Revamped ListAppender for thread-safety#4111
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ramanathan1504 wants to merge 4 commits intoapache:2.xfrom
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Revamped ListAppender for thread-safety#4111ramanathan1504 wants to merge 4 commits intoapache:2.xfrom
ListAppender for thread-safety#4111ramanathan1504 wants to merge 4 commits intoapache:2.xfrom
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* Returned snapshots no longer require an unmodifiable view
- Remove synchronizedList wrappers; replace with plain ArrayLists - Annotate all public methods as synchronized on `this` - Replace Awaitility polling in getMessages(int,long,TimeUnit) with wait/notifyAll - Update class-level JavaDoc to reflect thread-safety guarantee - Rewrite countDownLatch field JavaDoc with a self-contained example - Remove redundant explicit generic type arguments (IDE cleanup) - Add ListAppenderTest: unit tests + @RepeatedTest(10) concurrency tests that hammer append with 10 workers x 1000 deterministic events each and verify getEvents/getMessages are consistent Fixes apache#3926
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May 2, 2026
| public List<String> getMessages(final int minSize, final long timeout, final TimeUnit timeUnit) | ||
| public synchronized List<String> getMessages(final int minSize, final long timeout, final TimeUnit timeUnit) | ||
| throws InterruptedException { | ||
| Awaitility.waitAtMost(timeout, timeUnit).until(() -> messages.size() >= minSize); |
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We achieved the same wait/notify behavior using only standard Java (no external dependencies). If you prefer, we can revert to the old Awaitility-based approach instead.
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Fixes #3926
Revamp ListAppender: Thread-Safety, Clarity, and Robust Testing
Summary
ListAppenderfor consistent thread-safety:Collections.synchronizedListusage.synchronizedfor clear, uniform locking.getMessages(int, long, TimeUnit):Object#wait/notifyAllfor in-JVM notification and reduced CPU usage.countDownLatchJavadoc with usage examples and clearer intent.ListAppender.Testing