore::EventTarget::innerInvokeEventListeners(WebCore::Event&, WTF::Vector<WTF::RefPtr<WebCore::RegisteredEventListener, WTF::DumbPtrTraits<WebCore::RegisteredEventListener> >, 1ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>, WebCore::EventTarget::EventInvokePhase) + 1063 (EventTarget.cpp:326)
5   com.apple.WebCore             	0x00000001aba2d5c4 WebCore::EventTarget::fireEventListeners(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) + 356 (EventTarget.cpp:257)
6   com.apple.WebCore             	0x00000001abab3922 WebCore::Node::handleLocalEvents(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) + 178 (Node.cpp:2366)
7   com.apple.WebCore             	0x00000001aba18741 WebCore::EventContext::handleLocalEvents(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) const + 193 (EventContext.cpp:55)
8   com.apple.WebCore             	0x00000001aba1922f WebCore::dispatchEventInDOM(WebCore::Event&, WebCore::EventPath const&) + 383 (EventDispatcher.cpp:101)
9   com.apple.WebCore             	0x00000001aba18d67 WebCore::EventDispatcher::dispatchEvent(WebCore::Node&, WebCore::Event&) + 567 (EventDispatcher.cpp:157)
10  com.apple.WebCore             	0x00000001abab397d WebCore::Node::dispatchEvent(WebCore::Event&) + 29 (Node.cpp:2376)
11  com.apple.WebCore             	0x00000001abe7f6e1 WebCore::HTMLMediaElement::dispatchEvent(WebCore::Event&) + 225 (HTMLMediaElement.cpp:5879)
12  com.apple.WebCore             	0x00000001aba50933 WebCore::MainThreadGenericEventQueue::dispatchOneEvent() + 643 (GenericEventQueue.cpp:76)
13  com.apple.WebCore             	0x00000001aba578f7 decltype(*(std::__1::forward<WebCore::MainThreadGenericEventQueue*&>(fp0)).*fp()) std::__1::__invoke<void (WebCore::MainThreadGenericEventQueue::*&)(), WebCore::MainThreadGenericEventQueue*&, void>(void (WebCore::MainThreadGenericEventQueue::*&)(), WebCore::MainThreadGenericEventQueue*&) + 119 (type_traits:4366)
14  com.apple.WebCore             	0x00000001aba57870 std::__1::__bind_return<void (WebCore::MainThreadGenericEventQueue::*)(), std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<>, __is_valid_bind_return<void (WebCore::MainThreadGenericEventQueue::*)(), std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<> >::value>::type std::__1::__apply_functor<void (WebCore::MainThreadGenericEventQueue::*)(), std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, 0ul, std::__1::tuple<> >(void (WebCore::MainThreadGenericEventQueue::*&)(), std::__1::tuple<WebCore::MainThreadGenericEventQueue*>&, std::__1::__tuple_indices<0ul>, std::__1::tuple<>&&) + 64 (functional:2716)
15  com.apple.WebCore             	0x00000001aba57829 std::__1::__bind_return<void (WebCore::MainThreadGenericEventQueue::*)(), std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<>, __is_valid_bind_return<void (WebCore::MainThreadGenericEventQueue::*)(), std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<> >::value>::type std::__1::__bind<void (WebCore::MainThreadGenericEventQueue::*)(), WebCore::MainThreadGenericEventQueue*>::operator()<>() + 41 (functional:2749)
16  com.apple.WebCore             	0x00000001aba577ce WTF::Detail::CallableWrapper<std::__1::__bind<void (WebCore::MainThreadGenericEventQueue::*)(), WebCore::MainThreadGenericEventQueue*>, void>::call() + 30 (Function.h:52)
17  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void ()>::operator()() const + 130 (Function.h:84)
18  com.apple.WebCore             	0x00000001a92f4275 WebCore::GenericTaskQueue<WebCore::Timer>::enqueueTask(WTF::Function<void ()>&&)::'lambda'()::operator()() const + 181 (GenericTaskQueue.h:108)
19  com.apple.WebCore             	0x00000001a92f40ae WTF::Detail::CallableWrapper<WebCore::GenericTaskQueue<WebCore::Timer>::enqueueTask(WTF::Function<void ()>&&)::'lambda'(), void>::call() + 30 (Function.h:52)
20  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void ()>::operator()() const + 130 (Function.h:84)
21  com.apple.WebCore             	0x00000001ac92d0ef WebCore::TaskDispatcher<WebCore::Timer>::dispatchOneTask() + 223 (GenericTaskQueue.cpp:111)
22  com.apple.WebCore             	0x00000001ac92cdc5 WebCore::TaskDispatcher<WebCore::Timer>::sharedTimerFired() + 261 (GenericTaskQueue.cpp:86)
23  com.apple.WebCore             	0x00000001ac9335c1 WebCore::TaskDispatcher<WebCore::Timer>::sharedTimer()::$_1::operator()() const + 17 (GenericTaskQueue.cpp:60)
24  com.apple.WebCore             	0x00000001ac93357e WTF::Detail::CallableWrapper<WebCore::TaskDispatcher<WebCore::Timer>::sharedTimer()::$_1, void>::call() + 30 (Function.h:52)
25  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void ()>::operator()() const + 130 (Function.h:84)
26  com.apple.WebCore             	0x00000001a90b5cde WebCore::Timer::fired() + 30 (Timer.h:127)
27  com.apple.WebCore             	0x00000001ac980144 WebCore::ThreadTimers::sharedTimerFiredInternal() + 644 (ThreadTimers.cpp:127)
28  com.apple.WebCore             	0x00000001ac988aa1 WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::$_0::operator()() const + 33 (ThreadTimers.cpp:67)
29  com.apple.WebCore             	0x00000001ac988a4e WTF::Detail::CallableWrapper<WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::$_0, void>::call() + 30 (Function.h:52)
30  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void ()>::operator()() const + 130 (Function.h:84)
31  com.apple.WebCore             	0x00000001ac946b0b WebCore::MainThreadSharedTimer::fired() + 139 (MainThreadSharedTimer.cpp:84)
32  com.apple.WebCore             	0x00000001ac9f83c6 WebCore::timerFired(__CFRunLoopTimer*, void*) + 38 (MainThreadSharedTimerCF.cpp:75)
33  com.apple.CoreFoundation      	0x00007fff349b39b9 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
34  com.apple.CoreFoundation      	0x00007fff349b351f __CFRunLoopDoTimer + 859
35  com.apple.CoreFoundation      	0x00007fff349b3007 __CFRunLoopDoTimers + 322
36  com.apple.CoreFoundation      	0x00007fff34997daa __CFRunLoopRun + 1871
37  com.apple.CoreFoundation      	0x00007fff34996ffe CFRunLoopRunSpecific + 462
38  com.apple.Foundation          	0x00007fff3702b2a8 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 212
39  com.apple.Foundation          	0x00007fff370ddd2f -[NSRunLoop(NSRunLoop) run] + 76
40  libxpc.dylib                  	0x00007fff6eb2e51a _xpc_objc_main.cold.4 + 49
41  libxpc.dylib                  	0x00007fff6eb2e460 _xpc_objc_main + 559
42  libxpc.dylib                  	0x00007fff6eb2df93 xpc_main + 377
43  com.apple.WebKit              	0x000000010abc86db WebKit::XPCServiceMain(int, char const**) + 1499 (XPCServiceMain.mm:172)
44  com.apple.WebKit              	0x000000010bf737bb WKXPCServiceMain + 27 (WKMain.mm:33)
45  com.apple.WebKit.WebContent   	0x000000010a2f5ec2 main + 34 (AuxiliaryProcessMain.cpp:30)
46  libdyld.dylib                 	0x00007fff6e8e0cc9 start + 1

[Chris Dumez]

(In reply to Chris Dumez from comment #15)
> There was a crash on the bot after my fix:
> Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
> 0   com.apple.JavaScriptCore      	0x00000001c5edfc2e WTFCrash + 14
> (Assertions.cpp:309)
> 1   com.apple.WebCore             	0x00000001a8fda47b WTFCrashWithInfo(int,
> char const*, char const*, int) + 27
> 2   com.apple.WebCore             	0x00000001ab36f83f
> WebCore::JSEventListener::ensureJSFunction(WebCore::ScriptExecutionContext&)
> const + 639 (JSEventListener.h:125)
> 3   com.apple.WebCore             	0x00000001ab36ebad
> WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext&,
> WebCore::Event&) + 205 (JSEventListener.cpp:113)
> 4   com.apple.WebCore             	0x00000001aba313a7
> WebCore::EventTarget::innerInvokeEventListeners(WebCore::Event&,
> WTF::Vector<WTF::RefPtr<WebCore::RegisteredEventListener,
> WTF::DumbPtrTraits<WebCore::RegisteredEventListener> >, 1ul,
> WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>,
> WebCore::EventTarget::EventInvokePhase) + 1063 (EventTarget.cpp:326)
> 5   com.apple.WebCore             	0x00000001aba2d5c4
> WebCore::EventTarget::fireEventListeners(WebCore::Event&,
> WebCore::EventTarget::EventInvokePhase) + 356 (EventTarget.cpp:257)
> 6   com.apple.WebCore             	0x00000001abab3922
> WebCore::Node::handleLocalEvents(WebCore::Event&,
> WebCore::EventTarget::EventInvokePhase) + 178 (Node.cpp:2366)
> 7   com.apple.WebCore             	0x00000001aba18741
> WebCore::EventContext::handleLocalEvents(WebCore::Event&,
> WebCore::EventTarget::EventInvokePhase) const + 193 (EventContext.cpp:55)
> 8   com.apple.WebCore             	0x00000001aba1922f
> WebCore::dispatchEventInDOM(WebCore::Event&, WebCore::EventPath const&) +
> 383 (EventDispatcher.cpp:101)
> 9   com.apple.WebCore             	0x00000001aba18d67
> WebCore::EventDispatcher::dispatchEvent(WebCore::Node&, WebCore::Event&) +
> 567 (EventDispatcher.cpp:157)
> 10  com.apple.WebCore             	0x00000001abab397d
> WebCore::Node::dispatchEvent(WebCore::Event&) + 29 (Node.cpp:2376)
> 11  com.apple.WebCore             	0x00000001abe7f6e1
> WebCore::HTMLMediaElement::dispatchEvent(WebCore::Event&) + 225
> (HTMLMediaElement.cpp:5879)
> 12  com.apple.WebCore             	0x00000001aba50933
> WebCore::MainThreadGenericEventQueue::dispatchOneEvent() + 643
> (GenericEventQueue.cpp:76)
> 13  com.apple.WebCore             	0x00000001aba578f7
> decltype(*(std::__1::forward<WebCore::MainThreadGenericEventQueue*&>(fp0)).
> *fp()) std::__1::__invoke<void (WebCore::MainThreadGenericEventQueue::*&)(),
> WebCore::MainThreadGenericEventQueue*&, void>(void
> (WebCore::MainThreadGenericEventQueue::*&)(),
> WebCore::MainThreadGenericEventQueue*&) + 119 (type_traits:4366)
> 14  com.apple.WebCore             	0x00000001aba57870
> std::__1::__bind_return<void (WebCore::MainThreadGenericEventQueue::*)(),
> std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<>,
> __is_valid_bind_return<void (WebCore::MainThreadGenericEventQueue::*)(),
> std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<>
> >::value>::type std::__1::__apply_functor<void
> (WebCore::MainThreadGenericEventQueue::*)(),
> std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, 0ul,
> std::__1::tuple<> >(void (WebCore::MainThreadGenericEventQueue::*&)(),
> std::__1::tuple<WebCore::MainThreadGenericEventQueue*>&,
> std::__1::__tuple_indices<0ul>, std::__1::tuple<>&&) + 64 (functional:2716)
> 15  com.apple.WebCore             	0x00000001aba57829
> std::__1::__bind_return<void (WebCore::MainThreadGenericEventQueue::*)(),
> std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<>,
> __is_valid_bind_return<void (WebCore::MainThreadGenericEventQueue::*)(),
> std::__1::tuple<WebCore::MainThreadGenericEventQueue*>, std::__1::tuple<>
> >::value>::type std::__1::__bind<void
> (WebCore::MainThreadGenericEventQueue::*)(),
> WebCore::MainThreadGenericEventQueue*>::operator()<>() + 41 (functional:2749)
> 16  com.apple.WebCore             	0x00000001aba577ce
> WTF::Detail::CallableWrapper<std::__1::__bind<void
> (WebCore::MainThreadGenericEventQueue::*)(),
> WebCore::MainThreadGenericEventQueue*>, void>::call() + 30 (Function.h:52)
> 17  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void
> ()>::operator()() const + 130 (Function.h:84)
> 18  com.apple.WebCore             	0x00000001a92f4275
> WebCore::GenericTaskQueue<WebCore::Timer>::enqueueTask(WTF::Function<void
> ()>&&)::'lambda'()::operator()() const + 181 (GenericTaskQueue.h:108)
> 19  com.apple.WebCore             	0x00000001a92f40ae
> WTF::Detail::CallableWrapper<WebCore::GenericTaskQueue<WebCore::Timer>::
> enqueueTask(WTF::Function<void ()>&&)::'lambda'(), void>::call() + 30
> (Function.h:52)
> 20  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void
> ()>::operator()() const + 130 (Function.h:84)
> 21  com.apple.WebCore             	0x00000001ac92d0ef
> WebCore::TaskDispatcher<WebCore::Timer>::dispatchOneTask() + 223
> (GenericTaskQueue.cpp:111)
> 22  com.apple.WebCore             	0x00000001ac92cdc5
> WebCore::TaskDispatcher<WebCore::Timer>::sharedTimerFired() + 261
> (GenericTaskQueue.cpp:86)
> 23  com.apple.WebCore             	0x00000001ac9335c1
> WebCore::TaskDispatcher<WebCore::Timer>::sharedTimer()::$_1::operator()()
> const + 17 (GenericTaskQueue.cpp:60)
> 24  com.apple.WebCore             	0x00000001ac93357e
> WTF::Detail::CallableWrapper<WebCore::TaskDispatcher<WebCore::Timer>::
> sharedTimer()::$_1, void>::call() + 30 (Function.h:52)
> 25  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void
> ()>::operator()() const + 130 (Function.h:84)
> 26  com.apple.WebCore             	0x00000001a90b5cde
> WebCore::Timer::fired() + 30 (Timer.h:127)
> 27  com.apple.WebCore             	0x00000001ac980144
> WebCore::ThreadTimers::sharedTimerFiredInternal() + 644
> (ThreadTimers.cpp:127)
> 28  com.apple.WebCore             	0x00000001ac988aa1
> WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::$_0::
> operator()() const + 33 (ThreadTimers.cpp:67)
> 29  com.apple.WebCore             	0x00000001ac988a4e
> WTF::Detail::CallableWrapper<WebCore::ThreadTimers::setSharedTimer(WebCore::
> SharedTimer*)::$_0, void>::call() + 30 (Function.h:52)
> 30  com.apple.WebCore             	0x00000001a8fece22 WTF::Function<void
> ()>::operator()() const + 130 (Function.h:84)
> 31  com.apple.WebCore             	0x00000001ac946b0b
> WebCore::MainThreadSharedTimer::fired() + 139 (MainThreadSharedTimer.cpp:84)
> 32  com.apple.WebCore             	0x00000001ac9f83c6
> WebCore::timerFired(__CFRunLoopTimer*, void*) + 38
> (MainThreadSharedTimerCF.cpp:75)
> 33  com.apple.CoreFoundation      	0x00007fff349b39b9
> __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
> 34  com.apple.CoreFoundation      	0x00007fff349b351f __CFRunLoopDoTimer +
> 859
> 35  com.apple.CoreFoundation      	0x00007fff349b3007 __CFRunLoopDoTimers +
> 322
> 36  com.apple.CoreFoundation      	0x00007fff34997daa __CFRunLoopRun + 1871
> 37  com.apple.CoreFoundation      	0x00007fff34996ffe CFRunLoopRunSpecific +
> 462
> 38  com.apple.Foundation          	0x00007fff3702b2a8 -[NSRunLoop(NSRunLoop)
> runMode:beforeDate:] + 212
> 39  com.apple.Foundation          	0x00007fff370ddd2f -[NSRunLoop(NSRunLoop)
> run] + 76
> 40  libxpc.dylib                  	0x00007fff6eb2e51a _xpc_objc_main.cold.4
> + 49
> 41  libxpc.dylib                  	0x00007fff6eb2e460 _xpc_objc_main + 559
> 42  libxpc.dylib                  	0x00007fff6eb2df93 xpc_main + 377
> 43  com.apple.WebKit              	0x000000010abc86db
> WebKit::XPCServiceMain(int, char const**) + 1499 (XPCServiceMain.mm:172)
> 44  com.apple.WebKit              	0x000000010bf737bb WKXPCServiceMain + 27
> (WKMain.mm:33)
> 45  com.apple.WebKit.WebContent   	0x000000010a2f5ec2 main + 34
> (AuxiliaryProcessMain.cpp:30)
> 46  libdyld.dylib                 	0x00007fff6e8e0cc9 start + 1

Since my speculative fix did not suffice, I still need help reproducing this crash if anyone is able to.

[Chris Dumez]

Ok, I am finally able to reproduce:
Tools/Scripts/run-webkit-tests --no-build --debug --force --repeat-each=500 -f imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/ready-states/autoplay.html  -1

[Chris Dumez]

Event being fired when we crash is 'canplay'.

[Chris Dumez]

Created attachment 395185 [details]
Patch

[Darin Adler]

Comment on attachment 395185 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=395185&action=review

> Source/WebCore/html/HTMLMediaElement.cpp:5776
> +    if (m_creatingControls)
> +        return true;
> +
> +    if (m_asyncEventQueue->hasPendingActivity() || m_playbackTargetIsWirelessQueue.hasPendingTasks())
> +        return true;
> +
> +    // If there is playing audio, we need to make sure the media element we don't get destroyed so that
> +    // it does not get interrupted.
> +    if (hasAudio() && isPlaying())
> +        return true;
> +
> +    // We need to keep the wrapper alive as long as we may fire events and there are event listeners.
> +    return m_player && (!ended() || seeking() || m_networkState >= NETWORK_IDLE) && hasEventListeners();

I guess it’s nice that the multiple return statements give us a place to put comments. But I really like the "||" form to clarify there is no tricky logic, just multiple independent reasons:

    return m_creatingControls
        || m_asyncEventQueue->hasPendingActivity()
        || m_playbackTargetIsWirelessQueue.hasPendingTasks()
        || (hasAudio() && isPlaying())
        || (m_player && (!ended() || seeking() || m_networkState >= NETWORK_IDLE) && hasEventListeners());

There’s something so appealing to that style for me.

[Chris Dumez]

Created attachment 395190 [details]
Patch

[EWS]

Committed r259359: <https://trac.webkit.org/changeset/259359>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 395190 [details].

[youenn fablet]

This seems to create some leaks, let's tighten the heuristic at https://bugs.webkit.org/show_bug.cgi?id=226529