DATACMNS-1210 - Fix concurrency issue in BasicPersitentEntity. #259
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Make sure to use concurrent collection implementations for properties holding mutable state. Especially the ones making use of computeIfAbsent(). Usage of ConcurrentReferenceHashMap allows us to move on without additional changes as it allows to store null values, whereas ConcurrentHashMap would require us to store explicit NullValue placeholders for such cases, potentially causing trouble in downstream store specific projects. JMH Benchmarks done with the Spring Data MongoDB mapping layer showed a potential performance loss of up to 5%. However a comparison between ConcurrentReferenceHashMap and ConcurrentHashMap did not show any significant difference in performance.
odrotbohm
requested changes
Nov 14, 2017
| @Test // DATACMNS-1210 | ||
| public void findAnnotationShouldBeThreadSafe() throws InterruptedException { | ||
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| assumeTrue("Requires Java 9", |
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What's the reason we have to assume Java 9 here?
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I can remove it - the point was that the test would pass on Java8 regardless of the changes made.
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Okay, I'll just go ahead and remove it during the merge.
odrotbohm
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Nov 14, 2017
Make sure to use concurrent collection implementations for properties holding mutable state. Especially the ones making use of computeIfAbsent(…). Usage of ConcurrentReferenceHashMap allows us to move on without additional changes as it allows to store null values, whereas ConcurrentHashMap would require us to store explicit NullValue placeholders for such cases, potentially causing trouble in downstream store specific projects. JMH Benchmarks done with the Spring Data MongoDB mapping layer showed a potential performance loss of up to 5%. However a comparison between ConcurrentReferenceHashMap and ConcurrentHashMap did not show any significant difference in performance. Original pull request: #259.
odrotbohm
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Nov 14, 2017
More fixes of imports. Removed obsolete generics in constructor expressions. Removed a couple of compiler warnings in test cases. Removed assumption for test case to only run on JDK 9. Original pull request: #259.
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Make sure to use concurrent collection implementations for properties holding mutable state. Especially the ones making use of
computeIfAbsent().Usage of
ConcurrentReferenceHashMapallows us to move on without additional changes as it allows to storenullvalues, whereasConcurrentHashMapwould require us to store explicitNullValueplaceholders for such cases, potentially causing trouble in downstream store specific projects.JMH Benchmarks (for the mapping layer in Spring Data MongoDB) comparing
ConcurrentReferenceHashMapandConcurrentHashMapdid not show any significant difference between the two.