Improve performance by maintaining sort of application listeners [SPR-17308]

[spring-projects-issues]

Samuel Bratton opened SPR-17308 and commented

There's a slight but measurable performance hit due to sorting application listeners in AbstractApplicationEventMulticaster.java, even with as few as 2 listeners. The cost is incurred on every call to getApplicationListeners()when listeners are sorted (

spring-framework/spring-context/src/main/java/org/springframework/context/event/AbstractApplicationEventMulticaster.java

Line 390 in e366b20

AnnotationAwareOrderComparator.sort(allListeners);

) By maintaining a sorted list as entries are added/removed this cost is reduced. There is a proposed change which can be mad a pull request here: https://github.com/sebratton/spring-framework/tree/sort-application-listeners

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Affects: 4.3.19, 5.0.9

Issue Links:

• Unnecessary sort in AbstractApplicationEventMulticaster [SPR-17307] #21840 Unnecessary sort in AbstractApplicationEventMulticaster ("duplicates")

[spring-projects-issues]

Samuel Bratton commented

Hi, as I was working on opening this jira, I missed that a jira had already been opened on essentially the same issue an hour or so earlier, #21840, I reference a proposed code change in the description above but it only addresses one of the two listener types mentioned in #21840.

[spring-projects-issues]

Juergen Hoeller commented

The revision applied for #21840 should hopefully address this case as well, maintaining a pre-sorting list in the cached retriever (for the common singleton case). This will be available in the upcoming 5.1.1.BUILD-SNAPSHOT; let me know if this doesn't provide the effect that you expected.