https://bugs.webkit.org/show_bug.cgi?id=200138
<rdar://problem/52698157>
Reviewed by Geoffrey Garen.
Source/WebKit:
Revert most of r247822 and use an alternative approach to address hangs. In this patch, the proposal
is to add a SendSyncOption::ForceDispatchWhenDestinationIsWaitingForUnboundedSyncReply flag on the
WebPage::TouchEventSync() & WebPage::GetPositionInformation() sendSync() calls in the UIProcess.
Those will cause this IPCs to get dispatched right away in the WebContent process, even if the
WebContent process is itself currently stuck on unbounded (i.e. potentially slow) synchronous IPC
(JS alerts / prompts & sync XHR). Because re-entering WebCore on sync IPC is generally unsafe, this
patch also updates the WebPage::getPositionInformation() & WebPage::touchEventSync() to return early
(i.e. cancelled) if they get called while the WebContent process is stuck on a slow sendSync.
This approach should address the UIProcess hangs caused by the WebPage::TouchEventSync() and
WebPage::GetPositionInformation() sync IPC messages when the WebContent process is busy on a slow XHR
or a JS prompt / alert. It should be safe because we do not re-enter WebCore. The only drawback is that
those IPCs will be cancelled (early return with default value) when the WebContent process is busy.
However, I am being told that this is likely acceptable in practice.
* Platform/IPC/Connection.cpp:
(IPC::Connection::SyncMessageState::processIncomingMessage):
(IPC::Connection::sendMessage):
(IPC::Connection::sendSyncMessage):
(IPC::Connection::dispatchMessage):
* Platform/IPC/Connection.h:
(IPC::UnboundedSynchronousIPCScope::UnboundedSynchronousIPCScope):
(IPC::UnboundedSynchronousIPCScope::~UnboundedSynchronousIPCScope):
(IPC::UnboundedSynchronousIPCScope::hasOngoingUnboundedSyncIPC):
* Platform/IPC/Decoder.cpp:
(IPC::Decoder::shouldDispatchMessageWhenWaitingForSyncReply const):
* Platform/IPC/Decoder.h:
* Platform/IPC/Encoder.cpp:
(IPC::Encoder::shouldDispatchMessageWhenWaitingForSyncReply const):
(IPC::Encoder::setShouldDispatchMessageWhenWaitingForSyncReply):
(IPC::Encoder::wrapForTesting):
* Platform/IPC/Encoder.h:
* Platform/IPC/MessageFlags.h:
* UIProcess/Network/NetworkProcessProxy.cpp:
(WebKit::NetworkProcessProxy::testProcessIncomingSyncMessagesWhenWaitingForSyncReply):
* UIProcess/WebPageProxy.cpp:
(WebKit::WebPageProxy::handleTouchEventSynchronously):
* UIProcess/ios/WKContentViewInteraction.mm:
(-[WKContentView ensurePositionInformationIsUpToDate:]):
* WebProcess/Network/WebLoaderStrategy.cpp:
(WebKit::WebLoaderStrategy::loadResourceSynchronously):
* WebProcess/WebCoreSupport/WebChromeClient.cpp:
(WebKit::WebChromeClient::testProcessIncomingSyncMessagesWhenWaitingForSyncReply):
(WebKit::WebChromeClient::runJavaScriptAlert):
(WebKit::WebChromeClient::runJavaScriptConfirm):
(WebKit::WebChromeClient::runJavaScriptPrompt):
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::layerVolatilityTimerFired):
(WebKit::WebPage::markLayersVolatile):
(WebKit::WebPage::cancelMarkLayersVolatile):
(WebKit::WebPage::touchEventSync):
(WebKit::WebPage::didCompletePageTransition):
(WebKit::WebPage::updatePreferences):
(WebKit::WebPage::testProcessIncomingSyncMessagesWhenWaitingForSyncReply):
* WebProcess/WebPage/WebPage.h:
(WebKit::WebPage::sendSyncWithDelayedReply):
* WebProcess/WebPage/ios/WebPageIOS.mm:
(WebKit::WebPage::getPositionInformation):
LayoutTests:
Update existing layout test accordingly.
* fast/misc/{testProcessIncomingSyncMessagesWhenWaitingForUnboundedReply-expected.txt: Renamed from LayoutTests/fast/misc/testProcessIncomingSyncMessagesWhenWaitingForSyncReply-expected.txt.
* fast/misc/{testProcessIncomingSyncMessagesWhenWaitingForUnboundedReply.html: Renamed from LayoutTests/fast/misc/testProcessIncomingSyncMessagesWhenWaitingForSyncReply.html.
Canonical link: https://commits.webkit.org/213985@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@247868 268f45cc-cd09-0410-ab3c-d52691b4dbfc
9275dd3c14