[GPU Process] RemoteRenderingBackend::stopListeningForIPC() should not change the RemoteResourceCache on the main thread

[Ryan Haddad]

The following assertion failure is seen on iOS debug bots:

ASSERTION FAILED: imageBufferCount == m_imageBufferCount
/Volumes/Data/worker/ios-simulator-15-debug/build/Source/WebKit/GPUProcess/graphics/QualifiedResourceHeap.h(225) : void WebKit::QualifiedResourceHeap::checkInvariants() const
1   0x1438b6b09 WTFCrash
2   0x125dc1b4b WTFCrashWithInfo(int, char const*, char const*, int)
3   0x126a10bbd WebKit::QualifiedResourceHeap::checkInvariants() const
4   0x126a1daac void WebKit::QualifiedResourceHeap::add<WebCore::Font>(WebCore::ProcessQualified<WTF::ObjectIdentifier<WebCore::RenderingResourceIdentifierType> >, WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&, unsigned int&)
5   0x126a04cd4 WebKit::QualifiedResourceHeap::add(WebCore::ProcessQualified<WTF::ObjectIdentifier<WebCore::RenderingResourceIdentifierType> >, WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&)
6   0x126a03026 WebKit::RemoteResourceCache::cacheFont(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&, WebCore::ProcessQualified<WTF::ObjectIdentifier<WebCore::RenderingResourceIdentifierType> >)
7   0x126a02f46 WebKit::RemoteRenderingBackend::cacheFontWithQualifiedIdentifier(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&, WebCore::ProcessQualified<WTF::ObjectIdentifier<WebCore::RenderingResourceIdentifierType> >)
8   0x126a02e09 WebKit::RemoteRenderingBackend::cacheFont(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&)
9   0x1269b1817 void IPC::callMemberFunctionImpl<WebKit::RemoteRenderingBackend, void (WebKit::RemoteRenderingBackend::*)(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&), std::__1::tuple<WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> > >, 0ul>(WebKit::RemoteRenderingBackend*, void (WebKit::RemoteRenderingBackend::*)(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&), std::__1::tuple<WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> > >&&, std::__1::integer_sequence<unsigned long, 0ul>)
10  0x1269b044d void IPC::callMemberFunction<WebKit::RemoteRenderingBackend, void (WebKit::RemoteRenderingBackend::*)(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&), std::__1::tuple<WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> > >, std::__1::integer_sequence<unsigned long, 0ul> >(std::__1::tuple<WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> > >&&, WebKit::RemoteRenderingBackend*, void (WebKit::RemoteRenderingBackend::*)(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&))
11  0x12699c88a void IPC::handleMessage<Messages::RemoteRenderingBackend::CacheFont, WebKit::RemoteRenderingBackend, void (WebKit::RemoteRenderingBackend::*)(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&)>(IPC::Connection&, IPC::Decoder&, WebKit::RemoteRenderingBackend*, void (WebKit::RemoteRenderingBackend::*)(WTF::Ref<WebCore::Font, WTF::RawPtrTraits<WebCore::Font> >&&))
12  0x12699be51 WebKit::RemoteRenderingBackend::didReceiveStreamMessage(IPC::StreamServerConnectionBase&, IPC::Decoder&)
13  0x12727b778 IPC::StreamServerConnection::dispatchOutOfStreamMessage(IPC::Decoder&&)
14  0x12727b1a6 IPC::StreamServerConnection::dispatchStreamMessages(unsigned long)
15  0x127279ad4 IPC::StreamConnectionWorkQueue::processStreams()
16  0x1272827e0 IPC::StreamConnectionWorkQueue::startProcessingThread()::$_0::operator()()
17  0x127282799 WTF::Detail::CallableWrapper<IPC::StreamConnectionWorkQueue::startProcessingThread()::$_0, void>::call()
18  0x1438e4692 WTF::Function<void ()>::operator()() const
19  0x1439ba948 WTF::Thread::entryPoint(WTF::Thread::NewThreadContext*)
20  0x1439c8bb5 WTF::wtfThreadEntryPoint(void*)
21  0x7fff6bfee8fc _pthread_start
22  0x7fff6bfea443 thread_start
LEAK: 2 WebPageProxy

https://build.webkit.org/results/Apple-iOS-15-Simulator-Debug-WK2-Tests/r291751%20(2042)/results.html

[Radar WebKit Bug Importer]

<rdar://problem/90731372>

[Ryan Haddad]

crypto/subtle/rsa-indexeddb-non-exportable.html

[Ryan Haddad]

Created attachment 455580 [details]
crash log

[Said Abou-Hallawa]

This seems a threading issue in the RemoteResourceCache.

[Said Abou-Hallawa]

*** Bug 238299 has been marked as a duplicate of this bug. ***

[Said Abou-Hallawa]

Created attachment 455690 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 455690 [details]
Patch

We determined that there's a cleaner way to fix this.

[Said Abou-Hallawa]

Created attachment 455734 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 455734 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=455734&action=review

> Source/WebKit/GPUProcess/graphics/RemoteRenderingBackend.cpp:123
> +    m_workQueue->dispatch([&] {
> +        m_remoteResourceCache = { m_gpuConnectionToWebProcess->webProcessIdentifier() };
> +        m_renderingResourcesRequest = { };
> +    });
>      m_workQueue->stopAndWaitForCompletion();

I guess the idea here is that m_workQueue->dispatch() appends this item to the work queue so that stopAndWaitForCompletion() will process it last, after any existing work? Seems ok. Maybe the comment could make that clearer.

[Said Abou-Hallawa]

Created attachment 455781 [details]
Patch

[EWS]

Committed r291881 (248880@main): <https://commits.webkit.org/248880@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 455781 [details].