util-jvm: Fix invocation of GarbageCollectionNotificationInfo.from()

[takezoe]

Problem

Currently, Hotspot.gcFromNotificationInfo() causes a following exception:

java.lang.IllegalArgumentException: wrong number of arguments
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.twitter.jvm.Hotspot$.gcFromNotificationInfo(Hotspot.scala:260)
    at com.twitter.jvm.Hotspot$$anon$1.handleNotification(Hotspot.scala:95)
    at sun.management.NotificationEmitterSupport.sendNotification(NotificationEmitterSupport.java:156)
    at sun.management.GarbageCollectorImpl.createGCNotification(GarbageCollectorImpl.java:143)

Solution

Give null as the receiver of invocation of GarbageCollectionNotificationInfo.from() which uses reflection because this method is static.

[CLAassistant]

All committers have signed the CLA.

[codecov-io]

Codecov Report

Merging #243 into develop will increase coverage by <.01%. The diff coverage is 0%.

@@             Coverage Diff             @@
##           develop     #243      +/-   ##
===========================================
+ Coverage    47.12%   47.13%   +<.01%     
===========================================
  Files          231      231              
  Lines        14826    14826              
  Branches      1184     1184              
===========================================
+ Hits          6987     6988       +1     
+ Misses        7839     7838       -1

Impacted Files	Coverage Δ
...l-jvm/src/main/scala/com/twitter/jvm/Hotspot.scala	14.14% <0%> (ø)	:arrow_up:
...in/scala/com/twitter/logging/QueueingHandler.scala	93.93% <0%> (-6.07%)	:arrow_down:
...core/src/main/scala/com/twitter/util/Promise.scala	77.08% <0%> (-0.42%)	:arrow_down:
util-core/src/main/scala/com/twitter/io/Buf.scala	91.78% <0%> (+0.42%)	:arrow_up:
...ng/src/main/scala/com/twitter/logging/Logger.scala	64.92% <0%> (+0.74%)	:arrow_up:
...main/scala/com/twitter/concurrent/AsyncQueue.scala	98.52% <0%> (+1.47%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 0d9dded...1b46096. Read the comment docs.

[xerial]

This error message is also shown a lot when running the tests in Finatra.

[kevinoliver]

Apologies! This was a bug that I introduced then reverted then patched again, within a day.

Our internal code that pushes changes out to Github botched the revert and the follow-up patch. As such, this is broken in the 19.3.0 release.

I've pushed the fix (https://github.com/twitter/util/commit/52d49ad98c3ec3b08218a60d6ede322c0f7edc5e) and it will be released in 19.4.0.

In the meantime, this is a logging issue and can be turned off by setting the log levels appropriately.