HDFS-16228.[FGL]Improve safer PartitionedGSet#size.

[jianghuazhu]

Description of PR

The purpose of this jira is to make the operation PartitionedGSet#size safer.

Details: HDFS-16228

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 46s		Docker mode activated.
			_ Prechecks _
+1 💚	dupname	0m 0s		No case conflicting files found.
+0 🆗	codespell	0m 1s		codespell was not available.
+1 💚	@author	0m 0s		The patch does not contain any @author tags.
-1 ❌	test4tests	0m 0s		The patch doesn't appear to include any new or modified tests. Please justify why no new tests are needed for this patch. Also please list what manual steps were performed to verify this patch.
			_ fgl Compile Tests _
+1 💚	mvninstall	34m 4s		fgl passed
+1 💚	compile	23m 16s		fgl passed with JDK Ubuntu-11.0.11+9-Ubuntu-0ubuntu2.20.04
+1 💚	compile	18m 27s		fgl passed with JDK Private Build-1.8.0_292-8u292-b10-0ubuntu1~20.04-b10
+1 💚	checkstyle	1m 8s		fgl passed
+1 💚	mvnsite	1m 37s		fgl passed
+1 💚	javadoc	1m 8s		fgl passed with JDK Ubuntu-11.0.11+9-Ubuntu-0ubuntu2.20.04
+1 💚	javadoc	1m 42s		fgl passed with JDK Private Build-1.8.0_292-8u292-b10-0ubuntu1~20.04-b10
-1 ❌	spotbugs	2m 25s	/branch-spotbugs-hadoop-common-project_hadoop-common-warnings.html	hadoop-common-project/hadoop-common in fgl has 2 extant spotbugs warnings.
+1 💚	shadedclient	15m 48s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 54s		the patch passed
+1 💚	compile	20m 20s		the patch passed with JDK Ubuntu-11.0.11+9-Ubuntu-0ubuntu2.20.04
+1 💚	javac	20m 20s		the patch passed
+1 💚	compile	18m 24s		the patch passed with JDK Private Build-1.8.0_292-8u292-b10-0ubuntu1~20.04-b10
+1 💚	javac	18m 24s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
-0 ⚠️	checkstyle	1m 6s	/results-checkstyle-hadoop-common-project_hadoop-common.txt	hadoop-common-project/hadoop-common: The patch generated 1 new + 5 unchanged - 1 fixed = 6 total (was 6)
+1 💚	mvnsite	1m 33s		the patch passed
+1 💚	javadoc	1m 6s		the patch passed with JDK Ubuntu-11.0.11+9-Ubuntu-0ubuntu2.20.04
+1 💚	javadoc	1m 44s		the patch passed with JDK Private Build-1.8.0_292-8u292-b10-0ubuntu1~20.04-b10
+1 💚	spotbugs	2m 36s		hadoop-common-project/hadoop-common generated 0 new + 0 unchanged - 2 fixed = 0 total (was 2)
+1 💚	shadedclient	16m 7s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	unit	17m 2s		hadoop-common in the patch passed.
+1 💚	asflicense	0m 58s		The patch does not generate ASF License warnings.
		182m 54s

Subsystem	Report/Notes
Docker	ClientAPI=1.41 ServerAPI=1.41 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3435/1/artifact/out/Dockerfile
GITHUB PR	#3435
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell
uname	Linux e65925e7969a 4.15.0-156-generic #163-Ubuntu SMP Thu Aug 19 23:31:58 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	fgl / 877cfad44f1d09cab5724ad05de34f80c7bf9598
Default Java	Private Build-1.8.0_292-8u292-b10-0ubuntu1~20.04-b10
Multi-JDK versions	/usr/lib/jvm/java-11-openjdk-amd64:Ubuntu-11.0.11+9-Ubuntu-0ubuntu2.20.04 /usr/lib/jvm/java-8-openjdk-amd64:Private Build-1.8.0_292-8u292-b10-0ubuntu1~20.04-b10
Test Results	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3435/1/testReport/
Max. process+thread count	3152 (vs. ulimit of 5500)
modules	C: hadoop-common-project/hadoop-common U: hadoop-common-project/hadoop-common
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3435/1/console
versions	git=2.25.1 maven=3.6.3 spotbugs=4.2.2
Powered by	Apache Yetus 0.14.0-SNAPSHOT https://yetus.apache.org

This message was automatically generated.

[jianghuazhu]

Jenkins has been running for a long time (22h8m) without stopping, not sure why.

[xinglin]

LGTM. thanks for making the change.

[jianghuazhu]

Thanks @xinglin for the comment.

[jianghuazhu]

@shvachko @prasad-acit , could you help review?
Thank you very much.

[prasad-acit]

Thanks @jianghuazhu for reporting the issue & the patch.
Code changes are fine. But, AtomicInt shouldnt have any performance degrade.
Could you help to get the perf report with and without your changes? If there is a significant difference then we shall check for sync blocks or someother alternative.
Thanks @xinglin for the review.

[jianghuazhu]

Thanks @prasad-acit for the comment.
I noticed that your attention is very detailed.
Regarding performance, I will continue to pay attention, but this jira is mainly to solve the security problem of PartitionedGSet#size, because there was thread safety before this.

[prasad-acit]

LGTM. Thanks for the contribution.

[jianghuazhu]

Thanks @prasad-acit for the comment and review.