fix: ConcurrentModificationException on flag config change java 9 #954
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Signed-off-by: Todd Baert <[email protected]>
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toddbaert
commented
Sep 16, 2024
| Assert.assertEquals(expectedChangedFlags.keySet().stream().collect(Collectors.toList()), | ||
| storageStateDTOS.take().getChangedFlagsKeys()); | ||
| // flags changed from initial VALID_SIMPLE flag, as a set because we don't care about order | ||
| Assert.assertEquals(expectedChangedFlags.keySet().stream().collect(Collectors.toSet()), |
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This assert would inconsistently fail because of ordering inconsistencies.
toddbaert
commented
Sep 16, 2024
| @@ -98,9 +99,9 @@ public void changedFlags() throws Exception { | |||
| Map<String, FeatureFlag> expectedChangedFlags = | |||
| FlagParser.parseString(getFlagsFromResource(VALID_LONG),true); | |||
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This call would intermittently fail in Java 9+ due to concurrent modification exceptions.
toddbaert
commented
Sep 16, 2024
| private static final ObjectMapper MAPPER = new ObjectMapper(); | ||
| private static final Map<String, Pattern> PATTERN_MAP = new HashMap<>(); |
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This field presents a concurrency issue, since multiple threads can possible parse at the same time, and computeIfAbsent can throw an concurrent-modification-exception in Java 9+
toddbaert
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toddbaert
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aepfli
approved these changes
Sep 17, 2024
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We had a static hashmap that could possibly be modified by multiple threads since
computeIfAbsentmutates the map.This is specifically more visible in Java 9 due to some new additional checks. This is easily solved by making this static member a local variable.