JetBrains Said No Static Tool Catches This Freeze Bug. We Built One — And Found a Real Instance in Their Own Code.

Description and use

Background ReadAction Freeze Companion identified a real IntelliJ freeze bug that was not caught by existing static analysis tools.

Problem

IntelliJ IDE freezes caused by background threads calling blocking, non‑cancellable read‑lock APIs while a write action is pending, with no existing static‑analysis tool detecting the pattern.

Outcome

The plugin successfully identified a real freeze bug in JetBrains’ own code, leading to a filed issue and a suggested fix.

Workflow

• Identify background‑thread entry points
• Build interprocedural call‑graph traversal to blocking read‑lock APIs
• Distinguish deprecated vs discouraged APIs
• Detect cancellation checks and downgrade hits
• Validate against intellij‑community source
• Add uncovered background entry points
• Run on Java test‑execution module
• Find real hit in SearchForTestsTask
• File issue IJPL‑254654 with source reference and fix suggestion

Evidence

there's no static tool that catches this today. Detection is manual — reading a thread dump after the freeze already happened in someone's real IDE.

Source

Background ReadAction Freeze Companion, a free, open-source IntelliJ Platform plugin that statically traces exactly this pattern.

Source

I filed it: IJPL-254654, with the exact source reference and a suggested fix mirroring the pattern already used nine lines above it.

Source