IssueTracker

Aurimas suggested pulling a stack trace using:
jstack -l pid >> dump.txt

We'll make sure to do this next time it occurs.

Full instructions https://developer.android.com/studio/report-bugs#thread-dump

Hit the same problem opening AndroidX, attached 3 dumps, captured at about 1 minute intervals from same launch.

Not 100% frozen, just updating at about 1 frame / 30 seconds.

The AWT thread is blocked trying to acquire the write lock, while this is happening on a background thread inside a read lock:

"ApplicationImpl pooled thread 3" #37 prio=4 os_prio=0 tid=0x00007f19940bc000 nid=0x8cb4 runnable [0x00007f199e5f5000]
   java.lang.Thread.State: RUNNABLE
        at java.util.stream.Sink$ChainedReference.end(Sink.java:258)
        at java.util.stream.Sink$ChainedReference.end(Sink.java:258)
        at java.util.stream.Sink$ChainedReference.end(Sink.java:258)
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482)
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
        at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradlePropertiesDslElement$ElementList.getElementsWhere(GradlePropertiesDslElement.java:723)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradlePropertiesDslElement$ElementList.access$700(GradlePropertiesDslElement.java:692)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradlePropertiesDslElement.getElementsWhere(GradlePropertiesDslElement.java:313)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradlePropertiesDslElement.getElementWhere(GradlePropertiesDslElement.java:323)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradlePropertiesDslElement.getPropertyElementBefore(GradlePropertiesDslElement.java:348)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradleDslSimpleExpression.resolveReferenceOnElement(GradleDslSimpleExpression.java:470)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradleDslSimpleExpression.resolveReferenceInSameModule(GradleDslSimpleExpression.java:534)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradleDslSimpleExpression.resolveReference(GradleDslSimpleExpression.java:257)
        at com.android.tools.idea.gradle.dsl.parser.DependencyManager.resolveAll(DependencyManager.java:76)
        at com.android.tools.idea.gradle.dsl.parser.DependencyManager.resolveWith(DependencyManager.java:66)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradleDslElementImpl.updateDependenciesOnAddElement(GradleDslElementImpl.java:413)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradlePropertiesDslElement.addPropertyInternal(GradlePropertiesDslElement.java:75)
        at com.android.tools.idea.gradle.dsl.parser.elements.GradlePropertiesDslElement.setNewElement(GradlePropertiesDslElement.java:422)
        at com.android.tools.idea.gradle.dsl.model.GradleBuildModelImpl.buildscript(GradleBuildModelImpl.java:335)
        at com.android.tools.idea.gradle.plugin.AndroidPluginInfo.lambda$searchInBuildFiles$0(AndroidPluginInfo.java:138)
        at com.android.tools.idea.gradle.plugin.AndroidPluginInfo$$Lambda$3246/1940927677.process(Unknown Source)
        at com.android.tools.idea.gradle.util.BuildFileProcessor.lambda$null$1(BuildFileProcessor.java:78)
        at com.android.tools.idea.gradle.util.BuildFileProcessor$$Lambda$3248/406633831.process(Unknown Source)
        at com.intellij.openapi.vfs.VfsUtil$2.visitFileEx(VfsUtil.java:398)
        at com.intellij.openapi.vfs.VfsUtilCore.visitChildrenRecursively(VfsUtilCore.java:296)
        at com.intellij.openapi.vfs.VfsUtilCore.visitChildrenRecursively(VfsUtilCore.java:328)
        at com.intellij.openapi.vfs.VfsUtilCore.visitChildrenRecursively(VfsUtilCore.java:328)
        at com.intellij.openapi.vfs.VfsUtil.processFileRecursivelyWithoutIgnored(VfsUtil.java:394)
        at com.android.tools.idea.gradle.util.BuildFileProcessor.lambda$processRecursively$2(BuildFileProcessor.java:75)
        at com.android.tools.idea.gradle.util.BuildFileProcessor$$Lambda$3247/886482634.run(Unknown Source)
        at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:946)
        at com.android.tools.idea.gradle.util.BuildFileProcessor.processRecursively(BuildFileProcessor.java:52)

Bradley, would ag/7631084 apply here? If so, perhaps we should cherry-pick it to 3.5.

I71c7fcbe8 may reduce the number of files required to be parsed here. It changes from searching all .gradle files in the project to only searching the ones that are defined by the settings.gradle. Although I think we shouldn't even be parsing things here since we have just completed sync and the models should be available. I will create a cherry-pick for I71c7fcbe8 and follow up with a change to prevent parsing.

Parsing should be prevented in 3.5 RC2 and later.