java.lang.Throwable: Slow operations are prohibited on EDT. See SlowOperations.assertSlowOperationsAreAllowed javadoc.

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#1,540 opened on May 22, 2026 0 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty: 4/5
Estimated time: 3-5 days
Newbie friendliness: 35/100

Issue type: Bug
Clarity: Needs clarification
Activity status: Quiet
Tech stack: java
Domain: tooling

Research direction

Start at LSPIJUtils.getFileLanguage and LanguageServerDefinition.getLanguageId, following the stack through LSPDocumentSymbolSupport and breadcrumbs. Reproduce the document-symbol or breadcrumbs flow and determine why WorkspaceFileIndexDataImpl.ensureIsUpToDate runs on the EDT. Done means the reported slow-operation exception no longer occurs in that flow.

Written by the indexing model from the issue text.

Description

bug

java.lang.Throwable: Slow operations are prohibited on EDT. See SlowOperations.assertSlowOperationsAreAllowed javadoc.
	at com.intellij.openapi.diagnostic.Logger.error(Logger.java:376)
	at com.intellij.util.SlowOperations.assertSlowOperationsAreAllowed(SlowOperations.java:106)
	at com.intellij.workspaceModel.core.fileIndex.impl.WorkspaceFileIndexDataImpl.ensureIsUpToDate(WorkspaceFileIndexDataImpl.kt:149)
	at com.intellij.workspaceModel.core.fileIndex.impl.WorkspaceFileIndexDataImpl.getFileInfo(WorkspaceFileIndexDataImpl.kt:94)
	at com.intellij.workspaceModel.core.fileIndex.impl.WorkspaceFileIndexImpl.getFileInfo(WorkspaceFileIndexImpl.kt:260)
	at com.intellij.openapi.roots.impl.ProjectFileIndexImpl.isExcluded(ProjectFileIndexImpl.java:65)
	at com.intellij.openapi.project.ProjectLocatorImpl.isUnder(ProjectLocatorImpl.java:58)
	at com.intellij.openapi.project.ProjectLocatorImpl.lambda$guessProjectForFile$0(ProjectLocatorImpl.java:47)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.runReadAction(AnyThreadWriteThreadingSupport.kt:228)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.runReadAction(AnyThreadWriteThreadingSupport.kt:221)
	at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:857)
	at com.intellij.openapi.application.ReadAction.compute(ReadAction.java:66)
	at com.intellij.openapi.project.ProjectLocatorImpl.guessProjectForFile(ProjectLocatorImpl.java:45)
	at com.intellij.openapi.vfs.encoding.EncodingManagerImpl.guessProject(EncodingManagerImpl.java:260)
	at com.intellij.openapi.vfs.encoding.EncodingManagerImpl.getEncoding(EncodingManagerImpl.java:233)
	at com.intellij.openapi.fileEditor.impl.LoadTextUtil.getDefaultCharsetFromEncodingManager(LoadTextUtil.java:281)
	at com.intellij.openapi.fileEditor.impl.LoadTextUtil.guessFromContent(LoadTextUtil.java:336)
	at com.intellij.openapi.fileEditor.impl.LoadTextUtil.detectHardCharset(LoadTextUtil.java:260)
	at com.intellij.openapi.fileEditor.impl.LoadTextUtil.detectInternalCharsetAndSetBOM(LoadTextUtil.java:290)
	at com.intellij.openapi.fileEditor.impl.LoadTextUtil.processTextFromBinaryPresentationOrNull(LoadTextUtil.java:577)
	at com.intellij.openapi.fileTypes.impl.FileTypeDetectionService.detectFromContent(FileTypeDetectionService.java:545)
	at com.intellij.openapi.fileTypes.impl.FileTypeDetectionService.detectFromContentAndCache(FileTypeDetectionService.java:516)
	at com.intellij.openapi.fileTypes.impl.FileTypeDetectionService.getOrDetectFromContent(FileTypeDetectionService.java:247)
	at com.intellij.openapi.fileTypes.impl.FileTypeManagerImpl.internalContinueToDetectFileTypeByFile(FileTypeManagerImpl.java:843)
	at com.intellij.openapi.fileTypes.impl.FileTypeManagerImpl.getFileTypeByFile(FileTypeManagerImpl.java:829)
	at com.intellij.openapi.fileTypes.impl.FileTypeManagerImpl.getFileTypeByFile(FileTypeManagerImpl.java:744)
	at com.intellij.openapi.vfs.VirtualFile.getFileType(VirtualFile.java:356)
	at com.intellij.openapi.vfs.newvfs.impl.VirtualFileSystemEntry.getFileType(VirtualFileSystemEntry.java:617)
	at com.intellij.lang.LanguageUtil.getLanguageForPsi(LanguageUtil.java:45)
	at com.intellij.lang.LanguageUtil.getLanguageForPsi(LanguageUtil.java:35)
	at com.redhat.devtools.lsp4ij.LSPIJUtils.doGetFileLanguage(LSPIJUtils.java:495)
	at com.redhat.devtools.lsp4ij.LSPIJUtils.getFileLanguage(LSPIJUtils.java:488)
	at com.redhat.devtools.lsp4ij.server.definition.LanguageServerDefinition.getLanguageId(LanguageServerDefinition.java:299)
	at com.redhat.devtools.lsp4ij.LanguageServerWrapper.createFileConnectionInfo(LanguageServerWrapper.java:1795)
	at com.redhat.devtools.lsp4ij.LanguageServiceAccessor.getFileConnectionInfoMap(LanguageServiceAccessor.java:162)
	at com.redhat.devtools.lsp4ij.LanguageServiceAccessor.getLanguageServers(LanguageServiceAccessor.java:386)
	at com.redhat.devtools.lsp4ij.LanguageServiceAccessor.getLanguageServers(LanguageServiceAccessor.java:356)
	at com.redhat.devtools.lsp4ij.features.AbstractLSPDocumentFeatureSupport.getLanguageServers(AbstractLSPDocumentFeatureSupport.java:83)
	at com.redhat.devtools.lsp4ij.features.documentSymbol.LSPDocumentSymbolSupport.getDocumentSymbols(LSPDocumentSymbolSupport.java:57)
	at com.redhat.devtools.lsp4ij.features.documentSymbol.LSPDocumentSymbolSupport.doLoad(LSPDocumentSymbolSupport.java:51)
	at com.redhat.devtools.lsp4ij.features.documentSymbol.LSPDocumentSymbolSupport.doLoad(LSPDocumentSymbolSupport.java:39)
	at com.redhat.devtools.lsp4ij.features.AbstractLSPFeatureSupport.load(AbstractLSPFeatureSupport.java:94)
	at com.redhat.devtools.lsp4ij.features.AbstractLSPDocumentFeatureSupport.load(AbstractLSPDocumentFeatureSupport.java:73)
	at com.redhat.devtools.lsp4ij.features.AbstractLSPFeatureSupport.getFeatureData(AbstractLSPFeatureSupport.java:51)
	at com.redhat.devtools.lsp4ij.features.documentSymbol.LSPDocumentSymbolSupport.getDocumentSymbols(LSPDocumentSymbolSupport.java:45)
	at com.redhat.devtools.lsp4ij.features.documentSymbol.LSPBreadcrumbsRefreshListener$LSPBreadcrumbListener.breadcrumbsChanged(LSPBreadcrumbsRefreshListener.java:118)
	at com.intellij.xml.breadcrumbs.BreadcrumbsPanel.notifyListeners(BreadcrumbsPanel.java:243)
	at com.intellij.xml.breadcrumbs.BreadcrumbsPanel.applyCrumbs(BreadcrumbsPanel.java:220)
	at com.intellij.xml.breadcrumbs.BreadcrumbsPanel.lambda$updateCrumbsAsync$4(BreadcrumbsPanel.java:209)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.lambda$safeTransferToEdt$7(NonBlockingReadActionImpl.java:717)
	at com.intellij.openapi.application.TransactionGuardImpl$1.run(TransactionGuardImpl.java:194)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.runIntendedWriteActionOnCurrentThread$lambda$1(AnyThreadWriteThreadingSupport.kt:184)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.runWriteIntentReadAction(AnyThreadWriteThreadingSupport.kt:84)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.runIntendedWriteActionOnCurrentThread(AnyThreadWriteThreadingSupport.kt:183)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:836)
	at com.intellij.openapi.application.impl.ApplicationImpl$2.run(ApplicationImpl.java:425)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.runWithImplicitRead(AnyThreadWriteThreadingSupport.kt:122)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWithImplicitRead(ApplicationImpl.java:1162)
	at com.intellij.openapi.application.impl.FlushQueue.doRun$$$capture(FlushQueue.java:78)
	at com.intellij.openapi.application.impl.FlushQueue.doRun(FlushQueue.java)
	at --- Async.Stack.Trace --- (captured by IntelliJ IDEA debugger)
	at com.intellij.openapi.application.impl.FlushQueue$RunnableInfo.<init>(FlushQueue.java:230)
	at com.intellij.openapi.application.impl.FlushQueue$RunnableInfo.<init>(FlushQueue.java:220)
	at com.intellij.openapi.application.impl.FlushQueue.push(FlushQueue.java:60)
	at com.intellij.openapi.application.impl.LaterInvocator.invokeLater(LaterInvocator.java:83)
	at com.intellij.openapi.application.impl.ApplicationImpl.invokeLater(ApplicationImpl.java:287)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.safeTransferToEdt(NonBlockingReadActionImpl.java:700)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.insideReadAction(NonBlockingReadActionImpl.java:607)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.lambda$attemptComputation$4(NonBlockingReadActionImpl.java:567)
	at com.intellij.openapi.application.impl.AnyThreadWriteThreadingSupport.tryRunReadAction(AnyThreadWriteThreadingSupport.kt:291)
	at com.intellij.openapi.application.impl.ApplicationImpl.tryRunReadAction(ApplicationImpl.java:965)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils.lambda$runInReadActionWithWriteActionPriority$0(ProgressIndicatorUtils.java:93)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtilService.runActionAndCancelBeforeWrite(ProgressIndicatorUtilService.java:66)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils.runActionAndCancelBeforeWrite(ProgressIndicatorUtils.java:155)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils.lambda$runWithWriteActionPriority$1(ProgressIndicatorUtils.java:138)
	at com.intellij.openapi.progress.ProgressManager.lambda$runProcess$0(ProgressManager.java:96)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:217)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$executeProcessUnderProgress$13(CoreProgressManager.java:660)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:735)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computeUnderProgress(CoreProgressManager.java:691)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:659)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:79)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:202)
	at com.intellij.openapi.progress.ProgressManager.runProcess(ProgressManager.java:96)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils.runWithWriteActionPriority(ProgressIndicatorUtils.java:135)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils.runInReadActionWithWriteActionPriority(ProgressIndicatorUtils.java:93)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.attemptComputation(NonBlockingReadActionImpl.java:567)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.lambda$transferToBgThread$1(NonBlockingReadActionImpl.java:466)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.lambda$transferToBgThread$2(NonBlockingReadActionImpl.java:481)
	at com.intellij.util.concurrency.BoundedTaskExecutor.doRun$$$capture(BoundedTaskExecutor.java:249)
	at com.intellij.util.concurrency.BoundedTaskExecutor.doRun(BoundedTaskExecutor.java)
	at com.intellij.util.concurrency.BoundedTaskExecutor.access$200(BoundedTaskExecutor.java:30)
	at com.intellij.util.concurrency.BoundedTaskExecutor$1.executeFirstTaskAndHelpQueue(BoundedTaskExecutor.java:227)
	at com.intellij.util.concurrency.BoundedTaskExecutor$1.run(BoundedTaskExecutor.java:215)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:735)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:732)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:732)
	at java.base/java.lang.Thread.run(Thread.java:1583)

Dominant language: Java
Stars: 344
Forks: 113
Avg merge: 5h 22m
Merged PRs (30d): 15

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