ReferenceManager.maybeRefresh releases the new reference it has just made current when releasing the old one throws, so every later acquire() throws IllegalStateException (since 3.5.0)

Finding LFV-1221Area: core / search: ReferenceManager (SearcherManager, ReaderManager and other subclasses)Priority: lowImpact: minorNovelty: new

Finding page for LFV-1221

AI-assisted finding, confirmed by automated checks, not yet triaged by a human Lucene committer. This site files nothing upstream.

What it shows

You call maybeRefresh on a ReferenceManager (for example a SearcherManager), and releasing the old reference inside the swap throws an IOException, which decRef is documented to do; you expect maybeRefresh to throw it and the manager to stay usable, with acquire() returning the new current reference. Instead swapReference has already made the new reference current (ReferenceManager.java:56) before it releases the old one (:57), and doMaybeRefresh's cleanup finally, which exists for a new reference the swap never installed, releases it anyway (:174-178), so the manager drops its own count on its current reference and closes it. Every later acquire() then throws IllegalStateException 'The managed reference has already closed - this is likely a bug when the reference count is modified outside of the ReferenceManager', blaming the caller for a state the manager created itself.

Expected vs actual

Expected: After maybeRefresh() throws the IOException, acquire() returns the new current reference.
Actual: acquire() throws IllegalStateException: The managed reference has already closed ... (ReferenceManager.java:112).

Files

src/org/apache/lucene/search/TestReferenceManagerFailedSwap.java (JUnit test)

Run it

Tested on Lucene main 5adff78bb168 (2026-11-02): reproduced.
How to read the outcome: a failing test is the finding reproducing (the failure message states expected against actual).
Seeds: a rerun with the same seed replays the same random choices. Assertions off (-da -dsa -Dtests.asserts=false) is the production-like setting.

# Lucene checkout at the tested commit, built with: ./gradlew --no-daemon assemble   (JDK 25)
LUCENE=/path/to/lucene; V=12.0.0-SNAPSHOT
CP=$LUCENE/lucene/core/build/libs/lucene-core-$V.jar
CP=$CP:$LUCENE/lucene/codecs/build/libs/lucene-codecs-$V.jar
CP=$CP:$LUCENE/lucene/test-framework/build/libs/lucene-test-framework-$V.jar
CP=$CP:randomizedtesting-runner-2.9.2.jar:junit-4.13.2.jar:hamcrest-3.0.jar   # test-framework dependencies (Maven Central)
CP=$CP:junit-platform-console-standalone-6.1.3.jar   # JUnit Platform console launcher (Maven Central)

javac -d classes -cp "$CP" $(find src -name '*.java')

# run 1: assertions on, seed DEADBEEF, default flags
java -ea -esa --add-modules jdk.incubator.vector --enable-native-access=ALL-UNNAMED -Dtests.seed=DEADBEEF \
     -cp "classes:$CP" org.junit.platform.console.ConsoleLauncher \
     execute --select-class org.apache.lucene.search.TestReferenceManagerFailedSwap

Gradle alternative: copy the test into the matching module's src/test/ tree of the checkout and run ./gradlew -p lucene/<module> test --tests <class> -Ptests.seed=<seed> (add -Ptests.asserts=false for a run without assertions).

Files shown on the finding page

TestReferenceManagerFailedSwap.java

Feedback

Open an issue in lucene-ai-bug-hunt. Please do not open issues or pull requests in apache/lucene about this finding unless a Lucene committer agrees it should be filed.

Snapshot of 2026-11-03. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.